Hook!!!

[gcarter]

I currently have the Minx off the trailer and on some dollies while I'm redoing the bottom.
While under there, I mapped out the extent of the hook that exists on both the port and stbd side of the boat.
The port side is worse, but both sides are about four ft. long, and the port is about 5/16" deep at about two feet in front of the transom.
I'm going to fix this while I have the boat like this. And I wouldn't mind some input from anyone that has some experience.
The first two pics are the port and stbd sides, note the pencil scribbles.
The third pic is from the port side where it's noticeable to the naked eye.
You may be thinking that the dolly sitting in the middle of it is exascerbating the issue, but it looks just like this while sitting on the trailer.

[DonziJon]

GEORGE: I just went out to the garage to look at my Minx. I've had the boat for almost 10 years and that hook has always been there. Sighting foreward along the lifting strake I don't think the hook is anywhere near 5/16, but I havn't put a strait edge along it yet eather. The side view looks similar to your side view picture though. I have always wondered if the hook was intentional. Wouldn't a hook help to dampen pourposing if that had been an early problem? I don't know. After all, don't you induce a big hook when you lower the trim tabs??? Have you looked at any other classics for this anomily?

So whats the solution, IF indeed one is required? Jack the hull outward from inside and add additional fore and aft stiffeners inside to keep it straight? ..OR..just build up the "hollow" on the outside to flatten it out cosmetically? DJ

[boatnut]

Our '69 18' has a hook (do not have a precise measurement). I have always wondered if the design goal of the boat was to have a straight bottom and these hooks resulted from the way the boats were cured etc. or if some hook was intentional. Most of the high performance boat guys I know try to true the bottoms (straight and flat) and then adjust the surface dynamically with afterplanes or rocker plates etc. I do know that this 18 performs well without plates and without a trimmable drive (it runs on the max trim hole on the 250 Volvo) and at speed the hull seems to run free and does not feel glued in so I don't know if the hook is good or bad. Of course it has always been a less than 55mph boat. George, I am glad to see you are tackling this issue, we will all learn a lot. Ed

[Cuda]

I think the hook is built in on purpose. I've heard of people removing the hook, then the boat handled like crap. I'd get another opinion from someone who knows more about it. Maybe CDMA can answer this.

[boatnut]

I guess improper trailer beds could cause a hook over time as well as mold imperfections??? However, I have always been led to believe that unintentional hook (not in the plug or the mold), was more likely caused by the layup process and time the boat is left to cure in the mold. Heat is genereated in the hull during curing proportional to the thickness of the hull at a given point and frequently there is a significant thickness variance near the transom and of course right at the transom. If this thickness difference is allowed to become excessive and/or if the hull is removed from the mold prior to complete curing of the interior plastic as well as the surface there could be sort of a heat warpage that causes hook near the transom. Now if any of this is factual, it would explain why some of us see hook in these boats (mine is a '69 and I have owned it since '71 and it always had it) and some of us don't (I don't think my '67 had hook but I am not certain) as certain layup teams at Donzi over the years and certain timing/production demands would result in process and curing time differences. We know there hasn't been a strict quality control process followed over the years :) or we wouldn't see such variance in tank mounting and many other differences. Someone who worked at Donzi should be able to tell if the hook was in the mold -- I don't see it on my '97 22 (haven't carefully measured it) but it also likes to porpoise and is hard to settle down. I don't remember if my '82 22 had a hook but it did not have the tendancy to porpoise that the '97 has (of course it had a different drive and prop also). In summary, regardless of origin, it would be nice to know if it is wise to try and remove the hook on these older classics as we restore them--- or if we should leave them alone if the handling is proper.

[gcarter]

I'm planning on removing it unless Mr Allard or someone else can give me a good reason not to.
Ed, I tend to agree with your Hypothesis. I know there is a tremendous difference between boats.
Jim Collins Sr's Minx lives about two miles from me. I'll take a look at it this week.

[boatnut]

as an added note, I also think any attempt to blueprint the bottom which involves grinding and applying glass/gelcoat should be done with the boat upside down -- which is another challenge to most of us.

[gcarter]

as an added note, I also think any attempt to blueprint the bottom which involves grinding and applying glass/gelcoat should be done with the boat upside down -- which is another challenge to most of us.
In a perfect world.............
but not this time. I think I've figured out a way to accomplish it.
As usual, I'll do it by myself.
I just need to find an extremely long and stiff straight edge and make a long board.

[Formula Jr]

My JR has a 1/4 inch hook. Brownie says it should not be there.

Lenny can confirm if his hull has a hook also.

Whether intentional or not, I think they improve the handling of sub-22 foot boats.

I think they help air-out boats that have alot of bow lift.
I also think they stabilize the boat when you hit a large wave train and bounce off the top of them. They create a low pressure area when the entire hook area is wetted and bring the bow down slightly.
Pre-tab era, they would have been helpful to come on plane with a straight Deep Vee.

Some how, the group thought has become that Hooks are bad for some reason. I think they are in boats bigger than 21 feet. But in the smaller, I/O drive boats I think there is real benefit in having them. Think of the hull at speed and where is the wetted surface in relation to water pressures.
Even Wynne said a boat doesn't like flat surfaces.

You can blue print a hull to exactly match the mold. A Perfect Straight Bottom. If the makers thought this was a consistent problem with how Glass cures they could have corrected it. It seems they didn't, as so many boats have a slight hook. So this might be part of the ART of letting a hook form during the curing process. Or letting a glass boat mature into its perfect form.

[Cuda]

George, I'll go out and put a straight edge on mine.

[fasttrucker]

Iam hoping to have the hook in my 28zx taken out over the winter:smash: .Looks like this was put in on the single engine configurations:kaioken: .Waiting for the glass shop.Using the best shop here in md. and they promised me they will get me in before spring.:chillpill

[Cuda]

George, I just put a six foot straight edge on mine, and there is definetly a hook in it on both sides. I've got it sitting on the 22 trailer right now, so it's kind of hard to get to, or I'd have taken a picture for you. I couldn't measure it, but it feels like the port side has more hook in it than the starboard side. Being how mine is just like yours, I'd say it was made that way on purpose.

[Cuda]

I can put my finger between the hull and the straight edge.

[Cuda]

Matty, that's what makes me think it is there for a purpose.

[gcarter]

My boat has had its share of problems, but being soft in the hull anywhere wasn't one of them.
What do I know, but think about this......if it were on purpose, for trim purposes, wouldn't the center be closer to the transom? As it is the center of the depression is about two feet in front of the transom. And then there's the point that the length is FOUR FEET LONG!!
So, it may be normal for it to be there, but it still might be a characteristic of the layup schedule, heat, etc......
I'm still tempted to do it!

[Cuda]

Have at it,you can always put the hook back in it. :)

[joseph m. hahnl]

well it's way too cold over here to even think about crawling under my Minx.
But i was thinking that would be close to the area where the wood stringer for the motor is.Seeing as how wood expands and contracts greater then fiberglass. it could be the stringer bowing as it grows or shrinks. If this were true
there would be certain times that the hook may disapear do to temperature, humidity, being wet wet or dry. It would seem you would definatly need to find the cause before modifying any thing.



joe

[DonziJon]

HI AGAIN GEORGE: I'm listening to a double CD by "Artie Shaw". Anybody ever hear of this guy?? OH wait: ... I also have a nice glass of Red Wine.

Back to the original topic. I measured the hook in my '86 Minx with a nice long strait edge. I think you told me back when it's hull #20. I measured the port side....maybe the starboard will be different. I'll measure that tomorrow. The port side hook just inboard of the full length lifting strake is 5/32. Half of your measurement. Is it possable you MIS- measured..or MIS-typed?? My trailer is a roller type.

I think someone noted that at WOT, your only riding on a patch of the keel a foot wide and maybe three feet long...aired out.

I'm curious: Where do you hope to find improvement by eliminating the hook?

JOHN

[gcarter]

DJ, my stbd side is about 5/32. The port is more.
I think if you, or anyone were to do a sketch of the bottom at the transom and project it forward at about a 10-12* incidence angle, I believe you'll find the strakes are in the water. besides, the hook continues inside the strakes.
What's wierd is the round keel actually has some rocker in it, for the most part.
There has to be a payoff, I hope. If for no other reason than uniformity of form.
Well, this is the perfect oportunity. Why miss it?

Joseph, this part of the hull is solid. No discernable movement, even when lowering the hull onto the dollies in different places.

[Cuda]

George, you know you're just itching to do it anyway!:)

[Carl C]

Removing the hook should improve the top speed and the tabs can compensate at lower speeds. George I say if you're looking for max speed then fill in the hook!!!!!!!!!!!!!:anchor:

[blackhawk]

Matty, that's what makes me think it is there for a purpose.

I agree. When hooks are put in a hull on purpose they are usually much bigger between the outer strake and the chine. That is because that part of the hull is in the water getting on plane, at slow speeds and in the rough water "sprays" that area. But at high speeds most of that hull area is out of the water. The port side seems to have a bigger hook quite often as well. Probably to keep the boat riding more level ar slow speeds.

I went from a boat that had a lot of rocker(Blackhawk) to a boat that had a lot of hook on purpose(Unlimited). The handing characteristics were night and day between these two boats. Blackhawk was loose, fast and unpredictable. The Unlimited was tighter, slower and very predictable. I know the hook shaved 2-3 mph off the boat but I could drive my Unimited through slop with NO TABS at all. That same slop would have me chittin a brick and droppin some tab in the Blackhawk. At one time I though about removing SOME of the hook but decided not too. I decided the loss of 2-3 mph was a fair trade for predictable handling.

My point is sometimes hooks are built into hulls on purpose and removing it may have negative affects on the handling. Not saying you shouldn't try it, just saying it could be a gamble. :D

[gcarter]

Scott, that makes a lot of senxe.......
I'll think about it some more.
Maybe I'll email Bud and CDMA.

[gcarter]

Here's a compromise I'm thinking about......
Fill in the strkes and the area inside the strakes, that area is quite small anyway.
It might be the best of both worlds, have a hook outboard of the strakes for lower speeds and a straight hull in the stakes and keel for top speed.

[blackhawk]

Here's a compromise I'm thinking about......
Fill in the strkes and the area inside the strakes, that area is quite small anyway.
It might be the best of both worlds, have a hook outboard of the strakes for lower speeds and a straight hull in the stakes and keel for top speed.

I agree, if you're going to do it that's how I would start! :D

[Trueser]

George,
Is the hook still there if you hang it from the rear hook?

Mike

[gcarter]

It doesn't change at all.

[boatnut]

Here's a compromise I'm thinking about......
Fill in the strkes and the area inside the strakes, that area is quite small anyway.
It might be the best of both worlds, have a hook outboard of the strakes for lower speeds and a straight hull in the stakes and keel for top speed.
George, this is likely a stupid question considering how careful you are with all of your work so I apologize in advance. Are you sure that you want to fill in the void area to remove the hook? This would be easier to explain with a pencil and paper but you have to determine what the proper plane of the bottom is and work from there. It is possible (I have seen this) that the rear (near transom) area of the hook is lower than the ideal plane surface and then you have to grind that area down as well as possibly filling some of the void area. You need long staight edges to analyze the entire running surface to determine what areas are concave (fill) and what areas extend beyond the ideal plane (grind). Obviously if the rear of the hook is too low (common) and you just fill the void you are not eliminating the hook. As I said, this is likely obvious to you but it is hard to determine all of this with the boat upright -- you also have to try to get both sides equal. After babbling about this I must admit I have never tried it but I have considered doing it and I have talked to people who have done it. I would think the running area on your hull should go about 10 or 12 ft forward along the keel and then angle back towards a point about 2 or 3 ft forward of the rear corners of the hull. I also think if you are planning to flatten part of this running surface and leave the rest as it is (your current plan) you are getting into some uncharted waters --- just an opinion. Ed

[Rootsy]

George,

if you had some fire breathing small block with a drive hangin off the back that was slipperier than **** and higher than hell and you wanted to do 80+ i'd say hell yeah fill it in and make those strakes and that transom sharp as a razor... but the reality is... i doubt you'll notice much of a difference in handling and performance for all of the work you are going to put into this... and i can honestly say.. sitting on your butt... or lying on your back with a 3 foot sanding board sucks the biggest donkey balls you'll ever see... :bonk: and it is very difficult to judge and achieve what you are desiring by working above your head...

and all of this coming from a chump who is gonna cut 12 inches of inner strake off of the bottom of a 1966 18 :eek:

JR

[Cuda]

I think George is just getting antsy and has got to put his hands on something. :)

George, if you need straight edges, I have them up to six feet.

[Morgan's Cloud]

And now the voice out in the boonies ...
First , for the record , the C16 AND the Hornet hulls both have these hooks. However they are unmistakably part of the design being incorporated into the chine. Not anything like what George has photographed.
I had the nearly identical hook in the bottom of the Magnum when I started it's resto back in Dec -98. It did'nt quite go up into the area between the full length strake and the chine though.
A similar drawing/photo sent to Magnum drew the response . "No. That is not supposed to be there. It is more than likely the result of being improperly bunked for a very extended period of time. It's removal will greatly enhance the performance of your boat"
So that's what I did .
Steve

[DonziJon]

George: I just finished measuring the stbd side of the Minx. I'm using a 5'6" aluminum strait edge. Just inboard of the full length lifting strake the hook measures 1/16 of an inch, and is deepest at about 20 or so inches ahead of the transom. (The port was 5/32 deep.)

I'm thinking about the old days.....back during the "Miss Americas". Single engine boats, particularly with big displacement slow turning engines had a problem with engine torque tending to roll the boat to one side. A fix at the time was "Shingles". They would add tapered pieces of wood similar to a wood shingle to the bottom of the boat at the transom and running foreward about 15 or 18 inches to add lift on one side to counter the torque rolling tendency. Which side the shingle was added depended on the direction of engine rotation. I believe this hook would also have helped get the boat on plane easier.

In 1924 there was a boat named Rainbow IV that was constructed with "multiple " shingles arranged at 45 degrees to the keel along nearly the full length of the boat forming what the race comittee called "Steps". Steps were illegal at the time so the boat was disqualified...after having placed First in the 1924 Gold Cup. The cup went to "Baby Bootlegger'. Just some thoughts. John

[gcarter]

Let's face it....I'm a sucker!:frown:
I probably own the worlds most expensive Minx. But it sure is a lot of fun.:smile:
And who knows, I may someday put something interesting in it.:checkered
But I'm planning on never (hopefully) ever having this thing in this position again.
So I just called Mini-Craft and ordered the putty and chopped fiber. I may get started on it tomorrow.


:wavey:

[gcarter]

It is possible (I have seen this) that the rear (near transom) area of the hook is lower than the ideal plane surface and then you have to grind that area down as well as possibly filling some of the void area. You need long staight edges to analyze the entire running surface to determine what areas are concave (fill) and what areas extend beyond the ideal plane (grind). Obviously if the rear of the hook is too low (common) and you just fill the void you are not eliminating the hook. Ed
Ed, I have indeed considered what you're talking about. But I really appreciate what your're mentioning. These "shorter" boats, although nearly identical to a 22, don't have as much straight run as larger boats do. So they are continuously transitioning from one set of planes to another. Then when you throw in a hook as large as this, it's really gets confusing. I'll have to be careful.

[Jamesbon]

To remove the hook in my GT, I used a straight edge on the bottom with the hull upside down on the trailer, then I "roughed out" the outline of the hook and filled with glass & filler. Then used the old blue machinist dye trick and plenty of sanding with a "straight line" pneumatic sander. All is flat now. Don't actually know what the implications are of removing the hook, but I'd be damn sure to rather have a "flat bottom," as opposed to a bottom with a hook involved.

..Just my $.02.......

[fasttrucker]

I was told that donzi put my hook in to stop porposing.Really not happy about it.

[RedDog]

I was told that donzi put my hook in to stop porposing.Really not happy about it.
Wouldn't a design including both a hook and a stepped hull be counterintuative? I doubt they did it on porpoise - I mean on purpose :confused:

[fasttrucker]

Thats what the guy that used to test drive all the new donzis in 1998 told me.I think cigSS is his net name.I guess he could be wrong.

[Dr. Dan]

Thats what the guy that used to test drive all the new donzis in 1998 told me.I think cigSS is his net name.I guess he could be wrong.


Ted is never wrong about anything,... don't belive him? Just ask him! :bighug:

Doc of Very Slow Donzis in the NorthEast :smash:

[fasttrucker]

Well,the story goes that my meck.....tony who races(CMS RACING) and has a big rep. here on the bay for his engine work.Took my boat out for testing and was expecting 80 mph.He didnt get that,the boat ran too flat in the water.So he checked the bottom and what the boat has is a hook:bonk: .I bought a used lab prop 26 pitch from bryan tuvell.:smile: That helped a lot.I also put on a set of sidewinders from drew marine.They are a shock steering system that keeps the bravo from moving around.That also helps with speed.:boat:

[boatnut]

This has been an informative interesting discussion on hooks re. the classic Donzi hulls of various vintages. However, I think the question remains: do we have any factual info on whether these hulls have original production intentional hooks? And, if they were intentional, is there any way of knowing what models and vintages had the hooks? I many year ago met a Donzi guru who I believe ran the production process and he could answer any question about what, how, and why concerning Donzi's in the 60's and 70's. His name if I remember correctly was Roy (can't remember last name). There must be somebody around like "Roy" that was involved in the production of these boats and knows if they did intentional hooks and why. It sounds like someone got a definitive answer from Magnum, have we gotten one on Donzis? If the hook on my hull was intentional I want to leave it alone, if it was accidental I would like to remove it. Ed

[Cuda]

IMHO, the hook is there to help negate the prop torque, and keep the bow down coming on a plane. Where the hell is CDMA?? :)

[joseph m. hahnl]

it feels like the port side has more hook in it than the starboard side. Being how mine is just like yours, I'd say it was made that way on purpose.

88 minx #163 Newest ,and possibly the last one ever made .

It has the hook exactly how cuda described it.

joe

[boatnut]

Roy Farmer.....
To go a step (Aww gawd, no pun intended) further: If the hook was intentional due to the limitations of the drive trim systems and propeller technologies of the era, would the same hook be induced into the hulls today??

That be he!! Very knowledgable nice guy --- I wonder if he still is around somewhere??? Good question, with trim and better props and trim tabs maybe flat is where it's at. A perfectly true and flat running surface seems like the best way to go to me. However, my 18 has always run so well, been so responsive and fun to drive (especially in a nasty chop) and has never had trim tabs that I hate to change the hook that is there regardless of whether it was a planned child or not. Ed

[gcarter]

Well, intended or not, the starboard side hook is GONE !!!:shocking:
I didn't have my camera today, I'll post pics tomorrow.
I also gelled the bottom today. I applied two fairly heavy coats. Looks pretty good.

[rustnrot]

So George, you and Michelangelo both (working overhead that is).

I trust this will be back in the water for Dora, hooked, unhooked, or heaven forbid, Hacked??

[gcarter]

So George, you and Michelangelo both (working overhead that is).
I trust this will be back in the water for Dora, hooked, unhooked, or heaven forbid, Hacked??
LOL!!:jestera:
And that's where the similarity ends.
It really wasn't too bad. I think it took about 12 hours of labor. I learned a lot, maybe I can do the port in about 8 hours.

[MOP]

GeeZuss George are you reporting that you are Half Hooked:garfield:

[gcarter]

Here's a few pics;
1) Stbd side is virtually ready to gel....
2) Look carefully at the side of the strake and you can see the build up to eliminate the hook.

[gcarter]

The port side is a lot worse. It requires several steps to ge it to the thickness reqd. I'm using some 'glass putty that I'm filling with some 1 1/4" cut fibers, a lot. This stuff is VERY hard to apply. It likes to roll up in a ball. What you end up doing is "massaging" it more than anything.
Any way it's a lot of work. Also, it likes to shrink a lot. So the idea is to over fill the area and then grind useing a 4 1/4" grinder to rough it to shape. Subsequent applications I use milled fibers as a filler.

[gcarter]

The second gallon of putty I bought from Mini Craft had a white pigment in it so that is the difference you see in color.

[boatnut]

After seeing the filled area, it sure doesn't look like an intentionally designed hook.

[gcarter]

I'm finishing up in the filling phase on the port hook.
Now all I have to do is fair....fair....fair. I should have it ready to gel by Thursday!
This isn't as difficult as I thought it would be. No where near as difficult as removing bottom paint with the boat on the trailer. Ya just gotta have the right tools.
BTW, this one is over four feet long!!!!

[gcarter]

Well, here are a couple of pics of the port side ready to gel. I actually did have it ready to gel on Thursday, when I happened to look down the strake from the end. I sort of wished I hadn't. I am more convinced than ever this deformation was caused by mold/layup/timing problems or by bad bunking (maybe a roller type trailer?). Right in the center of the greatest amount of "rise" in the side view, it was also "warped inward toward the center line. In other words, it was "warped/distorted" in two planes simultaneously.
But not any longer. As you can see in the pics, which I marked the outside and inside corners with a marker so they would be more visible, they are straight!!!!!:smash:
As to whether it was more difficult working upside down, I don't think it was more difficult. I didn't have to dis-assemble the boat and flip it. As always, you need the proper tools.
The dollies are Poodles, thanks Scott. If I had to do this again, I'd definately buy my own set, they are wonderful.
The only other thing I bought I didn't already have was an air file ($140.00) and paper for it, 35 and 80 grit.
I used two gallons of Mini-Craft putty, 1/2# of cut fibers, and 1/4# of milled fibers.
We'll see the rusults soon.
I'm going to gel the rest of the bottom today.

[Ed Donnelly]

George;Looked in my crystal ball lastnight and saw you looking for another Donzi.. What else are you going to do with your spare time later this year. There is nothing left to do on your Minx.
Well maybe you could fly up to Toronto for a couple of months this fall, and have your way with my Criterion..Anything for a fellow old fart...............Ed

[gcarter]

OK, I just finished gelling the aft end....
Here's a pic of the port side.....
Now all I gotta do is sand......sand.....and sand!!!!:biggrin.:

:wavey:

But starting tomorrow.

[gcarter]

George;Looked in my crystal ball lastnight and saw you looking for another Donzi.. What else are you going to do with your spare time later this year. There is nothing left to do on your Minx.
Well maybe you could fly up to Toronto for a couple of months this fall, and have your way with my Criterion..Anything for a fellow old fart...............Ed
Gosh, but I love this stuff!!!
Maybe, just maybe if I put it up for sale, someone would pay me what I asked for it. There's no mysteries on this boat.

[gcarter]

Well maybe you could fly up to Toronto for a couple of months this fall, and have your way with my Criterion..Ed

Like pulling a splash of the deck, and start producing them?:wink:

:wavey:

[gcarter]

I'm finished w/the bottom. Besides removing the hooks in the stern, I re-gelled the entire bottom, sanded all of it to 1200, and buffed the bottom all the way back to the front seats.
It's not perfect, but about 1000% better than before.
And I didn't expect it to be perfect as this is the first time I've tried doing this.

[Morgan's Cloud]

And now it's time for the water test ! :biggrin:

I keep forgetting to ask you George ... Did you ever resolve the issue you had with the sudden listing problem ?

Steve

[gcarter]

Steve, as far as I was able to determine, it was a prop problem.
And I'm getting it wet next Tuesday or Wednesday.

[gcarter]

One more.....

[Carl C]

That's awesome, George. I hope she really rips now. Better keep your hand near those tab rockers in case some nasty tendencies show up.:)

[boatnut]

Very impressive (as usual) George! Care to venture a guess on how many hours to true and gel both sides? Ed

[onesubdrvr]

Gosh, but I love this stuff!!!
Maybe, just maybe if I put it up for sale, someone would pay me what I asked for it. There's no mysteries on this boat.
Well George,

I can always go pick up the X from Poodle and bring it up to you!! Heck, it'll give 'ya something to do :wink: :wink: :wink:

Talk at 'cha later, see 'ya at Dora!

Wayne

[gcarter]

Very impressive (as usual) George! Care to venture a guess on how many hours to true and gel both sides? Ed


Well, I was doing more than this, but I'll guess 4-5 hours/day, almost 7 days /week for around 30 days.
Maybe 120 hours.
Hmmmm....is that about $6000.00?
I know there are people here who would pay that or more.

[Cuda]

George, at the $75/hour my glass guy charges, that would be $9000!:eek:

[Cuda]

Plus material!:eek:

[gcarter]

Materials were between $3-400.00.

[boatnut]

Well, I was doing more than this, but I'll guess 4-5 hours/day, almost 7 days /week for around 30 days.
Maybe 120 hours.
Hmmmm....is that about $6000.00?
I know there are people here who would pay that or more.
Labor= 6K to 9K
Material= 1/2 K
personal satisfaction/pride for a job done right= priceless
Nice Work George

[joseph m. hahnl]

George: regardless of if it makes your boat faster or not. I understand your determination to remove the hook.Some times when you see something wrong it nags you and nags you. You just have to fix it. You really have no choice.It can be a worse disease than just owning a Donzi. When you combine the two together you end up with an exceptional boat. looks great from here! I hope you can spend your liesure time driving it now.

I still Think the stringers may be the culprit during lay up .


joe

[Cuda]

I hope you can spend your liesure time driving it now.

joe
I'm convinced that working on the boat IS G's leisure time. He'd rather work on it, than drive it. I'm about half like that myself.

[VetteLT193]

resurrecting this thread from the dead...

George, what was the outcome of removing the hook?

I finally got a chance to jack the boat up this weekend and really fit the trailer to the hull and I was looking at the hook in my Minx. With the eyball meter the hook looks the same on both sides and not too prominent but noticeable.

[gcarter]

I did some testing afterwards and posted this thread;

http://www.donzi.net/forums/showthread.php?t=45180

The bottom line is, it's a lot of work. In my case, the bottom was a mess and had many scratches and lots of chips missing in gel anyway, so it was worthwhile.

[VetteLT193]

I did some testing afterwards and posted this thread;

http://www.donzi.net/forums/showthread.php?t=45180

The bottom line is, it's a lot of work. In my case, the bottom was a mess and had many scratches and lots of chips missing in gel anyway, so it was worthwhile.

Thanks, I figured you had it somewhere but I couldn't find it

[zelatore]

hmmmm...in reviewing your above post about hook and bottom designs, doesn't this pretty much contradict the Huckins quadraconic hull design ideas?

I'm not really sure - I've never seen a Huckins bottom study, I just know it's something they really brag about.

And I have a soft spot for their boats anyway.

[gcarter]

hmmmm...in reviewing your above post about hook and bottom designs, doesn't this pretty much contradict the Huckins quadraconic hull design ideas?

I'm not really sure - I've never seen a Huckins bottom study, I just know it's something they really brag about.

And I have a soft spot for their boats anyway.

Don, good point. While Lord did develop the "Quadraconic" hull form, it wasn't necessarily the hull form used in the Huckins PT boat hull.
The Quadraconic hull is covered in his book and it's simply a method of developing the more challenging portions of the bow of a hull using two cones. It's not a method of being able to develop any size of hull that may have the same characteristics.
Also, it's no where as identifiable as Levi's "Delta" form of hull, for instance.
So over the years, a "Huckins Quadraconic" hull is whatever they want it to be.

[zelatore]

So over the years, a "Huckins Quadraconic" hull is whatever they want want it to be.

I've often wondered if it wasn't more marketing than engineering.

Regardless of what the bottom of the boats look like, the top sides are pretty sweet!
http://www.huckinsyacht.com/

[VetteLT193]

Here's pics of mine just for reference on another Minx. It's dirty, so look through that :eek:

[gcarter]

I've never seen a Minx w/o them, also many 22's from the same period....including mine.
Well, not as much as much as it was.
In fact, my 22 is pretty good now.

I'd wait awhile to see if I were going to keep it before I'd correct it if I were you. It's a LOT of work

[gcarter]

If any of you are interested, I can scan some of the drawings from Lord's book showing lines drawings of some of the "problem" hulls as well as his "monohedron" hulls.

[DONZI]

I just went and researched your threads the other day also George.So they are still providing valuable insight. Thank you for taking the time to share !
I've been hemming & hawing on this for awhile. I went out and bought a new I.R. Straightline sander and jacked the Donzi half off the trailer. My slight hook isn"t as obvious compared to those recent Minx pics..
More meausuring and planning to be done for me.
I noticed when i picked up the sander that only 35 grit & 80 grit offered for straightline there.
Is that why you used the orbital also for more paper choices or can it all be done with the Straightline ??
Min craft putty still the choice also ??
Thanks Ken

[VetteLT193]

The first pic is the absolute best angle I could get to show it as much as possible. it really doesn't look that bad from any other angle and in real life I didn't even notice it until this weekend. I even checked for any hook *visually only* when I bought it and didn't see one

I also put it on this trailer not long ago. The vertical bunk really shows it off well because it is a straight edge. I'm curious about something really simple. If a hook can get into a hull because of lack of support in the trailer can it also start to work itself out?

My new trailer has a combo of vertical and horizontal bunks. If there is any hope of the hook working itself out the vertical bunks would do it, and it just so happens that the hooked area is sitting right where those bunks are. I'm just thinking out loud here so don't rip me a new one if this is a crazy idea:eek:

It also leads me to something I have held back in reading trailer threads. Everyone seems to like horizontal bunks but to me it seems that a combo is much better. The verticals are unforgiving and will support the transom no matter what. The horizontals will bend with the boat as needed while only unforgiving where the brackets are mounted. When I bought my boat it was on a custom made horizontal bunked trailer (although a rusted pile of crap) it really should have supported the hull perfectly as far as the 'book' goes for trailers.

as far as fixing mine... forgeddaboudit. My bottom was nice before I had it re-done. now it's almost flawless besides the hook... I know for sure because I just spent a couple hours underneath it messing with the trailer. The boat runs and rides fantastic as is. the paint/fiberglass guy had it on slings and sanded and smoothed the whole bottom. he did a really good job... and had I had the new trailer before taking it to him he probably would have knocked the hook out too. you really couldn't see it before. all well... maybe in another ten years when I redo it again:) the idea of a 'toon is growing on me

[gcarter]

I just went and researched your threads the other day also George.So they are still providing valuable insight. Thank you for taking the time to share !
I've been hemming & hawing on this for awhile. I went out and bought a new I.R. Straightline sander and jacked the Donzi half off the trailer. My slight hook isn"t as obvious compared to those recent Minx pics..
More meausuring and planning to be done for me.
I noticed when i picked up the sander that only 35 grit & 80 grit offered for straightline there.
Is that why you used the orbital also for more paper choices or can it all be done with the Straightline ??
Min craft putty still the choice also ??
Thanks Ken

The Minicraft putty, especially w/milled or cut fibers in it, is VERY tough stuff to sand so to save time use the coarsest paper that works. Actually, I'd use a 4 1/2" rt. angle grinder w/35 paper on it held completely flat to the glass surface to speed things up. It'll cut the high points off very quickly so you can do some good w/the air file.
Actually, you can get most any grit paper to 400 w/adhesive backing. After it's roughly to shape and flat, you can add more putty w/o any filler. It's a lot easier to sand w/ finer grit paper for a better finish. After you gel the bottom, sand to 400 w/the airfile, then switch to wet or dry on a hand held block.

[gcarter]

The first pic is the absolute best angle I could get to show it as much as possible. it really doesn't look that bad from any other angle and in real life I didn't even notice it until this weekend. I even checked for any hook *visually only* when I bought it and didn't see one

I also put it on this trailer not long ago. The vertical bunk really shows it off well because it is a straight edge. I'm curious about something really simple. If a hook can get into a hull because of lack of support in the trailer can it also start to work itself out?

My new trailer has a combo of vertical and horizontal bunks. If there is any hope of the hook working itself out the vertical bunks would do it, and it just so happens that the hooked area is sitting right where those bunks are. I'm just thinking out loud here so don't rip me a new one if this is a crazy idea:eek:

It also leads me to something I have held back in reading trailer threads. Everyone seems to like horizontal bunks but to me it seems that a combo is much better. The verticals are unforgiving and will support the transom no matter what. The horizontals will bend with the boat as needed while only unforgiving where the brackets are mounted. When I bought my boat it was on a custom made horizontal bunked trailer (although a rusted pile of crap) it really should have supported the hull perfectly as far as the 'book' goes for trailers.

I really think the problems of that era was a molding problem. Even the sides of the TR suffered from "hooks" right in front of the transom just like the bottom of many '80's boats. I think Lenny touched on the problem once about not getting enough glass into the hull before a particular amount of time had passed.

[BigGrizzly]

Here is my question. Why do all, it seems, that all the boats of that era have the strake hook. This seams to stop when the inverted chine appeared. I wonder if removing it will cause a porpoise and or more/ less speed. I am really up in the air on this one. I will have to wait untill george id finished his to find out:yes:

[mattyboy]

my question is was the hook put there intentionally or was it from being pulled to early from the mold or from the life it lead, I looked at an early 70's 18 that lived on it's lift rings all it's life it had no hook??

[VetteLT193]

my question is was the hook put there intentionally or was it from being pulled to early from the mold or from the life it lead, I looked at an early 70's 18 that lived on it's lift rings all it's life it had no hook??

seems that hanging from the rings would be better than a trailer because the transom is the lifting point so if the hull changed it would add more rocker if anything.

on a trailer, supported from the bottom the transom weighs the most but isn't really supported the best because the bunk brackets are always forward of the transom so the wood can bend down after the bracket.

If I took a guess the hook starts after the point of where the trailer bunks are attached to the trailer.

My brother's 1987 22 has zero hook. It has spent half of it's life hanging from the rings and the other half on a South Fla trailer like my new one with the vertical and horizontal bunk combo.

So with all that said, it still doesn't answer anything. we've got some ideas though, either pulled from the mold too early, not supported on the trailer right, or intentionally built in to some extent.

[mattyboy]

Vette,

I agree that is why sometimes it pays to have a custom trailer made designed specifiaclly for the boat , look at the pics of these performance custom made trailers look at how the transom is supported with the bracket for the bunk right at the end.

http://www.donzi.net/forums/showthread.php?t=56772


the only two classics I know that hook was intentional was the 16 and the Hornet

[VetteLT193]

that is a nice trailer. My old one was almost identical except the bunks hunh off more, which in hindsight was really dumb because the trailer was big enough to just slide everything forward just like yours.

On an separate note, I really like the spare tire carrier. great location, out of the way but easy to access.

[BigGrizzly]

The hook I am talking about is the one on the top strake . It starts waw befor bunks would end. As for hanging from lift rings some boating mags say it is bad but I thinl it is how the lift rings are designed into the boat,

[gcarter]

Just a reminder of my TR and the conditions of both sides in front of the transom;

http://www.donzi.net/forums/attachment.php?attachmentid=41423&d=1230170301

http://www.donzi.net/forums/attachment.php?attachmentid=41459&d=1230347029

So you see here the same sort of "hook" as we see in the bottoms of many of the boats of the same period.
These obviously didn't occur from bad bunking or hanging from lifting rings.
It simply didn't have enough glass in the sides!

All I'm saying is let's not kid ourselves.

[BigGrizzly]

George I could se one or two because of the lack there of but all, I question that especially since it is manually done and not a machine. It could be a bad mold or maybe it was designed that way. I really do not know.

[mattyboy]

George

judging from the last pic you posted looking at the white shaded area between the last strake and the chine, to me that appears to be rocker not hook???

[gcarter]

George

judging from the last pic you posted looking at the white shaded area between the last strake and the chine, to me that appears to be rocker not hook???

Matty, I just hadn't sanded very far forward at that point, but the "hollow", or "hook" was obvious just like on the port side except only near the chine.

[mattyboy]

it very well could be an optical illusion or a decieving camera angle

but if you reference the edge of the strake that is facing the camera, from the point of the spot that is sanded or in the area of the white pad that the hull is resting on. as the strake goes back you should see less and less of it and also the hull between the strake and the chine and less of it as the hook takes over but in your shot you see more which means the end of the hull is rising away from the strake not curling down??

next time your out there take a shot with a straight edge for me will ya


I tried on photo shop but it isn't the best

http://www.donzi.net/forums/attachment.php?attachmentid=44793&d=1239206416


and for clarification for all the boy and girls out there in television land here is the hook on a 16 intentionally put there look from the lifting strap back to the transom along the chine

http://www.donzi.net/forums/attachment.php?attachmentid=42970&d=1233895253

[gcarter]

Matty, here's a link to the work I did;

http://www.donzi.net/forums/showthread.php?t=50476&page=17

It goes for several pages where I ground off the gel in the depression, beefed up the inside of the hull w/24 OZ. double diagonal Knytex because the hull sides were so thin in the depressed area, and filled the depressed area w/glass filled polyester putty.

Take a look at the hull sides, the repair I did to correct the problems, and I'd like to hear your comments on the original Donzi layup in the sides.

My point is, I believe the hooks in the hull bottoms of Minx's, and some 22's, and the issues I ran into are the same problem.

[mattyboy]

I am not sure but I didn't see a straight edge on the bottom in all that work you did ;) . If your point is the layup was not strong enough or done correctly then I can't see why in a 20 year old boat that is sitting on a trailer would not have an adverse effect on the bottom weather it causes an unintentional hook or a depression.
can't really comment on the overall layup procedures in an 88 boat but I am sure there some problems that can be found in certain boats with voids, materials and curing time that are evident in your TR. I have not really dug into a donzi of that era, I know you have done 2 now both of which were rough to start with and turned out very nice . The older boats I have seen have had some minor issues but most can be attributed to their age or the life they lead. The question is, is there a hook in the molds?? the hook or depressions that appear now were they there when they were popped from the mold or did they appear slowly over time, I bet some boats had them when they were pulled from the mold to early and then finished curing on a dolly.
Surely you knew what you were getting into after the minx like the old joke

Doc it hurts when I :wavey:,
doc: well then don't :wavey:

;)

[gcarter]

Here's another picture taken just after I shot this very first coat of gel. The shine comes from the wax.
At this point, I'd remove about 95% of any existing hooks and other repairs.
The sides of the stakes are clearly visible.
The bottom at this point is pretty flat...not perfect but close. Ya gotta move on at some point.

http://www.donzi.net/forums/attachment.php?attachmentid=43770&d=1236022763

[mattyboy]

I am trying to track down a minx in very mint shape low hours again it hung on it's rings all it's live if I find it I'll let you know how the bottom is

[DONZI]

Mine has voids, not hook. Low spots varying in location side to side approx. 2' ft from transom.

So it's finally reached above 60 deg. for the 3M Vinyl Ester Filler to be able to cure and get to work. I started with a glass short strand filler 1st and it was tough sanding(brown in pic.) . Now it's onto the 3m easy sandable,30 min. dry time stuff. http://www.boatfix.com/catalog/737.pdf
http://www.boatfix.com/bykeywordnew2.asp?textfield=MMM46006&texttype=2&submit=Search
So we will see how this goes. It's drying right now !:biggrin.:

Almost done !
http://inlinethumb42.webshots.com/39209/2937312960101021175S425x425Q85.jpg (http://rides.webshots.com/photo/2937312960101021175ErFsWC)

http://inlinethumb60.webshots.com/20731/2886752970101021175S500x500Q85.jpg (http://rides.webshots.com/photo/2886752970101021175mJnEjU)
Thanks for the inspiration George !

[Greg Guimond]

Here is the hook on the port and starboard side of my 16. I'm on a roller trailer and I can't imagine that helped over the last 36 years

[gcarter]

Greg, as Matty posted above, 16's have a built in hook that looks like a partially extended tab.
If you have additional voids, or hooks, forward of that point, then you can sort of map it out w/a straight edge like I did w/the Minx.
I just worked along the bottom w/the hull on dollies and used a pencil to mark the outline of the inverted "bowl" that will appear.
Actually fixing it is fairly easy, but time consuming. Part time, I think it took me about a month.

[Greg Guimond]

George, searching through your old thread got me wondering if all 16's have the same hook regardless of year and model. I am going to post up some pics of the bottom now that it is pouring rain here! More fodder for the archives !!