PDA

View Full Version : Replacing a deck.



Madcow
08-21-2007, 09:12 PM
I'm thinking about replacing the deck on my 79 18' 2+3. Anyone done this? I called Donzi and the indicated they are not sure if the new ones will fit. I'm thinking about just running the hull down there and seeing if it will fit, but seeing as how I live 1300 miles from Donzi I sure would like some input from you guys first.

mphatc
08-21-2007, 09:33 PM
Find a new or very recent 18 . . close by

then measure every possible thing . . and measure it all again . .

I suspect it will fit, certainly around the rail, but you'll be more interested in the changes made below deck . . stringers, heights to supporting structures . . etc.

Does this mean I can buy a new hull for my Corsican deck??? Just kidding!

Mario

Rootsy
08-21-2007, 10:14 PM
what is wrong with your current deck?

LKSD
08-22-2007, 08:00 AM
Yes, dont they sell viagra for a limp deck??? Just kidding.. :D

Is it rotted? If so why not recore it? Jamie / Lakeside


.

Madcow
08-22-2007, 01:47 PM
what is wrong with your current deck?

The cockpit well was not properly supported from the start, so with years of bouncing up and down it is surounded with litteraly hundreds of stress cracks. I cant see how I can fix them all and not have some of them come back. Add to that the dash is kinda busted up and there is a 2 foot chunk missing from the shorbox joint on the foredeck. With all the work and money I'm putting into this thing I wand everything right.

gcarter
08-22-2007, 07:55 PM
If you were to put another deck on and not change the cockpit floor support system, and reinforce the floor, the new deck will soon be in the same shape.
If you weren't so far away, I'd do it for you but there're folks right there in your neighborhood that can take care of all those issues.
maybe they'll pipe up.

rustnrot
08-22-2007, 09:21 PM
Check with Ramsey Bros. Restorations right there in Toledo. They do great work, lots of wooden boat stuff but they have done fiberglass and I bet they would take a look at yours. They can be reached at 419-255-2628. Talk to Scott Ramsey, they are right downtown on 20th St.

Tell Scott that Tom Lang sent you!

Madcow
08-22-2007, 09:36 PM
I have had two fiberglass experts look at it already (Dave Sikorski[Glassdave] and Greg Reno [Tizbad]). It can be fixed, but they won't guarantee the cracks wont come back. As to supporting the floor, that will be easy. The problem was originaly all Donzi did was throw a couple peices of roven woven from the floor to the stringers. When I removed the deck both were broken loose. I think it needs a solid filler glassed and encapsulated to make the stringer system and the floor act as one peice.

mphatc
08-22-2007, 10:04 PM
Madcow,

somewhere we've discussed how early decks are like tramploines and the problem with the poor supports as you found . .

I solved this real easily on my 69 Corsican by reinforcing all of the stressed areas on the deck structure while it was apart, and also adding solid epoxy laminated marine plywood blocks between the stringers and the deck and cockpit floor . . building the deck hull structure to function as a single unit . .

Pitty the poor Baahstaad who takes it apart next time . .

The stress cracks on the visual side can be repaired, done properly they should not return, as long as the supporting work from underneath is done correctly . .

Mario L.

olredalert
08-22-2007, 10:43 PM
--------Maybe if you sweet-talk a certain member of this sight you can make it into a bench seat X-18. You would have to travel quite a ways west to pick it up, but it would be worth it as the quality would be the best and you would have a one of a kind as well. Ill let someone else track down the former posts on this subject for you. I know they are out there somewhere ........Bill S

gcarter
08-23-2007, 06:07 AM
Another problem w/the floors is the coring used was in the form of blocks pieced together w/spaces in between leaving thin areas. These thin areas are where many of the stress cracks occur. Like around the corners of the "cooler" in the floor.
When the deck comes off, these thin areas must be filled until it's flat and roving laid over the entire bottom.
When it goes back in, you won't believe how much stiffer it is.
I bolted in two pieces of 2" X 2" X 1/4" anodized aluminum angle to the stringers so that the horizontal legs of the angles formed a surface that becomes the floor support. I cut long strips of 4" exhaust hose that cushioned the floor to the angle. Then I had a local machine shop make some countersunk "washers" w/beveled edges from some 1 1/2" round SST stock. I ran 1/4" machine screws through the washers and directly into the aluminum angles. I think there were six total. That way the floor was VERY well supported and could be taken apart.

LKSD
08-23-2007, 06:39 AM
You should be able to pop it off & reinforce it from the backside with cloth & resin to strengthen it before repairing all of the cracks.. You can also add supports carefully for the floor.. I have done it in the past, it is just a bit time consuming..

If an area has enough support to keep it from flexing too much it will not recrack most of the time.... Like George said, it is usually the thinner spots that start the cracking (under most circumstances). The other thing that can cause a crack is if the resin was mixed too hot with MEK.. Other than that abuse or a hard impact can cause anything to crack.

I am recoring a deck now.. It is a real PITA, but it can be done.. If your deck is strong, but just cracked you can support it & have it flipped if you make a little jig for it.. That would make it easier & faster to work on.. :)

Jamie / Lakeside


.

Rootsy
08-23-2007, 08:19 AM
Madcow,

My 18 has a whole buttload of gel stress cracking and crazing throughout the deck... It's going to be a long hard road to get it back and make sure that a few grand worth of new paint doesn't crack and craze from what is beneath it... In some places I'm going to have to take it right to glass and build with a filler...

As for your deck... If you can get it off and flipped upside down you can remove the plywood coring easily with a pneumatic cutoff saw and a chisel and mallet...

Get a flat piece of plywood and some screw jacks and use it to support the floor and create a level surface to work against from the outside (against the gel). Impregnate the raw glass surface where the coring was removed with a good epoxy which will get into any structural cracks... chances are the cracking is only gel deep and you should be able to see if it is structural once the coring is removed.

Recore the floor with new marine plywood and get a couple of layers of 24 oz biaxial stitchmat on it and it'll be solid as a rock... I would actually lay down a stitchmat layer prior to adding the coring...

you can then turn your attention to getting rid of the stress cracking with an air file, DA and a lot of sanding. Smooth it with some good filler and sand and shape.. lay a layer or two of light weight weave on top and then fair that in, most likely going to have to do some filler on top of that also to get it smooth... and then refinish... in a nut shell...

As for the dash, not much of an issue either honestly... replace the missing plywood, build up with glass and then lay a whole layer of light weave across the dash to keep any cracks from coming through.. fill any irregularites and fair it...

Also for bracing the floor... not sure if you want a totally rigid bond to the stringers. The hull and stringers will flex somewhat and may cause the floor to again crack if it pulls or pushes... This is most likely why the glass wads broke away in the first place... A better alternative may be to build a dam down each side of each stringer and fill it with ITW Plexus. put the deck on and let them cure and bond... The Plexus has some elastic properties (more or less depending upon which one you use)... Therefore it has a bit of give...

The plexus bond to the substrate is so strong that it is said that the substrate will delaminate or fail before the plexus to substrate interface... This is something I am considering for the "Mistress"

Lenny
08-23-2007, 10:01 AM
--------Maybe if you sweet-talk a certain member of this sight you can make it into a bench seat X-18.

Maybe if the guy would just put down all of his other projects and focus for a couple weekends this could be a reality. :D :rolleyes: :rolleyes: :rolleyes:

I have not seen any recent pics from the loser...this was his last report.
http://www.donzi.net/forums/attachment.php?attachmentid=19022&d=1141330579

zelatore
08-23-2007, 01:05 PM
Another problem w/the floors is the coring used was in the form of blocks pieced together w/spaces in between leaving thin areas. These thin areas are where many of the stress cracks occur. Like around the corners of the "cooler" in the floor.
When the deck comes off, these thin areas must be filled until it's flat and roving laid over the entire bottom.
When it goes back in, you won't believe how much stiffer it is.
I bolted in two pieces of 2" X 2" X 1/4" anodized aluminum angle to the stringers so that the horizontal legs of the angles formed a surface that becomes the floor support. I cut long strips of 4" exhaust hose that cushioned the floor to the angle. Then I had a local machine shop make some countersunk "washers" w/beveled edges from some 1 1/2" round SST stock. I ran 1/4" machine screws through the washers and directly into the aluminum angles. I think there were six total. That way the floor was VERY well supported and could be taken apart.


That's why George is my hero :)