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Admeister
08-23-2014, 01:21 PM
Well.. Hate to say it, but I have a rotten transom... The other day a mounting screw made it's way out of the transom, causing the trim pump to lean. That's how I noticed it. So I got in there and turned the other screw to remove it and (unfortunately) it spun free inside the transom. No bueno. So I guess I'll have to pull the motor and drive?? The transom is hollow halfway down....

MOP
08-23-2014, 02:49 PM
You will also find the aft sections of the stringers rotten, Donzi like most other manufacturers does not isolate the stringers from the transom wood with a layer of glass. When one goes so does the other, you will also find the transom plywood is 5" square chunks not solid pieces. You can preform your replacement pieces which was done on mine. You can go different way, two pieces of 3/4" or three layers of 1/2" both setups with a layer of glass between the pieces. Another point is when cutting your transom pieces cut them straight across the bottom eliminating the V section. Once the plywood is glassed in place build the lower V area up with glass then drill for your drain tube. Doing this way completely eliminates the possible weepage from the drain tube which seems to cause much of the transom rot as does the limber holes. Make a cut the back end of the stingers on a 45 degree angle 4" high, This cut off allows for water to get into the bilge with -0- restriction. The stringers should have one layer of glass on them before the are set in place, having the transom done and the stringers glassed will isolate them stopping any possible water migration. Far to many people redo these items just like the factory putting them in future jeopardy! A job done right will last the life of the boat.

Admeister
08-27-2014, 05:08 PM
You will also find the aft sections of the stringers rotten, Donzi like most other manufacturers does not isolate the stringers from the transom wood with a layer of glass. When one goes so does the other, you will also find the transom plywood is 5" square chunks not solid pieces. You can preform your replacement pieces which was done on mine. You can go different way, two pieces of 3/4" or three layers of 1/2" both setups with a layer of glass between the pieces. Another point is when cutting your transom pieces cut them straight across the bottom eliminating the V section. Once the plywood is glassed in place build the lower V area up with glass then drill for your drain tube. Doing this way completely eliminates the possible weepage from the drain tube which seems to cause much of the transom rot as does the limber holes. Make a cut the back end of the stingers on a 45 degree angle 4" high, This cut off allows for water to get into the bilge with -0- restriction. The stringers should have one layer of glass on them before the are set in place, having the transom done and the stringers glassed will isolate them stopping any possible water migration. Far to many people redo these items just like the factory putting them in future jeopardy! A job done right will last the life of the boat.

Thank you. So is the glass laid thick enough that I can cut out the wood from inside the bilge and not have to cut through the hull? I have one of those Rockwell tools. Would that do the trick? I'm hoping these repairs can be done without the need to re-gel the stern. Is that realistic?

hardcrab
08-27-2014, 05:18 PM
Thank you. So is the glass laid thick enough that I can cut out the wood from inside the bilge and not have to cut through the hull? I have one of those Rockwell tools. Would that do the trick? I'm hoping these repairs can be done without the need to re-gel the stern. Is that realistic?

I used an air chisel / no problems ..........................:smash:

Admeister
09-01-2014, 10:40 AM
I'm prepping the garage to repair the transom. Hopefully I can "knock this out" before next spring. I guess it comes down to time and money. One question for all the guys that have been down to fiberglass in the bilge, how thick is the glass typically laid on the transom? Just curious.

I plan on documenting the process here. I also would like to sell my 460 OMC and replace with a 454 merc in the whole process. Depends on $$$. King cobra may stay for another season unless I can find a bravo I can afford but first things first.. Rotten transom...

Wish me luck!

Ghost
09-01-2014, 10:56 AM
I'm prepping the garage to repair the transom. Hopefully I can "knock this out" before next spring. I guess it comes down to time and money. One question for all the guys that have been down to fiberglass in the bilge, how thick is the glass typically laid on the transom? Just curious.

I plan on documenting the process here. I also would like to sell my 460 OMC and replace with a 454 merc in the whole process. Depends on $$$. King cobra may stay for another season unless I can find a bravo I can afford but first things first.. Rotten transom...

Wish me luck!

Not sure about the KC, but Merc has an exact spec for the overall thickness where the transom assembly is installed. Something like 2 1/4 or 2 3/16 maybe. I think people usually build up the glass over their coring to hit that spec. A few years back they gave a range, now they specify an exact thickness. If you go to the Merc website and find an engine/drive installation guide, it'll be in there. If you can't find one, yell. I have one on my laptop somewhere.

Conquistador_del_mar
09-01-2014, 12:30 PM
Thank you. So is the glass laid thick enough that I can cut out the wood from inside the bilge and not have to cut through the hull? I have one of those Rockwell tools. Would that do the trick? I'm hoping these repairs can be done without the need to re-gel the stern. Is that realistic?

The outside fiberglass of the transom is probably around 3/8" so it is plenty thick enough that removing the rotten wood from inside the engine compartment is the correct way to replace the transom wood. I always used an air chisel to break out the stubborn sections. You will probably find some sections are completely rotted to sawdust and other sections might still be fairly intact so the air chisel really helps (much easier than chiseling by hand). You will need a grinder to prep the transom fiberglass before starting the rebuilding process.
This would definitely be the time to replace your outdrive before cutting out the transom assembly holes in the fresh transom. You might want to get a professional to help you on the conversion process for many reasons including getting your x dimension as high as possible. Just some thoughts.

MDonziM
09-02-2014, 08:57 AM
+2 on Bill's input. If you are thinking of replacing the drive do it now, not sure but I think the cobra is a larger footprint than a bravo. I didn't see the year of your 22 but as MOP said, your stringers are most likely bad too due to the factory layup process. I replaced stringers gussetts and shelves, and sistered a new engine bulkhead. Also, depending on the year, you should think about adding layers to the bottom. Using a bi-axel cloth and mat like 1708 about 7-8 layers equals 1/4" which is what I would have on the inside of the transom.
- M

JayZ
09-02-2014, 06:55 PM
I've been told the cutout for the King Cobra nearly the same as the Bravo I and that you only had to drill one new hole to do the conversion. ...I've thought about it but my King is pretty happy behind the 502 now that I've got rid of the obsolete OMC specific parts.



+2 on Bill's input. If you are thinking of replacing the drive do it now, not sure but I think the cobra is a larger footprint than a bravo. I didn't see the year of your 22 but as MOP said, your stringers are most likely bad too due to the factory layup process. I replaced stringers gussetts and shelves, and sistered a new engine bulkhead. Also, depending on the year, you should think about adding layers to the bottom. Using a bi-axel cloth and mat like 1708 about 7-8 layers equals 1/4" which is what I would have on the inside of the transom.
- M

MOP
09-03-2014, 02:38 PM
If you have a good King one with the hump it is nuts to swap to a Bravo, the King has proven to be stronger and more hydrodynamic IE faster with the same power.

Admeister
09-03-2014, 05:39 PM
If you have a good King one with the hump it is nuts to swap to a Bravo, the King has proven to be stronger and more hydrodynamic IE faster with the same power.

Yes it's a KC. Keep it??

Admeister
09-28-2014, 05:42 PM
Got my garage cleared out this weekend and the boat is in with fans on it. I will start pulling the motor and drive soon. Question for you guys that have "been there done that"... would I save time in the long run if I pull the deck to pull the engine and replace the transom/stringer wood? or should I just leave it for now and only pull it if I need to get to the stringers under the bench seat? also wondering 'round about how much it costs to replace the fuel tank if I get that far into it. Thanks guys

gcarter
09-28-2014, 06:51 PM
Got my garage cleared out this weekend and the boat is in with fans on it. I will start pulling the motor and drive soon. Question for you guys that have "been there done that"... would I save time in the long run if I pull the deck to pull the engine and replace the transom/stringer wood? or should I just leave it for now and only pull it if I need to get to the stringers under the bench seat? also wondering 'round about how much it costs to replace the fuel tank if I get that far into it. Thanks guys

Pull the deck, the sooner the better.
It's pretty easy to do and can be done in half a day, even by yourself.
Once it's off, everything is so much much easier.

HallJ
09-29-2014, 08:12 AM
I started out like you did. Wet transom. Okay, I'll pull the drive, engine and replace. No big deal.
Cut the top skin off of one of the stringers to see if they were wet too.
I thought, "hmmm should be dry after a bout a foot forward of the transom".
Not a chance in hell! Pulled the deck off and they were finally dry about six inches from the front.
Scraped all of the soggy wood out out. I'ts nice to replace everything and fix/replace the poor build quality. I completed all of the work in one winter.

Jeff

HallJ
09-29-2014, 08:22 AM
Pictures of the frame to pull the deck. I completed all of the work on the hull while it was still under the deck and sitting on the trailer. When it was finished, I pulled the hull off and rolled to the side to fix the low spots on the hull.

Jeff



8095780958

Admeister
09-29-2014, 09:55 AM
Thanks for the pictures! A picture is worth a thousand words. I was thinking about doing this very same thing with 6x6s, looks like I'll save a few dollars going the 2x route for the deck lift.
I got under the deck last night and noticed that the rub rail was bolted on with locknuts. I was also happy to see that the deck was all hand laid. I didn't see any chopper gun mess.
I wonder if Donzi or baja or whoever they are now are making stronger stringers/transoms by building them the way we are re-building them...
Either way, makes no difference to me, I practically stole my 22, knowing it would need work. After this winter I'm sure I'll never want to sell this boat!

yeller
09-29-2014, 05:33 PM
Pulling the deck was a lot easier than I had thought it would be. You can easily have it off in a day.
Jeff's setup looks great and a good way to go. I didn't have the garage to be able to use an overhead hoist, so I pulled and installed mine with an engine hoist.

I put a 4x4 through the speaker holes to lift with the hoist.

80961


Lenny came up with the idea to support the deck with a couple of 2x6's. They were bolted to the deck using the lifting ring holes.

80962


Setup worked great and we were able to move the deck around while on the engine hoist. In this pic you can see bolt through the front lifting ring hole.

80963

I had lots of help removing the deck, but when I installed my new one, I was able to do it by myself using the same setup. I didn't have any holes in the deck to bolt the 2x6's to, so I ran straps over them from one side of the deck to the other.

The hardest part of the deck removal/install was reinstalling the rub rail. Even though it had been on the deck for years, it didn't just simply screw back on. I had to put in some #12 screws at an angle, every couple feet to "stretch" the rub rail. (I removed the #12's after it was properly installed). The rub rail easily took me 8hrs to install.


Here's a pic of my transom thickness to give you an idea of what the thickness might be of your fibreglass.
Mine's an 04 and has about 3/8" on the exterior with about 1/4" on the interior. Mine is also foam cored instead of wood.
80964

Admeister
09-29-2014, 07:55 PM
So far, I have removed all but one piece of rubrail. I was wrong about an earlier post stating that the deck was bolted. Only the front rubrail was bolted, everything else was held on with screws. Funny how the deck was fastened before the gelcoat went on. Is that factory? Some of the countersunk screws were covered over by gel. Also found that there seems to be no rhyme or reason as to placement of the deck screws. Some are as close as two inches while others are as far apart as 22 inches! And I found a screw hole near the transom that had been countersunk and then abandoned and filled with caulk. While another deck screw was drilled through by a rail screw. I'll be sure to use tape and mark all my deck screws and rail screws so that doesn't happen again. And, just as previously stated by a few of you guys, so far... deck removal is a quicky. :biggrin.:



8096580966809678096880969

Admeister
09-29-2014, 09:28 PM
(can't figure out how to turn my pictures right side up)
80970
This 1990 22' has a cleat on the bow. Obviously not structural for lifting. There is no lifting eye, so maybe i'll remove the fuel cap to get a brace under this part of the deck to lift it off the hull.


8097180974
Can't figure out the point in this? My guess is it's where you'd bolt the eye through the deck?? doesn't look like it would hold much as you can see the voids around the outside where it was glassed to the hull.


8097280973
These two ^^ are upside down and can't figure out how to get them right side up... but i'd love to know what in the world the piece of pvc glassed onto the deck is for?? it's right between the cleat and the nav light. looks like it's even been worn as if they used it to suspend the deck upside down and work on it at the factory.


8097580976
Just another picture before and after of one of the gelled over deck screws. I found them all and once I get my lift rigged up, I will raise the deck off the hull and get busy cleaning! I'll be glad not to get back under the bow for a while...

murfman
09-29-2014, 09:30 PM
Do yourself a favor and buy an Oscillating saw. Harbor Freight sells one for ~20$, of you can buy a Fein for 200$ Either way go buy one and get the offset cutting blades for it, it is the perfect tool to cut out the remaining wood in your transom, quiet, and pretty much dust free. I just used one to remove the transom from my 27' Magnum sedan.

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps6032cbde.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps6032cbde.jpg.html)

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps2aa28bd4.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps2aa28bd4.jpg.html)

I cut my plywood like this, and filled the round hole with layers of Fiberglass mat:
http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zpsb46989cd.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zpsb46989cd.jpg.html)

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zpsac1a0b0e.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zpsac1a0b0e.jpg.html)

I used 2 layers of 3/4" Okoume, glassed together with CSM:
http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps7b8ac52d.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps7b8ac52d.jpg.html)

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps8a891f38.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps8a891f38.jpg.html)

I also mage clamps out of 2x6 and 2x4 lumber bolted through the transom cutouts for the drives as I didnt want ANY extra holes in the transom

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps3a9199a8.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps3a9199a8.jpg.html)

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps5ece2269.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps5ece2269.jpg.html)

Admeister
09-29-2014, 09:34 PM
Now that's legit ^^^

murfman
09-29-2014, 09:37 PM
I used Corebond to bond the ply to the transom then covered the inside with 2 layers of 1708 and 2 layers of tabbing.

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zps5480f73a.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zps5480f73a.jpg.html)

I have to say Glassdave from OSO was instrumental in me doing this project, with out him I would still be lost.

I also opted to beef up the stringers with a layer of 1/2" Okoume on each side of the originals (Mine were bone dry, so I only had to cut out the last 6" or so to fit the transom and scarf in replacements) and added diagonal 2" tall stringers of 3 pieces of 1/2" laminated together. creating a Chevron pattern to reinforce the bottom of the hull

http://i184.photobucket.com/albums/x205/murfman_photo/Magnum/image_zpsbada5f01.jpg (http://s184.photobucket.com/user/murfman_photo/media/Magnum/image_zpsbada5f01.jpg.html)

Lenny
09-30-2014, 09:38 AM
I will second the purchase of a Fein oscillating saw... It is the PERFECT tool for glasswork and cutting out old junk.

http://www.homedepot.com/p/FEIN-Multimaster-Oscillating-Multi-Tool-Kit-FMM-250-Start-Q/202980163

Admeister
06-21-2015, 12:07 PM
I threw in the towel before I started. I'm far too busy to take on this project by myself, so it's in the shop. Going to have the engine and drive pulled and stringers, transom redone by a local professional. He's even going to gelcoat the bilge. Anyone ever done that? I can imagine it is going to look immaculate by the time he's done! And I'll get to use the boat this summer. (Something I'd have never been able to say, had I taken on this project myself)


"Props" to all you guys who have done this work on your own boats!

gcarter
06-21-2015, 01:57 PM
Sprayed on gel is not shiny, also it's quite porous, and you may not be crazy
about the results, especially in the bilge when it absorbs oil and other things.
There're some other finishes you may like more that you can apply yourself, like
Rustoleum 9100 System DTM Epoxy Mastic w/emersion activator.
http://www.rustoleum.com/product-catalog/industrial-brands/high-performance/epoxy-coatings/9100-system-dtm-epoxy-mastic

Morgan's Cloud
06-21-2015, 02:50 PM
To add to George's suggestions , when I finished off the bilge areas of mine I used the Interlux barrier coat system that I had already barrier coated the hull bottom with .

http://www.yachtpaint.com/usa/diy/products/primers/interprotect-2000e.aspx#

The grey finish looks identical to what Donzi used on the classics , is easy to apply by brush - one coat will do it . It's hard as nails and easy to clean plus you never have to worry about water sitting in the bilge for long periods of time.

Just another idea , nothing more , or less :biggrin.:

Ed Donnelly
06-21-2015, 07:55 PM
Glyptal is bulletproof and comes in gray. Oil and grease just wipe off..Ed