TRANSOM deck and stringer replacment

Joined
Sep 1, 2009
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15
1961 15ft kenway fiberglass runabout



i ordered some new back to back loung seats and was going to install them but...



i found a little rot ...



 
Last edited:
Joined
Sep 1, 2009
Messages
15
Re: deck and stringer replacment

Re: deck and stringer replacment

after removing all the old rotten plywood decking i started trimming/grinding down the fiberglass edges of the old decking












i was going to use 2x4 and 2x6 pt for stringers but now after what i have read on here i am worried that this is not a good idea? i already have the
2x's available and two are roughly cut.

i understand it doesnt matter how much i save on free materials and work i have already done cutting the 2x's if they arent going to work properly
i know there are probly alot of post on this topic already but i am asking for one more
thanks
oh and ps im a noob
 

TojosMojo

Petty Officer 2nd Class
Joined
Aug 13, 2009
Messages
128
Re: deck and stringer replacment

Re: deck and stringer replacment

Welcome to the forum, you have all the usual suspects, rotten floor, stringers, and transom should be shot to...

Good news is you are in the right place to get it fixed.
 
Joined
Sep 1, 2009
Messages
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Re: deck and stringer replacment

Re: deck and stringer replacment

thanks !
the transom was replaced at some point and looks good so im hoping it is...
any pointers/advise would be gladly excepted !
 

TojosMojo

Petty Officer 2nd Class
Joined
Aug 13, 2009
Messages
128
Re: deck and stringer replacment

Re: deck and stringer replacment

I am not an expert on the subject but first off dimensional lumber has a problem with swelling and contracting more than a plywood product would, thus causing more movement which can crack fiberglass and pull away from your flooring (Pressure must be dried out completely at least 3-6 weeks in a dry environment, and is a lot heavier than you may want in that boat). Also if the lumber you are using is not dry you will be incasing it in fiberglass thus sealing in the moister and causing rot to set in, also the resin/epoxy will not adhere well if at all the the wet PT.

I'm sure someone will be along to tell you the absolute reasons not to use 2x4 and 2x6's but until then that's my $.02 worth. You do not have to use marine plywood, you can get away with a good exterior grade ply since it will be sealed in fiberglass and resin, to help keep cost down.
 

ghamby

Petty Officer 2nd Class
Joined
Aug 3, 2009
Messages
193
Re: deck and stringer replacment

Re: deck and stringer replacment

Some nice,really dry, pressure treated lumber under there would serve you
better. Same with the deck ply. Dry the wood completely. Coat all surfaces
with marine epoxy, edges and ends included. Glass in the stringers, Glass in the
deck. Paint the glassed deck with marine paint with nonskid mixed in.
You can go with what you have using the same procedure, but water will
find a way in. You don't want to do a job like this twice.
Good Luck, GH
Sorry, I missed the "pt" notation. You're on the right track.
 
Joined
Sep 1, 2009
Messages
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Re: deck and stringer replacment

Re: deck and stringer replacment

well it looks like i was wrong about the transom. there is no iner skin on the very bottom and any water in the boat was sucked right up from there. it seemed solid but its full of water and the bottom is all rotten. i have unscrewed the top half of the boat somewhere around 200 50 year old screws (not so fun) and removed the splash well so i can acess the transom for replacment. I really like the idea of sea cast but like i said there is no inner skin on the bottom of the transom. i also like the chain saw idea to remove the old transom wood. sounds like fun. so i guess im looking for some advise on where to go from here. do i cut the fiberglass from the old deck smooth against the transom glass it in and then remove the old wood? should i cut out all the inner skin to remove the transom wood and then make a new inner skin? not sure what to do. I hope the pics will help







 

jhs5150

Seaman Apprentice
Joined
Jul 5, 2009
Messages
34
Re: deck and stringer replacment

Re: deck and stringer replacment

I'm watching what you do very carefully, I may be in the same boat (pun intended).
 
Joined
Sep 1, 2009
Messages
15
Re: deck and stringer replacment

Re: deck and stringer replacment

hoping i can get some advise from other boaters on this forum but im thinking maybe i should try contacting seacast as well
 

andgott

Master Chief Petty Officer
Joined
Sep 2, 2009
Messages
801
Re: TRANSOM deck and stringer replacment

When it rains, it pours... as is typical with an old boat, when you find one problem, you are bound to find things lurking underneath!

My transom was the same way- No 'glass on the bottom 2" or so, and it rotted from there up. It also rotted from the top down, too- Through leaks, and the rot met in the middle. I'm in the process of rebuilding everything-

http://forums.iboats.com/showthread.php?t=355668

It looks like you aren't too far off!

-Andrew
 
Joined
Sep 1, 2009
Messages
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Re: TRANSOM deck and stringer replacment

andgott, i have actually been following your rebuild and a couple others.
keep posting new pics and let me know how the transom goes

When it rains, it pours... as is typical with an old boat, when you find one problem, you are bound to find things lurking underneath!

My transom was the same way- No 'glass on the bottom 2" or so, and it rotted from there up. It also rotted from the top down, too- Through leaks, and the rot met in the middle. I'm in the process of rebuilding everything-

http://forums.iboats.com/showthread.php?t=355668

It looks like you aren't too far off!

-Andrew
 

NoKlu

Senior Chief Petty Officer
Joined
Feb 23, 2008
Messages
786
Re: TRANSOM deck and stringer replacment

I'm not an expert but I would remove the inner transom skin completely. Get a couple of sheets of 3/4 ply and build the transom and stringers with it,then glass the whole thing in. Seacast is nice but it's expensive and if you seal all the wood in,it will last a very long time. Pt is not necessary. It takes a long time to dry and the new stuff eats screws in no time. The trick is to seal the wood with the glass so the water can't get at it.Check out the completed projects threads and you will get some good ideas. oops! hull extension thread is one of the better projects in the forum and a great learning tool. Good luck.
 
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Re: TRANSOM deck and stringer replacment

thanks NoKlu, the more I look at seacast the less sure i am that it is the way I want to go.
 

NoKlu

Senior Chief Petty Officer
Joined
Feb 23, 2008
Messages
786
Re: TRANSOM deck and stringer replacment

All of the answers are in this forum you just have to read lots. Use the search function to help find things. Start at the top of the forum for tips on tools,safety equipment you will need,and suggestions on some materials. The more you learn the easier this job will be.
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: TRANSOM deck and stringer replacment

In my opinion Seacast is great for one specific use....replacing the transom on a substantial sized boat where everything on the interior is fine (solid floors, stringers, etc) but the transom is shot. Pull the motor, chainsaw out the rotted transom, pour in new one, done. For a boat like yours where you already have everything stripped out, I'd do what NoKlu suggested.
 
Joined
Sep 1, 2009
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Re: TRANSOM deck and stringer replacment

well I got a little more work don this weekend


I removed the wood storage doors up front



seperated and lifted the top half of the boat
pulled it forward and used 2x4s to suport the top half so i could get to the transom



i used a sawzall and prying to remove the inner transom skin



first layer of ply was easy to remove and only along the top of the transom




second layer was alot harder i had to cut it out in sections using a skills saw set to the depth of the board



 
Joined
Sep 1, 2009
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Re: TRANSOM deck and stringer replacment

third section was in the best shape and came out mostly intact





I vacumed out all the debree/mulch



all that is left is the outer skin

 
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Sep 1, 2009
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Re: TRANSOM deck and stringer replacment

so Now What? I think I am ready for a materials list. I know I am going to use maraine ply to rebuild everything and that it all needs to be sealed laminated and fiberglassed in but I am not sure how to do it. what kind of resin,laminate, matting, fiberglass cloth ext. i have been trying to search the fourm for pics and write ups of other people going through the resin/poly/epoxi step but i am having some trouble finding them.
also for the stringers i see that i need to bed them in something ( peanut butter) what is peanut butter? thanks in advance this fourm have been very helpfull so far
 

HVAC Cruiser

Lieutenant
Joined
Sep 12, 2009
Messages
1,254
Re: TRANSOM deck and stringer replacment

so Now What? I think I am ready for a materials list. I know I am going to use maraine ply to rebuild everything and that it all needs to be sealed laminated and fiberglassed in but I am not sure how to do it. what kind of resin,laminate, matting, fiberglass cloth ext. i have been trying to search the fourm for pics and write ups of other people going through the resin/poly/epoxi step but i am having some trouble finding them.
also for the stringers i see that i need to bed them in something ( peanut butter) what is peanut butter? thanks in advance this fourm have been very helpfull so far


Nice boat looks like your moving along pretty good. for your transom you are going to want to layer it using csm, you really don't have to go the added expense of marine ply alot of folks use ACX, thats actually what I built my stringers and deck out of. either poly or epoxy is fine epoxy is stronger BUT if you use epoxy you will not be able to Gelcoat if thats what you plan on as a finish. Epoxy will stick to poly, but poly will not stick to epoxy.

OK, now, transom builup with Poly:
1- After the peices are cut to size and shape cut CSM to match
2- Thin some poly with styrene and soak the surfaces, this will help seal the ply, don't forget the edges
3- wet out the ply with poly lay your csm and apply a thickend mix of resin, thicken the resin using cabosol and glass bubbles not too thick I made a mayonase consistency.
4- screw or clamp peices together

Using epoxy:
1- After the peices are cut to size and shape cut CSM to match
2-Heat the ply with a heat gun and roll epoxy on mating surfaces and edges. DO NOT THIN thinning will break down the epoxy and render it almost useless. heating will thin the epoxy and make it watery and soak in
3-lay out your csm, thicken some epoxy I used west 404 additive, and apply
4- screw or clamp peices together

With using epoxy youcan layer without waiting for it to cure, if you let it cure you have to sand cause it blushes.


Peanut Butter is poly mixed with chopped strand and glass bubbles

Oops is doing an incredable rebuld with step by step instructions for everything
http://forums.iboats.com/showthread.php?t=234392
its a good read, you can find everything you need there for info, it even has an index
Good luck with your project
 
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