Sylvan Transom Replacement

[Super Sportster]

Hi,
I'm new here. Bought this boat new in '89 and it hasn't been used since '93. Thought I would start using it again. Looks like the wood in transom is rotted. It looks like it would be fairly easy to replace this after doing some reverse engineering. What I see to do is remove the corner plates, top cap along the transom, remove every bolt and screw into the wood the lift it out through the top. Has any done this and am I on the right track?

Thanks,
****

 

[Bob_VT]

Re: Sylvan Transom Replacement

Welcome to iboats!

Yup, it's not rocket science and you are absolutely on the right track. The goal is to duplicate the old wood by using exterior plywwod that has been sealed on all edges/surfaces with epoxy resin.

A small package of CSM will make it even stronger

Aluminum boats are the easiest to work on and replace transom wood.

 

[Super Sportster]

Re: Sylvan Transom Replacement

Thanks Bob for the input.
I'll have to be ignorant here, what is CSM? I've been reading through some of the other posts, most are saying seal the wood with epoxy resin as you suggest. A co-worker stopped by to look at my problem and was saying the wood should be allowed to breathe on on side. My thoughts would be if it's been dried why not seal it. Any thoughts on this?

****

 

[proshadetree]

Re: Sylvan Transom Replacement

Chopped strand mat .Looks like a weave of hair rather than cloth.

 

[Bob_VT]

Re: Sylvan Transom Replacement

SEAL IT UP!! If it has any moisture contnent....it will keep it encapsulated in resin If you let it "breathe" it will absorb water

It is just for strengthe and not necessary but CSM is described above. Some people use gorilla glue to glue sheets of plywood together..... think about this .... it will have bolts through it so even if it it is glued and sealed it will hold.

 

[5150abf]

Re: Sylvan Transom Replacement

Use your old board as a template to cut the new one, use exterior grade 3/4 ply and I did use Gorilla glue and it worked out fine.

I actually used marine ply as I have access to it but exterior grade is fine, if you don't like messing with resin something like a Thompsons water seal will work and remember to mount the board and drill all your holes then pull it again and seal the holes also.

And yes seal everything, you don't want it to breath.

 

[Super Sportster]

Re: Sylvan Transom Replacement

Oh man is it rotten! I had my 40hp Evinrude on there but am replacing it with a Bearcat 55 and at 239lbs I'm certainly glad I found this before it tore off the transom. About all that's left to do is get the fish finder transducer cable out and the well deck drains then the fun begins.

****

 

[Super Sportster]

Re: Sylvan Transom Replacement

It's out of there and came out in one piece, barely. Now the fun really kicks in

 

[Silver Heels]

Re: Sylvan Transom Replacement

Forget the "CSM" Just take two sheets of plywood (stay away from treated), glue with gorilla, pl200, or whatever floats your boat. Seal with resin if you want to get fancy. No need to over-engineer it as doing this works on large boats as well as smaller sylvans.

 

[danond]

Re: Sylvan Transom Replacement

CSM/resin or epoxy top-coating and sealing from the bottom is not over-engineering - it's sensible. It works great, is cheap, and provides excellent protection from punctures and moisture. That's the point!

 

[NickAndJena]

Re: Sylvan Transom Replacement

Working with epoxy resin is easy to do. Just ordered a bunch from www.uscomposites.com and included a pair of pumps to make mixing the appropriate ratio very easy. First time with this stuff this weekend and it worked extremely well. No real ties to that web site mentioned earlier but it was cheap and worked very well.

If you want to seal wood, this is the stuff to use.

 

[Super Sportster]

Re: Sylvan Transom Replacement

Thanks for all the advice. I bought a sheet of ACX 3/4" and Gorilla glue. I've rough cut the main transom pieces and glued both halves together to get my 1-1/2" thickness. It is now clamped and weighted. When dry I will lay it out for the final cut. Then it's on to the epoxy.

****

 

[Super Sportster]

Re: Sylvan Transom Replacement

It's going back together, the wood is done and coated with West System Epoxy. All the through holes are drilled, transom well drains are in and lots of 5200 marine sealant. It's been an interesting experience and really it wasn't a hard job. It's now better than factory and should last for many years. I should have it completed this weekend. Then onto the setup of the Bearcat power.

****

 

[Clyde59]

Re: Sylvan Transom Replacement

I have a 1978 18' Sylvan open bow with an aluminum hull. The transom is bowed and the transom has pulled the motor well screws attached to the inside of transom. The transom wood is also rotten.

my biggest concern is getting it all apart and just want to confirm that I can remove the transom in one piece with out removing the motor well.

The photos of your supersport are very similar to mine from 1978.

Thanks for any comments.

 

[CKANGLING]

Re: Sylvan Transom Replacement

Why do you suggest using "not treated" wood....That treated plywood is supposed to last for years and years.....Our local boat repair suggests using it in place of marine plywood which is special order in our area. Just completed removing the transom of our "newly acquired" 92 Sylvan....can't believe it was TOTALLY rotted...Came out with ease...mostly chips....lots of screws, a few bolts, some small rivets, but overall, just a time-consuming job. I'll have to make a cardboard template/pattern whereas there was very little wood salvaged.. Our boat repair guy that sold Sylvans says Sylvan never used treated or even marine grade plywood in the transoms, resulting in them quickly rotting.

 

[ezmobee]

Re: Sylvan Transom Replacement

Because pt eats aluminum!!!!!!!!!

 

[Doug Hendrickson]

Re: Sylvan Transom Replacement

I have a 1981 sylvan with simular problems. I guess to get the transom off I have to grind off the countless number of rivets, pull the entire back out and go from there. any suggestions please pass them on.
In to Deep

 

[ezmobee]

Re: Sylvan Transom Replacement

Please start your own thread Doug. This one is getting a little old.