Transom Trouble

spidermonkey · 18 March 2009, 14:40

Boat : Avon 5.5 SIB - 1970's !!

Well, I went out to put a couple of coats of varnish on the transom last night. Started sanding the existing stuff back, ended up chiseling lumps of rotten plywood.

Looks like I'll be mostly replacing the transom this weekend then.

The plan is to pull the transom out, get hold of a couple of sheets of marine ply, laminate the ply together up to 40mm thickness. 'Borrow' next doors bandsaw to cut the new transom. Thinned coat of varnish all over transom to seal it. Glue it back in place. Apply lots of coats of varnish.

Sounds simple, can't imagine that it will be.

Any tips?

IBWET · 18 March 2009, 15:03

Quote:

Originally Posted by spidermonkey

Boat : Avon 5.5 SIB - 1970's !!

Well, I went out to put a couple of coats of varnish on the transom last night. Started sanding the existing stuff back, ended up chiseling lumps of rotten plywood.

Looks like I'll be mostly replacing the transom this weekend then.

The plan is to pull the transom out, get hold of a couple of sheets of marine ply, laminate the ply together up to 40mm thickness. 'Borrow' next doors bandsaw to cut the new transom. Thinned coat of varnish all over transom to seal it. Glue it back in place. Apply lots of coats of varnish.

Sounds simple, can't imagine that it will be.

Any tips?

The varnish has more than likely caused the rot in the first place by stopping water getting away after it's got in behind the varnish.

I would'nt varnish the finished wood,sand it to as smooth a finish as you can get, then Dek oljeys (I think thats how you spelt) the wood, really soak it in it.
They use this stuff on teak decks,to protect from sun salt etc. There may be better suggestions to come, from more knowledgable folk than me,but I've done it that way and know it works.

benc · 18 March 2009, 15:03

Ah man, thats not good. Good luck with the repair - im sure someone will comment shortly. Plenty of experience here!

Hope to see you on the solent someday whens its all done

jyasaki · 18 March 2009, 15:29

Someone makes a rot treatment; it's similar to a really thin epoxy mix designed to penetrate the damaged wood, then cure up stronger than the original (unrotted) material.

Here's one:
http://www.jamestowndistributors.com...t.do?docId=263

I've seen repairs to glass boats where the transom cap was cut off (must be an interesting feeling to go after your boat with a chainsaw), rotted wood picked out, a repair solution was basically poured in to fill all the voids, and the transom cap rebuilt.

For yours, I'd assume, if you went this route, that you'd have to come up with some sort of form to contain the goo.

Or you could, as you're doing, replace the entire transom piece. Make sure you seal the entire piece, and seal any holes that are drilled later.

Have you thought about replacing the wood with a fiberglass transom?

jky

K&S · 18 March 2009, 15:31

What about thining some epoxy as a base coat then some more unthickened epoxy over that (with maybe a layer of surface tissue for extra strength?)
Got to be harder wearing and less maintenance long term?

chewy · 18 March 2009, 15:38

I did a similar thing but mixed normal amounts of resin and added some wood stain.
It came out fine, harder wearing than varnish but looked just the same.

K&S · 18 March 2009, 15:39

Quote:

Originally Posted by K&S

What about thining some epoxy as a base coat then some more unthickened epoxy over that (with maybe a layer of surface tissue for extra strength?)
Got to be harder wearing and less maintenance long term?

Ignore the 'unthickend' bit.... thats something i need to do lol

Also you could add pigment to the final layer of epoxy and match your tubes

spidermonkey · 18 March 2009, 16:35

Quote:

Originally Posted by K&S

Also you could add pigment to the final layer of epoxy and match your tubes

Do you know where I can get dirty, oxidised, faded, grey pigment from ?

I don't think its worth repairing as there are a couple of other dubious areas.

jyasaki - A GRP one is my second option, and having seen the price of marine ply might be the cheaper option (got some mat and other bits and bobs knocking about). I'd have to build it myself though and that would add a fair bit of time to this 2 minute varnishing job that I started last night.

Thanks for all the replies guys, looks like there's not much work being done today by some of us

spidermonkey · 18 March 2009, 21:05

I got the transom off. Was surprisingly easy, though I was helped by the fact that the wood was soaking wet at the base and the hypalon practically fell away.

Now I've just got to decide whether to build a wooden one or a glassfibre jobbie. Anyone done this before?

PeterM · 18 March 2009, 21:10

I'd go with wood. looks like water got in behind the wheel mounting bolts ?

K&S · 18 March 2009, 21:25

Quote:

Originally Posted by spidermonkey

Boat : Avon 5.5 SIB - 1970's !!

The plan is to pull the transom out, get hold of a couple of sheets of marine ply, laminate the ply together up to 40mm thickness. 'Borrow' next doors bandsaw to cut the new transom. Thinned coat of varnish all over transom to seal it. Glue it back in place. Apply lots of coats of varnish.

Sounds simple, can't imagine that it will be.

Any tips?

Seems straight forward enough to me .. you have a template or as good as.

I sugested the epoxy idea to coat your new transom which in original post you said you would be making of m.ply.
Id still go with this option as a fiberglass transom is going to be a messy and expensive job i'd imagine.

perhaps someone else can advise...

Cookee · 25 March 2009, 09:23

Whatever you do treat the ply first with something like G4, and for total protection why not laminate the outsides as well - you can get a piece of formica for the back to laminate to and have a gelcoat rear, and then topcoat the inside, not much more work, but it'll last!