Transom repair questions please help

Ok I bought my first boat a 1978 waco 14 foot flat bottom
Jon boat the wood in the transom is old and rotted and I'm
going to make a new one it has two knee braces (rated for20hp)
I'm planing on chisling the old rivets out because I can't put the
new transom in with them in the way. Ok here are my qustions

what kind of rivets shud I use (steel, almn?)

what kind of epoxi do I use to seal it

What kind of bolts do I use on the knee braces that go through
the transom (steel,brass?)

marin plywood cost to much for me I only paid 40$ for the boat
so what's the second best wood to use ?

Thanks for any responses Im new to boating and this fourm
and I have know idea where to start on this rebuild
Robert

Re: Transom repair questions please help

hi welcome to i boats !

most of your questions are covered in the completed projects forum.....

you can use exterior grade plywood...

polyester resin and fiberglass matt is far cheaper than the epoxy.

and as far as the rivits go we need to see pics before making that judgment....however, rule of thumb is to replace what was there.

Re: Transom repair questions please help

Thanks for replying so quick, it will try to have pics up tomrrow
what kind of resin like the bondo brand stuff? I work at pepboys
autoparts and we have some bond products

Re: Transom repair questions please help

we use boat resin.......but thats just a small job...so the bondo, or any dept store resin will work fine.

just remember....that stuff is all waxed resin...that means you cant do multliple layers of glass after its cured with out sanding.

but for your job you will just need to put 2 layers of the chopped strand matt at once.

Re: Transom repair questions please help

jonboatcatfish said:

Ok I bought my first boat a 1978 waco 14 foot flat bottom
Jon boat the wood in the transom is old and rotted and I'm
going to make a new one it has two knee braces (rated for20hp)
I'm planing on chisling the old rivets out because I can't put the
new transom in with them in the way. Ok here are my qustions

what kind of rivets shud I use (steel, almn?)

what kind of epoxi do I use to seal it

What kind of bolts do I use on the knee braces that go through
the transom (steel,brass?)

marin plywood cost to much for me I only paid 40$ for the boat
so what's the second best wood to use ?

Thanks for any responses Im new to boating and this fourm
and I have know idea where to start on this rebuild
Robert

Click to expand...

I ran across your thread today after spending the morning working on my 14 foot Waco Jon boat that has a rotten transom. You have probably already completed your repairs but this is what I am doing. First there is no need to remove the two knees. Those things are really heavy duty and well riveted in. I chiseled out the old transom because it was obviously installed at the factory and ran completely across the back or the boat and was effectively locked in because it was not possible to remove it. The angles on each end prevented it from slideing down and it couldn't go from side to side and was impossible to pull straight up because of the welded angle braces on each corner. I used a chisel and cut out a 2 inch wide area down the center and all the way through the old wood until the old transom was in two pieces. I then pulled one piece toward the center and used a screwdriver to reach up under the lip on top and pull it out. This worked very well and didn't damage the top aluminum piece. I got the other piece out and went to Home Depot and bought a 3/4 inch thick by 2x4 treated plywood. I cut a piece the exact width (9 inches) as the old piece and cut the length to be 38 inches which clears the coner brackets. There is no reason for it to go about 5 more inches on each side and take the angle the old bracket took. You just slide it in the Knee brackets and slide it down and then when it clears the top lip just push it back and up. All this took about 2 hours. This is where I stopped for the day. I will next cut another piece of the treated 3/4 treated plywood and use my router to remove 1/4 inch along one edge where it will fit up under the top aluminum lip. This was the way the transom was originally built. There was not a metal mounting plate for the motor on the old plywood but I found an aluminum plate at Home
Depot (16 guage) that I may use or buy two for more thickness and epoxy or rivet together or both. A good junbk yard should have something usable. Using brass wood screws I will attach the aluminum plate to the wood. The wood screws will be countersinked. There will also be othere fastenings and epoxy and preservatives to finish this job. Let me know how yours worked out.

Re: Transom repair questions please help

You do not want to use pressure treaded wood on an aluminum boat. The copper used to treat the wood will cause pitting in the aluminum hull.

Re: Transom repair questions please help

lckstckn2smknbrls said:

You do not want to use pressure treaded wood on an aluminum boat. The copper used to treat the wood will cause pitting in the aluminum hull.

Click to expand...

Thanks for that info. I wasn't aware of that. However I did intend to paint the whole transom after I got it fitted up. I have been using some paint that I know has a history in all kinds of weather 24/7 for over 2 years now and has held up beautifully.This transon is never going to get that kind of exposure at least as long as I own the boat. Let me know what you think. I am just not going to buy marine plywood at about $90.00 a sheet plus shipping. I haven't even found any in this area. BC plywood has one side sanded and is laminated with waterproof glue from what I read today after getting your post and looking for a possible substitute. let me know what you think.

Re: Transom repair questions please help

I used exterior grade plywood and many coats of primer and exterior latex paint.

Re: Transom repair questions please help

OK, What you did on your transom was what I was bascially doing except using the treated plywood. I have since read the post on treated plywood and the consensus is like you said. Its not good to use it. Some did use it without any trouble but I am going with the untreated exterior plywood. The trouble I saw with this old Waco jon boat was the clamps on the motor was digging into the transom up to 1/2 inch. I believe this probably happened over the years where they would just tighten up the clamps as the transom became weaker and more rotten. I found some 1/8 inch sheet aluminum at a junk yard and intend to attach this so the motor clamps will tighten down on it. Are you using anything on your transom to keep the motor clamps from really digging in. Some of the jon boats I have looked at recently (Lowes etc.) are clamping down on metal thats over the transom wood. I also read with some interest about aluminum and the different types of it. Whatever I have is ok with me and I am not concerned. If it starts to corrode or whatever then I will just take it off.

Re: Transom repair questions please help

I have a 1971 Wards Sea King 1436 jon it has an aluminum plate on the transom.

Re: Transom repair questions please help

Hi Guys,

I replaced my Transom several years ago, and used multiple layers of Luan glued together with resourcinol (SP?) Glue. Resourcinol is water proof, and is a structural adhesive, unlike most woodworking glues. Luan is basically Phillipean Mahogany, which marine plywood is.This made a very good transom which in my case was 1 inch thick. I finished mine with spar varnish. All hardware was type 316 Stainless steel. The other readers are correct in that you do not want to use ACQ treated wood anywhere near aluminum. The metal will deteriorate very rapidly. Please keep in mind that most inner plies of plywood are trash, and filled with voids. In using a thin sheet of many lamination's you will end up with A veneer inner plies. Using this method you get marine quality at shade tree prices. As far as mounting your engine, watch out with putting a metal plate inboard. Vibration can make your motor walk right up off your transom. Better to dig the cups into the wood a little so the motor doesn't walk.

Hope some of this helps someone