Transom issue

[EchoNovember]

Use the slow hardener -- you want it to have time to soak into the wood. If you're going to be working in hot weather, use Xslow.
Give it at least 2 coats, 4 on the edges.
No, you don't need filler.
No, you don't need to bond the plywood to the aluminum skin of the transom. It would add more strength, yes, but would mean extreme headaches if you (or whoever owns the boat after you) ever needed to replace the transom wood again.

It's been varying between 75 and 95 degrees out, gotta love Minnesota weather. I will be doing all of this outside as the garage is full, but I will be setting up a dining fly for shade. Do I do the edges, let it harden, do one face, let it harden, do the edges again, let it harden, flip it over, do the next face, let it harden, rinse and repeat? that way each face is done twice and edges are done in between each face to create "overlap" on the epoxy layers to ensure a tight seal?

Also, really dumb question I didn't think to ask sooner, how do I apply it? Paint brush? Roller? Squeegee? College car wash girl bent over too far going for the extra tip?

 

[kcon]

You're gonna want the 209 hardener for those temps, I was working with 205 hardener at around 70 degrees and it was setting off within 5 minutes. For applying it you'd want a foam roller and a plastic spreader. Though it's been 70-90 degrees here in NY and around 70 in the warehouse I work in, and 206 has been working great for me, so if you work quick 206 will work well for you too.

Personally, if I let a layer cure entirely overnight I'll do a light sanding before applying a fresh layer to enhance the mechanical bond. I believe if you're applying a new layer within X amount of time before it's fully cured you have the advantage of a chemical bond.

 

[Dabbler_E]

One benefit of the extra slow hardener is that if it's still tacky you can apply another coat without scuffing, and the 2 layers will form a chemical (not just mechanical) bond. The 209 hardener also doesn't produce a bunch of blush that needs to be cleaned off.

What I do is apply to 1 face and all 4 edges, allow to partially set, then give it another coat. Then after that's mostly set, flip and repeat with the other face and all 4 edges again 2X. If it sets hard, use scotch brite pad and water to scuff and remove amine blush, allow to dry, then go with the next coat.

 

[someone11]

I used clark craft epoxy for mine. Super easy to use and cheaper than west systems. Its a 1:1 ratio of hardener to resin

 

[EchoNovember]

I used clark craft epoxy for mine. Super easy to use and cheaper than west systems. Its a 1:1 ratio of hardener to resin

What's the durability like? Did you apply multiple layers? I like cheaper for many things, but for the transom I don't want to compromise strength as I'm going to be towing people and possibly disabled boats.

 

[SHSU]

I would check the prices there vs uscomp. UScomp looks cheaper and is bigger bang for buck. Note many companies do 1 Gallon (1/2 gallon resin and 1/2 gallon hardener). Looks like US does 1 Gallon resin and then how ever much hardener you need. I just don't know about shipping, that one you would have to figure out.

 

[EchoNovember]

I would check the prices there vs uscomp. UScomp looks cheaper and is bigger bang for buck. Note many companies do 1 Gallon (1/2 gallon resin and 1/2 gallon hardener). Looks like US does 1 Gallon resin and then how ever much hardener you need. I just don't know about shipping, that one you would have to figure out.

Check the prices where? Locally? I'm not sure where you mean by "there".

What do you mix the epoxy in? Any clean sacrificial bucket? What do you use to mix it? A drill with mixing attachment? (Say yes so I have an excuse to buy a new tool...)

 

[someone11]

What's the durability like? Did you apply multiple layers? I like cheaper for many things, but for the transom I don't want to compromise strength as I'm going to be towing people and possibly disabled boats.

It's the same quality as west systems. And yes multiple layers. Other iboats members have used Clark craft epoxy.

 

[Crawfish Dundee]

Do I do the edges, let it harden, do one face, let it harden, do the edges again, let it harden, flip it over, do the next face, let it harden, rinse and repeat? that way each face is done twice and edges are done in between each face to create "overlap" on the epoxy layers to ensure a tight seal?

Do not apply any extra to build up any thickness, the slot that the transom board sets in is only so wide, you may have issues if you make the new transom board to thick. I suggest only a thin sealing coat of epoxy only. It will soak in deep enough to do the job, sqweegie off any extra so you do not have a build up.

 

[SHSU]

Use this link for US comp:
http://www.uscomposites.com/epoxy.html

Look at how much shipping is going to cost you as that isn't stated, but the cost seems to be cheaper than other systems. As someone11 has said Clarks has been used by other members. Sames as US Comp. You just need to dercide on which one you want.

 

[ondarvr]

Any low viscosity epoxy will work, coating plywood with epoxy doesn't add any strength, you're just trying to make it waterproof.

 

[EchoNovember]

Any low viscosity epoxy will work, coating plywood with epoxy doesn't add any strength, you're just trying to make it waterproof.

NOW someone tells me... >

 

[SHSU]

Straight epoxy wont add strength, but epoxy with some mat will. I think you said earlier that you were going to use some. I can't remember if it was you or someone else that mentioned it.

 

[kcon]

Straight epoxy wont add strength, but epoxy with some mat will. I think you said earlier that you were going to use some. I can't remember if it was you or someone else that mentioned it.

Is there any mat that's more compatible with epoxy? Is it just CSM that's not technically compatible because of the poly adhesive that holds it together?

 

[ondarvr]

You wouldn't use mat, instead cloth or biax would be used if you wanted to increase the strength. It would make the plywood thicker, so that might be an issue, you may need to start with a thinner plywood section. Thin glass skins make it only slightly stronger, you need to add more than just a small amount for a significant increase in strength. Thin layers of glass are used more for abrasion resistance.

​Why do you feel you need to make it stronger? You may have mentioned it prior, but I didn't go back and read everything.

 

[EchoNovember]

Straight epoxy wont add strength, but epoxy with some mat will. I think you said earlier that you were going to use some. I can't remember if it was you or someone else that mentioned it.

That was me, but I was only thinking about using it if it would be worthwhile too. I had forgotten about keeping dimensions to what will fit in the transom slot, though. Unless I use a 3/4 sheet and a 1/2 sheet, and then use fiberglass as well, I think the new transom would end up too large to fit.

 

[EchoNovember]

You wouldn't use mat, instead cloth or biax would be used if you wanted to increase the strength. It would make the plywood thicker, so that might be an issue, you may need to start with a thinner plywood section. Thin glass skins make it only slightly stronger, you need to add more than just a small amount for a significant increase in strength. Thin layers of glass are used more for abrasion resistance.

​Why do you feel you need to make it stronger? You may have mentioned it prior, but I didn't go back and read everything.

I am going to be using the boat for towing skiers, tubers, and the occasional disabled boat since my brother is still ironing out his engine issues. Also, this weekend we saw a few small sailboats who just couldn't get back to the launch because the winds were just too strong and a small 14' alumacraft with a 15 HP motor had to haul them back in. Lol. So I want to make sure that my transom is up to the task of being a good Samaritan.

When I do a full restoration I plan on reinforcing the back of the boat with some extra bracing like SHSU is going to do, and possibly reinforcing the hull a little as well. She won't be a tugboat, but I should be able to pull a few disabled boats back to shallower waters if needed.

As someone else here says in their signature, "I consider over-engineering a job well done."

 

[EchoNovember]

It was jus a straight one the U shape went on the trailer and is cinched down with a ratchet strap. But I live 2 blocks from the marina. And I've got you solution to making your merc more quiet........make sure the next time you go out there's another boat with ya go somewhere nice and quiet and deep....unbolt that pos and let her sink you'll never hear it again. That's the exact motor I had on ours. The best thing ever was putting this 90 hp rude on it. It was a 1/4 the noise of that @&$)$&@@() merc. And know we've got a 22' liberator with a bbf 460 open exhaust soo not really talking over this motor.

Ended up getting on that had a slight bend and shoving the U shaped end (that is supposed to sit on a roller) on the frame, and called it good. It worked just fine too and from the lake. I'll be monitoring it for signs of warped and bending, though.

 

[EchoNovember]

Going to pull the trigger on the transom rebuild. Ordering the epoxy today, and hopefully pulling the engine off tomorrow to get to the transom. We have until next Wednesday to get it done if we want to bring it on our trip. Wish us luck!

 

[EchoNovember]

Will a quart be enough to seal the transom? I don't want to spend too much and get more than I need.