More Epoxy issues/questions

[Mary K]

I sat down tonight to search the forum to learn more about epoxy and found John's (Micro469) post about his epoxy problems. Now I am scared.

http://tnttt.com/viewtopic.php?t=25254

I used spar Urethane on the my TD and now I have a crack in the urethane on the roof trim where it sits on the skin. It leaked under it and I have a moldy spot on the roof. Steve Cox said its fixable, and that I should seal the edges of the trim with epoxy.

SO, I was planning on putting a fillet of epoxy on all the edges of the trim work where it touches the skin. Just the edges, not the top of the trim. But after reading John's post, I'm wondering if I am making the right decision.

If y'all have any advice for me on this I would sure be appreciative.

Mary K.

[elmo]

Bummer Mary!! I wish I could help you, but the only thing I could suggest is......







it has lots of other uses also....

[Steve Frederick]

The only trouble I have had was a result of a break in the epoxy film itself.
(Road, or mechanical damage)

I agree with Doug's response in the other thread. As long as the wood is sealed anywhere that water can set, you should be alright. I saw John's issue first hand, and really believe that the epoxy was thinner on the corners of the trim. As was mentioned elsewhere, easing the edges of corners will help ensure that the epoxy, or any finish, covers better.
If I were building a "traditional" woody, I would seal the trim all around before applying it.

[Micro469]

The only trouble I have had was a result of a break in the epoxy film itself.
(Road, or mechanical damage)

I agree with Doug's response in the other thread. As long as the wood is sealed anywhere that water can set, you should be alright. I saw John's issue first hand, and really believe that the epoxy was thinner on the corners of the trim. As was mentioned elsewhere, easing the edges of corners will help ensure that the epoxy, or any finish, covers better.
If I were building a "traditional" woody, I would seal the trim all around before applying it.

Where were you when I started to put on my trim??????

[Micro469]

Just wondering... In Mary's case...... can you put epoxy OVER varnish? and will it still hold?? or does she have to sand of the varnish to put on the epoxy??

[Mary K]

Elmo, Actually, I do have a piece is duct tape on my crack...er the crack on the trim I mean...


Steve, Your first sentence stated you had a break in the epoxy due to road or mechanical damage. Do you mean the flexing and bumping that happens when pulling the trailer?

This is a big concern of mine. I know the TD has to flex a bit when bouncing down the road. I think this is what caused the original crack to begin with. This is why I wanted to epoxy all trim edges. Is there still the possibility of the epoxy cracking?


John, You ask a valid question, without knowing the answer myself, I just assumed I needed to sanding off all varnish where I plan on putting the epoxy.


Thanks everyone for your help.


Mk

[Miriam C.]

oH YEAH me too. You do need to sand the varnish off or mostly. Per Rot Doctor. I made epoxy dams at the edges of my trim where I could. Some of the trim on the side pulled away and cracked the epoxy. I put more there for the camping season.

Later I am taking off all the trim (due to spalting) and doing it over. The next trim will have CPES on before it goes down. I am also sealing all the seams before I trim with epoxy or CPES.

Mary K I have a patch of epoxy on the varnish to see if it will hold. Sanded it and it seems to be sticking. I will see how long it stays.

[Mary K]

:o oH YEAH me too. You do need to sand the varnish off or mostly. Per Rot Doctor. I made epoxy dams at the edges of my trim where I could. Some of the trim on the side pulled away and cracked the epoxy. I put more there for the camping season.

Later I am taking off all the trim (due to spalting) and doing it over. The next trim will have CPES on before it goes down. I am also sealing all the seams before I trim with epoxy or CPES.

Mary K I have a patch of epoxy on the varnish to see if it will hold. Sanded it and it seems to be sticking. I will see how long it stays.

Thanks Miriam, Okay whats the difference between Epoxy and CPES??


Mk

[S. Heisley]

It's my understanding that CPES (Clear Penetrating Epoxy Sealer) is better because it actually penetrates the wood whereas the other epoxies just lay on the surface. (In Doc. Rot's write-up about their tests of the product, they said that they were surprised at how much better it worked than other such products, too!)

My sister lives in Maine, where it's wet more than it's dry and people have old houses with lots of rot to fix. The people in her area swear by Doc. Rot's products. My sis used their products to fix some spots on her house and, so far, has been happy with the results.

However, don't underestimate the fume danger from that stuff. I worked all afternoon near a very small, open margarine tub of mixed CPES, in a garage with the door halfway down. I felt a little sick and 'off' for a week afterwards. I learned the hard way that it's nothing to mess around with.

Regards,
Sharon

[Miriam C.]

CPES penetrates and hardens/waterproofs the wood. Epoxy will penetrate some but you put the CPES on liquid and you let the epoxy start to thicken. If you have water damage use CPES on that and If making a dam to keep out water use marine epoxy as it starts to thicken. You can also add wood flour or micro balloons to fill larger areas. Mine looks like clear caulking and I layered it on sanding between coatings. Just added some every day for a few days.

It didn't keep the trim from pulling away in a couple of places though. I just added some more.

[Steve_Cox]

MK,

You haven't fixed that yet? I have a place on the front of my TD that was a thin spot in the Helmsman polyurethane, guess I missed a spot with the second coat. I have a little darkening and raising of the wood grain like you did. I was hoping to get some advise from you on fixing it.

[TomW]

I was worried about cracking with epoxy in the beginning. I talked with an application person at U.S. Composites. I ordered their "thin" epoxy system with their slow hardener (12 hours to set, 24 to 36 to cure). The thin epoxy was about 550 centipoise viscosity, maybe a little thicker than latex paint. It hardens but still stays somewhat flexible.

I did a test piece of my wall (1/2" ply) and roof seam (1/4" ply) rounding the corner with a 1/4" round bit. After cutting a cross section of the joint, I had about 1/8" inch penetration in the roof and about 1/16 in the wall.

The final application on my project, I put 3" fiberglass wide tape along each seam and then floated with the epoxy. Takes longer to do but after three coats, I have a nice seam reinforced with fiberglass tape and about 3/16" of epoxy coating over the entire tear. Sanding between each coat and the final coat, the finish should look like an automotive finish.

I figured if the fiberglass bodies of the Corvette, etc. can hold up, then it should be strong enough.

I did not use the CPES due to other peoples responses about the fumes but I hear it is a great product.

Good luck

[Mary K]

MK,

You haven't fixed that yet? I have a place on the front of my TD that was a thin spot in the Helmsman polyurethane, guess I missed a spot with the second coat. I have a little darkening and raising of the wood grain like you did. I was hoping to get some advise from you on fixing it.

Noooooo

I keep putting it off until its cooler. Dont worry, last time I took the TD out and went camping I saw you.

I'll get started on the mildew spot this weekend and let ya know how it goes.

Mk

[Mary K]

I was worried about cracking with epoxy in the beginning. I talked with an application person at U.S. Composites. I ordered their "thin" epoxy system with their slow hardener (12 hours to set, 24 to 36 to cure). The thin epoxy was about 550 centipoise viscosity, maybe a little thicker than latex paint. It hardens but still stays somewhat flexible.
I figured if the fiberglass bodies of the Corvette, etc. can hold up, then it should be strong enough.

Good luck

Tom, Thank for the info. I am hoping I can get some flex out of epoxy.

Mk

[Steve_Cox]

Dont worry, last time I took the TD out and went camping I saw you.

Mk

Me too. All I am going to do, since the bad spot it isn't by the trim is lightly sand the grain on the plywood and coat with polyurethane. When it gets a little cooler and dryer, it will be about time to lightly sand the whole TD and recoat, it will have been 3 years by then. I've been considering a product called Bristol Finish. You can put on 4 or 5 coats in a few hours and it looks as deep as a dozen coats of varnish. Kim used it on a sailboat's trim before and it was many times more durable than varnish or poly coatings.


TomW,

How is the UV rating on the epoxy you mentioned above?