Teardrops n Tiny Travel Trailers

First: The tar was put down a week ago, still curing but not going well. Couldn't find Henry's so I went with what Home Depot recommended. Since the last few days have been warmer, we brought the floor outside in the hopes that it would help the process - well, not so much. The tar is bubbling up and shifting....We did go a bit thick and wondering if that's causing the problem.

Second: Put a coat of epoxy on the exterior wall last night and let it set up in the garage. After the sun was high enough, brought the panels outside, again, hoping the higher outside temp would help. Well, that's still tacky and doesn't seem to be setting up either.

Any thoughts or ideas on what went wrong and how to fix it???

The black goop, seems to be reacting or dissolving what ever is underneath and causing the bubbling. Not knowing what was used, I doubt anyone can say for sure. If it were me, I'd scrap off that goop before it really hardens. Then, make sure there is no interactions between the materials you are using (polyester resign WILL dissolve foam insulation). Perhaps do a test on a sample before committing to the project.

The epoxy? Is it epoxy/resin like West Systems or polyester resign (horribly strong and nasty smell)? Epoxy/resin will cure depending on the temperature. Also, the type and amount of hardener added. When I used the polyester resign, it did take longer to cure than when I had used epoxy/resin. As long as you had some hardener, it will eventually cure.. but may be a week before it is no longer tacky to the touch.

I too think something is outgassing from under your tar. What exactly is the product you used? Can you post a link to Home Depot's webpage? I'd probably suit up and start scrapping it off.

And your epoxy, what brand did you use? I gotta believe it's gotten harder by now. There are some epoxy hardeners that are a slow set.

TL

tony.latham wrote:I too think something is outgassing from under your tar. What exactly is the product you used? Can you post a link to Home Depot's webpage? I'd probably suit up and start scrapping it off.

And your epoxy, what brand did you use? I gotta believe it's gotten harder by now. There are some epoxy hardeners that are a slow set.

TL

This is what Home Depot recommended in place of the Henry: http://www.homedepot.com/p/Gardner-3-6- ... /100317809

We brought the floor in last nite and it seems to have settled. It's not wet to the tough, but still big bubble pockets. The bubbling actually stared on the wood edges and then to where the foam is.

The epoxy is West Marine penetrating 2 part. The exterior panels are still outside, we're expecting highs in the mid-60 today so maybe that will help.

The bubbling actually stared on the wood edges and then to where the foam is.

Is the black-goo directly on foam, or is the foam inside the floor and it's covered in plywood? (Hitches like this tar problem are why teardroppers lay awake at night and study the dark ceiling.)

Assuming you correctly mixed the epoxy it'll be just fine.

Tony

tony.latham wrote:

The bubbling actually stared on the wood edges and then to where the foam is.

Is the black-goo directly on foam, or is the foam inside the floor and it's covered in plywood? (Hitches like this tar problem are why teardroppers lay awake at night and study the dark ceiling.)

Assuming you correctly mixed the epoxy it'll be just fine.

Tony

Both, we did the all the wood edges first, then spread tar into the sections, added the foam, then topped off with a final layer of tar on top....Up until yesterday, there was some bubbling but mostly on the wood. Woke up to a bit of frost yesterday, didn't think that would be a problem, needed the space for the exterior walls so we set the frame up against the house and that's then the bubbling got worse and starting dripping...

If I understand it, you put the goo down, then the foam over the top and more goo slathered on top of that? Could the bubbling be coming from the space between the foam and the plywood? (outgassing around the sides of the foam?) The expanding fumes hit the semi-dry surface and starts bubbling.

Is that possible? If the floor turns into something you can't work with, seal your second one with epoxy.

Tony

tony.latham wrote:If I understand it, you put the goo down, then the foam over the top and more goo slathered on top of that? Could the bubbling be coming from the space between the foam and the plywood? (outgassing around the sides of the foam?) The expanding fumes hit the semi-dry surface and starts bubbling.

Is that possible? If the floor turns into something you can't work with, seal your second one with epoxy.

Tony

Correct, we don't see any bubbling in between, just on top. So far, no dripping from standing on end.

Sounds like the solvent in the tar is melting the foam. Any signs of degradation (gooey-ness) in the foam?

On the epoxy, when working at the low end of the manufacturers stated temperature range, you want to give it a little extra time in the cup to get the exothermic action started before spreading it out. if you don't stir it adequately, or it is too cold and gets spread too quickly, it will either take a long time to cure, or won't cure; either way you probably will never develop full strength (not as important when being used as a sealer, but may make a difference when used structurally).

Wests System Use guide for cold temperature bonding
"4. Stir the resin and hardener thoroughly. Mix the resin and hardener longer than normal (two minutes minimum) and scrape the sides and bottom of the mixing container. Use a mixing stick shaped to reach the corners of the pot. For a given volume of resin and hardener, a smaller diameter mixing pot will improve the chemical activity because the limited surface area will not dissipate heat produced by the chemical reaction."

I'm not a fan of the tar and won't use it for messy reasons such as this. I'm with everyone else... seems like outgassing to me. As KC asked, is there any degradation of the foam? Solvents and foam don't mix. As for the epoxy... Cool temps will greatly affect cure rates. I would be more interested though in knowing how you mixed the epoxy. Did you use the premeasured pumps? Or a mixing cup with graduations? I've used a lot of West Systems. Literally 55 gal barrels of the stuff. Accurate mixing is critical.

Atomic77 wrote:I'm not a fan of the tar and won't use it for messy reasons such as this. I'm with everyone else... seems like outgassing to me. As KC asked, is there any degradation of the foam? Solvents and foam don't mix. As for the epoxy... Cool temps will greatly affect cure rates. I would be more interested though in knowing how you mixed the epoxy. Did you use the premeasured pumps? Or a mixing cup with graduations? I've used a lot of West Systems. Literally 55 gal barrels of the stuff. Accurate mixing is critical.

The foam seems to holding up quite well - just bubbles on top, both the wood and foam. It's still dry to the touch, but with a little bit dripping down

The epoxy came pre-measured in, all mixed into one bucket and then followed directions. Even set a timer on both how long to mix and how much time we had to spread...that too seems to finally be setting up.

KCStudly wrote:Sounds like the solvent in the tar is melting the foam. Any signs of degradation (gooey-ness) in the foam?

On the epoxy, when working at the low end of the manufacturers stated temperature range, you want to give it a little extra time in the cup to get the exothermic action started before spreading it out. if you don't stir it adequately, or it is too cold and gets spread too quickly, it will either take a long time to cure, or won't cure; either way you probably will never develop full strength (not as important when being used as a sealer, but may make a difference when used structurally).

Wests System Use guide for cold temperature bonding
"4. Stir the resin and hardener thoroughly. Mix the resin and hardener longer than normal (two minutes minimum) and scrape the sides and bottom of the mixing container. Use a mixing stick shaped to reach the corners of the pot. For a given volume of resin and hardener, a smaller diameter mixing pot will improve the chemical activity because the limited surface area will not dissipate heat produced by the chemical reaction."

The foam seems to be holding up well, it's not soft or mushy at all.

We did set a timer for both mixing and to know how much time we had to spread. The container used was similar to a round ice cream container and a round stick was used for mixing...

dakippen wrote:

Atomic77 wrote:I'm not a fan of the tar and won't use it for messy reasons such as this. I'm with everyone else... seems like outgassing to me. As KC asked, is there any degradation of the foam? Solvents and foam don't mix. As for the epoxy... Cool temps will greatly affect cure rates. I would be more interested though in knowing how you mixed the epoxy. Did you use the premeasured pumps? Or a mixing cup with graduations? I've used a lot of West Systems. Literally 55 gal barrels of the stuff. Accurate mixing is critical.

The foam seems to holding up quite well - just bubbles on top, both the wood and foam. It's still dry to the touch, but with a little bit dripping down

The epoxy came pre-measured in, all mixed into one bucket and then followed directions. Even set a timer on both how long to mix and how much time we had to spread...that too seems to finally be setting up.

On the epoxy, my thinking is the cool temps have retarded the cure. That happens. In the race shop, 73 degrees is about the perfect temp for a good cure. We've used it in conditions below 70 in a pinch, but the cure time becomes unstable. If your mixing ratio is exact, the way you mixed it is appropriate, spreading it evenly on a dry surface, I think temperature is the problem. With that said my guess is, and it's only a guess, temperature is the problem with your tar as well.

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Atomic - I pretty much believe you hit the nail on the head with both...building a teardrop in February in MN is probably not the best thought out plan....

dakippen wrote:Atomic - I pretty much believe you hit the nail on the head with both...building a teardrop in February in MN is probably not the best thought out plan....

How'd the two issues come out? I hope you're up and rolling on this project.

Tony