Periodic PMF cold weather bubble.

[Patrio]

Just what it says. Finished the camper last week, and it's only stayed out in the weather a handful of days so far.

Last night, temp dropped to the mid 20's. Went out this morning and noticed a few bubbles under the PMF, only in one spot.

Waited a couple hours, went back out. Bubbles are gone. Seems to be caused by a difference in expansion/contraction due to cold.

No breaks in the paint or canvas. We've had rain/snow the last several days and there have been no signs of water leaks. In fact, the whole panel is under a 2.5" overhang and barely gets wet.

Should I worry? Should I attempt repair? Or, should I just slap another coat of paint over it and call it good? How long will it hold up to extreme temp changes?

I'm not concerned about appearance, I just don't want a leak situation.

 

[rjgimp]

Without a visual, this sounds like something GPW has described in a couple of his builds. If a bubble has been large or persistent enough that he wanted to do something about it, I believe his solution was injecting glue into the bubble and then pressing it with a household iron.

 

[Pmullen503]

If you used Titebond to adhere your canvas you can use heat to reactivate the glue (assuming it's there and not a spot that was starved for glue in the first case.)

Use a wet towel, not dripping but wet. Place it over the spot and put a hot iron on it to make stream. After you've steamed it for 5 or ten seconds, press the canvas in place for a minute until it cools (wear a glove it will be hot initially.) Repeat if necessary.

You need steam; too hot and you'll melt the foam underneath. I've done this on a few spots on my foamy. Most stayed put forever. A couple are still there and I assume that's because there wasn't enough glue in the first place. The steam did not harm the latex house paint I used.

 

[Patrio]

Thanks for the input. For the record, it's ply underneath.

I THOUGHT I glued this well. Problem was, first time I glued it, I had a minor plywood delamination.

http://tnttt.com/viewtopic.php?f=2&t=72585

I pulled the canvas, fixed the delamination by filling it and coating it with more Titebond, then recovered it.

So, this is the second "skin" that the plywood has had.

I went out this morning and the bubbling is minor, but now it's doing the delamination thing again just like it did before. Will temperatures alone cause this problem, or has water gotten inside somehow? I don't have any idea where moisture could be getting in, except perhaps condensation because I did heat up the interior of the camper last night to do some work on it. If this is the case, is it going to be impossible to use the camper in cold weather without destroying it? Because that was the primary reason why I built it.

Should I have installed a vapor barrier under the interior paneling?

How can I prevent condensation at this point?

 

[Patrio]

Pics for reference...

The bubbles:

The delamination:

Obviously, the bubbles aren't severe, and I'm fine to live with them if it doesn't mean that my trailer is going to rot. Same with the delamination. Not happy about it, but if I can stop it, I'm fine to live with what's there.

But, what's my next step forward?

Walls = 1/4" interior ply, painted with exterior latex, core is 3/4" foil faced ISO foam between furring strip framing/outside 3/8" ply covered in PMF and 4 coats exterior latex.

Any advice appreciated.

Also, there has been no rain here for two days.

Here's what led up to this:

Outside temps approximately 36F

Heater: Coleman 1100 BTU catalytic propane

Temperature inside: About 65 degrees

Ventilation: Approximately 12x2 gap. Small fan running to circulate air.

Duration: Between 1/2 hr - 45 min.

 

[Tony Latham]

3/4" ply

What is the exterior plywood?



Tony

 

[Patrio]

3/4" ply

What is the exterior plywood?



Tony

Not sure, but I'm sure it isn't the best. Here's a pic as I was framing it up. BTW, correction, that's 3/8" ply.

Could it be that the rapid change in temps probably contributed to this? Should I have left the heat running longer or dropped the temp more slowly?

 

[Tony Latham]

Could it be that the rapid change in temps...

I have no hands-on knowledge concerning PMF. So keep that in mind.

I had a minor plywood delamination.

It looks to me that it's the plywood at least in the second photo.

Tony

 

[Patrio]

Oh, it's definitely the plywood. Hard as a rock when you press on it.

I had this problem with the same piece and in the exact same place before. If I'd stopped and done some reading, I probably would have just removed that piece, replaced it, and kept going. But, I "fixed" it. See the link above.

The end is "checking". Likely, the rapid heat-up/cool down resulted in some internal condensation, which caused the checking to re-appear after I thought I had fixed it.

And generally, once that starts, it's nearly impossible to stop. So, the question becomes, do I let it go until I have a bigger problem to repair, or do I tear into my brand new camper and start ripping pieces off of it?

I guess I need to be more careful about warming up and cooling down the camper so quickly. Bring the temps up slowly, keep them there, and let them drop slowly when I'm finished. The "shock" of the rapid temperature change undoubtedly contributed to this.

*sigh*.

I was hoping to make something that would be fun for me to have. I think it might end up being an albatross around my neck.

 

[Patrio]

OK. Sorry I keep posting to my own thread, but I am probably going to attempt a fix of this.

Evaluate my "fix" plan...

1st, I would cut and peel back (if possible) the PMF over the delamination.

2nd, I would cut a narrow slice consisting of the delaminated area + maybe 3/4 - 1" on each side, back to the first furring strip, and lift that section of plywood out.

3rd, I would cut a piece of planed 3/8" lumber to the same shape as the ply I just removed. I would paint the exposed edges where I cut the plywood to prevent water intrusion.

4th, I would insert and nail/glue the lumber at the front and 2nd furring strip, as well as gluing the edges to the existing plywood using PL Premium, wiping any excess to ensure a good smooth surface.

5th, would fill the area around using wood filler and sand smooth.

6th, would glue the canvas back down with PL Premium and smooth, covering the seams with more PL Premium and smoothing again.

7th, Four coats of paint.

Would this work?

 

[rjgimp]

Sounds reasonable to me.

 

[Patrio]

Sounds reasonable to me.

I think that might wait until spring, though. I don't think that it will hurt much to let it go until I get better weather, as long as it doesn't expand enough to cause the fabric to tear.

 

[rjgimp]

That also sounds very reasonable. LOL!

 

[pchast]

Are you sure you are using exterior grade plywood?

If not, you are using latex paint which is water based.
Perhaps all that water is releasing the interior glues.
If it is to work, each coat of paint, and the wood its
applied to, must dry out, cure, between coats.

 

[OP827]

So this looks like plywood delamination of manufacturing glue, not directly related to PMF. If you have scrap leftover pieces of your 3/8" plywood then I would do a test by placing it in a bucket or water for a couple days and see if it will delaminate and if it does, then repairing this delamination could be only a temporary solution. But if the plywood layers stay together then delaminated layers could be repaired. Note that PL Premium will expand and create bubbles while curing if left to itself. Clamping is recommended.

 

[Tom&Shelly]

"It's normal for PMF to react to extreme temp changes, especially if there's no damage or water leaks. But keep an eye on it, just in case!"

This guy's a worthless spammer. His last post was on a year old thread (mine, as it happens) and he later added a link to something totally unrelated to us. True to form, this is a vacuous post on an old thread. As you can see, no indication at all that he even suspects this is a teardrop and tiny travel trailer forum, and I doubt he knows what poor man's fiberglass even is!

Tom

 

[rjgimp]

"It's normal for PMF to react to extreme temp changes, especially if there's no damage or water leaks. But keep an eye on it, just in case!"

This guy's a worthless spammer. His last post was on a year old thread (mine, as it happens) and he later added a link to something totally unrelated to us. True to form, this is a vacuous post on an old thread. As you can see, no indication at all that he even suspects this is a teardrop and tiny travel trailer forum, and I doubt he knows what poor man's fiberglass even is!

Tom

Y'know... <leaps up onto soapbox>

In recent months I haven't been around as much as I had been the last few years, and this nonsense is a big reason why. In the time surrounding the somewhat recent "ownership change" there was big talk of significant changes and improvements, faster approval of new memberships, etc. There was a request for volunteers to step in and take roles on the admin team. (I volunteered and have sent multiple reminders and have heard zilch.) The big change I have CLEARLY seen is an enormous wave of spammers that I almost never saw previously.

I just looked again at "The Team" link at the bottom of the page listing the admins and moderators. Of the 14 admins only about 5 have been online at all this year. Most have not in at least 5 years and one has been absent over a decade. Exact same situation among the 7 moderators. One has been absent over a decade three for a few years. Only three appear active. This spammer you referenced here is still around, as are his two posts. You said you reported it. I report every one I stumble across. Why is the garbage still here and stinking up the joint? Is there an admin in the house??? Very frustrating.

 

[PaulC]

I’m still here people. Report it, I check it and nine times out of ten I delete them and their posts. I must admit I think the new owners need to step up and get some fresh blood in. I’m 70 now and haven’t had a TD for over ten years.

Cheers
Paul

 

[Tom&Shelly]

Thanks Paul!

Tom

 

[Tom&Shelly]

Dealing with that cold weather bubble situation, huh? It's understandable to be concerned, but let's take a calm approach.

Hi Spammer! Thank you for showing yourself--I've reported your three posts too!

Tom