PMF bubble

[Sanuk.Sanan]

Hi friends,

Last weekend I bought a homebuilt teardrop. It will need a little bit of love to make it shine.

The front wind facing outer skin has some bubbles in it. It's like the PMF came apart from the plywood but the PMF has not broken. I'm assuming I need to fix this or eventually water will enter, yes?

So my question is how do I fix this? Can I cut the bubbles out, sand, and then re-PMF, sand again and paint?

Thanks for your help!!
Julie in SoCal

[Pmullen503]

You may be able to iron the bubble out depending on what they used to adhere the canvas to the foam. First poke several pinholes in the bubble to allow the air to escape. Then lay a couple layers of wet paper towel over the bubble an apply a hot iron. The steam produced will limit the temperature the paint experiences. Hold the canvas down with a dry towel until it cools a bit.

Nearly all paints can handle the steam temp. If that works you'll have perfect repair. If not you can try a warmer temp (dry towel) but at some point the paint will be damaged so be careful.

[Sanuk.Sanan]

Thank you PMullen!

Will this work for old PMF? I bought the trailer with the bubbles in it, so I don't know how long it's been there.

Thanks again!
Julie

[Pmullen503]

You can try it without fear of serious damage. No guarantee it will work without knowing how it's adhered.

[Sanuk.Sanan]

Thanks! This is worth a try and seems easier than patching it.

Julie

[Sanuk.Sanan]

Ok, I tried the pinhole, steam, and iron trick and no joy. I think the bubble was too big and I just couldn't push hard enough.

So tell me, are these bubbles anything more than an aesthetic eyesore? How badly do I need to fix them?

Julie in SoCal

[tac422]

Can you tell if the bubble is caused by the canvas separating from the plywood?
Or is the bubble actually in the plywood ?
How much pressure does it take to push the middle of the bubble in ?

[Sanuk.Sanan]

Hi tac422,

It takes a lot of pressure to push the bubble in. And there are many of them. I don't know if the PMF has come off the plywood or if the plywood has peeled.

Julie

[Pmullen503]

Poke a pin through the bubble. You can tell if there is air or plywood beneath the canvas. If the plywood has failed, that's a major headache to fix.

You may just have to live with them.

Some photos would help.

[Sanuk.Sanan]

Thank you, friends, for your kind replies!

A couple of comments:
1. It was very hard to poke a pin through the PMF. It was very stiff. Eventually, I took a nail and I could lightly hammer it through. I can't see jack through the hold, though.

Here's a couple of pictures of the bubbles:


Now that I've taken a pix of the problem and developed it to show the defects, it seems that this is not a new problem, and the previous owner tried to fix it, too.

Besides the aesthetics, how bad of a problem is this?

Thanks for your patience. I'm still learning all of this.
Julie in SoCal

[RJ Howell]

I don't see it as a All-is-lost thing. Just something to be dealt with or live with.

I agree with puncturing the bubble. Resistance to the paint is one thing, yet if it's plywood than that's going to take some effort. If you can puncture and press it down with your hand easily, should just be fabric. I've used my hypodermic needle to inject glue/paint and press/clamp it. That has worked for me. On a curve like you have, think of something tall enough to reach the bubble and something stiff enough yet pliable to form the curve and place shims (of whatever) to hold it against the wall. My thought goes step ladder, 5 gallon bucket with water for weight, rags and cardboard as filler/shim material. Wax paper on the skin to not glue whatever shim material you use to stick.

One bubble at a time to work out the system of repair.

Hope this helps..

[Sanuk.Sanan]

Hi RJ,

Thanks. I can puncture and press it, so I'll see if I can get some glue in there to fix it. I can probably build a jig to hold/clamp it with bungie cords and flexible plastic. The wax paper's a good idea. Thanks.

I'll give this a try and will post pixs when I"m done.

Thanks again,
Julie in SoCal

[RJ Howell]

I like the bungee idea! That's getting creative!

I had to as well while building my unit. I made string clamps!