PMF on foam door squishy

[Rick Tyler]

I did a test comparison between 10 oz (IIRC) cotton canvas duck cloth PMF, and 6 oz FG and epoxy over blue foam. Once fully cured the both could be depressed with my thumb and not too much force; although they both sprung back fine w/o delamination.

It wasn't until I tested 2 plies of 6oz FG and epoxy that I was happy with the ability to resist point loading. I can still make the cured 2 plies move a little, but it takes a bunch more force and doesn't move much.

I was noodling over this last night and was thinking that 10- or 12-ounce FG cloth would work over foam, and it looks like I wasn't far off. Has anyone ever had sheer-failure inside the foam blocks? Residential insulation isn't marine foam, and isn't really made to be a structural component. I would never use it in structural locations on a boat, but a glassed Foamie certainly has real weight-saving potential.

I was also thinking of 12-ounce 45x45 biaxial tape 6" wide on the joints. Is this going to be overkill? For the theoretical trailer I haven't decided to build yet.

Rick

[KCStudly]

I like using 2 plies of 6 oz because it gives me the weight/strength I want and adds flexibility to the process. Not structural flexibility, but the ease of going over smaller radii, the option of lapping layers without building excess thickness, the option of using a single ply (such as when reinforcing wood grain that doesn't otherwise need extra strength) and the ability to lay plies with differing bias.

Having said that, I haven't really worked with heavier cloth except for the 2 inch wide 9oz tape.

Taping corner joints with glass tape is perfectly legit.

[rustytoolss]

[Bob Hammond]

Everybody seems to be concentrating on the covering, but just to ask, was the foam clean (no surface contamination) and was it roughened up before applying glue?

[rustytoolss]

good points

[nagnificent]

Everybody seems to be concentrating on the covering, but just to ask, was the foam clean (no surface contamination) and was it roughened up before applying glue?

Hi guys, (I mean men and women). I thought it had been a year since I stopped working on my build and just realized looking at this, that it's been two.

I'm not sure how far I'm going to get this time only because I found out that I can't even pull a trailer with my trike yet. I was told that attaching a tow package is an instant warranty killer. I have the extended warranty until 2020, so I just put it on hold.

I had been working on my build outdoors and at about the same time I found out about the warranty, we had a killer wind blast blow through and it destroyed my walls. I was ready to put it all together and start on the inside which wasn't going to be much, just basic shelves for simplicity sake as well as weight saving.

It all happened for a reason, I learned that my floor was way to heavy and thick, and my chassis didn't need to be as big and bulky either. I went over build. But I know I haven't ever read about that with you guys. . So I figured it all happened at once, so it was for a reason. I just put it on hold for awhile, but as you all know, once the teardrop bug is caught, it never dies. Lol.

I did realize what I did with the door. I followed a video I saw on PMF. The guy submerged the cloth into the watered down glue. I didn't do that exactly, but it was put on with glue on both sides of the cloth. So I'm sure that's why it was squishy, it couldn't breathe to dry all the way. I did clean the foam well, as well as rough it up with some sanding first. So a new door with a new wall it will be next time.

Thank you all so much for your input. I will still be a quiet stalker watching builds behind the scenes here.

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