Teardrops n Tiny Travel Trailers

I have a 1" steel framed tear with interior plywood skin. I have cut pieces of the 1" pink foam insulation to go between the steel spars prior to exterior aluminum skin over the foam and steel spars. My husband is running the wiring now. I am wondering if I need to glue the foam in place somehow to the plywood to avoid moving and squeaking? Also, do you cut the foam on the roof curves? If so, should I fill the cuts with spray foam after it bends to the curve? Sorry for the newbie questions, but this is a first process for me. If I should glue the foam in place, what should I glue it with that won't melt the foam? Thanks for any advice,

I used 3M Fastbond 30 contact adhesive to glue my 1" rigid styrofoam insulation to the aluminum walls of my trailer. The stuff works great, cleans up with water, and has no solvent odors. Bad news is you can apply it to surfaces warmer than 60F only, or it won't bond, and it's not cheap ~$40 per quart. It is rated to hold foam to metal at temps up to 200F.

I bought mine through Amazon, but the merchant was actually local to me, so I paid shipping for something I could have picked up.

It comes in green and neutral colors, I believe the green changes color when dry enough to contact the other surface. The neutral has no such indicator, you just have to look at the surface to see if it's fully dry.

<Chas>

I'm using thickened epoxy - sticks to foam like (something stinky) to a blanket.

I have built two tears using 1" steel tube. I just cut the foam for a snug fit---no glue. Both of my tears have plywood inside and aluminum on the outside. I used a saw to score the foam about 3/4 of the way through to make the radius bends on the top. Just a note--make sure your foam board measures 1". The first foam I bought was 1/16" oversize on thickness --had to take it back and go to another store to get some that was a true 1".

Jim

corncountry wrote:I have built two tears using 1" steel tube. I just cut the foam for a snug fit---no glue. Both of my tears have plywood inside and aluminum on the outside. I used a saw to score the foam about 3/4 of the way through to make the radius bends on the top. Just a note--make sure your foam board measures 1". The first foam I bought was 1/16" oversize on thickness --had to take it back and go to another store to get some that was a true 1".

Jim

Jim, thank you for that. It was my original thought to go about it as you mentioned and my husband was worried that it might cause squeaking or movement. It seems that perhaps you haven't had a problem with that. It seems I may be on the right path. I started to score the curves but I wondered if I had to fill the scored void with anything or is it fine to leave the gaps in the scored foam. How did you attach your skin? Did you use screws or rivets? If rivets, what kind? Did you put something to hold or protect the dissimilar metals (i.e. steel frame to aluminum skin). Thanks again,

Loyal

Loyal - if you haven't yet, check out the Foamies board.
Your questions about the kerfs has been answered there (Gorilla glue expands to fill them) - answers are a bit wordy and things get horribly off track sometimes, but it's all good.
viewforum.php?f=55

Thank you Brian,

I seem to struggle getting around in the right places of this board at times. I think I see the post on the kerfs. I think I cut the kerfs on the opposite side as I'm seeing and was bending it the opposite way as in that post. I was bending it so that the gaps were outside of the curve (if that makes sense) rather then on the inside and was thinking I should fill it with spray foam or something. Again, I am a little green on this stuff. I see I just asked Jim a question about his build as well that I finally found he used rivets (not sure which kind) on one and VHB tape on the other. I have so many questions and sometimes I can find the answer and sometimes I get lost. Thanks for directing me to this thread as I didn't realize there was a thread just devoted to foam.

No worries, there's lots of great info in the really long thread but you have to wade through nearly 300 pages to get it all. Just go ahead and post your question in the long thread and someone will recall the answer.
kerfing the inside allows the outside to keep a smooth finish and makes the curve a little stronger, but if the kerfs are filled with glue, you should be fine.
Is it too late to flip the foam over so the kerfs are on the inside ?

Siouxgirl2 wrote:Thank you Brian,

I seem to struggle getting around in the right places of this board at times. I think I see the post on the kerfs. I think I cut the kerfs on the opposite side as I'm seeing and was bending it the opposite way as in that post. I was bending it so that the gaps were outside of the curve (if that makes sense) rather then on the inside and was thinking I should fill it with spray foam or something. Again, I am a little green on this stuff. I see I just asked Jim a question about his build as well that I finally found he used rivets (not sure which kind) on one and VHB tape on the other. I have so many questions and sometimes I can find the answer and sometimes I get lost. Thanks for directing me to this thread as I didn't realize there was a thread just devoted to foam.

I see you found answers to most of your questions
I used closed end pop rivets on my first trailer--a dap of silicone on them when installed. I like the 3M tape, I used on the second one, best. Here is a link to the 3M tape.
http://multimedia.mmm.com/mws/mediawebs ... r3COrrrrQ-

Jim

I used Gorilla Glue to glue the 2 layers of blue foam to a very thin cedar strip interior. It took countless large bottles of glue but the end result is a very, very strong and light frame. All my framing was made of two 3/4 inch strips of opposing grain cedar that was biscuit joined with alternating dowel pins. The thin cedar strips and 2 foam layers made for a much overbuilt but still lightweight torsion box. If I was starting over I would use 1/2 inch framing with this same method. I do not plan to use wood under floated aluminum.