Toby Foamie

[Dan Gary]

Howdy guys, new kid on the block at TNTTT. Man what a cool site this is. Deb and I sold our 03 Starcraft popup camper recently and thought about an UL travel trailer replacement. Holy smokes, have you seen the cost of these rigs? My brother recently bought a Geo 19ft for nearly 30k. Most of what we’ve seen also has a substandard build and just too heavy to tow with our Honda Ridgeline. Our 2500 pound Popup pulled like a dream.

The idea of building my own looked interesting, especially since I’m a carpenter by trade and still own and operate a small construction company (age 71). A few requirements for our build are rear entry, standing height at inside galley and a toilet. We loved having a Thetford cassette toilet in our popup. The overall build size will be 5x11 or 6x11x 6.5 ft. high. I like the idea of using 2”foam walls and roof over 2x3 wood spars. Is this camper too big as a foamie. Think I read here that sandwiching the foam with 1/4” ply int/ext and skinning with canvas would strengthen the build. What do you guys think? How about the idea of going 6ft. wide vs 5ft ? Obviously, with foam, weight won’t be an issue but wondered with a wider build if structural integrity might be a concern or increased wind resistance and stresses on the foam at highway speed? Also wondered if 5x might be a bit narrow for a 6.5 ft high build vs 6ft. wide. Seems like I saw a pic here at Foamies with a plywood roof gusset beam to brace the side walls.

BTW, the Toby Camper is named after Toby, our Morkie who camps with us.

[ghcoe]

Might read though this build http://tnttt.com/viewtopic.php?f=55&t=62527#p1117189.

[Dan Gary]

Might read though this build http://tnttt.com/viewtopic.php?f=55&t=62527#p1117189.

Thanks George and what a great read this was this morning. So it appears using 2” foam and PMF on a larger than TD build can be made structurally sound. Originally I had considered a stick frame with plywood skin clad with aluminum. Perhaps the foam would afford a much greater weight savings and eliminate the dreaded water intrusion issues. Even thought about using 80/20 for my galley build instead of plywood box construction with hard points glued in for wall attachment to shave weight and use a minimum of wood for cabinetry.

[ghcoe]

Glad it helped

I use dado's to install shelves and bulkheads. I use a hot wire.

dado's

20200906_171115 s.jpg (281.03 KiB) Viewed 637 times

Also, I would not run the rafters all the way to the outside like he did. I would make pockets like I did on this build. Wood and foam have a much different expansion and contraction value and any wood exposed will telegraph through the canvas.

pockets

20200925_165516 s.jpg (283.34 KiB) Viewed 637 times

Of course this would also include how he did his windows. I would stay away from making the hard points like he did. Wood exposed like that will telegraph though the canvas.

[Dan Gary]

Glad it helped

I use dado's to install shelves and bulkheads. I use a hot wire.
d.

20200906_171115 s.jpg

Also, I would not run the rafters all the way to the outside like he did. I would make pockets like I did on this build. Wood and foam have a much different expansion and contraction value and any wood exposed will telegraph through the canvas.

20200925_165516 s.jpg

Of course this would also include how he did his windows. I would stay away from making the hard points like he did. Wood exposed like that will telegraph though the canvas.

I saw those pocket cuts you did George with the hot wire and your point about exposed wood to PMF might migrate through the canvas. So, you’d do the same with hard points and recess them into the foam but not through it? How does that work on window and door openings where wood framing is installed that eventually gets wrapped with canvas too?

[CRZ42]

I use 80/20 at work and it is expensive and heavy imo. A 1x2 and foam with PMF or 5mm ply assembly would be lighter and cheaper even with current lumber prices. But I understand 80/20 is cool, I want to build a stand for my turntables and mixer out of it, but it was cost prohibitive for me.

[ghcoe]

Depends on the way the door or window mounts. Most modern RV windows are a clamp fit. The inside beauty ring screws into the exterior window frame so there is no need for any wood what so ever.

Most doors are surface mount. The inside and outside pieces need to be screwed into wood. I basically convert them to a clamp fit too. I channel the foam 1/4" wide and 2" deep in the middle of the door opening. Then I insert a 1/4' x 1 3/4" piece of plywood or hard board into the channel I made. Then I seal the wood into the foam with caulking. I can then screw the door on from the outside. The screw will go through the foam and into the 1/4" wood I slipped into the channel. Same with the interior garnish piece.

Hope that makes sense. George.

[Dan Gary]

I use 80/20 at work and it is expensive and heavy imo. A 1x2 and foam with PMF or 5mm ply assembly would be lighter and cheaper even with current lumber prices.

I’ve got a friend doing a van build and using 80/20. He has deep pockets though and I don’t. Good advice buddy.

[Dan Gary]

Depends on the way the door or window mounts. Most modern RV windows are a clamp fit. The inside beauty ring screws into the exterior window frame so there is no need for any wood what so ever.

Glad you shared about the windows not needing wood. Seen pics of other’s builds that includes wood at windows that wasn’t necessary. I like the way you cut a spline for 1/4” ply and glue it in with adhesive caulk. You guys really know your way around foam. I’m learning allot here from your vast experience. Thanks for helping us newbies.

Dan

[ghcoe]

I don't post much here anymore. Just too busy. Your catching me on a good day.

Good luck!

[Dan Gary]

I post much here much anymore. Just too busy. Your catching me on a good day.

Good luck!

Thanks George, appreciate all your help.