Time to build my teardrop foamy.

[fishwithpeter]

I have been living in Montana and throughout the Rocky Mountains for a lond time. Now that I'm retired I finally went south for the winter. I used my old pop-up camper and really enjoyed the warm weather all winter long. It was a rough winter in Montana this past year so I'm glad I missed it. The winter in Ehrenburg,AZ was delightful. I used my little boat in the backwaters off the Colorado river and even caught a few fish. The pop-up trailer was adequate for the moderate weather but I intend to build a foamy teardrop that will be easier to heat. I am wondering if anyone else has tried to build a foamy and might have some experience to share. I'm an old time maker and I have some ideas but probably enough to dead end at some point.
So far I have purchased a 7x14 flatbed that wieghed in at 1,000 lbs. I stipped the wood deck out and then removed the rear ramp. I cut off a railing that didn't seem needed and that brought the weight down to 500 lbs. I sanded the frame and repainted everything. I built an insulated subfloor and the next step will be to build the side walls. I'm currently experimenting with the composite wall construction. I'm using 1-1/2" pink ridgid foam sheets with 5mm Revolution paneling for the interior surface and FRP(fiberglass reinforced panels) for the exterior. I used Great Stuff spray foam to do a mock up and it worked well. I am amazed at how strong the composite panel is. The Great stuff spray foam is messy so I am going to try Foam Fusion glue next. I saw a video on Glidden Gripper and will try that as well.
If this build is of interest and I get some response I would like to post pictures and share the process. I'm hopeful that someone will be able to help out with ideas if I get going down the wrong path. I have a lot of experience and I'm an adventurous builder. This is going to be a fun project. Let me know if you want to follow along and throw your 2 cents in. ~fishwithpeter

 

[WanderingRose]

Sounds like quite a project, and kudos to you for taking it on.

As you progress with it, might take it camping and I suspect you will find helpful others with experiences to share, particularly in public campgrounds.

You may also find help here, and I encourage you to post pictures as you go.

Good luck!

 

[maki2]

There are a number of threads in this forum about building Foamies. I am sure you will find plenty to read on the subject. If those individuals are still
actively looking at or participating in the forum is an unknown. Sometimes people disappear after their builds are completed. The forum makes a good support group while working on a build. You can of course lookup and try to private message the author members of the foamie threads if they have become inactive.

 

[bullfrog !]

There is a wealth of information and stickies on tnttt.com in the foamies thread. Since you built the floor first I would recommend you over lap the outer side wall to create a drip edge, preventing water from seeping through the seam as it often does when the skin of the outer wall ends and rests on top of the floor. It is much better to have a solid side wall extending beyond the floor surface to allow water to run off below the floor and frame with no seams to interrupt it’s flow.

 

[rruff]

I'm currently experimenting with the composite wall construction. I'm using 1-1/2" pink ridgid foam sheets with 5mm Revolution paneling for the interior surface and FRP(fiberglass reinforced panels) for the exterior. I used Great Stuff spray foam to do a mock up and it worked well. I am amazed at how strong the composite panel is. The Great stuff spray foam is messy so I am going to try Foam Fusion glue next. I saw a video on Glidden Gripper and will try that as well.
If this build is of interest and I get some response I would like to post pictures and share the process. I'm hopeful that someone will be able to help out with ideas if I get going down the wrong path. I have a lot of experience and I'm an adventurous builder. This is going to be a fun project. Let me know if you want to follow along and throw your 2 cents in. ~fishwithpeter

Definitely appropriate to this site!

Foamies are usually canvas and titebond over cheap XPS foam... but I guess there can be other variations. In my experiments I thought titebond and canvas was too weak as a structural skin, and it had a lot of creep as well. I ended up using much stronger PVC foam, and epoxy with carbon or fiberglass skins, hand laid. I figured with all the time as was going to spend, I'd go ahead and spend the money on better materials.

I like your ply inside with FRP outer; that's a very viable way to do it. Did you use the non-expanding Greatstuff? That's the one to use for gluing. Also, what is you FRP exactly? The typical hardware store variety is usually quite thick, heavy and weak. There are better varieties for RV exteriors that even have a gelcoat coating, so no need to paint.

 

[bullfrog !]

Lol!!! I used damaged interior doors filled with foam covered with Poorman’s Fiberglass which has worked all the time just not as well when I cut holes in it and didn’t seal it water tight!. Cheap but not as pretty, easy to fix and very durable. Parts of my present one are probably coming up on ten years old!

 

[maki2]

Research “torsion box”. It is another way to have a ridged foam filled inside combined with strength and lightweight and weather resistant exterior. You need to have a complete bonding across all of the surfaces of the structure. You can add a ridged foam interior that is also fully bonded in across all of its surfaces. That full bonding is what makes the structure very strong and stable. A torsion box filled with ridged insulation that is fully bonded on all surfaces is known as a SIP, “structural insulated panel”.

 

[maki2]

If you are going to use fiberglass over foam you must use a slow setting epoxy. Fast cure epoxies produce enough heat to melt the foam which prevents adhesion to the foam and creates a lumpy mess instead of a well bonded smooth surface.

“Foamies” their own set of materials and rules and an adhesive that produces heat is not suitable to the process due to the low melting point of foams.