Thrifty Alternatives ..Building Foam Campers

[eaglesdare]

i just had to add one more thing. if this could work, ( i am now thinking i have to buy a sheet of that stuff and test it), but if it does in fact work, i could start building this right in my house! winter is too cold for me to be outside. but i would do the walls inside my house. at least it would be a start.

and i never even gave it a thought about just sanding it down for a smooth curvy feel/look. now i feel like that was a duh moment.

i don't mind some wood around for structual reasons. i was just thinking that if those 2 walls could be light then overall the camper will be light. so i am pretty convinced that i will use some wood for framing here and there as needed. but those walls could be so light weight. i am so excited about this possibility.

[GPW]

The foam we have experience with is made by Dow ... and T2 will NOT melt it ... http://building.dow.com/na/en/products/ ... idfoam.htm

These big box stores are convenient , but they really don't know what's going on with "experimental" things like this ... and you can get better materials and prices at something like an Insulating company that handles insulation for large projects like industrial coolers , etc...
The second problem is , the glue T2 cannot be used for construction , because it will not dry between two pieces of non-porus foam plastic (dries by evaporation ) so you'll need something like epoxy (or Gorilla glue) glue for joining the foam sheets .. which dries quickly and holds Very well ... For stitching pieces together , you can use a hot glue gun to "spot weld" ... but epoxy is the best for general construction ...

Now I know everybody's excited about using their old sheets for covering , and this would probably be fine for light duty (and Thrifty) there are a number of better alternatives... light weight canvas, or even light fiberglass cloth (2 oz.) attached with T2 will provide much more strength than a sheet ... just for those worried about towing at speed , we've built planes out of foam (for 10 years now ) that fly at speeds much faster than we could legally tow anything (or would want to @ 100mph +) ... These are constructed with Dow Blue foam , covered with everything from brown Kraft paper, thin cardboard (non corrugated type ), silk, and light 3/4oz. fiberglass ( some with no covering at all) ... None have had a structural failure at speed ... and as far as planes go the foam holds up well in a crash , with only localized damage , easily repaired , because the foam is a homogenous material and the bad pieces can be cut away and new pieces inserted , without regard to grain (such as wood )..
Best thing with any foam construction is to obtain some scraps for test samples ... and do some experimenting with different glues , and coverings to see which ones You like the best , and give you some familiarity with the material ... cutting , sanding , etc.

I have some 1/2" Dow blu-foam ... I guess I could make a scale model of a TD just to prove the concept ... Might be a fun evenings project . and should answer most questions ...

Anybody wanting to see some of my foam planes can find them at http://www.foamfly.com/gallery2/v/Photos/Glen/ and for further foam plane info ... http://www.rcgroups.com/foamies-scratchbuilt-428/ Many ideas of foam construction ... all applicable to foamie TD building ...

[eaglesdare]

thanks so much for all the great info. the main reason i look to lowes is that is about the only place around. we are in the sticks. lowes happens to be the closest with 1/2 drive. anthing else i would have to go at least 1 hour one way.
..now we do have another shop even closer, not sure if they carry insulation, i will check that one out also.

now lets just say for example only...that you have one piece of foam completely sealed with t2 and canvas (complete). and lets say the whole piece, front and back and sides are covered. could you not then connect 2 pieces together with ts and perhaps a screw here and there? actually though my first thought was to just use a frame piece of wood for a situation like that. but asking another way never hurts.

[eaglesdare]

gpw...thanks for all the info, and wow, i never knew the plane world was out there. my boys (big and small) would love that hobby. i am not going to show them that link or even mention it yet. but i may someday get them started on something like that. pretty cool.

i know my hubby loves flying things. he bought one of the boys a remote controlled helicopter for christmas, about 2 yrs ago. well, hubby took it outside to test it out. that poor chopper just kept flying and flying and flying. the higher it went, the farther away it went also. i started yelling at him to land it, land it. my hubby rarely listened to me back then. so to make the long story short. the chopper did land, but we have no idea where. we searched high and low for that thing, but still haven't found it. we live in a rural area, surounded by water, woods and fields.

back to topic. i just sent hubby to back to lowes to get me that foamboard. i am going to test it out myself. if it works great, if not, then he can use it in his rv redue. in the end it all works out.

[GPW]

You know my thoughts (FWIW) was to build/glue the whole trailer shell out of Foam pieces/panels, sand/round everything nicely , and then cover the whole assembly (much as I would build a fuselage ) inside and out with fabric .. then paint it ! You'd have to add all your hard points/ bracing (?) in before you cover it , although for an "additional" attachment , you could easily cut through the outer fabric and route the foam for an insert , then just cover over it again ... and you can use a "pinked' edge on the spot covering fabric for a neater aircraft look ..

But that "modular" idea sounds pretty cool too .... I'd just try to keep as much wood out of the formula as possible , because wood rots ....the foam will be around forever Less wood , less possible things can go wrong ... Just think of it as a Plastic TD ... a big rolling ice chest ...

[eaglesdare]

well i just received 2 lessons learned.

1: never send hubby to the store for something i want. he brought home some strange piece of insulation, but not the blue stuff we are talking about. this stuff had an aluminum look on one side and blue plastic on the other side. i suppose he was trying to go cheap and get me insulation. "insulation" persay was not what i was after.

2: never send hubby to store to get a large piece of material. he broke the insulation stuffing it into the van.

so while today was a bust for getting what i wanted, i did learn a few things when i do get it, which "I" will go get myself.

now making the entire shell out of this stuff? i would be so worried that it would just blow off the trailer. never was thinking entirely. that does lend to some possiblities and more thinking. likely the modular idea also.

[GPW]

The thinking , so far, is to glue the sides , front back walls to the floor ( Plywood ) and then wrapping the fabric around and under the floor slightly , (inside and out) , anchoring the shell to the floor , which is bolted to the trailer frame ... perhaps a double layer of fabric (extra strip) for those who are cautious ...

Just FY! , we never had anything blow off on our planes , even without a fabric reinforcement ( > 100 mph)
And although the foam will not glue to itself with T2 , it will glue fine to wood , since there is one porous surface , allowing the T2 solvent (water ) to evaporate ...


I would use nothing smaller than the 2" thick foam for the sides ... more gluing area ... but that's just me ..

[eaglesdare]

i am with you on the 2". had that in my head. in my sketch up i have alotted 3" for the sides. so 2" for foam and then the fabric. i have another 1 for the fabric, i am sure i will not be using that much, so left overs will just be that much more room inside.
thanks for reinforcing my thinking that foam to foam wouldn't be good with t2.

i must not have understood what you were trying to say. i see what you are looking for now. the whole thing wrapped to under floor. yeah i wasn't looking at it like that. i had only thought of doing individual pieces then just using them like single pieces of wood and attaching.

still too early in the morning for me, but i am liking what i am seeing in my head. i like the total wrap idea.

[GPW]

Eagle , the total wrap would tie everything together , like a sock (sorta').... and the idea of extra reinforcement fabric around the supposedly high stressed areas seems judicious .. With a heavier fabric (than a sheet) like canvas or fiberglass , it should be Very Sturdy... especially after being painted with a latex paint , which after about a week or so dries very hard ... Unibody construction ... works on cars ...

Thinking for someone in the Arctic region , you could use 4" or even 6" for the walls ... less space inside , but you could plan for that ... Sure would be Insulated , probably body heat would keep it comfortable , like an Igloo ...

[GPW]

Couldn't help myself ... just had to make another drawing ...

[eaglesdare]

you know i love it.

my neighbor is giving me his boat trailer. we are going to make some mods on that and then my fun starts. (of course i don't know when he will give it up, i am trying to push him now though).

but so far i am assuming you are using one standard size of foam board for he walls. 4x8?

what if you wanted taller? like a 5' in height? or even wanted larger than 4x8, like 5x8? or any other size that would require more than 1 single piece? do you think that would still work?

[GPW]

Foam being a homogenous material can easily be glued together for larger sizes ... The glue will be stronger than the foam , so no worries ... especially after the fabric is attached ...

For much larger TDs , you could always glue in a foam arch across the inside ceiling/walls for extra strength , like I did in my 6X12 TD ... much strength added , and it's "decorative "...

[eaglesdare]

any links to your build threads?

[GPW]

Build threads ... Naaa!!! Just my album ...

[aggie79]

Dave (davel) and Cindy built their second Bluebonnet teardrop using primarily epoxy and fiberglass over foam for the sidewalls and the roof.



They worked out many of the details for hard points, openings, etc. This is a link to their build photos:

http://www.tearsoftexas.com/gallery/main.php?g2_itemId=673