Has anyone done fiberglass over foam trailer?

[walking eagle]

Way back in my college days, I built a outboard cowl extension for an electric outboard we did for Senior Design. I built it out of 3" Pink House Foam (something I haven't been able to find here, don't know if it's cause I'm in the warm south or what) - then encapsualted it with fiberglass and resin - actually was lucky and got to use some of the left over carbon fiber cloth.

Anyway - That was more than a decade ago - and I haven't had any experience with it since. There doesn't seem to be a hole lot of information on it out there except this:

http://www.rqriley.com/frp-foam.htm

I ordered a set of plans from them for the Phoenix Van a couple years ago to get an idea how they did the pop top part.

So, the question is has anyone else actually done this? Not necessarily the van, but this type of construction for a trailer? I've searched on fiberglass, and I found some people fiberglassing over wood, but none with the foam.

The pheonix van certainly looks interesting, and a person could use the design from the cab back to either put on the back of a pick-up or as a base for a lightweight camper.

Thoughts? Experiences?

http://www.rqriley.com/phx.html

 

[rk_az]

Google info on surfboard construction. Surfboards are basically fiberglass over foam. At least they used to be, maybe they make 'em different in modern times!

 

[walking eagle]

The design I'm contemplating doing with this construction method has 3 drawers - one on each side, and kitchen drawer out the back

 

[walking eagle]

Constuction theory is do a cage out of angle iron - the cage should make it all very stout w/o having to use a super heavy frame - the whole thing will be a stressed member. On top, I'm not sure if I want to do a pod as shown, a RTT (dang expensive), or a phoenix style pop up... Part of the module idea is that I could change my mind, or use the top for bikes / canoe, and the other part is doing it all at once is WAY to much of a task w/ two toddlers and a wife working swing shift - so that way I can just do it piece by piece.

 

[scarysharkface]

Check out the Experimental Aircraft Association. Homebuilders use that that technique quite a bit and have it figured out.


John

 

[mudbutt]

2 different shops I have worked in used this method to make prototype parts.

The first was fiberglass over foam, encapsulated like a surfboard. That won't work because you don't want the foam in there after you are done.

The second was a tube shape. The foam was shaped then the glass laid over it (also like a surfboard), leaving the ends unglassed.

Then they poured acetone down the inside to melt away the foam leaving only the glass tube.

I don't remember much else, accept it was a HUGE mess and some of it spilled on the ground behind the shop. HAZMAT showed up, fined the company and charged them for the clean-up. I was glad not to be a part of that project.

Your idea seems very plausable, something like the TenTrax, only on a larger scale, No?

The biggest thing about fiberglass (for me) is the mess (and smell), and you have to engineer everything just right so the trailer will stand up to the abuse without cracking all over the place.

 

[cruisertoy]

We make mold all the time for for both glass work and Vac.forming. If you are going to use a foam like EPS(the white stuff in your new computer box) you will need to coat it with a compatible spray or brush on coating to give you a hard shell. You can then wax that coating and spray your gelcoat directly on it. Lay your glass and pull the foam core out. EPS does not make the longest lasting mold surface for this, but if you wax it well enough you can get several pulls from it. We do a lot of our glass molds out of MDF.

Don't do the acentone removal of the foam. Really not a good way to go.

 

[walking eagle]

did some more googling - West System seems pretty good - though the price of the resien sorta surprised me. Guess it was cheaper when I was just getting it from the engineering lab at school.

I don't have any intent to hollow it out with acetone or anything else. Doing both sides of each piece not just doing the whole outside, so it will become a stressed member as opposed to just a covering. If I do the drawers of the same construction, will likely try to use 2" faom on the front drawer, or at least one of them - instant cooler (of course, need a drain and a seal ect).

Figure I'll do the frame, put in the foam for everything but the top, grove around the outside so it sets flush in the frame -like attached -
Then fiberglass the outside and inside of the trailer. Then, take the top piece, and glass one side of it. Place it glassed side down on the frame, and then glass over the top of it. Hope that isn't too confusing a discription

If I was to do the pod idea, or even the phoenix pop up idea, I also wouldn't hollow it out, I'd leave the insualtion in, cause having it well insulated would be a good thing.

 

[blue94yj]

This all got me thinking. I don't have any experience with fiberglass but would it be possible to build something like a tear drop trailer out of ridgid foam and then fiberglass it inside and out? Seems like you would be left with a well insulated shell.

Charlie

 

[walking eagle]

That would be a perfect use of fiberglass over foam construction. I'm surprised with all the home builts on the forum that I haven't been able to find any made this way. It would certainly be lighter and better insulated than building a tear drop from wood. Maybe it's just everyone is intimidated by the mess.

The technique for putting in doors and windows 'apears' straight forward. That might be part of my hesitation, cause it apears so straight forward, but we don't have 100 examples of it, so my mind thinks "Why not? What is there that I'm missing?"

 

[Bullseye240]

From what I've seen this would work. Look up Stripbuilt Kayaks and you'll see they use basicly the same method. Except instead of fiberglass wood is used. I think I remember seeing on one of the teardrop sites that someone built one this way but I'm not sure. As far as I can see it would work. Just plan ahead to prevent the foam from sagging and the glass from stress cracking. If fiberglass is stroung enough for a boat to be made out of then a trailer with a frame supporting it should be no problem.

 

[Colorado Ron]

This technique is very doable. I too am surprised it is not done more. I was looking into it a couple years back when I had my Pinzgauer. I was going to convert the back into more of a tall camper. Did not end up doing it, sold it. But I met a guy up here that did aircraft design. He built his stuff that way.

I have thought about making a full trailer this way. Its actually very hard. I took a hammer and hit it fairly hard. I was scared to hit it "as hard as I can" like he wanted me to, but you could tell it was seriously stout and very lightweight.

 

[blue94yj]

I figured I was missing something because I don't know anything about it. Seems like it wouldn't be any harder then the guys building from wood and then coating with fiberglass.

Seems like there has to be a reason why people aren't doing it.

Charlie

 

[mudbutt]

I figured I was missing something because I don't know anything about it. Seems like it wouldn't be any harder then the guys building from wood and then coating with fiberglass.

Seems like there has to be a reason why people aren't doing it.

Charlie

So do it...... Look how it turned out for Bruce Meyers....

 

[bigreen505]

Look up Stripbuilt Kayaks and you'll see they use basicly the same method. Except instead of fiberglass wood is used.

I have to second that. I like your concept, but I think foam is the wrong way to go for most of the trailer. Unless you are making your skins super thick, the core still takes the brunt of any impacts. Nidacore could be a good way to go as long as you understand its limitations. Corecell foam, aka Sanfoam has decent impact characteristics and could be good. Personally if I were in your position and I was building from a mold I would go with balsa and if you are not using a mold go with cedar strips.

If you are absolutely set on pink foam, laminate it with a thin layer of e-glass, 1/8" door-skin mahogany, than a few layers of thick e-glass.

As for epoxy, call West Systems, explain what you are doing and ask for a recommended epoxy. They may much, much more than the standard 105/205 system. You need a resin that is extremely durable and can handle insane vibration. 105/205 is strong but brittle, probably not the best combo for an off-road trailer. Some variation of ProSet may be better.

The guy behind flyingfoam.com will make anything you want.