Crazy ideas

[Bippy]

Hi there, I'm interested in building an ultra light TTT, kind of like the Puffin (in fact, a LOT like the Puffin- I read that thread strait through until 7:00 in the morning. Wow. Amazing stuff.)

I was thinking of building it with fiberglass, since it's lighter than wood, and the difficulty and learning curve seems to be about the same with wood construction as with fiberglass.

The best site I've found describing how to build with foam and fiberglass is http://www.rqriley.com/frp-foam.htm but I will flat out admit I don't know what I need to know about what all the various parts do and how they interact with each other, but I DID notice that there were people building with foam, and then taking the foam away later to just leave the fiberglass shell.

That got me thinking that perhaps the foam is NOT so important to the finished process, and wondering if I could find something cheaper than foam to build with...

I am currently toying with the idea of building a frame with poplar or some other light and lovely wood, and then instead of using plywood, using fiberglass screening, like this stuff from home depot

Home Depot product display

Then I'd lay the fiberglass cloth over that, use one of the epoxies, and lay a few layers over in different directions for strength.

Does anyone have any idea if this would work?

My thoughts are that the plus side to this is, it's cheap as heck, would be sturdy and rot-proof, and very very light.

So, what do you guys think? Good idea, bad idea, good idea but I need to know X,Y or Z, bad idea and I need more pills to get the brain working right?

I'd love to hear from you about it!

Bippy

[Miriam C.]

to the playground Bippy.

First answer is I dunno

Then if you lay fiberglass cloth over something that is not as heavy or rigid as the cloth (is it?) then it will sag...

Third--- is very thin plywood will do to use as a base and is not expensive. I of course think every new thing should be tried though sooooooo......

Maybe a model first.

[SteveH]

First, Welcome Bippy.

About the fiberglass...I think when you start adding up the price for all the resin and glass cloth you will need, you will find it is not so cheap. Additionally, when you start computing the number of layers of cloth, and the amount of resin needed for those layers, it's also not so light. As an example, compare a fiberglass boat to a wood boat of the same size.

Anyway, these are my thought on the matter, but I only have limited experience with fiberglass, so good luck with whatever construction type you choose.

[eamarquardt]

First Window Screen material is not the material of choice for anything structural. There are many types of fiberglass, cloth, mat, and roving are the three types commonly used in boat construction. Each has it's own characteristics and specific uses.

A friend of mine has built several boats of foam, glass, and resin. the idea is to separate two layers of fiberglass (each composed of several layers of cloth, roving, or mat depending on the specifications) with a light material. The separation of the two layers provides the stiffness. Think about a hollow core door where the two skins are separated by the cardboard inside as opposed to two pieces of masonite skin right next to one another.

There is a fair amount of skill involved when making panels and I wouldn't recommend a teardrop as your first project. Start small and work your way up if you want to use this medium.

For a first, and maybe, last effort, plywood would be a better bet.

Hope this helps.

Cheers,

Gus

[doug hodder]

I'd agree with Steve...I think you'll find that it isn't as cheap as you might think. You might want to do some fiberglass supply shopping, once you determine how thick you want your surface. Just what I've experienced. Doug

[madjack]

...cheap, it ain't gonna be and built properly, it won't be paticularly light either...if you want a "Puffin" styled camper at a "Puffin's" weight, I would suggest, you build it, just like Steve did, when building the Puffin.....
madjack

[starleen2]

The foam core techniques as described by the R.Q Riley article is the fastest way to a one off fiberglass construction. It uses the minimal amount of fiberglass to provide a rigid structure (two bi-directional layers). The essential idea behind cored-composite structures is to maximize the stiffness-to-weight ratio. Since flexural stiffness is proportional to the cube of its thickness, it would at first seem desirable to make everything thick—but if the material is solid, that can become absurdly heavy. Fortunately, we can play a trick: use a lightweight core to add thickness. While this may seem attractive at first, there are some drawbacks.

First – everything need to be designed in its place. You cannot go back and just saw out and recore and patch and then go one. Example: Window frames need to be reinforced with some type of support block (see draw back two)

Two – since the middle core is a non structural material, it can be crushed rather easily when trying to bolt though, such as mounting a hinge. Unfortunately, all cored composite structures introduce fabrication challenges. Imagine the simple problem of bolting on a piece of hardware: on a single-skinned panel, this is so trivial as to barely be worth mentioning. But with a cored panel, the compressive force of the bolt can be quite enough to crush the relatively soft foam, introducing a stress riser that can cause structural failure (or at least the eventual loosening of the bolt). It’s a nuisance that prevents the casual slapping-on of impromptu hardware. The solution to this is to make a nut plate and glass it in place, thus back to drawback one.

Third - getting a perfect bond between skin and core—if we don’t, then bending stresses will tend to separate the two and lead to buckling. It’s not always obvious just how thick to make the skins and cores, what kind of cloth to use, the optimal orientation of the fibers, and how gradually to distribute localized loads across a wide area. And finally, remembering our rule that an infinite number of very light things becomes infinitely heavy, it is important to use just enough resin, but not TOO much.

And then, we’re already up to a stock of resin, two flavors of hardener, cups, pumps, sticks, gloves, and a scale… plus acetone, methyl ethyl ketone, and isopropyl alcohol for various cleanup jobs. That’s just the beginning…

Not saying that it can’t be done – someone out there is building a floating fiberglass tear! If this method of construction is what you want – just be warned that it involves an incredible amount of planning ahead of the build and all materials must be on hand for exact measurements

[WebFoot]

Bippy,
Welcome to the board, Im a newbie here also.
I'd have to agree with the above post...it would end up much heavier & expensive then a traditional build for the same effect...and might I add, a bit messer during the process as well. Your final fit & finish time would take forever by comparision.
Im looking for similar materials to make a semi-ultra light construction.

I commend you for your thought process however..thinking outside the "box"..or in this case "teardrop"...thats what makes much of this hobbie so much fun!

Webfoot

[Rem]

Check out Rems Dream inn in the Hall of Fame. 1x4 frame work around styrofoam board covered with corrugated plastic roofing. Very light and cheap. 1/8 in plywood paneling on the inside.

[angib]

Bippy, welcome.

If you want a finish that's somewhere near as good as ply, building in fiberglass your way will take lots and lots, and lots, of work to finish it. Where Steve might measure the built time of the Puffin in hours, the fiberglass version would be measured in months.

That RQ Riley must be the source of more unfinished projects than any other - many people spend several years building car bodies his way. It can be done quicker, but only by someone experienced working a 40-hour week.

If you had you mind set on fiberglass for some reason, the sensible way to build it would be to layup the fiberglass on a smooth waxed surface (kitchen laminate in an unfashionable colour is the economical material for this), starting with a gel coat. Peel the fiberglass off the surface and you've got do-it-yourself Filon. That would only be two or three times as much work as using plywood.....

Andrew

[Esteban]

Bippy, welcome dreamer. Maybe building a Puffin inspired trailer with sandwich construction using thin inner and outer layers of plywood with epoxy and or fiberglass on the outside would work for you.

[Bippy]

Wow, you guys rock SO HARD I can hardly believe it. This is EXACTLY why I wanted to float this idea before it got too deep- I didn't know enough to know if what I was doing made sense.

Cheap, easy, and easy to fix are very important to me. I am, fundamentally, a lazy person who is always looking for short cuts that will get things done just as well (I tell my boss I'm efficiency motivated- seems to work for them )

The whole thing about near equal weight and twice the work, if I'm clever, does not make me happy. Not at all. No, thank ye, but no.

I have a few friends who have rather large workshops, so let's see if I can borrow one of those so I don't have to buy a ton of tools that I can just stick in storage for a year as I tour.

You are all brilliant and thank you so much for taking the time to share your knowledge with me.

[GPW]

Bip, we've been entertaining the idea of building a simple light duty TTT with 2" Dow blu styrofoam ... 4'X8' sheets with appropriate bracing (more styrofoam) and perhaps a cardboard (non corrugated) skin on both sides coated with several coats of outdoor Latex...Sort of a disposable TD, not made to last for 70 years, but a quick alternative to traditional TD construction.. totally insulated , great for this cold weather...and it's LIGHT!!!!!!!

We've built airplanes with this stuff for years and it is Cheap , STRONG,easy to work with and repairs are ultra simple with such a homogeneous material ...Great for a simple project to camp in while you're building something long term ...we were thinking of building one to slide in the back of the old pickup truck ...sliding on to a utility trailer would be just as easy ...

[madprinter]

Hi, I'm also a newbie. And actually never built a TTT, mostly cabinets and houses, so light weight construction is also new to me, altho I've been doing a little thinking myself. First I've been looking at what others have done with success and whats used in commercial aplications. Looking at truck trailers and campers. I looked at a uhual box the other day. It was made of fiberglass panels on a aluminuim framework. It was very interesting , alto overkill for a camper. I have an old truck box made with small steel chanels and covered with aluminium skin. I've thought of disasembling the old box and using the chanel as my wall and roof frame work and reusing the sheet aluminuim to cover the outside. Then spray gluing ridgid foam panels inplace for insulation, and covering that with headliner cloth on the ceiling and very thin paneling on the walls. I'm still in my thinking things over stage. Has anyone else made a TTT or TD in this manner???

[2bits]

Bippie, I'm a "youngin" from Texas too doing my first Teardrop. My friend is building a plane out of fiberglass and foam. The foam stays in on alot of his panels. He has been working on it for years now, (but it is a plane too, not a
trailer)



All I have to say about fiberglass is you better love sanding, I mean be in love with it too haha! It is very labor/time intensive, but the upside is that the drawing board is unlimited for unique styles.

I thought about it too, but for speed and classic styling I am doing the spar-and-wrap method of making curves on my Modernaire.