Nice to meet you, looking for advice

[razvancuceu]

Hello everyone, I'm Razvan and few months ago I discovered the teardrop trailers and now I can't stop thinking of it.

I plan to start a DIY project and build a fiberglass teardrop trailer from scratch. I am an electrical engineer and I want to implement a lot of "smart" features to it, starting from bluetooth connection to audio until a wall mounted touchscreen to control the lightning, temperature and many more.

My question, as a newly initiated in fiberglass molding, is what material is often used to create the mold?

I mean, I will create the final mold (mother) from strengthen fiberglass, but to create this I need to have a 1:1 shape of the trailer.

I could use wood and steel sheets, but I want to make edges rounded and more friendly looking. My idea is to have the outer shell in one piece as much as possible.

I saw some use polyurethane foam and shape it with a 3d CNC machine, but at this point looks too expensive for me.

Any advice a newbie can get (except buying one already made) is much appreciated.

I will keep you updated as it goes.

Happy RV-ing

[Mikmay]

Originally Posted by razvancuceu

Hello everyone, I'm Razvan and few months ago I discovered the teardrop trailers and now I can't stop thinking of it.

I plan to start a DIY project and build a fiberglass teardrop trailer from scratch. I am an electrical engineer and I want to implement a lot of "smart" features to it, starting from bluetooth connection to audio until a wall mounted touchscreen to control the lightning, temperature and many more.

My question, as a newly initiated in fiberglass molding, is what material is often used to create the mold?

I mean, I will create the final mold (mother) from strengthen fiberglass, but to create this I need to have a 1:1 shape of the trailer.

I could use wood and steel sheets, but I want to make edges rounded and more friendly looking. My idea is to have the outer shell in one piece as much as possible.

I saw some use polyurethane foam and shape it with a 3d CNC machine, but at this point looks too expensive for me.

Any advice a newbie can get (except buying one already made) is much appreciated.

I will keep you updated as it goes.

Happy RV-ing

When you say teardrop style ,most are made with frame and flat panel construction and can be made by a diy motivated person but probably still cost more than just buying a finished trailer. If however you are talking molded fg , and you are only planning to build one for yourself and do not have the tools,equipment,or knowledge needed to build a plug,than the molds than put all the finished product together and are willing to spend a ton of money and 2-3 years sourcing and developing products to put it all together I’d recommend buying a finished product or at least a finished shell of some type . Not trying to discourage you, just giving you my been there advice.

[Kai in Seattle]

No matter what you use for the mold, you are going to either have to use a hollow mold or a solid mold, meaning you put the fiberglass INTO the mold or OVER the mold. You could use chicken wire and newspaper for a solid mold, covering it well with waxed paper, then start layering on the matte and resin. Then, when you have the whole shell completed (which really wouldn't take all that long, you could cut a doorway (carefully) and start clipping the interior mold apart and pulling it out through the doorway in bits. You could, actually end up with a solid, no seams shell. I thought about it a lot in 2015-2016 while we were laboring over Peanut.

Ever make a Pinata? You start with a balloon. Then you layer your flour/water paste and newspapers over it, all around, turning and turning as you go, assuming you want the final thing actually balloon-shaped. With your chicken-wire/newspaper center, you could add any bumps, outties, innies, etc...better think through your design carefully. You might have to use some kind of wood bracing inside the inner "balloon" so it doesn't sag down. Again, keep the pieces small enough you can remove them through the doorway eventually.

It sounds like a hoot. A LOT of work, but amazing. You had better figure what frame you want to attach it to and get that first, so you can build it to fit exactly. Be sure to consider what kind of flooring you'll use, how to attach it to the frame, and by all means, watch some YouTube videos about boat fiberglassing and other fiberglassing, and try some smaller fiberglass projects first. We started by patching the lawnmover shell. Then we did a small fiberglass motorcycle trailer with some divots and bad spots. Then we worked on the rock shield of our Peanut. THEN Paul tackled the main body of our trailer. But fiberglass is so versatile! WE used epoxy type for several reasons, the only drawback was the cost compared to the other type. The other type is more flexible, though. But epoxy sticks to everything, including you.

I'd start on something small and work up. See if you like doing it enough to spend the time it's going to take. Be sure you have somewhere to work on it so it isn't out in the rain. We used a huge tarp over Peanut in the driveway, but a teardrop ought to fit inside almost any garage. Be aware you need ventilation.

I'm probably preaching to the choir.

But now I'm excited about the idea of building from the beginning, again, and will have to daydream a little and make a few sketches before realizing we'll never do it.

But, it could be so super!

BEST. How about sending us pics of whatever you decide to do?

"K"

[Kai in Seattle]

PS: buying a finished trailer, even if it's an empty shell, really, really would be a whole lot easier. But good luck with whatever you choose!

[Glenn Baglo]

Originally Posted by Kai in Seattle

PS: buying a finished trailer, even if it's an empty shell, really, really would be a whole lot easier. But good luck with whatever you choose!

And a whole lot cheaper.

[Kai in Seattle]

Glenn: yes you're right. Buying a ready-made one would be a whole lot cheaper by the time you factor in everything.

Starting from complete scratch is one of those things that at age 20-40 we might've tried to do ourselves, only to look back and think, Oh, brother, what possessed us?

BEST
"K"

[Glenn Baglo]

Not sure where I got this number, but I believe a mould costs around $20,000 to build. Of course it would be built to manufacture many trailers before it needs to be refurbished.

[Mikmay]

Originally Posted by Glenn Baglo

Not sure where I got this number, but I believe a mould costs around $20,000 to build. Of course it would be built to manufacture many trailers before it needs to be refurbished.

$20.000 maybe if you were skilled enough to do everything yourself and already had the equipment and tools and were able to get Oem pricing for materials and could make everything with one mold which would be almost impossible.

[Franswa]

unless somebody is planning of manufacturing trailers, why do you need a mold???.....
LOTS of people have built boats by building a somewhat flimsy structure in the shape they want for a boat....turn it upside down and then fiberglass the whole thing to create a strong hull....with all the wood inside to finish/attach anything you want


Having just sold my BF, I'm toying with the idea a building a one-off trailer just for me with JUST what I want in it....and NONE of what I don't need...and that's the way I'd do it.


It could start with an aluminium trailer....6x8or10' box (ones I've looked at have 2' sides...a "utility trailer".....3000 dollars, 500lbs, 2500lbs payload)
My "creation" would slide into the utility trailer much like a camper in a pick-up truck bed and somewhat shaped like it. End result: have a get-away "trailer" AND a utility trailer when needed.



2x2" studs, 2x3" floor / ceiling joists, inside finish would be 1/4" by 4" T&G pine....once all the wiring and fixtures are installed fill all cavities from the outside with styrofoam boards...next use expanding foam to fill voids and then fair as best you can....after that start with the fiberglassing....as many layers of cloth as you think will make it strong enough...won't be pretty but it doesn't have to be....saw one just the other day, and the "beauty" of it was that the guy had done it himself....looked real good to me.


This would be a "trailer for one"...10gal fresh water, 10 gal grey...12V sink pump on a switch, 5 gal porta-potty, the only hot water would be water heated on the non-pressurized alcohol stove....small microwave...750W inverter, 100W solar panel on roof (on a sliding rack to make it easy to position exactly around/away from the trailer)...one 12V battery



I already have a few items for it like the alcohol stove...I "lived" with one of these on a boat for years and LOVE it...pick it up and cook outside on a whim...I think I could come up with a heat exchanger/air intake and exhaust solution for heating the inside of trailer on cold nights too.


just a daydream at this point though....not sure if I have the energy to follow through on it.....if I happened to come across a great deal on a trailer (like a used boat trailer) it would probably give me the kick in the behind I need to start on it....(that would kill the "slide in camper" idea, but so be it...given the cost saving)

[Kai in Seattle]

Franswa: Glenn is talking about the kind of mold you'd make of the "inside" of the piñata balloon and use to make many piñatas; I mentioned the chicken-wire, wood, and newspaper mold that you'd build your shell on the outside of--

Though I also thought you could do one over an inflated weather balloon resting on your frame so it kind of draped down nicely like some of the bathtub bottom-trailers do. Like Peanut) One-use mold.

Of course, doing it the way you said would give you a wood structure for attanching things, even better.

BEST
"K"

[Jon in AZ]

There are alternatives to the time-consuming and expensive plug - mold - shell process, but if you want a nicely contoured, aerodynamic result with a glossy gel coat finish, that’s what it takes. If you just want the fiberglass shell, sure- build what you want and lay up fiberglass over it. You’ll have textured fiberglass on the outside, which you can smooth and paint.

But why start from scratch?

Not sure what size and features you want, but the Little Guy MyPod is a nicely molded smaller teardrop-sized trailer. Pricey new, but I’ve seen used ones in the $8K range, which likely compares favorably with what you’d invest in materials and time to make your own. No kitchen.


If you want something a bit larger, vintage teardrop-sized units show up occasionally. The Mity Lite is sized like a teardrop but has stand-up headroom and an inside galley, thanks to the pop-top. Pretty cool-looking, too, with a gull wing door. Many show up essentially gutted, so you can build out the inside to suit, but you already have the all-important molded fiberglass shell.

[Doctor Harold]

Buy one of these and trim to fit:

https://en.izoplas.com/30m3-fiberglass-water-tank/



Seriously, Kai has great advice if you want to make a one-off fiberglass unit.

In metal forming you build a "buck" out of wood. I would build a buck in the shape of the trailer's cabin sans the floor, and stretch fiberglass cloth over the buck and then paint fiberglass over that. Do some research to figure out how to insure the finished shell will release from the buck. It really doesn't sound all that difficult if you do your homework first.

Best of luck, and keep us updated on your progress.

--Harold

[HVance]

I will suggest that for any one off structure be it boat, airplane or trailer you should look at cold molding. The technique uses a series of wood veneers bent over a series of frames and glued together with epoxy resin. Some of the frames are for providing shape and are removed as the structure becomes strong enough to hold it's shape while others are permanent and become bulkheads. Cold molding produces a structure that, when properly designed and built, is light, hugely strong, rigid and fatigue resistant. The technique lends itself to use of glass fiber, graphite fiber and other exotic materials that contribute to the overall structure. Tanks are commonly built into the structure and contribute to the overall strength. The finish quality is a product of the resources that go into the surface being finished. Look at a well finished cold molded boat or airplane.

Search on terms like "cold molded" 'lofting" etc.

Tools required are things like band saw for cutting curves, air compressor for driving air tools, hand wood working tools, ventilation for controlling dust and etc.

cold molding is not exactly fiberglass but close enough that I hope I won't get in trouble here, Hugh

[Thomcat316]

Having built a pair of ultralight fiberglass/epoxy over honeycomb trailers, total cost ca. $3,000, I'd be happy to share what was learned and what I'd do differently next time.

Go to tnttt.com, search my username there, and look at the build journal in the .sig file.