Teardrops n Tiny Travel Trailers

Hi Gang,
I am in the middle of a Pico light TD. And I have been doing a TON or reading and research here. You folks are a treasure trove. I am at the point of epoxy and glass for the sides and then to tape,epoxy,glass the top. Now what is the best way to do this? Do a small epoxy batch and tape the roof to the sides then cover the roof with cloth and epoxy? also how to epoxy the roof? prop it up and work in one area at a time and then prop it up at a different angle and do the same? I would like to get this into epoxy and glass by the middle of Sept. Any info is reatly appreciated.

Thanks.

Marc

I too am planning to go the epoxy and Glass over plywood although I have not worked with epoxy I have done a bit of fiberglass and the important thing is have everything ready before you mix up anything and be very accurate in the way you measure your resin and harder. I'm planning to "practice" on something that does not matter too much until I get the hang of the materials. Other than that watch some YouTube on ceder strip canoes they are usually skinned with Glass and epoxy and the techniques are essenatilly the same

There are a couple of schools of thought on this. Some people feel that the wood (or other substrates, like foam) can soak resin away from the cloth/tape layup so they prefer to paint the wood with epoxy first (sometimes lightly thickened with laminating filler to help fill any pores, etc.). Some will do this as a preliminary operation, allow it to cure, wash amine, and then scuff sand to get a mechanical bond when they laminate with the cloth.

Others will lay the cloth "dry on dry" and wet it out by squeegeeing epoxy down thru the cloth, but this can lead to what I call "fish eyes", little air bubbles under the cloth after the cure. Not sure if this is from the substrate soaking away wet, or just because it is harder to tell that everything has been wet thoroughly; might also be some sort of temperature change induced out gassing.

Still others swear that you should always do your layups in one complete operation (wet the substrate, wet the cloth, place the cloth, allow to kick off some; apply wet coat; allow to kick; apply second wet coat and allow to kick; repeat however many times it takes to fill the weave plus two more coats for sanding. I have never had the stamina or patience to do it this way as it takes hours upon hours.

If it were me, I'd do the corner tape first, let it cure, trim any sharp poky stuff, wash amine, and then sand enough to smooth things out fair and scuff for the next operation. Then I'd do one side at a time, tilting the cabin as far over as you can (either jacking it up on blocks or getting some help and laying it right over on its side). This would also make it much easier to wrap the wall cloth under the floor. Then I would do the roof and front wall. Again, when you get to the front wall jack it up as much as you can (If the vertical part of your front wall is small enough you can use the Poor Man's Pre-Preg technique (PMPP)).

I didn't actually tape my wall to roof joints, but I overlapped the wall cloth onto the roof, and the roof cloth onto the walls. You will want at least a 1/4 inch radius at this edge for 6oz cloth or tape (maybe get away with less for lighter weight cloth... I happened to use a 3/4 inch radius here, but in other areas found 1/4 inch to be forgiving enough). It can be done with less radius if you are careful, but I had inconsistent results with tighter radii; the cloth can spring back and lift away along tight corners. To handle smaller radii you can lay the cloth on the bias, or cut your own bias tape... which will mean that you will have more seams and waste... but it is easier to just use a larger radius. For crisp corners I recommend a flox corner be built up prior to laying cloth.

Charlie Brown wrote:Hi Gang,
I am in the middle of a Pico light TD. And I have been doing a TON or reading and research here. You folks are a treasure trove. I am at the point of epoxy and glass for the sides and then to tape,epoxy,glass the top. Now what is the best way to do this? Do a small epoxy batch and tape the roof to the sides then cover the roof with cloth and epoxy? also how to epoxy the roof? prop it up and work in one area at a time and then prop it up at a different angle and do the same? I would like to get this into epoxy and glass by the middle of Sept. Any info is really appreciated.

Thanks.

Marc

Hello Marc,

The Gougeon Brothers on Boat Construction book is a great read and expert source to start from. An older free version of the book used to be available for download in .PDF format from the West System website but it now appears to be unavailable. Not sure if the site if temporarily out of service. You can get a copy of their latest version from Amazon. There are also good video resources in the West Marine website and online. If after epoxy coating the wood you want a mirror-like wood finish on any surface, take a look at this tutorial YouTube video on varnishing by Tips from a Shipwright: https://www.youtube.com/watch?v=_VdFzj48BOQ

In addition to mixing the right size epoxy batch for each task, using the right hardener is key to having enough time to work on long pieces or large work areas and achieve a good bond before the mix hardens. A proper pot life is golden!

Good thing you're researching this beforehand. Do it right, do it once!

I hope this helps. Good luck!


Julius

Working with glass tape and epoxy:

Cut three foot sections of glass tape.

Prep the trailer body corner to be taped by rounding it slightly with an orbital sander and wiping it down with mineral spirits and a rag. It should be clean and dry.

Using masking tape or duct tape, tape down a section of plastic sheet (dropcloth, etc.) on a table, at least 4 feet long. Put a 3 foot section of glass tape on the plastic and use a paintbrush to gob and brush epoxy on it. The glass tape will wet down and stick to the plastic sheet. Using gloves, pick up the tape by the ends and bring it to where you are going to place it on the trailer body. Set it down, and use the paintbrush with epoxy to gob it down in place.

Repeat.

I preferred to apply epoxy and fiberglass cloth to my plywood walls which are flat/horizontal on my work bench or on supportive sawhorses. In other words I fully fiberglassed the walls before permanently attaching them to the floor. Then the roof can be built and fiberglassed.

I prefer the Steve Fredericks "Inside-Out" way to build a teardrop trailer. There's helpful information at his website campingclassics.com

Thanks Gang for the info. I had planned to do epoxy and glass sides flat before I screwed them to the floor. The plastic down then soak your strips Idea I will try. Would make things easier.

Now on the curved roof, I was thinking using the same cloth on it as I was the sides. I cant remember where I read it but someone sugested glass weave. Is that just random glass fibers in a cloth form? If so what weight there? Nore info is needed and appriceated.

Marc

Glass mat (random fibers) has a binder in it that is only acceptable for use with polyester/vinylester resins, not epoxy.

Did you say if you are going over foam or wood? I'm assuming wood. If foam, the std blue/pink/green foam available in the home centers is not compatible with poly/vinylesters.

Either way, in my book, mat is heavier than what is required to cover or reinforce either, and requires additional finishing (usually capped with cloth) to get a presentable surface. Totally inappropriate for a woody look, if that is what you are going after.

Thanks for the info on the glass mat. So 6oz it is on the roof. not looking forward to doing the roof in glass but it has to be done. Thanks for all the insight and help

Marc

Hi Gang,

I need a bit more insight on Epoxy, cloth and roof. I'm doing a test peice of wood with epoxy and cloth to get the hang of how it works. It amazes me on how much wood soaks up epoxy. I just wetted out the 6oz cloth for the first time and I wasn't real happy with the finish. It was clear with the weave still visable with the light on it at the right angle. Is it suposed to be that way after a wetting out. Also I had a few very mild waves in the cloth, from when it was rolled up and shipped. I left the cloth out over night to drape over the test panel and then today I wetted it out. Im planning to do two more coats to to the test peice before I get onto the sides.

Now the question, can I get away with just epoxing the sides and taping-epoxing the sides of the roof with biaxial tape? As for doing the roof-- let the epoxy set up a bit before spreading it out so it dosn't end up on the floor? The rear of the Pico is a tight radius. the only other way to the roof is to do one end at a time, let dry and do the other end and then meet in the middle. Does this sound like a good plan?

thanks

Marc

There is no in between with epoxy. It is either still workable, or once it starts to "kick" it is done... don't try to keep using it. So to answer your question, don't let it sit and expect the texture to change, if it does it's too late.

If you are expecting a super clear woody like finish, are you using light weight cloth (like 4oz) and a clear curing hardener (like West System 207)?

One way to help avoid kinks in the weave is to tape the cloth or tape down into position first using little pieces of painters tape to hold a little tension in it. Then wet right thru the glass "dry on dry". This only works well for one (or maybe two) light plies at best (my experience is with 6 oz cloth). I have come to accept that it will never be perfect for me. Even when I stick around and tend to all of the edges and blisters, or "tape" down the wet edges with plastic sheet (poor man's peel ply), there always seems to be at least minor inconsistencies that need more work after.

Not sure how those guys get such fine results building kayaks.

I have read that some folks like to wet the wood out in a preliminary operation; cure; wash and scuff for a mechanical bond; and then layup the glass on top. The reasoning used was that this ensures that the wood doesn't soak away wet from the cloth. Some will argue that it gives up too much strength due to missing the chemical bond, but others will say that epoxy sticks so well that it isn't a concern (...unless you are building airplanes or high performance racing boats).

I'm doing a paint finish, and most likely something with random pattern to hide as many flaws as possible (I officially hate bodywork!).

thanks for the info, since this is a test peice I wasnt really woried about it, but wondered how to work them out or around the problem. The question about the roof is what I am wondering now, just epoxy and cloth tape where the sides meet the top, and then just epoxy the roof no cloth? I belive it will be strong enough. But what does the eperts say?

Marc

For a wood roof that is bent over a curved profile and will not be covered with aluminum, I believe in the idea that you want to reinforce the stressed fibers of the grain so that they don't split open and allow moisture in later. Epoxy alone may not be enough as it isn't that strong in tension, and plywood is usually bent in the direction trying to separate these fibers. For a faceted profile with flat panels this may be less of a concern. Personally I wouldn't risk it.

Some people may argue that they feel the cloth is unneeded (like the venerable Doug Hodder, with full respect), but you also need to consider the conditions. Will your camper be garage keep most of the time, or will it be exposed to the weather (including rain, freeze/thaw and/or sun)? Do you plan to keep it for just a couple of years before selling it on to the next guy, or keeping it for many years to come (for the record, I do not advocate selling potential problems 'down the road' to the next guy)?

Hi Gang,

Spent the better part of yesterday Epoxing the sides of the Pico. Went OK, I got a few low spots and on the last coat. I am letting the whole mess cure, giving it a sanding and one more coat.

On the tape between the body and roof how much overlap? One inch? Two? I am planing to round the corners off with a .250 R router bit. My roof is 3/16 inch bendy ply.

I also have learned that doing two coats to the wood THEN cloth was easier than the one caot, then cloth, then another coat. The wood pulled too much out of the cloth for a second coat.
Marc