Exterior Options

[rruff]

I didn't use marine grade, but it was still $70/sheet. Hubby had done some research on the CPES, we have a guy at work that highly recommended it, so that's what we ended up with.

That better be good ply! Definitely better than the $10 laun I have. I'd be inclined to glass it, but it might be ok with the CPES and varnish.

[dakippen]

I didn't use marine grade, but it was still $70/sheet. Hubby had done some research on the CPES, we have a guy at work that highly recommended it, so that's what we ended up with.

That better be good ply! Definitely better than the $10 laun I have. I'd be inclined to glass it, but it might be ok with the CPES and varnish.

Mahogany laminate.....

[KCStudly]

Some of the more prolific builders here will tell you that they don't bother with fiberglass and seal their woodie panels with epoxy. That's great, but I wonder, if they are building so many campers and selling them within a season or two, how well does it really hold up over the long haul?

For interior panels that aren't exposed to weather, sure, I bet it is fine as a clear coat finish. Maybe even for flat panels where there isn't much stress on the wood grain.

For curved panels where the wood grain is stressed and then exposed to weather, there have been too many reports of sealer/paint failure, open grain wood exposure and subsequent dry rot problems. This is where having the glass fibers to take the tensile loading off of the wood grain is especially important.

So hypothetical: now that we have established that we really want to lay glass on the roof (and are willing to learn those techniques), and we are already planning to use epoxy on exterior wood, what's the hang up about doing glass on the flat walls? A few extra bucks for cloth that costs about $7/yd. Okay, yeah it takes more epoxy to saturate the weave than it does to wet a surface, and then you have to use more product to fill the weave and fair the seams, but hey... you pays yer money and ya makes yer choice.

If it (building TD's) was easy everyone would be doing it.

[dakippen]

Some of the more prolific builders here will tell you that they don't bother with fiberglass and seal their woodie panels with epoxy. That's great, but I wonder, if they are building so many campers and selling them within a season or two, how well does it really hold up over the long haul?

For interior panels that aren't exposed to weather, sure, I bet it is fine as a clear coat finish. Maybe even for flat panels where there isn't much stress on the wood grain.

For curved panels where the wood grain is stressed and then exposed to weather, there have been too many reports of sealer/paint failure, open grain wood exposure and subsequent dry rot problems. This is where having the glass fibers to take the tensile loading off of the wood grain is especially important.

So hypothetical: now that we have established that we really want to lay glass on the roof (and are willing to learn those techniques), and we are already planning to use epoxy on exterior wood, what's the hang up about doing glass on the flat walls? A few extra bucks for cloth that costs about $7/yd. Okay, yeah it takes more epoxy to saturate the weave than it does to wet a surface, and then you have to use more product to fill the weave and fair the seams, but hey... you pays yer money and ya makes yer choice.

If it (building TD's) was easy everyone would be doing it.

Well, for this particular project - we don't have much wiggle room for extra layers. And hubby just doesn't want to deal with the mess...We did however make sure the edges were well covered and on the bottom portion, added leftover epoxy to the other side. It's a learning process and should we ever (God forbid) decide to this again, may try foam and fiberglass. At this point - it is what it is and I don't want to go back and redo what's already been done.

[Atomic77]

I admire you. As KC said, if it was easy everyone would do it. So good for you for plunging head first into this fantastic journey. Participating in the forum is a great step in the direction of knowledge. There are many seasoned builders here who have learned from experience and the experience of others. We hope to pass on something good that you can use. I believe your wish is to build a quality piece that you can be proud of and from your comments it sounds like this may be the one and only; therefore you want to do it right. So please, no offense... but I believe the wrong person is reading this forum.

Good luck on your build journey and I'm looking forward to seeing your progress...

[Esteban]

Fiberglass cloth comes in a big variety of weights, widths and costs. A "yard" of fiberglass rarely is actually nine square feet. For instance at RAKA fiberglass cloth may be as narrow as 24" (6 actual sq. ft. per "yard") or as wide as 60" (15 actual sq. ft. per "yard") per "yard". The yard you'd pay for (the price) is sold by its length not its width. What I'm trying to say is that lighter weight fiberglass cloth often costs considerably less than $7 per (nine square feet) yard.

I bought all of the fiberglass cloth I used for my teardrop from RAKA and was very pleased with its quality, cost and their service.

I also bought discounted carbon fiber fabric from uscomposits.com and was pleased with its quality, cost and their service. They sell a wide variety of fiberglass cloth as well as other kinds of cloth.

A general rule of thumb is that for each actual square yard (9 sq. ft.) of fiberglass cloth you'll need to use an equal number of (liquid) ounces of epoxy as the nominal weight of the cloth. As a beginner doing hand layup you may as much as 50% more epoxy than the ideal 1:1 ratio.

For instance for 4 oz. cloth you'd use about 4 oz. of epoxy. For 6 oz. cloth you'd use about 6 oz. of epoxy.

4 oz. or 6 oz. fiberglass cloth and epoxy would strengthen/reinforce plywood to prevent checking and and help water proof the plywood.

Edit: Corrected ideal ratio of weight of fiberglass cloth used to the ounces of epoxy used to a 1:1 ratio and corrected that a yard of 24" wide fiberglass has 6 (not 4) sq. ft. of cloth. Thanks KC for finding my errors so I could correct them!

The Fundamentals of Fiberglass would be very good reading for anyone considering fiberglassing a teardrop.

The heavier the fabric, the more resin it will take to wet it out. A good hand laminate consists of about 50% fabric and 50% resin by weight. For example, if an application requires 3 square yards of a 4 ounce-per-square-yard fabric (total fabric weight is 12 ounces), 12 ounces of resin will be needed. However, if 3 yards of 10 ounce-per-square-yard fabric is chosen (total fabric weight is 30 ounces), 30 ounces of resin will be needed.

[KCStudly]

Yes, cloth is sold by the linear yard regardless of width, but when we are talking about fabric weights I'm pretty sure that cloth is specified by the square yard. So for a 24 x 24 inch piece that may only be 2/3 of a linear yard (yardage) but it is equal to .44 sq yds.

In other words: 2 ft / 3 ft/yd = 2/3 yd

...and: 2 ft x 2 ft = 4 ft sq, therefore 4 ft sq x (1 yd sq / 9 ft sq) = .44 yd sq

My research suggested that ideal epoxy to cloth weight was actually 1:1, but I never seem to be able to achieve much better than 1.5:1. I think this has to do with the amount that is being soaked into (filling the pores of) the foam or wood substrate. YMMV.

[dakippen]

I admire you. As KC said, if it was easy everyone would do it. So good for you for plunging head first into this fantastic journey. Participating in the forum is a great step in the direction of knowledge. There are many seasoned builders here who have learned from experience and the experience of others. We hope to pass on something good that you can use. I believe your wish is to build a quality piece that you can be proud of and from your comments it sounds like this may be the one and only; therefore you want to do it right. So please, no offense... but I believe the wrong person is reading this forum.

Good luck on your build journey and I'm looking forward to seeing your progress...

Thank you! I'm only going to do this once and we're already learning a lot. And no offense taken, I just appreciate the time everyone is taking to chime in.