questions for the epoxy experts

[Curiouser]

I'm not a boat builder (but you guys do amazing work), I am planning on renovating the bathroom in my travel trailer in the near future and I want to put old barn siding on the walls in the shower. I thought who would better know how to waterproof wood (or anything else for that matter) than people who build wood floating things that in theory don't leak?

I've done a lot of reading and research and I had read somewhere once marine epoxy was about the best there is in waterproofing however, it seems like it' s 1 part science, 1 part alchemy and 2 parts mystery. There are some clarifications I need before I understand how this works.

*Good epoxy is a fairly thick honey like substance that turns to a plastic like substance filling all seams, small gaps and making the object waterproof?

Epoxy can also be a glue that will bond wood, metal, some plastic, fiberglass. Anything else?

Heat cures epoxy and will also "uncure" it? Would shower water be a problem since it usually runs 99- 105 degrees F?

Not all epoxy will be clear when it dries.... is there one or two that will be clear?

I should use a clear coat overtop of the epoxy to protect it from heat and possibly sunlight ( there are no windows in the bathroom so I'm assuming this won't be an issue.

Epoxy is a mix; a resin and a hardener.
The easiest is a 1:1 ratio (less guessing).

Fiberglass cloth is a thin fabric like material that can be bonded to wood for added strength and additional waterproofing.

I've read conflicting reports on epoxy application
some say roll or brush a thin amount on the wood but if it's honey like that seems a bit untrue... when I think of thin I think of cheap watery paint. Once it has cured (a few days -to a week, I should sand the epoxy, wash it with soap and water and add another coat of epoxy. Or I should wait to sand until after the last coat but before the clear top coat..... which is better? How many coats of epoxy should I use?

What clear top coats are good over epoxy and waterproof?

[Lowka53]

OK spend a couple of dollars and get this http://www.boatdesigns.com/Epoxy-System ... fo/12-536/ not all epoxy is thick as honey. Poxy-Shield is quite runny and is a 5-1 mix it can be used to bond material and to water proof wood for gluing we usually add other materials with it to get it to thicken up to get it to the honey state. Poxy-shield is already at the honey thickness and is used mostly for gluing up and is not at piratical to coat for water proofing it is a 1-1 mix ratio. I am sure you could use epoxy to make a shower with since that is what most showers are made of these days. fiber glass comes in many forms http://www.boatdesigns.com/Fiberglass-F ... ducts/289/ this is just some. we use it mostly for scuff proofing our builds to protect our boats from rocks and other things. there are other products on the market for epoxy and not all are the same. If you plan on doing fiber glass work I suggest you also get this book or video http://www.boatdesigns.com/How-to-Fiber ... fo/12-437/ i think this would bring you up to speed on use of the material. also continue reading this forum.

[Curiouser]

When I have the money I will definitely buy those books.

This whole fiberglass cloth stuff really has me thinking.... didn't know it could be bought as a cloth. Would it be possible to fiberglass and encapsulate the exterior of a trailer (before installing windows and doors) just like a boat then paint the exterior?
Also, can fiberglass and epoxy be done in segments? For instance, I live in my RV so I have to do one room at a time back to front. Which means I have to do the exterior one section at a time as well. I was planning on doing some kind of vetical wood siding but I'm worried about the additional weight.

[Lowka53]

When I have the money I will definitely buy those books.

This whole fiberglass cloth stuff really has me thinking.... didn't know it could be bought as a cloth. Would it be possible to fiberglass and encapsulate the exterior of a trailer (before installing windows and doors) just like a boat then paint the exterior?
Also, can fiberglass and epoxy be done in segments? For instance, I live in my RV so I have to do one room at a time back to front. Which means I have to do the exterior one section at a time as well. I was planning on doing some kind of vertical wood siding but I'm worried about the additional weight.

yes you could do this but it does add weight how much weight I couldn't say. And epoxy and fiber glass cloth is expensive not to cost effective but you could use it in this manner :roll:http://www.glen-l.com/supplies/epoxyindex.html

[Andy Garrett]

I'm no expert, but if the wood has a coarse texture with lots of crevices, you should select a thin epoxy with no amine blush (more on this in a second). If it is fairly smooth, go with Poxy-Shield which you can buy right here. Do at least two coats.

The reason to avoid the amine blush with coarser wood is because that blush has to be washed off before the second coat. The blush itself is a waxy, sometimes sticky film which occurs on the cured surface of most epoxies. It makes it seem like the epoxy is not quite cured, but that is not the case. If the wood is very porous, it'll be tough to get the film and wax out of the crevices, and the second coat won't bond there very well.

I have had good success cleaning the blush with alcohol.

Good luck with your project.

[Mr Hot Rod]

Yes you could do this but it does add weight how much weight I couldn't say.

Here are some rough weight estimates for fiberglass cloth applied at a 50/50 glass/resin ratio :

• • 7.5 ounce = .104 LBS/SQ.FT (3.32 LBS per 4'x8' panel)
    10 ounce = .140 LBS/SQ.FT (4.48 LBS per 4'x8' panel)
    
    Source : Figure 8-14, Page 75, Fiberglass Boatbuilding for Amateurs by Ken Hankinson.

We're in the process of replacing the aluminum skin on our Palomino pop-up truck camper with a fiberglass skin to eliminate the leak-prone joint caps and caulking.

Here are some photos of the project :

• 
  We completely rebuilt the cabover structure.
  
  
  The cabover bottom skin was built by laminating some 10 ounce fiberglass cloth to a sheet of 3/8" exterior
  grade plywood.

You can see more build photos on our website :

• Truck Camper Repair Page

____________________
Paul Kane
Kane Custom Boats Ltd.
Chelsea, Quebec

Building the Glen-L Hot Rod : http://www.kanecustomboats.com

Glen-L Boat Video Directory : http://www.kanecustomboats.com/pages/vi ... ctory.html

[leakcheck]

My two cents:

DO NOT put barn board in a bathroom. Bathroom equals moisture. Barnboards equal uneven surface (even if you fill it with epoxy!) ......

MOLD MOLD MOLD !!!!

That is why most kitchen and bath surfaces are very smooth!

SS

[Bill CNC]

I'm really not sure why some of you have such an issue with blush between every single coat of epoxy you apply. Lay another down before the first one is completely cured and you will have no blush.

It's as simple as that!

[rjw]

Another possible concern with glassing solid barnboard.

First note that I have absolutely no experience (yet) with fiberglass, but I have a lot of experience with wood.

Wood is hygroscopic - solid wood will expand and contract (across the grain) as moisture and humidity levels change. Plywood doesn't because of the cross banding of the grain.

Unless the solid barn board is completely encapsulated, there is at least a theoretical - I think think real - risk of the wood's expansion and contraction leading to problems with the fiberglass surface - separation from it and/or cracking of the FG.

I might be entirely wrong, of course.