Fiberglass over resin suitable for steam shower walls???

Builder's Forum
1

Hi,

Sorry I have an odd question/situation about fiberglass resin usage:

Remodeling our bathroom installing a steam shower.  

To meet our artistic and unconventional desires, our handyman was certain he could create interior shower walls using plywood and the plywood covered with bondo fiberglass cloth coated with liquid polyester resin from home depot and silicone caulk the wall seams. 

Additionally this would allow random single pages from a book to be placed on the wood under the cloth so it could be slightly visible through the resin for a unique look.

Our handyman created the shower wood walls but then his health declined and can no longer work.

I don’t remember what kind of plywood grade he used.  

He did install plastic sheeting between the wall studs and the plywood.

The fiberglass and polyester resin has not been purchased yet.

We are talking to a new handyman about finishing the job and he is uncertain such a wall covering will be sound over the long run.  

Before he attempts to finish he asked us to investigate this further.

So I know this may be unorthodox but Any input would be great please! 

I’ve asked a shower forum with no response.

I see it appears this system is used on wooden boats, so very simlar…..

Q’s that come to mind: 

1.  Might this wall design be reasonably sound for this application?

 

2. Should the wall design use the fiberglass cloth or the fiberglass matt or I see bondo has a fiberglass strands filler, or should no fiberglass reinforcement at all be used for these walls?

 

3.  Is the polyester resin hard to apply on vertical walls, I see bondo has a jell formula for vertical surfaces, should we use that?

 

4.  Will the random single pages from a book interfere with the adhesion?

 

5.  At what stage should the single pages from a book be installed into the fiberglass & wall resin buildup?    

 

6. Is there a better suited product than bondo from home depot?  

 

7. Is there a better final finish coat to use?  

 

8. Will the finished surface be smooth enough to resist mold, mildew, soap scum etc?

 

Thank-you for your time!

 

2

OK, I'll bite.

Jim, to be blunt- I believe the project is doomed. You have many other concerns here beyond the plausibility of epoxy resin as a shower enclosure surface. You can do some serious structral damage to a house by flubbing a shower install.

"Handyman" skill levels vary dramatically and it sounds like your first hire was acting well beyond his pay grade. I'd get in touch with a tile specialist who at least has a firm grasp of shower system requirements and can tell you precisely why this may fail. A steam shower in particular requires a sophisticated enclosure, and even that is assuming standard materials. This is a far more punishing enviroment than your average lake or stream.

Good luck,

Patrick

 

3

   Several issues...

-the plastic behind the plywood, depending on your climate zone and wall construction and whether this is an exterior wall, can be a bad idea since it can prevent wall cavity drying.

-if this is fir plywood, it is very difficult to prevent surface checking and print-through of the very coarse wood grain. Even if sanded flat, it has a very strong memory of once being curled in a tree-shape, and resents being sliced and laid flat!

-since the plywood appears already installed, you will be coating just one side. This creates an unbalanced panel, where one side is sealed and the other is free to absorb and release moisture. This will exacerbate the wood curling (above), and lead to overall panel curling/cupping/potatoe-chipping as well, which will make your face-coating more likely to fail sooner.

-applying polyester resin in an enclosed space like a shower is a bad idea unless you're pretty savvy with its use, which you clearly are not.

-limiting your material choices to what is in stock at HD is not a good idea.

If I was your handyman...

-I'd remove the plywood panels from the shower and asses whether they were of sufficient quality to use- no core voids, tight face veneers, and whether I could convince you to let me go buy some decent marine ply and use the old ones as templates.

-I'd test the paper laminating by tearing out an extra page and epoxying it to a test panel. It could be the case that it will work better if the pages are copied onto the back of rice paper, or some such trick. Work out what works before proceeding.

-I'd buy some inexpensive slow laminating epoxy resin and some basic 6 oz fiberglass cloth (try Raka or US Composites, or C&J Composites on ebay) and laminate the shower panels on all sides and edges while laying flat on saw horses, adding an extra coat or two to the good side to fill the weave.

-I'd add a final layer of tabletop or other final-surface type resin, wetsand it flat and polish the surface. If there is significant UV exposure for the panels, I'd add a 2-part clear coating, or convince you that varnishing every few years isn't too hard.

-I'd install the panels by adhering them to the substrate, and using a polysulfide caulk in the corners.

-I'd suggest you use the leftover materials to begin building one of the fine kayaks that the forum owners would like to sell you!

4

 A few other thoughts:

If I were to try this,I would use MAS epoxy, which does not have amine blush and which sets up clear. That's what CLC provides for its kits and it works well. 

The way a lot of us lay up cloth, we drape the fiberglass cloth on our decks or hulls, smooth it out wearing latex gloves (so as not to catch the cloth on our rough hands), pour in small qualtities of resin and then use a squeegee or other scraping tool to embed a thin layer of resin into the cloth the wood underneath. This might be rather difficult to do on a vertical surface, as the cloth would be likely to pull away from the wood.

When the resin sets up to the point where a cotton ball sticks, we then lay on another coat of resin and let it set overnight. We put these first two coats of resin on after the heat of the day to keep air bubbles from expanding. Then we let it sit overnight, lightly sand the second coat of resin, and put on a third coat. We then sand that smooth, let it cure per manufacturer's specs (variable with heat and resin) and varnish.

To be honest, I would not continue as you've started. I would find a contractor to set you up with a good framing and plumbing  install designed for a regular fiberglass shower that you would buy at Home Depot.

Then, taking the dimensions from the contractor, I would build a fiberglass on marine plywood shower enclosure just like we build boats, fiberglassed on the inside and outside. Then I would take it to an auto refinishing shop and have it gel coated. Then install it. There are books available on this site telling you how to do all this, or perhaps you can find a kayak/boat builder familiar with these techniques.

I'm not sure about the pages and how to keep them from bleeding through and becoming gooey messes when you lay them on resin. What I would tend to do is lay the pages on the third resin layer when it's sticky, and then gel coat over them. Not sure. And, to be honest, all of this is pretty speculative. 

5

I disagree with the above that this cant be done...a few thoughts:

   Do you want the pages from a book to be a total covering and not trying to have some of it show through to show the plywood?  If you arent trying to have some of the plywood show thru, cement backer board (ex: Hardie Board) may be better than plywood:

"The great value of cement board is does not rot, warp, grow mold, or deteriorate, when subjected to water. Wood obviously is not a great material to use in wet applications, and even green board, a more hardy type of drywall, is not recommended for places with constant water usage, such as showers. Cement backer board is mainly used as a sub-surface for tiling. "

Source:http://homerenovations.about.com/od/floors/a/cementboard.htm

You may want to study up on use of cement backer board and consult a tile expert that knows all about epoxy (perhaps a hard to find dual talent) on epoxying the surface with pages from a book onto the backer board. 

============

Also, suggest you call Lisa Rhymer who owns a business that does decopage on floors.  We had it done and loved it in our last house!  She is in the business of gluing down pieces of paper and covering them with urethane so she likely will know how to recommend you handle your desire for a shower.  I'm sure she can give you good advice...tell her Curt Dennis says hi.

https://www.facebook.com/DecoupageFloors/photos_stream

http://www.decoupagefloors.com/home.html

===========

Suggest you then call John Harris at CLC and get his recommendations on substrate and how to finish the epoxy if it needs any at all...perhaps then ordering MAS epoxy from CLC.

===========

Consider doing  your epoxy work on pre-cut to shape pieces of hardee backer board flat, then put them up in the shower using a lap method and caulking with urethane caulk that actually hardens and acts as a glue too.

 

Good luck!

 

 

   

6

   One more thought...thanks to advice from this forum, I was able to apply a printed item on rice paper which can be seen thru the cloth and epoxy. (yours would be pages from the book)  I very lighlty applied epoxy to the bare surface and gently placed the paper on that surface, and then used a dry brush to smooth out any wrinkles in the paper and LET IT CURE.  Then come back normally with cloth, wet it out, apply more coats, etc. Really this is simply doing decopage with epoxy instead of elmers glue, a throw back to the 60's.