I need ideas for what and how to finish bathroom walls please

Discussion in 'Materials' started by magentawave, Jan 22, 2014.

  1. magentawave
    Joined: Jul 2013
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    magentawave Senior Member

    I want to make the luan plywood walls, ceiling and floor of a tiny RV bathroom highly water resistant so I can use a garden sprayer for showering and hang wet wetsuits to dry, etc.

    At 2.5' wide x 4' long x 6' tall this bathroom is approximately 100 square feet.

    From cheapest to most expensive, I considered the following...

    a) White oil base enamel paint over epoxied plywood.
    b) White pigmented epoxy rolled on plywood.
    c) White FRP panels from Home Depot glued over plywood.
    d) White 2 part LP rolled on plywood.
    e) White Monstaliner rolled over plywood (approximately $350 plus shipping!).

    I decided against 2 part LP paint or Monstaliner because it was too expensive. I'm also pretty sure the white FRP panels from Home Depot won't work cuz there are lots of weird imperfect angles and stuff in this Sunrader that the FRP panels won't cover that will require lots filling and sanding and how to blend those areas in with the FRP panels without it looking funky would be far too time consuming.

    So I'm left with either rolling a couple coats of epoxy on everything with lots of filling and sanding where needed and then paint it with a white oil base enamel like Rustoleum...or epoxy the every lovin crap out of everything with white pigmented epoxy.

    So here are a couple questions please...

    1) Would you go with the white oil base paint over epoxied plywood or just white pigmented epoxy over plywood?

    2) The plywood is cheapo 1/8" and 1/4" luan from Home Depot and I'm wondering how many coats of white pigmented epoxy I will need to get a solid opaque finish?

    3) What can I do to get a clean non drippy/droopy finish when rolling the white pigmented epoxy on vertical and overhead surfaces? Multiple thin coats? Add a thickener like talc? If so what kind?

    thank you!
     
  2. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Coat the plywood BEFORE building your bathroom. Paint doesn't run on a horizontal plane.
    Use white sanitary silicone to seal the gaps.
     
  3. jehardiman
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    jehardiman Senior Member

    I would not have used plywood. There are much better sheet materials for a wet space than wood and just as light. I would have used a synthetic like Swanstone and epoxy terrazzo for the pan. Common shipboard installation when all SS is not used. You will never replace it, it needs no maintenance, will not wear through, can be secured with screws,...etc. all-round a more cost and time effective product. Researched it and used it in my home re-model just for those reasons.
     
  4. waikikin
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    waikikin Senior Member

    Seeing as you've already built the space I'd use plain epoxy but glass or dynel the pan & 150mm/6" up the sides & 50mm either way on the corners then use paint, then use..........., 10 years away there "might" be a couple of issues but after 10 years your enjoyment of the RV is complete & you fix or flick>
    All the best from Jeff.
    PS: sometimes we get hung up on "perfect" when Ideal is what we need.
     
  5. magentawave
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    magentawave Senior Member

    I would like to coat the plywood first flat/horizontal, and I guess I could, but but all the irregularities in the RV's fiberglass shell (angles, curves, and some inconsistencies in the shells original female mold), will require me to do a lot of filling in some areas AFTER I install the pre-coated panels. I'm pretty sure some of those areas will be much larger than what I could use silicone for. My concern with that will be in trying to match the plywood sheets with the areas I have to fill with thickened white epoxy. Got any suggestions? And whats the difference between white silicone and what you called "sanitary" silicone?


    The walls are framed but I haven't used plywood yet. The "pan" is currently the original plywood floor of the motorhome that I was going to fiberglass up the walls a bit on all four sides with epoxy. I considered 4 x 8 x 1/8 white FRP panels at Home Depot ($34 per sheet) and will look into Swanstone but the filling in some areas might not make it a suitable material. Is Swanstone the same weight as Corian? How much did it cost per sheet? What does "SS" mean? Solid surface?



    I have only framed the walls and epoxied all the wood stringers as attachment points for whatever material I'll decide to use for the actual walls. The floor pan is currently the plywood floor of the motorhome. I will be fiberglassing the floor there with epoxy and run it up the sides a little. Since you now know I haven't skinned the walls yet, do you have any suggestions?

     
  6. PAR
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    PAR Yacht Designer/Builder

    The cost of some of these materials will just piss you off. They work well, but you pay for it.

    I'd approach the problem a little differently. I'd skin everything in thin plywood (no epoxy), then attach an "isolation/mitigation" barrier, which is typically a polyester fabric, pressed into a embossed checker board thing, with a modified thin set. Next you can tile it or just skim coat with regular thin set or my preference would be epoxy thin set, which is more costly, but bullet proof.

    The isolation membrane will keep the moisture from getting at the structure and will prevent cracks mitigating through, from slight movements in the structure. This permits you to put pretty much anything you want over the affixed membrane.

    On these sort of things, much can be said for a continuous 'glass enclosure. You can toughen up the 'glass surface with fillers, resin rich 'glass mat (or polyester or modi-acrylic fabric) or simply by gluing something to it, so it doesn't easily scratch.
     
  7. alan white
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    alan white Senior Member

    Better to use 1/4" "Wonderboard", or cement board available at Home Depot in 3 x 5 ft sheets for about $10.00 each. Tape tape joints with mesh tape and use thinset to "mud" the joints flat.
    Moisture has no effect on this substrate and it should last for decades with no problem.
     
  8. magentawave
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    magentawave Senior Member

    The Toyota Sunrader has a fiberglass body and I know I'll be hitting some rough roads as I meander down towards the tip of South America so I am concerned about flex and especially if I were to cover the walls with wonderboard (which is heavy) and/or tiles.

    Why not just coat the thin plywood and fill gaps with highly pigmented white epoxy and be done with it?
     
  9. alan white
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    alan white Senior Member

    Ohhhh. An RV. Sorry... no, cement board is kinda heavy for a vehicle like that.
     
  10. gonzo
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    gonzo Senior Member

    You can get 4X8 fiberglass sheets for cheap at Home Depot or Menards. They can go right over plywood and all you need to do is make sure the edges are well caulked.
     
  11. Westfield 11
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    Westfield 11 Senior Member

    Mix microfibers into the epoxy, they will prevent the runs. Use wood flour and epoxy putty to make a filet where the panels join and then fiberglass or just paint with epoxy. Add a dye if you want a color other than clear.
     
  12. jehardiman
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    jehardiman Senior Member

    SS is stainless steel. Remember that fire is one of the driving issues shipboard that you may not have in a RV or house (you can always step outside and watch it burn...not an option at sea). Metal outfitting, though more costly initially, is usually lighter, longer lasting, and safer. It is comon to find complete metal outfitting in commerical and military ships. In passenger ships, where a higher level of finish is expected, the trend is toward low flame/low smoke solid/composite sheet material that includes noise and thermal abatement, and because there are so many identical cabins, multi-piece prefab drop-ins that can be refreshed.

    If you already have the ply in place, and want to leave it,...ask yourself how long do you want it to last? I doubt the ply is marine grade, so just the damp is going to get to it in a couple of years.
     
  13. magentawave
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    magentawave Senior Member

    Yup, I was checking out the job a little closer today from the perspective of how to deal with corners, etc. and it will take a lot of back and forth to fit them to the surfaces, but those white FRP panels might work for me after all. Do you think regular old Liquid Nails would be okay for gluing the FRP panels to the plywood substrate...and even in a bouncing/jostling RV?



    No plywood in place yet but if the panels and their edges were thorougly coated with epoxy then why would they last only a couple of years?

     
  14. PAR
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    PAR Yacht Designer/Builder

    Use the thin plywood and tape the corners where the 'glass panels will land. Bond the panels to the plywood (I'd use something more flexible the Liquid Nails, like a polyurethane adhesive/sealant), with special attention to the corners. Tape off the corners once bonded in, and apply a small fillet of epoxy, say 1/8" - 1/4" wide, just to insure it's a seamless, sealed enclosure. On the other hand and healthy bead of 3M-5200 in the corners will likely last longer then a few years too.
     

  15. hoytedow
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    hoytedow Old Woodbutcher

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