Forum Discussion

AndyfromTucson's avatar
Oct 22, 2016

Alternatives to luan?

Has anyone used anything other than luan when repairing a delaminated sidewall? I am replaced water damaged luan in the sidewall of my cabover (as described in other recent posts), and I would like to substitute something waterproof for the luan so any future leaks are less likely to cause delamination.

Here are the possibilities I have come up with so for:

- Azdel. It sounds perfect, but I can't find anywhere to purchase one sheet of it.

- Lexan. This was suggested by user fourthclassC. The only problem is that it is very expensive for the amount I need (like $200 or more)

- Pebbled FRP panel. You know, the stuff they use on bathroom walls. It seems waterproof, comes in the right thickness, so why not?

- Acrylic panel. Waterproof and affordable.

Has anyone used any of these, or something else, in lieu of luan when repairing delamination caused by rotted luan?

P.S. I know that preventing leaks is the best way to prevent luan rot; I just want a backup defense in case a leak does happen.
  • I have used FRP in several places that I know will probably get wet, like the door and to the sides of same.

    After I fixed a window leak, I used FRP there too, but wanted it to look "wood" to match. Contact paper worked.

    Matt
  • When I repaired the water damaged floor and bunk in our Hybrid TT, I used 1/4" Oak Plywood.

    -Michael
  • agesilaus wrote:
    1/4" marine plywood?

    Concur ! But you need real marine plywood tested to the BS1088 standard. What is sold in most "big box" stores does NOT meet the standard.
  • I used marine 3/8" plywood under the Corian in my galley. Before I wised-up and canned the garbage grade RV fittings for marine the wood got flooded. So did the deck. After it dried (3 or 5 accidents) I looked at stuff through a magnifying glass and there is not a speck of evidence of getting wet. This was some 20 years ago so if there was going to be dry rot it would have happened. I wish I could have got it at a real deal price like the Teak but had to pay full bore. Ship's chandleries know where to get authentic marine plywood. I had John the ship's carpenter spray marine varnish over the wood. That bus will get passed down to my grandkids. The skin is 16 gauge hot dipped galvanized 1013 steel. Look for that certification number applied to both sides of each sheet. And GOB marine varnish onto all edges. This helps seal the lamination. Good luck.
  • Real marine plywood has several characteristics
    • The plies are made out of rot resistant imported hardwood
    • The interior plies must be solid; no voids
    • There are typically more plies per inch making it stronger for the same thickness
    • It is sold in mm thicknesses, not fraction of an inch
    • They are glued with "Water and Boil Proof" (WBP) glue
  • If I recall, I used a sandwich of FRP, plywood (marine) and FRP to rebuild my rotted walls under my front window. It was the exact thickness I needed so I would choose the materials you need to meet the thickness you need and go that route.
  • Gjac's avatar
    Gjac
    Explorer III
    I would use the cheapest material that I could find in the right thickness that you need. I have a piece of white Unreinforced Thermoplastic sheet that I have used for minor repairs. I don't know why the outer layer of luan is used to begin with. A thicker FG skin would be stronger, more durable and would not rot like the luan. There are a lot of high density foams available but would be an overkill.

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