It’s been 8 years..
AC grade plywood, mudded with green top joint compound, primed probably with Regal Primer and then painted with Muralo Ultra paint.
The wood is in the top part of a rough opening of a basement window.
The sides and bottom are finished tile..
The top is the painted piece.
The paint is now peeling/cracking with the JC coming right off the plywood.
I know now expansion rates is a issue but surprisingly, it’s held solid for 8 years !
I’m trying to determine the best course of action of fixing it.
Removing the plywood and replacing it & or putting 1/4 sheetrock ontop is not really a option. The *finished side* on the edge of the plywood has tile.
Option A : Sand clean the plywood, seal 2X with wood glue, sand and then apply wallpaper liner and then paint on top.
Option B: Still thinking but maybe bondo, sand, and then paint with some sort of elastomeric paint.
Thoughts, suggestions, ideas ?
Has anyone painted over plywood successfully.
Replies
Assuming the plywood isn't exposed to high levels of moisture, the liner sounds like a good idea. I recall a painter friend mentioning that he used liner over rough plaster walls. You might want to consider something like Titebond III for your glue if there's some moisture. I think your second idea would work also, but I'd substitute thickened epoxy for the bondo. I don't think bondo adheres to wood especially well. There's stuff called fairing compound that's added to epoxy. It makes a material similar to joint compound but with the adhesive properties of epoxy. You apply unthickened epoxy first, then trowel the thickened epoxy over top of it. It trowels like joint compound and sands almost as easy. You do have to be aware of the cure time, because once it "kicks" you'll have a mess, but otherwise it's great. I just used some to repair a hole in a masonite door. Here's a link.
http://www.westsystem.com/ss/fairing/
Thought "outside the box"
With several references to Epoxy, why not think about using an Epoxy Garage Floor paint. One-stop shopping and application.
Frosty
Adherence/abrasion is not the issue.
The goal is the topcoat (paint) will be on a sound material.
The base of the material needs to play well with the paint. My issue right now is the expansion rate of the plywood & mud/paint probably caused the issue in the 1st place. Still looking in other mediums to use but if I could replace the plywood with sheetrock, it would sure make things a whole lot easier...
I am aware they use wallpaper liner often when people paint over ~wood paneling~. Thus at least I know that this is somewhat used. However, wood paneling is way different than plywood to a degree...
Are both sides finished the same? Is one side directly exposed to the outside elements? If so, how is it prepared and finsihed?
The other edge is is ~capped~
The RO is actually a concrete. The sides and bottom were framed out....and sheetrock was used as a base for tile.
The *top* which is the plywood...is the painted (problamatic) issue. The front edge of this is tiled along with the rest of the wall.....
From your description my best guess is that you have a moisture problem. The symptoms you describe are almost always caused by moisture behind a plywood panel. Concrete is quite porous and does not provide a barrier to water vapor (moisture).
My first thought is not expansion, but moisture. Do you have a moisture meter with which you could measure the moisture content of the plywood? If not, does the plywood feel cool? I've been told that dry wood does not feel hot or cold as it lacks water. There could be flashing or other situation outside that's now allowing moisture to build up in the concrete, then move into the plywood. If that's the case, it's likely also affecting the tiled drywall, just not as fast.
My suggestion would be first to absolutely rule out moisture.
Epoxy is difficult to trowel on, and drips and runs could make an infernal mess. Durfham's Rock Hard Putty and even setting type drywall mud (Durabond is one brand) probably adhere more tenaciously than premixed joint compound.
Just my two cents.
No Moisture meter....
Durabond while harder...isn't that the same principal...regardless if my issue is expansion rates.
In doing research, on the wood vs. paint medium, wallpaper liner was what seem to be the recommended application when painting over wall panels, and I'm thinking that may be the closest thing to the issue I am seeing. Surprisingly enough, only 10% of this small area 13" x 24" is where the joint compound/paint literally blistered and peeled right off the sheetrock. I have taken a putty knife and scraped hard on the plywood and nothing else is budging off. I do plan regardless to sand the entire thing down clean and figure out the *next fix*
"Blistered and peeled" sounds
"Blistered and peeled" sounds like moisture problem. Expansion/contraction I would expect to cause fine cracks.
This forum post is now archived. Commenting has been disabled