The Stovebolt Site Forums The Shop Area Paint and Body Shop coating underneath plywood floor

I'm getting ready to undercoat my '59 suburban and noticed that the floor is 3/4" plywood in relatively good shape.

Does anyone have recommendations for sealing up the plywood to prevent swelling & degradation from moisture?

There are a few oily areas on the plywood above the U joints & transfer case, and I'm thinking about using minwax polyurethane since that might stick better to oil soaked wood?
For all the frame and metal areas I'm planning to use SPI epoxy primer. Not sure if it makes more sense to apply one before the other?

To clean things I'm planning to first pressure wash, and then spend a couple days with wire brushes.

[img]https://i.imgur.com/yXHNfGU.jpg?1[/img]

I would paint the frame first, then I'd brush the plywood with motor oil. That part has already begun by the transfer case. Might as well finish the job.

Linseed oil rather than motor oil is probably a better choice for the wood. That may even be what was originally used.

I have had wood treated with boiled linseed oil grow mushrooms. It never happened prior to that treatment. It acted like fertilizer.

Was the wood in sunlight, Carl?

Linseed oil has no ultraviolet resistance - it breaks down.
It has a few other negative "features".

I use a "weed sprayer" to treat the underside of my trailers wood bed with wood sealer. Please use your PPE.

Thanks for the tips guys! Will definitely wear my respirator and run the fan.
The wood boat guys seem to like this stuff called clear penetrating epoxy (CPES)

https://www.vintagetrailersupply.com/ProductDetails.asp?ProductCode=VTS-592

I'm thinking about using it near the wheel wells and edges of the plywood.