I am just finishing a room for a new HO layout and I covered the walls with Masonite. Don’t ask me why, if I was doing it again I would be using Sheetrock. I will be painting the walls blue behind the layout and need to cover the seams between the Masonite sheets with something, will some kind of tape work?
Drywall compound and tape might work, since you’re going to be painting over it. Pre-mixed drywall compound, drywall joint tape, and spatulas for applying same should be available from any well-stocked building supply store in your area, such as Home Depot, Lowes, or even a Wal-mart. The biggest problem you’re going to be facing is that the joints will crack with the least bit of pressure against the Masonite unless you have it very firmly attached to the wall.
See my post under “curve background”
I recall in the past reading something about using a product called “Durham’s Rock Hard Water Putty”
which should be available at any hardware store or home center. Be sure to apply with a WIDE putty knife and feather out as smooth and thin as possible to eliminate excessive sanding, which I would ASSume is kinda difficult on this hard drying product.