Hey everyone, and Happy New Year! (almost)
Novice woodworker here. For Christmas this year, I made my brother an engraved and painted sign out of pine wood. I was generally happy with how it came out, but had a few issues with paint bleeding through the grain of the wood. I'll describe my process below, and would very much appreciate any help that you guys may be able to offer in getting cleaner paint lines / preventing that bleed through the wood grain.
1) I got some pine board from my local big box store.
2) I sanded the board with 60, 120, then 180 grit sandpaper and shop-vac'd and wiped to remove dust.
3) I applied a coat of spray-on oil based polyurethane and let it dry overnight.
4) I applied a sheet of oramask 813 stenciling vinyl, squeegee'd out any air bubbles, and let it sit for two days. (Steps 2 and 3 were to ensure that the oramask had a good surface to stick to).
5) I used a V-bit and CNC router to cut out the pattern on my sign and shop-vac'd out any sawdust.
7) I applied a coat of clear enamel spray paint to attempt to seal the cut edges of my stencil, and let it dry overnight.
8) I applied a coat of each of my enamel spray paint colors and let dry for several hours before removing the stencil. At this point I observed the bleeding of the paint through the wood grains.
9) After observing the paint bleed, I sanded with 60, 120, and 180 grit sandpaper again, removing about 0.10" of wood off of the surface. This did not eliminate the paint bleed, which is what makes me think that this is bleeding through the wood grain and not just paint leaking under my stencil.
So how would you go about preventing this problem in future projects? Is there a sealer that you would recommend that would do a better job of sealing the grains than oil-based poly? I want it to be clear so that the grain of the wood still shows through in areas where I haven't painted, and I want to be able to spray paint on top of it. Is there another solution other than a different sealer?
Related question: is there another (commonly and cheaply available) wood that would inherently have less grain-bleed issues than pine?
Many thanks in advance!