How to get paint to stick to sides laser cut baltic birch?

Hey everyone,

Last night I printed my first name sign on our GF and I bought spray paint to paint the letters, but it doesn’t seem to want to stick to the sides where the laser has charred the wood. I even tried spray paint that also has primer in it.

Anyone have tips for this? Do I just need to use an actual primer before going in with the paint? I see so may beautiful signs with the sides of letters fully painted!



yeah. most spray paint has very little actual pigment, even the stuff with “primer + paint” (which is kind of a gimmick, unfortunately). End grain sucks paint into itself, so don’t be surprised if you need two or more coats of primer before it really seals up. Even the clear sprays will help to stop the capillary action that sucks the paint in. remember to let it dry between coats! Gesso is another traditional artist’s product to consider for priming.


Okay, great! Thank you!

Wax rub and buff looks amazing on edges of plywood.

1 Like

it does! Unfortunately I find that Rub-n-Buff also reacts poorly with certain finishes/topcoats, so testing is a good idea.

1 Like

I just leave the edges alone and paint only the surface areas. My projects come out real nice with the natural charred edges.

1 Like

If the pieces are big enough, could you just give them a coupe of swipes with sandpaper to rough them up for the paint? Or, if you have one, run a sander roll over it with a Dremel?
Neither of these would work if there’s a lot of fine detail to the edges, of course.
Best of luck!


Do you use spray paint, just only top down onto the surface? I feel like I could’ve done that and it would’ve looked good.

The surface of the cut wood is “glazed”. Paint isn’t going to want to stick to it because it’s a very smooth surface and it’s impregnated with whatever organics cooked out when the laser got things it didn’t cut, hot. So the surface won’t “wet”, the paint’s surface tension wants to pull it away from the edges. Auto body primer will work but it requires a couple of light coats. If you lay it down thick, it behaves a lot like normal paint. Normal paint will do it, too, but it requires a lot of light coats. The best method I’ve found requires a little “elbow grease”, you have to at least lightly sand the glazed surface to rough it up so the paint has something to want to stick to… I have these little flappy-disk sanders that attach to a dremel makes quick work of it, can get in to most creases. Though if the edge has a lot of complexity I do it old school with a little strip of sandpaper.


This topic was automatically closed 32 days after the last reply. New replies are no longer allowed.