I just completed some built-in, painted cabinets. I used birch plywood, dados, rabbets, and yellow glue. To simplify the finishing process, I pre-finished all of the pieces—except the ends that fit into joints–with primer and latex paint. I skipped the ends, thinking that the glue would not bind well because the moisture in the glue would not penetrate paint into the wood. The cabinets came out fine, but the painting touchups were a pain. A friend told me today that I could have painted the ends and that the glued joints would be just as strong. Anyone have an opinion on whether it’s safe to pre-finish ends that will be joined by yellow glue? Assuming that my friend is correct, are there some finishes that should NOT be used before gluing (e.g., stain, shellac, varnish, oil-based paints)? Thanks. -Rich
Replies
Just my opinion, but I think your friend is mistaken.
I can't think of any finish that wouldn't weaken a glue joint. Maybe shellac, which always stays semi-permeable, but why risk it? By "ends" do you mean end grain? You are trying to bond wood to wood, not wood to paint. The water based glues also swell the wood a bit, tightening the joint. Why not just mask any part that will recieve glue, then spray all the parts?
Rich, its common today to have a painter finish the cabinets on site. As you have already found out, prefinishing usually ends up with a lot of touch up when paint is involved. My suggestion would be to assemble it and then paint it. If you can spray it that would be the easiest.
The finishing on site thing is all about lighting. What looks correct under your shop lights might not look the same when it is installed so staining or painting on site lets you achieve the correct tones or colors that you or your customer expect.
John
Thanks to all for your comments. I will either mask the end grain or find a way to spray the finish after assembly. I don't have a spray gun, but I do have a small air compressor. Perhaps I'll find a spray gun that fits the capacity of my compressor. I really appreciate everyone's comments!
Brief comment on touch up's.
When masking and pre-finishing, I've moved to using a quality air brush for most of the touch up, making it much faster and easier. Even the smallest air compressor can run one, while few small compressors can run anything more than a touchup spray gun. The lower pressure and air volume from the air brush also makes it much easier to hit interior locations without having the air turbulence drive the finish back in your face.
This has also worked nicely for thinned paint, allowing you to feather it in and blend well.
Caveat: Don't bother trying with an el-cheapo air brush.
Gerry
This forum post is now archived. Commenting has been disabled