Inspecting for Glue Drips Before Finishing
Drips show up when you wipe with denatured alcohol, but new fluorescent glues and a "black light" work even better. December 2, 2006
Question
I am having trouble with the guys in my shop that do the paint prep not getting all the glue off before stain is applied. Somewhere I read of a chemical that makes the glue a little easier to spot, but now I can't find it.
Forum Responses
(Adhesives Forum)
From contributor S:
I use denatured alcohol. Not only will glue spots show up, but so will sanding scratches/swirls and other defects that are easier to fix before finishing. It also has the added benefit of cleaning the piece, and it dries in under a minute. No residue, no fuss.
From contributor J:
Good info about the alcohol - that does work. But does anyone know of a fluorescing that can be added to the various glues? One could use a black light then to find boo-boos.
From Jeff Pitcher, forum technical advisor:
Woodworker's Supply sells a "blacklite" additive which does exactly what you're looking for.
From contributor I:
Titebond makes a glue with the additive already in it that you can buy in large or small volume. There's also a black-lite sensitive additive you can add to any glue. Also helps if you have light shining at an angle to the work piece for spotting glue blotches. Just get one of those halogen work lights and angle it at the work piece. Direct light won't show the glue as well as light coming in from an angle.
From contributor R:
We just received a bottle of Titebond fluorescent glue. We have tried some test pieces and assembly of solid wood doors. I would highly recommend this to everyone. The cost of the glue and light is nothing compared to the cost of rework in the finishing department. We are going to get a modern automotive type treble light for inspection. I think that in two years, everyone will be using this glue and asking how we did without.
