Ultraviolet-Light Tracer Dye for Glue

For easy detection of glue streaks before finishing, use a fluorescent glue or add a fluorescent additive. February 7, 2009

I'm having a hard time seeing glue spots on Anigre wood before I stain it. Once I use a dark stain they show up like a sore thumb. Is there some type of light or filter to go over a light that would expose these glue spots?

Forum Responses
(Adhesive Forum)
From contributor B:

Here’s an article that might be of help.




From contributor K:
I am not experienced with the wood you are using, but I have found that when you run across a glue patch when you are staining, you can use sand paper and sand/stain the spot away. Use automotive wet/dry paper and use the stain itself as you sand. It works pretty well.

From contributor R:
I am the Works Manager at a door factory in Indonesia. We work with several pieces of veneers and are always on the lookout for glue bleed and spots. The only way we have found to detect glue spots before staining is to add an ultraviolet detectable dye to our glue mix before pressing the veneer. We add a product to our glue called Pluracene and it only requires a few drops. If we have glue bleed, seem lines on our panels or spots they show up clearly under a black light and then they just need to be sanded off.

From the original questioner:
This product Pluracene - do you have a link to where you get it?

From contributor C:
We make a product called WA20 that works as a standard yellow woodworking glue. For about the last 2-3 years, we have made it available with a fluorescent dye for just this purpose.

From contributor L:
You can buy a cheap hand held electric light and put a black light in it. This should do the trick. I have several customers that I sell the lights to and they convert with the black light bulb. Don't know if watts make a difference or not. I will look when I go for future reference. We have been doing this for about two years now.

From contributor O:
I can usually see the glue spots by wiping the wood with mineral spirits and they show up.

From the original questioner:
I have since ordered WilsonArt WA-20 yellow glue with a fluorescent additive for the same cost as their normal type. So if anyone else is looking for a solution to this problem try the WinsonArt WA-20 with additive.

I have also tried the alcohol wipe and that does seem to bring up most spots but not all. I'm hesitant to try the mineral spirits because of the finishing system we use and because the drying time of the spirits.