Ultra Violet Inspection Light

[Rob Sack]

Anyone have any experience using an ultra violet light for locating glue residue? It seems they are either several hundred dollars from a test equipment company or $12-13 from Amazon.

[Robert Hayward]

I have a cheap one I have had for years. Never used it to look for glue though. Have used it for many other things, finding dog urine, scorpions and freon leaks in my work van to name a few.

[Stan Calow]

Yes. A guitar collecting friend gave me one - one of the cheap ones. He liked to check instruments for messy or undocumented repairs. I have used it, and it is entertaining when checking other things as well.

[Richard Coers]

Don't you have to add something to the glue? Titebond II has a black light visible version.

[Edward Weber]

Also good for telling certain species from one another, some fluoresce.

[Kent A Bathurst]

I used to do this some years back. As Richard mentions, I got an additive for the glue - pretty sure there wasn’t that TII version at the time. The backlight itself was nothing special - $15 - $20 IIRC

Did the job with curtains drawn tight and lights out. Assume more $$ gets more power and better visibility

Anyway/ it works. I guess you need to try a light to see if it’s strong enough and return if you need to trade up

Sold light and additive to someone here. I became a convert to “finish before glue-up”

[Alex Zeller]

The expensive ones are expensive for a reason. I use to do magnetic particle inspection. It uses a strong electro magnet to magnetize metal. You then put iron filings on the metal. If there's a crack the iron filings are attracted to it. Sometimes you use colored fluorescent died iron. A UV inspection light will make a crack show up like a neon sign. But, like every kind of testing you need to document everything. One of the things is to measure the strength of the UV light. If it gets too weak then you must replace the bulb. It's also more powerful than a cheap UV light. If you are just using it for woodworking I wouldn't buy an expensive light. If the cheap lights don't work I probably could borrow an expensive UV light and see if it will work so you can decide if it's worth investing money.