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I think naphtha can be used to wet wood to show any glue left from binding before paint, without requiring resanding. Are there any other substances that perform the same function?
And what is naphtha called in Canada?

Naphtha and lighter fluid are the same thing Med!

You could use any flash off type fluid. Heck "solvent" found at HD would be fine.

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There was a time in Canada that you could buy bulk naptha. It was used mostly by plumbers for blow torches and firepots. At that time it was always called naptha. Don't think it's sold that way any more.
Tom

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I use camp stove fuel or lighter fluid that I buy at Canadian Tire. If you read the labels you will find that many of them say something to the effect of "this product is or contains naptha".

Personally I have found good lighting to be more valuable when spotting glue around the binding than wiping with naptha.

Josh

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I find that applying an alcohol burst is always a great way to find any glue left behind, deeper sanding scratches and any other little dings you didn't get out the first time around. It's a bit of a PITA to sand back to wood every time though. I'm looking for a better way also. Next time I will put the close up glasses on.

Mohawk just off Marine does sell naptha which is probably the next best thing.

Cheers,
Danny

Mohawk!
Face palm!

Yup, Canadian Tire is the place to get it. They sell it as Coleman Fuel.

They sell it in different sizes :
http://www.canadiantire.ca/AST/browse/5/SportsRec/Camping/CampingStovesAppliances/PRD~0760044P/Coleman+Fuel%2C+Naphtha.jsp?locale=en

http://www.canadiantire.ca/AST/browse/5/SportsRec/Camping/LanternsHeaters/PRD~0760093P/Coleman+Naphtha+Fuel%2C+946+mL.jsp?locale=en

Rob

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Has anyone tried doing what Taylor Guitars does, and add phosphorus their glue (Elmers or Titebond)?
All they do is stick the body under a black light, and any glue left over shows up instantly.

I think it's a pretty cool trick, one that I'd like to try out if it's not that difficult (doesn't' seem to be so).

Camping fuel has oil added to it to prevent rust; not the best for our use!

Home Hardware stores carry a product called "low odour paint thinner" which turns out to be (drum roll......) pure naphtha. Excellent stuff.

Red Phosphorous? In the US if you get that stuff the DEA would show up, because it seems people used it to make meth.

I guess you mean some kind of a florescent compound? I am not sure if it does anything to the glue but I guess it would really help.

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Yes, some sort of florescent. I don't know what ratio in the glue, but it probabaly isn't much - just enough to show up under the blacklight.

I'd sure like to find out how to do this. Seems better than Naptha...

Has anyone tried a black light on the various glues? Some may have a natural fluorescence.
Tom

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I wipe-on a thin "sealer coat" of tung oil or Waterlox, over the entire instrument and neck. It really wakes-up the grain and figure as nicely as anything, acts as a tie-coat for the rest of the finish, but the most beneficial reason for doing it is that it will show --any-- amount of glue that might be on the surface(even a fingerprint), as well as any stray sanding scratches that weren't visible previously. When something shows up, I simply use a razor blade to scrape the spot, and wipe-on some more oil. A thin "spit coat" of shellac will do nearly as well if that's what you're more comfortable using and is perhaps more compatible with the rest of your finish.

Thanks everyone!

That would be my first instinct, as well. I suspect a Google search will find all kinds of substances that fluoresce under black (near-UV) light which won't have any effect on a glue you add them to.

I think Taylor buys their glue with the dyes in it already, but it definitely wouldn't be a big deal to DIY.

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Any suggestions for what to add to get the glue to fluoresce?

I was once advised that normal Titebond fluoresces anyway. Never checked it, but maybe someone could and report back.

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Titebond does not naturally fluoresce. Until 5 or 6 years ago a product called titebond fluorescent existed, and for several years it co-existed peacefully alongside titebond II fluorescent. Now only the titebond II variety is still available through cabinet shop distributors and specialty stores such as rockler and woodcraft. All water-based wood glues can be made to glow under a black light using water-based fluorescent dye. Very little is needed to produce a dramatic effect... well under 1% by weight, although most formulations call for between 0.3 and 0.6%. This will work for *all* water based wood glues including LMI, Elmer's, titebond, Gorilla, etc.

http://www.blacklightworld.com/Tracers.htm sells 8oz bottles of water-based concentrated dye that is clear under normal lighting conditions and glows blue under black light for $25. That's enough to last several lifetimes, so setting up a group purchase might not be a terrible idea if there's sufficient interest.

You guys are going to love what I have to tell you about naturally fluorescent glue. I've stated on many occasions that its only weaknesses are ease of preparation and water resistance... Hide glue. Both HHG and liquid hide glue will glow under black light because they are composed of proteins, so the same is true for fish/rabbit/any other animal-based glue. Other than that, none of the PVAs glow naturally and will require dye.

If there are any additional questions feel free to ask or send me a PM. I used to work for the makers of titebond and, having been unemployed for almost a year now, answering questions makes me feel like I am still contributing something of value to the world.

Hugh, thanks for the insight. I know about the not working thing. As an entrepreneur, I recently had a period of about three years where I was paying others for the privilege of working... not fun either.

Do protein based glues have enough fluorescence to be easily seen? I know nothing about this - just liked what I learned at the Taylor factory tour.

Yes, they fluoresce quite brightly. From a theoretical standpoint, if you want hide glue to stand out further, the same dye I recommended above can be mixed into hot hide glue or liquid hide glue with no impact on performance. Taylor makes extensive use of titebond products, and titebond II fluorescent would make sense in their process due to its compatibility with RF curing. That is almost certainly what you saw. For luthiery I would personally prefer several other PVA based adhesives with added dye adhead of titebond II. My personal favorite general purpose wood glue for guitar assembly is titebond extend original due to its long open time as well as its position for having the best thermal and creep resistance of the entire titebond PVA-based product line. If there is a need to speed things up a tad super titebond easily places second on my list.

Being an entrepreneur is quite an adventure. I have a couple of leads for potential investors, but I am also actively seeking a "day job" to help get my business rolling. One would expect with two other major adhesives companies in central Ohio that I could land a position in one of them. Getting my resume past HR seems to be the real trick, and I don't have any solid connections within the management chains of either Elmer's or Ashland. Otherwise I'm certain both companies could benefit from my background.

You can get Naptha in Canada at Goudey http://www.goudeymfg.com/solvents.html if you're near the Toronto area.

When I was at Larrivee in the '70's, we would just have a damp rag that we would wipe around the binding (on the back & sides only, not the top) and it would show up any residual glue, then just swipe down the raised grain with 320 grit.