Official Luthiers Forum!

How do you guys avoid yellow stains on European spruce when using CA glue? I thought I was alone in this back when I used European spruce in builds, but I just saw another luthier's work and the yellow stain is just all over any place where CA was used (for example bindings, rosette, etc.). He said he had sealed the top with shellac prior to putting CA on the wood but still the CA penetrated the shellac and stained the wood yellow in such a way that no amount of sanding would remove.

Is it even avoidable? Or maybe just tint the top yellow to hide it...

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Did he seal the rosette and binding ledges with shellac or just the top. This staining happens when CA gets into the endgrain. If he just sealed the top then cut his ledges there would be no protection from this issue. That said, we recently had a thread where this staining happened even though shellac was used so it may be a case that sometimes one "coat" is not enough.

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Well, I used to just do one coat of shellac but you may have seen the recent thread I started where this happened to me as well. I think it's best to do at least two coats, some suggested 3. From now on I will be doing 3. But I have used this same method on many guitars and NEVER had a problem, till I did.

I have always sealed my ledges with a wet coat of nitro. Never had it bleed and I flood with ca.

Glen, do you brush it on? I never would have thought of using nitro for this.

Or maybe a quick spritz of Deft? I'm interested, too.

3 coats 1lb shellac or 2 coats 2lb cut applied with a brush, in the channel and around, or on the end grain and top surfaces. Let dry between coats.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I had this on my first build... broke my heart... Over time the wood darkened to hide it and wit euro spruce this works well as aging tends to be yellowish as opposed to the golden orange of sitka say... anyway...

These days i do not go near a top with CA glue... i use a cellulose glue for rosettes (Duco in the states, UHU hart in Europe)... and i use titebond for binding / purfling.

G.

_________________
www.leddingtonguitars.com

No I just spray a wet coat full strength, not thinned. McFadden/seagraves.