Official Luthiers Forum!

You know the scenario. You have meticulously prepared the body for finish, sealed it up, sprayed the first coats and then once you start sanding back, you notice a little tiny gap that didn't get comlpetely filled.



I have filled with lacquer, but it always seems to leave a little dimple a few weeks down the road. I have used CA but that leaves a little bump only visible (to me) after buff out.


So, what do you do?

Dave

I do like Filippo and use thickened lacquer. If you use thick lacquer for the drop fill and then spray your final coats you should have an invisible drop fill when all is said and done. The key I have found is to drop fill before the final coats are spayed and give the guitar proper dry time. I use a minimum of 2 weeks dry time for Nitro and 3 weeks+ is better.

Josh

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Same here, concerning the thickened lacquer. I use a small artist brush and do any necessary drop fill as early on as possible. I like to have a completely flat finish before shooting my final coats.

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Jim Watts
http://jameswattsguitars.com

for em 6000 I drop fill with a pipette. I drop fill during the spraying process but especially after the last coat...for small indentations I fill wait 30 minutes fill , wait another 30 minutes, and fill again until the gap is completely filled, even for the smallest cavity it may take 5 or 6 fills, then level sand ...works perfect , final buffing is after a week...love this stuff the more I use it the more I like it....

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MK5acoustics.com

How do you drop fill translucent finish or the transition portion of a sunburst, or even factory guitars with stained back/side/neck? Anytime I did a drop fill on those area I can't make it completely disappear. If I spray stain over it it's either too dark or too light, and if I wipe stain over bear wood (like if I needed to repair cracks and sand it level) it's always too light. One time I repaired a Fender Highway One Strat where the customer accidentally dissolved the finish with God knows what, I masked the damaged portion best I could and sprayed toners until I got a shade that I think closely matches the rest of the body, but there's still a big patch of difference in shades, and when the customer asked I just told him it's impossible to match the shade... only way is to refinish the whole thing. He didn't have anymore question after that.

And by the way every Gibson Les Pauls I have seen have very thick finish, so there's no way to simply make them disappear completely without using thickened CA for the drop fill. Blacks are easy but bursts are impossible to make them disappear unless there's some magical technique that veteran luthiers have under their belt...

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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

Anybody ever have a pinhole that just doesn't want to drop fill? I had a newly finished mahogany guitar with a pinhole that took several attempts to fill. The fill looked fine until I leveled and sanded, the pinhole was still there. Almost as if the thickened lacquer was bridging the hole.

Chuck

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It could be fish eye... Those you cant drop fill. This is one reason why I going to fp everything from now on. No more expensive spray guns, harmful fumes, and hazard to health.

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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

Yes, this can happen. When drop filling it is important to see that there is no air trapped in the hole you are trying to fill. Or you end up with the problem you describe. I would either use a pin to work the thick lacquer down into the hole, or fill the hole with slightly thinner lacquer that will run down into it.

I should mention that the method I described in my earlier post was for drop filling while spraying a new guitar. Drop filling as a repair on a damaged finish is different and more difficult to hide.

Josh

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Could be a solvent pop. Either way these type repairs I usually start off with a drop of retarder to soften and reflow the coating a bit. Sometimes that is all that is needed other times it is a prelude to a drop fill.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks Josh and Brian. I have used a pin to push the lacquer down into the hole, but once the drop is applied, the hole is no longer easy to see. But did finally work.

Brian, I am going to try the retarder next time.

Thanks, Chuck

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Here's a great video from Don Erlewine.

http://www.stewmac.com/tsarchive/ts0174 ... ign=ts0174

Steve

Thanks all for the replies.
Nitro thickened.
Drops going down.

Final spray hopefully later today.

Gosh, I just learned how successfully to drop fill.
Thanks fellers!

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wah
Wah-wah-wah-wah
Wah

I recently drop filled with CA on a top I'm finishing. Invisible from the top, but opaque from an angle. Will it disappear under another two or three top coats, or would you recommend going back to ground zero in the area and spraying a few localized coats to get the finish even as a whole?

I drop filled lacquer with CA once, and for some reason the CA reacted with the lacquer causing anything the CA touched to shrink like crazy. It means anything the CA touched is visible no matter what due to significant shrinking. Not sure why.

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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

Join a Highland regiment, me boy; there's no finer garment than the kilt for fornication and diarrhea.

- LIEUTENANT COLONEL JOHN MASTERS

Without hijacking the thread Todd that sentence is an absolute corker

Steve

Don/t know what CA , the other olfers use . But I have gone back to the super thin yellow.red bottle from the $$ store .It sems to work the best for me. I/ve tried loctite from the hobby store and it was too thick . I use med CA from zap gap and thick CA from slo flo. I/ve had good success with the med and thick .Is there another super thin CA that you folks prefer ? , and if so whY. sorry to get off subject, but would like to to find another water thin CA besides the $$ stuff, especially for my uke builds. PS Todd love that little ditty abt the kilts. We used to sing a different one in the army, which is unacceptable on the forum lol.

Again don't want to highjack the thread, but I agree with Kamusur, Todd's quote is fabulous!!

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Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

Wiped a thin coat of lacquer on to see if the leopard spots would go stealth. No such luck. Looks I'll strip the area back, seal, and start again. Thickened lacquer from now on.

I would be afraid the CA would yellow at a much different rate than the nitro over the years.

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Michael F Smith
Goat Rock Ukulele
http://goatrockukulele.com