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Filling a nasty little
Lacquer Check
© Frank Ford 2003; Photos by FF

Nitrocellulose lacquer does have some nasty habits. One of the most disappointing of those is the tendency to "check" or crack with a sudden drop in temperature. I usually don't recommend trying to fix such checks, because they are often an inevitable part of the nitrocellulose lacquer aging process. But, when the check is small, and on a NEW instrument like this one, the repair becomes something of a necessity, just to keep the instrument in salable condition as a new guitar. So, this time, instead of returning the guitar to the manufacturer for refinishing, I decided to fix the small check.

First, I made the damage much worse by taking my most pointy knife and running it through the check, widening the crack in the lacquer, roughing the edges of the crack, and not digging deep enough to scratch the wood underneath.

Then I dropped in a tiny bead of Cellosolve® to amalgamate the lacquer in and around the check.

I gave the area a few hours to dry a bit, and brushed in a small line of new clear lacquer. The new lacquer would tend to melt right into the old, but having amalgamated the area, I was certain that I'd get a seamless weld between the new and old finish. The next day, I brushed in another stripe of lacquer, so that I'd be sure the filled area would be higher than the original level after the lacquer dried. The hard part is waiting for the lacquer to dry. Because my new lacquer had a slow acting solvent under it, and because my new lacquer fill is actually deeper than the original finish, I wanted to wait longer to allow it to dry than I would have even for a full finish. So I set the calendar for a month, and put the guitar aside to dry. It would have taken more than a month, and a considerable UPS charge to return the guitar for refinishing, not to mention the manufacturer's cost to do the actual work. So, I didn't mind the wait, much.

After a month's drying time, I was certain that the new lacquer was about as solidly dry as it would get. I scraped it gently with a glass slide right down to the level of the original finish. I was able to scrape it without scratching the surrounding area, because I had protected most of the glass edge with some thin plastic tape.

A quick bit of block sanding with 2500 grit waterproof silicon carbide paper, and the area was ready to buff to the same high gloss it had originally.

It took a bit of shop time, and a long period to dry, but I figured it was a much better deal for both me and the manufacturer to fix this one "in house" rather than to take the chance of a similar problem cropping up in shipment. It was wintertime and mighty cold on the UPS truck.

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	Nitrocellulose lacquer does have some nasty habits. One of the most disappointing of those is the tendency to "check" or crack with a sudden drop in temperature. I usually don't recommend trying to fix such checks, because they are often an inevitable part of the nitrocellulose lacquer aging process. But, when the check is small, and on a NEW instrument like this one, the repair becomes something of a necessity, just to keep the instrument in salable condition as a new guitar. So, this time, instead of returning the guitar to the manufacturer for refinishing, I decided to fix the small check.
	First, I made the damage much worse by taking my most pointy knife and running it through the check, widening the crack in the lacquer, roughing the edges of the crack, and not digging deep enough to scratch the wood underneath.
	Then I dropped in a tiny bead of Cellosolve® to amalgamate the lacquer in and around the check.
	I gave the area a few hours to dry a bit, and brushed in a small line of new clear lacquer. The new lacquer would tend to melt right into the old, but having amalgamated the area, I was certain that I'd get a seamless weld between the new and old finish. The next day, I brushed in another stripe of lacquer, so that I'd be sure the filled area would be higher than the original level after the lacquer dried. The hard part is waiting for the lacquer to dry. Because my new lacquer had a slow acting solvent under it, and because my new lacquer fill is actually deeper than the original finish, I wanted to wait longer to allow it to dry than I would have even for a full finish. So I set the calendar for a month, and put the guitar aside to dry. It would have taken more than a month, and a considerable UPS charge to return the guitar for refinishing, not to mention the manufacturer's cost to do the actual work. So, I didn't mind the wait, much.
	After a month's drying time, I was certain that the new lacquer was about as solidly dry as it would get. I scraped it gently with a glass slide right down to the level of the original finish. I was able to scrape it without scratching the surrounding area, because I had protected most of the glass edge with some thin plastic tape.
	A quick bit of block sanding with 2500 grit waterproof silicon carbide paper, and the area was ready to buff to the same high gloss it had originally.
	It took a bit of shop time, and a long period to dry, but I figured it was a much better deal for both me and the manufacturer to fix this one "in house" rather than to take the chance of a similar problem cropping up in shipment. It was wintertime and mighty cold on the UPS truck.