Can a lacquer crack (checking) be fixed?

[livemusic]

I have been in Louisiana and there is high humidity there and I have never, not once, had this happen -- checking. The gorgeous D55 sunburst I bought recently is now the victim of a minor crack. The guitar is awesome but, dang, it was close to mint. Now, it has a 2-3 inch crack in the finish. I attribute this to low humidity in the home where I have been staying. I have noticed that I have sometimes waked with severely chapped lips and I have dry skin problems like never before. This house's furnace is cranking out dry heat.

So, it's no big deal but I do try to take care of my guitars and if I could fix this, I would. I am not aware of a fix.

I now have home-made "humidifiers" in my guitars in this house.

 

[adorshki]

So, it's no big deal but I do try to take care of my guitars and if I could fix this, I would. I am not aware of a fix.

Hi Live, I've seen a LOT of threads about checking and I can't recall one describing a fix either, (short of literally patching: ie, sanding and re-spraying, but on a sunburst that may be a problem)
There's more than a couple of guys here more intimately familiar with luthier's tricks: Acorn House, Cristopher Cozad, and even our recently "Authorized by Guild" Fixit.
Also, can't recall someone blaming checking on low humidity, usually it's the wood that cracks which takes the finish with it.
When it's just finish checking the most common cause is a sudden temperature change from too cold to warm, or a mechanical stress like some pressure or other form of torque being exerted on the top, in case you want to investigate other possible causes of the crack.

 

[Br1ck]

I find a few finish checks to be a bummer, but finish checks all over the top I find very appealing. Wait a few years for the patina to develop.:laughing:

 

[West R Lee]

I'm not sure I agree with Al completely on this one. What generally takes place is that wood expands and contracts with temperature and humidity. Nitrocellulose lacquer expands and contracts as well when these changes occur, but it can expand and contract at different rates than does wood. Humidity expands wood as dryness contracts it. Though I would agree that most cases of lacquer checking seems to happen due to abrupt temperature changes, most notably when a cold guitar is taken into a warm environment. When that happens, the wood expands at rates different than does the lacquer, and that's how nitro usually cracks. We've heard of cases here where people claim to have opened a guitar in a warm home that was shipped during cold weather and to have seen the finish crack before their eyes. But I feel pretty confident that big swings in humidity could do the same, maybe not so quickly, but definitely over time.

Your Louisiana weather doesn't differ too much from mine in Northeast Texas, and I assure you there is enough temperature and humidity change here to crack a guitar finish. This time of the year, with the central heat running in the house, I case and humidify mine, both to protect the wood and the finish. And you're right, when you see your hands and lips chapped, it's definitely time to humidify. I keep a digital hygrometer that lets me know what the humidity is here in the house, and I keep it where I store my guitars. I also notice this time of the year that if my guitars go a bit without humidification, they get out of tune......in fact, I've picked up buzz before on my guitars with very low action when those guitars were dry. I will say this though, to me, a dry guitar sounds better. I know that may sound funny, but I definitely notice the difference as this time of the year, they sound better before humidification than they do when I refill my humidifiers. But to me, long term preservation is what it's all about. It's also why I only use light gauge strings.

And for the record, I also believe a guitar can be dropped, or fall off a stand for instance, even onto the carpet, and crack the finish. It happened to me right after I bought my JF30. I had it standing on a stand in the carpeted living room at the time, and that sucker was so top heavy, it went right over onto the carpet. A noticeable finish crack appeared immediately. No real damage to the guitar, but it did crack the finish much as you describe.....about 2"-3" long, on the top a bit from the neck, starting at the pick guard and running towards the heel.

West

 

[Christopher Cozad]

...The gorgeous D55 sunburst ...has a 2-3 inch crack in the finish... I am not aware of a fix...

It can be done, and it is extremely involved. If you think of the finish like a large plate of peanut brittle that has snapped down the middle, imagine how you would go about repairing it...

You would re-melt the brittle, allowing it to re-join into a solid plate. Or eat it and be done with it, if we are still dealing with peanut brittle.

Essentially, the lacquer alongside both sides of the crack is dissolved or melted into the surrounding plate. You score the crack, apply an amalgamation medium, allow to dry, spot fill the crack with a bead of lacquer, allow that to dry (major curing time involved at this step - like a month or more), sand to level, then buff.

Then never, ever let it happen again! :highly_amused:

Seriously, most of the good advice you will receive here will be along the lines of "learn to live with it", as it is a major effort to repair. Should you really want to get your guitar back to "as close to mint" status as possible and are willing to pay the price, unless you are really comfortable with lacquer repair, it is a job left for a pro. I vote to outsource this type of repair.

Edit: Regarding the sunburst finish, repair is more complex or not, depending upon the severity of the crack and where it falls in the sunburst pattern and the experience level of the finish repairman. The sunburst (typically) resides as tinted lacquer beneath the clear finish coat(s). The repair lacquer can be tinted (ever-so-slightly) to minimize the transition, or applied clear and none are ever the wiser. It depends and is usually the call of the repairman.

 

[guildman63]

I have a strat that was with me through 3 years of grad school in New England, and was always in my apartment that had electric heat. The humidity level in the winter was in the single digits, and the checking that resulted to the poly finish is impressive to say the least. It is one of the foto flame strats. I would love to have it stripped and refinished or stained, but I was told that stripping such a strat is a major pain.

 

[SFIV1967]

Here's Frank Ford's guide how to repair such a simple lacquer crack (you can zoom in each picture there): http://www.frets.com/FretsPages/Luthier/Technique/Finish/Lacquer/CheckRepair/checkfill.html
Ralf

 

[idealassets]

I have had this type of repair done, but it is subject to what a luthier interprets as "looks good" or not, based on their ability and their concern for the guitar. After all they don't own the guitar, mostly they are on a production basis of normal (costly) billing rates.

Unfortunately in one case the entire guitar top was refinished, and it did not sound the same afterwards.

I'm not certain how many LTG'ers would concur with me, but in time nearly every guitar acquires a few wear spots and "mojo". For me next time I will probably leave the imperfections alone and pay more attention to the sound, since I hate selling off what used to be a nice guitar when it doesn't play nearly as well any more.

 

[idealassets]

My first Guild F50 guitar fell off a stand 2 times and acquired some small nicks. Various luthiers told me to leave it alone and declined to blend the finish to hide the damage. In time the small imperfections began to not bother me. BUT I did eventually sell this F50 after getting a chance to sound demo a lot more of them; the action on that F50 was always hard on my fingers. (I then replaced it with an identical 2007 new old stock F50 that plays a little easier)

This is another case where my concern for the looks of the guitar were a major thing at first, but that went away in time. My biggest concern now is for the sound first, and then the action of the guitar.

 

[West R Lee]

And I agree. Lacquer checks are more trouble and too expensive to repair unless you just can't stand to look at them. But if one were to chose to attempt a repair, I think they would be well advised to be aware that the repair could easily be "worse" than the blemish". I'd leave them alone.

West

My first Guild F50 guitar fell off a stand 2 times and acquired some small nicks. Various luthiers told me to leave it alone and declined to blend the finish to hide the damage. In time the small imperfections began to not bother me. BUT I did eventually sell this F50 after getting a chance to sound demo a lot more of them; the action on that F50 was always hard on my fingers. (I then replaced it with an identical 2007 new old stock F50 that plays a little easier)

This is another case where my concern for the looks of the guitar were a major thing at first, but that went away in time. My biggest concern now is for the sound first, and then the action of the guitar.

 

[GardMan]

Unless you take it to this guy...

 

[West R Lee]

I don't think I'd better try that. Very good Dave.

West