# Instruments and Equipment > Builders and Repair >  Cracked Lacquer

## Lefty Luthier

This mandolin left my shop perfect in every way, was dedamped and actually played a number of times. Was shipped in a case inside a foam padded box. Was returned by a very angry customer who stated that the shipping container had no physical damage. Since the volute is cracked as well as the flexing parts of the soundboard I can only surmise that it was thermal shock or chemical reaction that caused this terrible cracking. I would appreciate any opinions since after shipping nearly 100 instruments this is the first time I have ever seen such a mess.

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## Lefty Luthier

A better shot of the total soundboard.

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## MikeEdgerton

Looks like it went from warm to cold real quick.

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## Austin Clark

When shipping instruments, particularly in winter, I feel it is always important to let the customer know that they need to let the shipping box and instrument case acclimate to it's arrival environment to avoid cold checking.  This can take overnight.  It is pretty hard to wait overnight to open an instrument you may have waited a long time for, but really, what is one more day vs. potential problems with the finish.  

Unfortunately, I think you were in error to not warn them.  It puts the onus on them.  I suppose it could happen in the delivery process too, but the most common occurrences of this seem to be when the box/case is opened too soon.

Additionally, I think it pays to ship overnight.  That way the mandolin spends a day on the plane instead of 5 or more days in a semi on the freezing highway.

Sorry Lefty, tough luck...   :Frown: 

You could try a light spray of retarder.  I think there is another product out there that can remove blushing and may help with the cracking but I can't remember it's name.  Maybe someone else will chime in and know...
(try it on a small area first!!)  :Coffee:

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## Paul Hostetter

> Looks like it went from warm to cold real quick.


This usually occurs in the opposite order. The wood warms and expands faster than the lacquer can, hence the cracks. This is why people like Mandolin Brothers, f'rinstance, advise you to leave a shipped instrument in a box overnight before opening it when it's been shipped in cold weather.

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## Geoff B

bummer man!

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## Paul Hostetter

I actually like the look. I grew up in Michigan and Colorado and this was fairly common there. Has no real effect on the instrument other than the visual. Rick Turner should be along soon, he knows the name of the stuff that sinks into and welds the checks shut.

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## Big Joe

Yep.  Weather checking happens.  You can use an amalgamator and sometimes it will seal the finish together.  Not always.  This is why most companies do not warrant finishes.  A few extra hours in the case before opening would likely have kept this from happening.  I'm not certain the dedamper can't contribute to this as well.  Especially if the finish is not fully cured before its use.  Just my opinion.

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## MikeEdgerton

It looks like my Taylor. I guess it could have happened cold to warm but I found out it happened when I opened the case a week after it was left in car trunk overnight in cold weather. I always assumed it went the other way because it definitely had the time to warm up before the case was opened.

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## barry k

Was the whole mandolin cracked or just the top?    In the K&G days we finished 2 mandolins with a new batch of lacquer from the same company we had always used.....turns out the new batch  didnt have the  correct amount of plasticisors (sp?) mixed into the new lot.  The paint company reimbursed us for the lacquer and our time involved. They looked exactly like that  about 3-4 days after set-up. Only option for us was to scrape it all off and start over.  Did you change brands of Lacquer you normally use  or open a new can  or use paint that was stored a long time? Hope you have a sharp paint scraper....this is labor intensive.

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## Rob Grant

Lefty, nice instrument. It's bloody sad when something as simple as the finishing material lets you down! I didn't realize this was such a problem with lacquer. I was actually thinking about using lacquer on my next batch of four mandolins. I think I'll just stick with the French polish, thank you.

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## Michael Lewis

Generally the thicker the finish the more prone to checking.  In the future it will help to keep finish thickness to a minimum, or use a finish that remains flexible.

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## John Arnold

> This usually occurs in the opposite order. The wood warms and expands faster than the lacquer can


Lacquer has more thermal expansion than wood. That means that the cracking is more likely to occur when the instrument cools, rather than when warming up. That said, any rapid changes in temperature can cause it, and opening a cold case in a warm room should be avoided. 



> I think it pays to ship overnight. That way the mandolin spends a day on the plane instead of 5 or more days in a semi on the freezing highway.


It is colder at 30,000 feet than on the ground. The cargo hold of an airplane is not heated, either.

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## Paul Hostetter

Fresh finish doesn’t cold crack. It's still flexible (ask CF Martin). Badly formulated fresh lacquer does, though.




> Lacquer has more thermal expansion than wood. That means that the cracking is more likely to occur when the instrument cools, rather than when warming up.


There goes most of my adult life's experience. Sorry, I don't buy it, nor do many others.Just regard the sheer mass of wood vs. lacquer. 




> t is colder at 30,000 feet than on the ground. The cargo hold of an airplane is not heated, either.


Most UPS, FedEx and USPS cargo planes are nominally heated, and there's no hold: the entire plane is full of parcel cargo. You must have seen these planes at airports. Big paint jobs, no windows.

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## Bernie Daniel

I recall an incident in Ohio in the winter of 1978 (you may recall it was the coldest N. American winter in 200 years).  

But I digress.....anyway a very good young guitar player had left a fairly new D-41 in his car on the street -- overnight (it was about -20 F --i.e., cold!). 

He remembered the next morning and went out to bring it in.  Unfortunately he immediately opened the case in his warm bedroom to see if it was OK.  

If I recall the story right he claims it more of less cracked right before his eyes or at least over a short time frame. I suppose the cracks could have been there from the cold and were then exposed in the warmer temp?  

It was less than a year old and his parents were able to get some help from Martin on it in the end.

But where have we had weather cold enough in the USA to have produced the OP's observation this year?

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## MikeEdgerton

I'm pretty sure mine was cold cracking and the Taylor in question had been back to the factory the year before for some top work and the finish was indeed thicker than it had been as they had refinished that puppy. Either way, it now has character that it ddn't have before.

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## Richard Sanabia

> Was the whole mandolin cracked or just the top?    In the K&G days we finished 2 mandolins with a new batch of lacquer from the same company we had always used.....turns out the new batch  didnt have the  correct amount of plasticisors (sp?) mixed into the new lot.  The paint company reimbursed us for the lacquer and our time involved. They looked exactly like that  about 3-4 days after set-up. Only option for us was to scrape it all off and start over.  Did you change brands of Lacquer you normally use  or open a new can  or use paint that was stored a long time? Hope you have a sharp paint scraper....this is labor intensive.


.....This happened to me after spraying a project with lacquer that the factory had changed formulation....

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## Lefty Luthier

> Was the whole mandolin cracked or just the top?    In the K&G days we finished 2 mandolins with a new batch of lacquer from the same company we had always used.....turns out the new batch  didnt have the  correct amount of plasticisors (sp?) mixed into the new lot.  The paint company reimbursed us for the lacquer and our time involved. They looked exactly like that  about 3-4 days after set-up. Only option for us was to scrape it all off and start over.  Did you change brands of Lacquer you normally use  or open a new can  or use paint that was stored a long time? Hope you have a sharp paint scraper....this is labor intensive.


The entire instrument had minor cracks but nothing like the soundboard. Yes, it was a new batch of lacquer though I have been using Sherwin Williams B44CT6 for years with no problem. Now I am really worried since three other instruments were finished with that same batch. I checked the finish depth and it is a bit thicker than usual so that may have been a contributing factor but it is no thicker than dozens of others that I have built over the years.
Think that I will attempt to reset the finish by spraying with thinner and if that fails (probably will) will sand off to bare wood and start over. WHEE

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## J Caldwell

Lefty,

Try Behlen's Qualarenew. You can probably get it at Woodcraft, at least the one in Austin has it. It works on nitro and most solvent based finishes. I've used it successfully in a situation similar to this, but not as severe. I'm always leary of shipping nitro finishes this time of year for just this reason.

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## Rick Turner

Yep, Qualarenu.

Also, Sherwin Williams is notorious for changing formulas without informing their customers.  Happened to Stu Mossman 35 years ago with lacquer.  Happened to me 30  years ago with Polane.  I don't trust them.

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## Big Joe

We normally use McFadden and it is available directly through the company, or for an even better price, try Grizzly.  It will allow great coverage without being applied very heavy and it is a great lacquer for instruments.  We really don't like the Sherwin Williams.  It seems to be a bit more problematic and applies too thick and does not respond as well.  Any lacquer can check, but some are more problematic than others.  Still, rapid temperature changes can cause just about any finish to crack.  I've seen it with poly, nitro, and varnish.  It is just a part of life.  I try to instruct that when the temperature is an extreme...in either way...to let the package acclimate to the temperature of the environment overnight before opening the package.  Sometimes people listen, sometimes they don't.

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## Spruce

> Yes, it was a new batch of lacquer though I have been using Sherwin Williams B44CT6 for years with no problem.



Thanks for the tip on a great checking lacquer...
I'm having problems finding a lacquer that will check that nicely...

I'm _really_ sorry it had to come at your expense, though...   :Frown: 

Here's some Watco checking:

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## Paul Hostetter

> We normally use McFadden and it is available directly through the company...


If I'm not mistaken, Lawrence-McFadden bellied up last summer.

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## Dale Ludewig

That's what I thought also.  I still have a couple gallons, but then I thought it was over.  On the other hand, I can't imagine that some company isn't going to buy either the company or at least the formulas.  I'd hope so.

Spruce- I didn't realize Watco would craze.  I'm only familiar with their Danish oil products.  What is that?

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## Paul Hostetter

Wait a minute...




> It is colder at 30,000 feet than on the ground. The cargo hold of an airplane is not heated, either.


I just thought about this again: if holds in planes aren't heated, there would be a lot of stiff little corpses in little cat and dog carriers coming out of there. Of course they're heated.




> He remembered the next morning and went out to bring it in. Unfortunately he immediately opened the case in his warm bedroom to see if it was OK. If I recall the story right he claims it more of less cracked right before his eyes or at least over a short time frame.


I've seen this myself, and know the phenomenon is fairly common. Live and learn. 

Thanks, Bruce, for posting the gorgeous lacquer checking shots. Don't you use Watco to bring the checks out? They remind me of some of the raku ceramics my wife and I have done, where the burning organic matter does the same thing.

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## Spruce

> Spruce- I didn't realize Watco would craze.  I'm only familiar with their Danish oil products.  What is that?


What is what??   :Wink: 

Watco out of a spray can ('cause I heard the rattlecan stuff would check like crazy) on an Esquire I put together, and the same stuff on a Les Paul Historic refin....

Apply severe cold/heat/cold, and _bingo_...

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## Paul Hostetter

Ahhh, OK.

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## Rick Turner

McFadden seems to have survived.  There were rumors of involvement from Taylor and Fender maybe on the level of long term purchase orders that allowed financing for restructuring the company.  You can still get instrument finish products from McFadden, and I can't imagine that their casket finishes have seen a downturn...furniture, surely, but I think as many people as ever are waking up dead these days.

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## John Arnold

> Just regard the sheer mass of wood vs. lacquer.


That also is an argument for the lacquer moving more than the wood. More mass equates to slower changes in temperature. Wood has much less thermal expansion than plastic or metal. Look it up.



> Think that I will attempt to reset the finish by spraying with thinner


Straight lacquer thinner will evaporate before it amalgamates the finish, especially one that thick. You need to use retarder, or at least a mixture of retarder and thinner. Straight retarder will run like water, so spray very light coats until the finish softens a bit....then you can spray it on a bit heavier. After spraying, it will take a long time (+/- a month) for the finish to harden, since the solvent evaporates slowly, and the whole thickness of the finish will be affected.

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## Lefty Luthier

> That also is an argument for the lacquer moving more than the wood. More mass equates to slower changes in temperature. Wood has much less thermal expansion than plastic or metal. Look it up.
> 
> Straight lacquer thinner will evaporate before it amalgamates the finish, especially one that thick. You need to use retarder, or at least a mixture of retarder and thinner. Straight retarder will run like water, so spray very light coats until the finish softens a bit....then you can spray it on a bit heavier. After spraying, it will take a long time (+/- a month) for the finish to harden, since the solvent evaporates slowly, and the whole thickness of the finish will be affected.


Thanks for the info on using retarder, I have no experience with it since I generally use French Polish and only use lacquer when the customer insists.

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## Dale Ludewig

Well, that's interesting (the spray can).  I've never seen such.  But then I'm in the Midwest.  Maybe they only market that stuff on the west coast..........

I also didn't know that McFadden made casket finishes.  Are they catalyzed?  Sorry, I couldn't help myself.  Must be the season.  (Don't finish that phrase please)

I've wondered, on a slightly more serious note, if finish crazing has anything to do with the wood or other material under the finish.  Is it caused by the change in warming between the two substances or is it just that the finish can't take it, all by itself?  I don't have the time, but what if you sprayed or applied a finish onto something and then peeled it off so it was all by itself.  Now get it real cold and then bring it into a much warmer area fast and see what happens.  I can't help but think that it would craze.  Just thinking out loud..

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## Lefty Luthier

> Well, that's interesting (the spray can).  I've never seen such.  But then I'm in the Midwest.  Maybe they only market that stuff on the west coast..........
> 
> I also didn't know that McFadden made casket finishes.  Are they catalyzed?  Sorry, I couldn't help myself.  Must be the season.  (Don't finish that phrase please)
> 
> I've wondered, on a slightly more serious note, if finish crazing has anything to do with the wood or other material under it.  Is it caused by the change in warming between the two substances or is it just that the finish can't take it, all by itself?  I don't have the time, but what if you sprayed or applied a finish onto something and then peeled it off so it was all by itself.  Now get it real cold and then bring it into a much warmer area fast and see what happens.  I can't help but think that it would craze.  Just thinking out loud..


The mandolin that started this thread has a 28 ring per inch Alaskan Yellow Cedar soundboard. I built 5 soundboards from the same board and none others have this problem, so far. Two have French Polish and 3 lacquer from the suspect can. I seriously doubt that the wood is at fault, it had less than 5% moisture and very close even grain.

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## John Arnold

> Is it caused by the change in warming between the two substances or is it just that the finish can't take it, all by itself? I don't have the time, but what if you sprayed or applied a finish onto something and then peeled it off so it was all by itself. Now get it real cold and then bring it into a much warmer area fast and see what happens. I can't help but think that it would craze.


In your example, there is no force to make the lacquer craze. You must have differential expansion, either by attaching it to a material with a different expansion rate, or by a temperature gradient. The lacquer itself is so thin that there is little likelihood of a temperature gradient.

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## Dale Ludewig

How fast did it happen- the crazing?  5% is pretty dry but the crazing seems to have nothing to do with the grain direction and we all hopefully know that wood expands across the grain and virtually no movement in the other direction.  It looks from what I can see that the checking is all perpendicular to the grain.  Interesting.  I've seen the likes of what Spruce posted where it's like little patio stones.  I've even read somewhere that you can tell what finish, varnish vs. lacquer, it is based upon the checking pattern.

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## Dale Ludewig

John, good point.

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## barry k

If the lacquer used is defective in its chemical composition, would spraying with thinner, retarder or the combination of both really fix the problem? I say If you could close up the cracks, it would just crack again.  I had this same exact problem about 15 years ago , only solution for  us was to scrape and refinish. Its a shame, but unfortunatly this happens on occasion. Im not sold on the temp change senario, I used to live in the northeast, toted my mandolins, guitars from gig to gig, from an icy cold trunk to a overly heated honkytonk, then vise versa, leave them in the trunk for 2,3 4 days then repeat, never a lacquer crack to be found.

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## Rick Turner

Spraying straight lacquer thinner will not work.  You either need to use Qualarenu from Behlen or Butyl Cellusolve from US Cellulose which is now Azko-Nobel Chemical or some such.

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## Joe Mendel

On the first electric guitar I built, the sanding sealer was not compatible with the lacquer we were using, at least that's the conclusion we came to. While I was spraying the lacquer, the sanding sealer underneath crazed as I watched helplessly. Since it was for me anyway, after I got over the shock, I have to say it looks pretty cool. I never have done anything about it.
 I don't remember what products we were using.

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## Big Joe

I just got 3 gallons of McFadden today.  I ordered it through Grizzly.  I think they filed a chapter 11 for reorganization.  In any case, their lacquer is still available.  YEAAAHHH!

Spruce....beautiful checking.

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## MikeEdgerton

> If the lacquer used is defective in its chemical composition, would spraying with thinner, retarder or the combination of both really fix the problem? I say If you could close up the cracks, it would just crack again.  I had this same exact problem about 15 years ago , only solution for  us was to scrape and refinish. Its a shame, but unfortunatly this happens on occasion. Im not sold on the temp change senario, I used to live in the northeast, toted my mandolins, guitars from gig to gig, from an icy cold trunk to a overly heated honkytonk, then vise versa, leave them in the trunk for 2,3 4 days then repeat, never a lacquer crack to be found.


In my case it was the only explanation. It sat in a trunk on an 18 degree night, then moved inside and the case wasn't opened for days. I guess it could have been from getting cold after having been at room temperature or the other way around but it definitely happened in that time period. It was fine in the months leading up to it.

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## Gail Hester

> Here's some Watco checking:


Bruce, that looks so "right" you should stick with the Watco.

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## John Arnold

> we all hopefully know that wood expands across the grain and virtually no movement in the other direction.


You are describing the expansion/contraction due to changes in moisture content, not temperature. Thermal expansion of wood is so small that it rarely enters into the discussion.
That said, extremely high moisture content can swell the wood and cause lacquer crazing, but that is a different issue. In that case, the lacquer usually flakes off the wood.



> If the lacquer used is defective in its chemical composition, would spraying with thinner, retarder or the combination of both really fix the problem?


Maybe, maybe not. The only way to know for sure is to test it. In this particular case, the only example that crazed was exposed to low temperatures. That is an encouraging sign that amalgamation may work.



> I'm not sold on the temp change scenario, I used to live in the northeast, toted my mandolins, guitars from gig to gig, from an icy cold trunk to a overly heated honkytonk, then vise versa, leave them in the trunk for 2,3 4 days then repeat, never a lacquer crack to be found.


There is a lot of luck involved. The particular lacquer formula, the thickness of the film, and the type of sealer are all factors. And not all instruments are finished with lacquer.



> Spraying straight lacquer thinner will not work. You either need to use Qualarenu from Behlen or Butyl Cellusolve from US Cellulose which is now Azko-Nobel Chemical or some such.


I have had good success with lacquer retarder. Butyl Cellosolve is extremely toxic.

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## Spruce

You seem to be extremely knowledgeable on the subject of lacquer...thanks!

With that in mind, might you have some hints for how you would go about _intentionally_ checking lacquer or varnish??

The age of the finish seems to come into play (years in some cases), but as our OP found out, that may not always be the case...

Any thoughts on this would be greatly appreciated...

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## barry k

Spruce, you were probably asking John , but If I may,   Behlen sells a nitro-lacquer designed to crack. The more you spray on, the more it cracks. Also I have heard that a  coat of hide glue or egg white underneath the finish will crack it also.........I havent tried this yet.

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## Spruce

> Spruce, you were probably asking John , but If I may,   Behlen sells a nitro-lacquer designed to crack. The more you spray on, the more it cracks. .


I've got some of that here, but haven't tried it yet because I think the effect it produces is not what I have in mind--a natural-looking finish check.

Hell, I bought it, so I might as well fool around with it a little bit...

Lefty Luthier's checking problem is actually something I would _love_ to replicate on a Les Paul build...

Here's a real '52:

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## Andy Miller

Frank Ford has an article related to this on his site:

http://www.frets.com/FRETSPages/Luth...lgamator1.html

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## Michael Lewis

So much to learn.  That LP has checks in the direction I would expect is perpendicular to the wood grain.  This, to me, is counter intuitive.  Finish checks usually happen from stress (across grain as wood swells/shrinks).

Put acetone in your lacquer and it will check.  Also, compressed air sprayed on the finish can cause it to check.  Air in a spray can used for dusting off electronic parts can freeze your skin.  CO2 cartridges freeze when punctured and allowed to vent.   Valve stems on tires can freeze in the summer time when the core is removed and the air escapes.  Lots of possibilities. :Wink:

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## Jim Hilburn

Maybe it's string tension that caused that LP cracking.

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## jlsmandolin1952

Lefty,
        I had the same thing occur on just  (1) of my solid bodies using the same batch of lacquer from (Sherwin Williams) which I'm not crazy about. I never did find the reason behind it? I checked with a couple other builders, and they assumed that it was thermal change? The whole Instrument checked severly, like your pics. It sure adds some worry about future finishes! I know about acclamation, and this thread is a very good reminder for me, to let my customers know. One thing that i don't know, is did I spell acclamation right?
          If you strip it, and refinish, you might want to try some Formby's Furniture Refinisher? I used to use it when restoring Violins, and it works out quite well. removes the finish, and doesn't harm the wood. You can get it at most hardware/paint stores.
                              Good Luck,
                                            John
www.jlsmithmandolins.com

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## Rick Turner

That Les Paul crack pattern is totally typical.  All the old ones do that.  What's unusual is that the gold hasn't gone all green from the brass or bronze powder in the color coat tarnishing.  It will with more time...   It could be that they don't craze so much vertically because the wood shrinks as it ages and dries out more, and it shrinks across the grain, not length-wise.  In that case, the wood could be shrinking at about the same rate across the grain as the lacquer, but the lacquer is shrinking in two dimensions while the wood surface is only going in one dimension.  I'm ignoring the thickness of the wood here.   They do it on the back as well.  The tops on those early gold ones are maple and the backs are mahogany.

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## Spruce

> That Les Paul crack pattern is totally typical.  All the old ones do that.  What's unusual is that the gold hasn't gone all green from the brass or bronze powder in the color coat tarnishing.  It will with more time...


Yep...
Finally figured out how to do _that_ one...    :Wink: 



The more I look at Lefty's problem-lacquer, the more it looks like that batch of Sherwin-Williams would be _perfect_ for a Les Paul build I'm planning...

Long, side-to-side checking....

So-ooo, let me know if you want to sell a can of that stuff Lefty Luthier...   :Wink:

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## Rick Turner

Try sending those Les Pauls back to Gibson for warranty work on the finishes...

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## Spruce

I already did that, Rick...

They cracked in the UPS cargo hold coming back home, me thinks...

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## Dale Ludewig

So today I looked at a mando that I built in 1978.  It's black lacquer with clear coat over the top.  Sorry, but I don't have a picture handy.  It's checked.  I can almost remember when it happened.  But- it's structurally sound and checked.  And its checking is along the grain lines, with few exceptions.  And it never went anywhere via UPS.  Hmm.  Much to learn.

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## Michael Lewis

Bruce, those pics are some kind of guitar porn.  I'm not supposed to like things like that! :Laughing:

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## liestman

Has anyone here used Behlen's Qualarenu to fix a crazed lacquer finish? If so, do you just wipe it on and it is done or do you need to repolish the surface then or ? I have an old crazed guitar that could benefit from this maybe, but I do not want to ruin the finish as an experiment!

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## oldwave maker

Thanks for the cool pics Bruce. Sprayed sherwin williams on a mandolitter in the mid 90's, took them to the mid-winter festival in denver, got trapped in a blizzard near the top of Raton pass on I-25 for most of the day with that  freshly buffed, heavily lacquered litter in the back of my pickup under an uninsulated camper shell, when I arrived at the hotel in the evening to set up the booth, every time I opened a case it sounded like somebody was shooting bbs. Random, but mostly parallel to the grain,  cracking. 
Tried to repair with qualarenu, might have worked better on a much thinner finish. Whoever has David Long's old  f5, thats one of them. 
Fender might have used the same cheap, thick lacquer trick on the early 80's fullerton 57 pbass reissues, will try to post the checking on mine later.
moral of the story-NEVER LEAVE YOUR MANDO WHERE YOUR PET WOULD BE UNCOMFORTABLE!

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## Spruce

> NEVER LEAVE YOUR MANDO WHERE YOUR PET WOULD BE UNCOMFORTABLE!


Unless you're _trying_ to kill your dog or crack your instrument's lacquer...
125 degrees does the trick:







> Bruce, those pics are some kind of guitar porn.  I'm not supposed to like things like that!


I _love_ old lacquer/varnish shots...

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