Over spray - should I ?

Pukulele Pete

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I have a 60's Martin style O and have been thinking of doing an over spray. It has a few surface cracks that I would like to consolidate and then do an overspray. I've heard that an over spray is routine when a Martin guitar goes to the factory for a repair. I think I am capable of doing this but wonder if I should just leave it alone. The cracks are just in the lacquer, looks like maybe it was dropped on the lower bout. There are maybe 9 surface cracks 1/8 inch away from each other in the shape of the lower curve. This is my favorite uke at the moment and it would be pefect except for those surface cracks. Would I be commiting a sin if I do this? The cracks are on the back.
 
In some circles it's called patina and a sought after characteristic.
Not sure spraying over the cracks would completely hide them while it may help hold the 'skin' together to prevent further age checking.
My vote (may not be worth much) would be to wear the wrinkles proudly.
Be advised that as we got older my wife agrees on this less and less.
 
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my vintage Gibson has finish checking [cracking] all over the place. I think it just adds mojo, and have been told it would diminish the price if "fixed' I'm not a luthier, but I'd say leave it alone, it's perfect as it is.
 
My vote is to leave it alone. That Martin has worked long and hard for those wrinkles.. Same with Botox.. Just say "No"...
 
Leave it alone and stop thinking about the finish cracks. Or, sell it and get one without cracks.
 
You guys are right. I won't touch it. I thought I had decided that a while ago but I was playing it and then looking at it and focused on the cracks and said,.........Jeez,I wish those cracks werent there.
 
You guys are right. I won't touch it. I thought I had decided that a while ago but I was playing it and then looking at it and focused on the cracks and said,.........Jeez,I wish those cracks werent there.

There you go! The trauma occurred when you stopped playing the ukulele and started looking at it instead. My 60's Martin O has a few of those "issues" as well. When I am playing it, they magically disappear.
 
Overspraying rarely knits lacquer checks back together. All you do is put a temporary film over the crackled lacquer...and your new film will fairly quickly crack, too.

Look into Behlen's "Qualarenu", known here and by finish specialist Addam Stark as "the magic sauce". It can replasticize and knit together a good 90% of nitro lacquer checks. It's amazing stuff. I brush in onto and into checks with a tiny brush, and the fissures disappear before my eyes. In the best situations, you can deal with the crackling and dings and then just re-rub out the existing finish. Otherwise, do the cracks, then spray a very thin coat of Qalarenu over the whole instrument (except bridge and fingerboard) and then overspray. The Qualarenu will soften the existing old finish just enough to help the new lacquer bond better.

The nice thing is that you can do the first step and just see how good it works, and then decide whether to overspray or not. You can also do the Qualarenu thing and then French polish.
 
Overspraying rarely knits lacquer checks back together. All you do is put a temporary film over the crackled lacquer...and your new film will fairly quickly crack, too.

Look into Behlen's "Qualarenu", known here and by finish specialist Addam Stark as "the magic sauce". It can replasticize and knit together a good 90% of nitro lacquer checks. It's amazing stuff. I brush in onto and into checks with a tiny brush, and the fissures disappear before my eyes. In the best situations, you can deal with the crackling and dings and then just re-rub out the existing finish. Otherwise, do the cracks, then spray a very thin coat of Qalarenu over the whole instrument (except bridge and fingerboard) and then overspray. The Qualarenu will soften the existing old finish just enough to help the new lacquer bond better.

The nice thing is that you can do the first step and just see how good it works, and then decide whether to overspray or not. You can also do the Qualarenu thing and then French polish.

While reading through this thread, I was about to suggest this when I came to Rick's post. For a good while I was one of the only reps for both Behlen & Mohawk Finishing. They had recently merged when I went to work for them.

Nothing much to add to Rick's comments except that Pete, you really should do this. Cracks may look "vintage" at the moment, but in time they'll become flakes, then they'll be gone and an instrument without a proper finish is an instrument in jeopardy.

Behlen's Qualarenu is now the same formula as Mohawk's Ammalgamator. You can get whichever is most convenient. If you're using a lacquer overcoat, seal your crack repairs with shellac or even better, a shellac based sealer after the ammalgamating process Rick described.

You wouldn't let other parts of your Martin go bad. This "let your instrument's finish deteriorate" nonsense is an insult to a fine creation.

Pete: this is restoration - much different than refinishing. In America, the "shabby chic" has ruined the restoration business. I didn't think it had happened in Europe as well.
 
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Here's the basic thing about nitro lacquer...

It is NOT a forever finish. By it's very nature and makeup, it starts to decompose the day you spray it. The DuPont chemists figure nitro is good for about 75 years, and anything beyond that is borrowed time. Eventually, all nitro finishes will need to be restored or replaced. We are just now entering that critical post 75 year mark for nitro on instruments. That started in the late 1920s. French polished Martins from the 1880s look a whole lot better than late 20s lacquer jobs, and that beloved checked finish look is, as indicated by Mr. South Coast, just a "cool" look on the way to chunks of finish simply falling off. It's already happening on a lot of vintage Gibsons, for instance.

Nitro is a temporary finish that needs to either be refreshed or replaced eventually. By temporary I mean 75 to 100 years. Varnish and shellac are much better in the long haul. We don't yet know about the latest catalyzed finishes, but they do well in accelerated aging tests.

If I had to go back to "hand finishing", I'd do epoxy sealers, shellac, and then Epiphanes varnish top coats.
 
My first plan was to consolidate the cracks with a little acetone. Next I was going to wipe it down with naptha and then a light sanding with fine steel wool then another naptha wipe down. Then I would spray the body ( the neck is fine ) with lacquer. I thought the acetone would melt the cracks back together. I asked about doing the overspray before on this and another forum ( four string farmhouse ) and until now everyone has freaked out and told me not to do it ,I would ruin the value of the uke. I'm thinking I can do this and only an expert would be able tell if it had an overspray.
I've heard that Martin does this routinely to their guitars , why can't I do it. Thanks for the encouragement and the info. I'd hate to see all the vintage ukes turn to dust , at least this one won't. I'm looking at this as routine maintainance.
 
Don't use acetone, use Qualarenu; it's not as aggressive as acetone, and it seems to seep into tinier cracks. It also adds plasticizers, so it doesn't just flash off. Not sure what the naptha will do; probably can't hurt, but I wouldn't use it.
 
Thanks for the excellant advice.I will use Quarenu . My original plan came from advice at Frets.com . The naptha was to remove old wax or polishes and generally clean the surfaces to be oversprayed. What should I use ? I've done this before on a 30's Style 1 Martin I bought for 66 bucks a few years ago. It still looks good and sounds great. I've been going back and forth on this project for quite a while, whether to do it or not. Can't let these old ukes keep aging like this or they won't be around another 80 years .
 
Naptha is a good 1st step - a cleaner/prep. Then your Qualarenu or Amalgamator. Then a coat of french polish or spray a coat of Zinsser sealer. This shellac based sealer has a little nitro resin to promote a better bond on subsequent coats.

Then laquer sanding sealer, also for good bond, scuff, then your laquer topcoat.
 
Well, I didn't know much of this when I replied earlier! I guess it's good we have some pros who know what they are talking about on this forum. I am now reconsidering the finishes on my ukes. Most of all, I love to play mine, so the idea that the finish is a little messy has not been much of a concern. However, the idea that I will eventually have no finish left to protect my ukes IS a big concern. I am aware of what folks say about overspraying and refinishing adversely impacting the value, but given what Rick and Dick write, all of our ukuleles will be in the same boat eventually. Besides, I'm probably depreciating my ukes every time I play them.

One thing that Rick wrote is borne out with a couple of mine. I have an early 20s ukulele that was most likely French polished with shellac, and a late 20s one that was probably nitro'd. The finish on the earlier one is fine. The finish on the later one is beginning to deteriorate.

So, now I have another question. If I understand correctly, a couple of end methods have been proposed to address the problem. One involves overspraying, presumably with nitro, and the other french polish with shellac. Is one preferred over the other, or are there factors to consider in making this determination?

It isn't something I would try on my own, but should I have the opportunity to discuss it with an experienced luthier, I'd like to have more info in my pocket. Thanks for the advice.

Pete, I would certainly appreciate it if you would let us know how you go about working on your Martin, and how you like the results. Thanks for asking this question.
 
I think I may just go to my local Luthier and let him do it. My spray booth is my wife's garden shed and with all the different surface preps I think maybe I should let a pro handle it. As far as leaving it alone like alot of people say you should , don't let these great old ukes and guitars keep deteriorating , You have to stop the wear and tear at some point or they won't be around years from now. Just like an old house you have to maintain them or they become useless. Visit your local Luthier. Keep these old instruments in good shape so they will be around for years to come.
 
So, now I have another question. If I understand correctly, a couple of end methods have been proposed to address the problem. One involves overspraying, presumably with nitro, and the other french polish with shellac. Is one preferred over the other, or are there factors to consider in making this determination?

The method Rick spoke of, and I outlined above, pretty much repairs the crazing, but don't worry if it doen't all come out. It's an old instrument, and saving and prtecting the original finish is the most important aspect of a restoration - not a totally new appearance. The most important thing about Qualarenu are those plasticizers - they stop the crazing from continiung - in other words, they stop the breakdown of the original finish. Without that, the finish would continue to deteriorate below whatever you used for a topcoat, so the important part of any procedure on nitro (or an oil varnish) is the Ammalgamator or Qualarenu.

I would favor the method, I outlined above for Pete's instrument, since that is more of a ture restoration. The intermediate thin shellac & seal coats are only acting as binders for the repaired original base. Your then topcoat with nitro, which was also original to Pete's Martin.

If you were restoring a french polished finish, the preference would be to finish it off that way. The Ammalgamating is not as important with shellac - the resins don't break down like nitro - so sometimes just a cleaning, light sand, then polish over. If you see some cracking, Ammalgamate between the cleaning and polish.
 
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The method Rick spoke of, and I outlined above, pretty much repairs the crazing, but don't worry if it doen't all come out. It's an old instrument, and saving the original finish is more important in a restoration than a totally new appearance. The most important thing about Qualarenu are those plasticizers - they stop the crazing from continiung. That would happen with whatever you used for a topcoat, so the important part of any procedure, especially on nitro, is the Ammalgamator or Qualarenu.

I would favor the method, I outlined above for Pete's instrument, since that is more of a ture restoration. The intemediate thin shellac & seal coats are only acting as binders for the repaired original base. Your then topcoat with nitro, which was also original to Pete's Martin.

If you were restoring a french polished finish, the preference would be to finish it off that way. Simply french polish it out after the Ammalgamating process.


Thanks Dirk:

My 60s style O has very little crazing. The one I'm concerned about is a 3M from late 1920s. The finish isn't crazed, but there are a few spots where it has been abraded (on the lower bout where one's arm holds the ukulele) and also on the other side of the lower bout there are a few small spots where it is mottled in appearance, patches where the gloss is not glossy. There is also some strum wear on both sides of the upper bout. The finish is extraordinarily thin on this one, much thinner than on my 60s Martin. I'm wondering whether it is nitro at all. I understand that Martin didn't use nitro on the bound ukes until the 1930s.
 
I just reviewed an earlier post to which Rick had responded. I think what I have to do is have it cleaned and French Polished. In fact, I think I understand a lot better now about finishes. I also know enough not to mess with it myself.
 
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