nitrocellulose laquer soft (ruined) - how to re-cure?

[rml]

hey everyone

 

i bought an ES-325 a while ago. the previous owner did not take good care of it.

 

it was left in its case for a long time in a damp room. possibly in a wet basement.

 

when i got it the case stank of mould and there was mould inside the guitar.

 

the neck was smudging all up and down the neck when i played it. i used gibson restorative finishing cream for nitrocellulose finishes to get off what seemed like years of grime.

 

it played fine for a while, but then it started smudging again. i used the cream again, and it got it off again. and it keeps happening.

 

every time i play it now, the laquer dissolves into smudges which makes the neck really sticky to play and i have to use the cream to get them off.

 

i think years of being in a damp case has permanently damaged the finish on the neck. the strange thing is the body finish is fine, in fact the body has some slight aged nitrocellulose cracking on it.

 

the neck does not pass the fingernail check. i can easily dent it with my fingernail with hardly any pressure. the body laquer cant be dented with a fingernail at all.

 

is there any way i can get the nitrocellulose to re-cure? or get harder? or is it destined to just wear off and require a re-laquer?

 

cheers, rob.

[L5Larry]

Sounds to me like a reoccurring chemical reaction affecting the neck finish, from either the restoration product your using, or something leaching out of the case, or a combination of both.

 

I know of nothing that "permanently" softens a nitro finish, any chemical that effects the finish should eventually evaporate away. Before doing anything drastic, I would leave the guitar out of, AND away, from the case, and cease any "restorative" chemical applications for extended period of time, maybe a couple of weeks (or longer).

 

If the finish hardens up I would dump the case AND find a new buffing product.

[bigsby'd]

Use naptha. This is the only thing (besides, um, spit) that I ever use to clean guitars. You're going to have to use it again and again. UV exposure will also harden the finish (ie sunlight), but that will be useless until the guitar is truly clean. Naptha and a LOT of elbow grease are your friends here, and pretty much the only fool-proof solution.

[strat-o-steve]

I have a very old acoustic guitar that is doing the same thing, and have also seen the finish get "soft" on old furniture. My experience is that once a finish has gotten to a state where it does not remain hard, there is nothing that will make it normal again. Sorry to hear this has happened! Just keep it clean, before and after playing, or have the guitar finish removed to bare wood and refinish. Keep in mind that I have never had good luck fixing this issue, but maybe someone else has had success with resolving this. You may just decide to live with it if it is not too bad.

[Raptor]

Usually nitro will cure with time in the open air. It sounds as someone has already said that there is a chemical on the neck that is keeping the nitro soft. Water or mold shouldn't do that, at least it should dry out again. I don't know if you have a place and a way that you can leave the guitar out in the air without anything pressing on the neck finish, maybe face down on something. I would try cleaning the neck thoroughly, try using the naptha and if possible leave the guitar out in the open to let it dry. The problem is nitro can take several weeks to cure, especially if it is in a damp or humid location. If you can leave it out the way I suggest, try that and leave it for a couple of weeks then test the finish. If it is still soft wipe it off again where you tested it and leave it for another week or two and see if it even starts to harden again. If it won't harden, the only real options I can see would be to either remove the finish off the neck and go either bare or with an oil finish, or have the neck resprayed. Apart from taking it to a luthier and asking them what they might suggest, that is all that comes to mind for me. I would also buy another case for it in case there is something still in the lining that if affecting the finish.

If you decide to respray the neck, you will have to at least remove the clear coat. You could probably do it yourself if you are not too picky about the results. You might still be able to get spray cans of nitro clear from Stew-Mac and carefully do it yourself if it is too expensive to have a luthier do it. Let us know how you make out with it. I hope you get it fixed.

Cheers

[neilpanda]

TO THE LUTHIER! I think

[zigzag]

Nitrocellulose is a hard, fast drying resin that has very limited solubility in most solvents. It is resistant to most soaps and has some solubility in alcohol and glycol ethers (water soluble solvents) found in glass cleaners and Formula 409. It is insoluble in aliphatic and aromatic hydrocarbon solvents like those found in lighter fluid (naphtha) and gasoline. NC is very soluble in esters (acetates) and ketones that are most readily found in fingernail polish and polish remover.

 

By itself, nitrocellulose is somewhat brittle and has poor impact resistance, which means that NC coated wood can be easily dented. It does not form a good coalesced film when it dries. That is why it allows wood to breath (allowing air, humidity, and liquids to pass thru it). Nitrocelluose can be formulated with materials that will help it form a better film and give it more elasticity. It also can be dissolved with slow evaporating solvents which, if sprayed, are required to keep spray nozzles from plugging and to prevent the coating from drying from the top down (trapping solvent), and they must be driven off before the lacquer is fully "cured."

 

It seems that it would be very useful if Gibson would give players a better idea of how their nitocellulose lacquers are formulated or at least give us a better idea of how to care for our guitars. I can tell you for sure that many polishes are not effective on nitrocellulose lacquers because they can just sit on the top and get "boogery" and soft. Restorative cream sounds to me that it does not in any way dissolve the NC lacquer, but most likely is used to help emulsify and carry off the grime that gets into the coating. Again, if there is a residue from the cream, it should be buffed out as well as possible or it could, itself, be the cause of the smudging.

[Versatile]

Nitrocellulose is a hard, fast drying resin that has very limited solubility in most solvents. It is resistant to most soaps and has very limited solubility in alcohol and glycol ethers found in glass cleaners and Formula 409. It is insoluble in aliphatic and aromatic hydrocarbon solvents like those found in lighter fluid (naphtha) and gasoline. NC is very soluble in esters (acetates) and ketones that are most readily found in fingernail polish and polish remover.

 

By itself, nitrocellulose is somewhat brittle and has poor impact resistance, which means that NC coated wood can be easily dented. It does not form a good coalesced film when it dries. That is why it allows wood to breath (allowing air, humidity, and liquids to pass thru it). Nitrocelluose can be formulated with materials that will help it form a better film and give it more elasticity. It also can be dissolved with slow evaporating solvents which, if sprayed, are required to keep spray nozzles from plugging and must be driven off before the lacquer is fully "cured."

 

It seems that it would be very useful if Gibson would give players a better idea of how their nitocellulose lacquers are formulated so that we would have a better idea of how to care for our guitars. I can tell you for sure that many polishes are not effective on nitrocellulose lacquers because they can just sit on the top and get "boogery" and soft.

 

Restorative cream sounds to me that it does not in any way dissolve the NC lacquer, but most likely is used to help emulsify and carry off the grime that gets into the coating. Again, if there is a residue from the cream, it should be buffed out as well as possible or it could, itself, be the cause of the smudging.

 

Excellent post...shows detailed knowledge of the various solvents occuring in varnishes and cleaners etc

I think of nitrocellulose as a 'step up' from the shellac finishes pre 20th century

Sometimes wondering whether a shellac finish would suit a guitar in the same way it suits violins/cellos/basses

 

BTW shellac is alcohol soluble and an unsynthesised product from nature

 

V.....(4 Varnish)

[sok66]

Good feedback. FWIW, back in the early 90s I got a very nice '68 ES345 from Mandolin Bros. It was all original and from what I could tell had never been disassembled or otherwise fooled with. The finish was extremely soft as you describe, with a sticky residue that lifted on the neck & body. I cleaned it with naptha thoroughly a number of time but couldn't get the stuff to stop leaching out of the finish. I finally disassembled it and used a mild Meguiars professional automotive clear coat restoration product on it, hand applied rather than by machine polish. That did the job. I've still never determined exactly what the stuff was but have a feeling it was a combination of a silcone based funiture polish, combined with being in the case and never getting aired out. It was a righteous, gooey mess, but the guitar cleaned up perfectly after a lot of work. Worst was removing all the electronics..NEVER again on a 345 or 355!

[CR9]

It sounds like the finish has been polished with silicone in the past. Silicone will damage a nitro finish and with this one being in damp conditions the silicone may have penetrated the finish and gotten into the wood. Even a refinish may not completely help if there is too much silicone in the wood but some of the previous advice is good. The chemical is leaching from the wood back out to the top surface of the finish. Do not use the case. Clean with Naptha (available at a local hardware store). Store in the open air and exposure to sun light may help. I have had an older guitar with a similar problem that I cleaned and got back to normal after some work. I don't think the silicone had gotten into the wood on the one I had. I cleaned the neck several times with naptha and them used Meguire's #2 Fine Cut Cleaner several times and then again with naptha. After that I used Preservation Polish on it. #2 Fine Cut Cleaner is a mild abrasive (available at some local auto parts stores) and should be used with caution as it removes some of the finish and great for polishing out fine scratches. Meguire's Scratch-X also works but seems more abrasive to me but is easier to find. Back in the late 60's and early 70's a lot of dealers told us the the guitars were finished in "automotive finishes" and some would say to use a "car polish" on the guitar. Well this may be fine as long as there is no silicone in it. Clean that thing with naptha every few days and keep it out of the case for a long time and see what happens. Good luck and keep us posted on the progress.

[bobouz]

A few years back (early 2000's?), Martin's guitar polish was apparently being produced by a new manufacturer, and it was discovered to contain silicone. Bad stuff, indeed! The problem was eventually corrected. A person might reasonably assume Martin polish to be safe, so it always pays to know what you're putting on a nitro finish.

[rml]

hey guys

 

thanks for the awesome replies to my thread. i really appreciate it.

 

i stopped using the case as soon as it arrived. i kept the guitar out in the open with it turned around in the stand facing the sun through the window every day. every time it got sticky i cleaned it. and after a while it stopped. then it started again.

 

i was reading through the replies to this thread- many of which said "dont use the case" and i remembered that i did put it back in the case, and hid it in the cupboard for 2 weeks when i went on holiday- at the time i didnt put two and two together as it was not an immediate thing.

 

i dont know if it will ever stop. but im pretty sure the case is making it worse. it will never go back in the case again. which is a shame as it's the guitars original '72 lufton gibson stamped case.

 

i have seen pics of peoples '72 es-325 on the web with the varnish and "walnut" colour rubbed off in certain positions where the player plays a lot. ie, at the 5th for minor pentatonic blues leads in A. especially around the thumb, but underneath also. mine has some of this- so im wondering if its just bad laquer that was used on them in '72.

 

im still using the restoration cream, but not as much as when i posted a week ago- hopefully the laquer disintegration will slow right down again and the laquer starts to harden up.

 

thanks again for all of your replies

 

and have a happy new year

 

cheers, rob