# Nitro Lacquer Shelf Life?



## JMC Amps (Dec 19, 2009)

Hello Luthiers,

I haven't sprayed a body/neck with the nitocelulose laquer/sealer on my shelf since 2 1/2 years ago. Is this stuff still usable?

-JMc


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## shoretyus (Jan 6, 2007)

I use precatalized that has a shelf life printed on the can. It's probably ok. Try some on something.


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## ajcoholic (Feb 5, 2006)

Yes it will be fine.

I have regular nitrocellulose lacquer that is much older than that, that still is fine. When lacquer goes "bad", it gets orange coloured and thick. I have used lacquer many years old (maybe 5 or 6?) and it was fine. I guess it also depends upon the maker, storage conditions and so forth.

Precatalyzed lacquer is different, it can definitely change properties when it exceeds the "best before date".

Post cat (two part) laquer is also dated, but is good for much longer.

AJC


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## JMC Amps (Dec 19, 2009)

Hi Guys,

What I have is Chemcraft Opticlear 900 Pre-cat Gloss Black and Chemseal Sanding Sealer.

I finally found the data sheet and it says "three month shelf life, un-opened" 

I guess I'll have to try it out and see!

Thanks guys,

-JMc


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## ajcoholic (Feb 5, 2006)

JMC Amps said:


> Hi Guys,
> 
> What I have is Chemcraft Opticlear 900 Pre-cat Gloss Black and Chemseal Sanding Sealer.
> 
> ...


Pre-cat is pre catalyzed lacquer, ie, where the manufacturer mixes in the hardener and it is ready to thin and use.

I (we, my woodworking company) used to use that type of lacquer, but went to post cat (where the end user mixes in the hardener) about 12 years ago, as it is superior in terms of wear resistance, check resistance etc and also, has a much longer shelf life.

I would be suspect of the product - it may spray and appear to be fine, but it might not achieve the proper toughness - or be too brittle, etc. Guitars, unlike a dining room table for instance, dont take a lot of abuse (well, they shouldnt!). You may find it works, you may not.

I would spray a test panel on a piece of scrap plywood first. The only way to make absolute sure.

AJC


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## JMC Amps (Dec 19, 2009)

Thanks, 

I'll check it out.

-JMc



ajcoholic said:


> Guitars, unlike a dining room table for instance, dont take a lot of abuse (well, they shouldnt!).
> AJC



agreed, they shouldn't...


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