Question re: finish crazing

Hello:

I'm getting ready to post a couple of ukuleles and need a little help with describing the condition of one of them. It's a white label Kamaka, 12 frets above the sound hole, in pristine codition with the exception of some under the surface checking/crazing of the finish. You can't see it unless you turn thr instrument to catch the light a ceratin way, but once you do, it's visible on the right lower and upper right bout. It's spidery in appearance, but doesn't extend to or through the surface, and cannot be felt.

Is this called crazing? I have that in mind because I know the term applies to ceramic glazes. If that's not an accurate term, please help me with a better one, so I can describe this properly.

Thanks,
- David Maron

Yes, that is crazing. Crazing of the finish is common on older ukes. I've got an older Gstring that has it too. If it is not flaking off i try and live with it.

Thanks, Doc.

So, someone gave me a pretty good explanation, or at least one that made sense. They said that over time, the expansion, contraction and normal flexingof the wood cracks the harder, non-flexible coat which is attached to it. This movement dosen't necessarily extend to the upper layer, which seems to be the case with my Kamaka. Anyway, thought I'd pass that along.

Also, nitro lacquer continues to lose plasticizers (castor oil on the older finishes) year after year, and so the finish shrinks and becomes more and more brittle. It is highly unlikely that the finish checking is limited to undercoats as each coat of lacquer melts into the previous coats, essentially becoming one layer of finish. The checks may not seem open, but they probably are unless there has been some over coating with either French polish or oversprayed lacquer. This would all be somewhat similar with a hastily applied shellac or spirit varnish finish, too.

I love that old small antique checking

Well, the non-PC and very anti-green way to get it is to spray Freon on the finish.

Freon, im not familiar with that. I presume it is made from depleted uranium or something.
Oh, i just googled it.

The nitro i was using in Oz was from Durobond and i could never get it to craze even under electrical freezing spray.