cracks in my shellac, big deal or should i chillax?

[craigd]

Here are some pics. Why would this have happened?

 

[Gonk]

Any rapid and large temperature changes lately?

 

[Dingo40]

I've never seen shellac craze. Are you sure it's shellac, not lacquer??
Lacquer will definitely craze over time, simply due to age.?

 

[Lucio76]

Shellac should not crack in that way. In my opinion, it's some industrial varnish (very common in the 50es and in the 60es) and unless it begins to peel off the wood, you have nothing to worry about.

 

[craigd]

Thanks. Could well be lacquer or varnish. Shellac rhymes with crack though. Doesn't appear to be peeling off, so I'll chillax.

 

[JIM D.]

It's polyester (plastic) covering 'no longer used' that in time will shrink with age. It dried rapidly and saved time in construction.
Can be found in many Italian brands made in the 60's.

 

[Mullanphy]

Old thread, I know, but tossing in my $0.02 anywho.

Most likely reason for a finish to crack like that is improperly finished wood.

• Wood wasn't dry enough before sealing
• Too great of a temperature difference between finish and wood
• Finish applied in wrong temperature
• Wood not cleaned well enough,
• Wrong/no sealer,
• Finish applied to thick in one coat.

The wood vibrates when the instrument is played, so that will also be a factor if the finish is inadequate.

Even if the finish starts to peel or fall off in chunks this should not be a problem unless appearance is important. Maybe contact the manufacturer or an accordion repair shop to find out what the finish is, then do some light sanding and reapply a very thin coat.

 

[KiwiSqueezer]

I have seen a Victoria-made Titano, which has gloss-finished reed blocks. They were all crazed, including the insides, with bits of the finish loose, and threatening to get stuck in the reeds. Victoria replied to an email question asking what the finish was. Apparently the blocks were coated in (foul-smelling!) animal glue. This same material is used to produce an apparently desirable, intentional 'crackle finish' on objects d'art, so the reply all makes sense. The best way to remove it, though, remains uncertain. It should be soluble in hot water, but...