Lucida Clear Coat Finish Blushing

Construction and repair of Classical Guitar and related instruments
MikeVictor
Posts: 4
Joined: Sat Oct 07, 2017 11:11 am

Lucida Clear Coat Finish Blushing

Post by MikeVictor » Sun Oct 08, 2017 8:48 am

Good day,

I noticed some white blushing in the clear coat finish on the side of my lucida Artista LG 715.

Can someone tell me what material was used to clear coat this guitar?

Also, if you have a good method to remove the blushing to restore the finish without sanding or striping the finish, please share that with me.

I've reviewed a few videos about this, one used a heat gun, another an aerosol spray... your thoughts?

Thank you for your time,

Mike V

lux
Posts: 37
Joined: Tue Sep 19, 2017 6:33 am
Location: Medford, Oregon USA

Re: Lucida Clear Coat Finish Blushing

Post by lux » Wed Oct 11, 2017 5:19 am

Others on this forum will have more finishing experience than I do, but here's a tentative diagnosis. Blushing occurs when excess water gets trapped in a shellac or lacquer finish during the curing process. If a finish that was fully cured many years ago turns milky, either the instrument has been in an overly moist storage environment or a poor-quality finish has degraded over time. That's not really the same as blushing and refinishing may be the only realistic answer.
If the problem is blushing (incurred during curing), the usual remedy is to soften the finish with a thinned version of the original finish and sand down to where the trapped water can be released and then carefully rebuild the spot treatment in dry working conditions. Shellac is a more forgiving finish in this regard, but some have had success with spot refurbishing of lacquer blushing as well.

MikeVictor
Posts: 4
Joined: Sat Oct 07, 2017 11:11 am

Re: Lucida Clear Coat Finish Blushing

Post by MikeVictor » Thu Oct 12, 2017 3:31 am

Does anyone know what the clear coat on a Lucidia LG 715 is? Nitro, Poly, other???

Thanks,

MikeV

OldPotter
Posts: 1754
Joined: Thu Dec 06, 2007 7:31 pm
Location: Channel Islands

Re: Lucida Clear Coat Finish Blushing

Post by OldPotter » Thu Oct 12, 2017 11:24 am

I don't know what finish is used, possibly nitrocellulose. There is a way of getting a clue here;

http://www.frets.com/FretsPages/Luthier ... etest.html

There is also a method of using laquer retarder shown, to remove some blushing. I'm not sure that it would work on a thick and well cured finish.
Its hard to understand why the blushing is showing up now. As lux says its usually moisture trapped in the finish.

If its a really good guitar it might be worthwhile trying to correct the fault. If its just a modest guitar, it won't do any more harm to just leave it as it is.
"When I was younger, I could remember almost everything, whether it happened or not." Mark Twain

MikeVictor
Posts: 4
Joined: Sat Oct 07, 2017 11:11 am

Re: Lucida Clear Coat Finish Blushing

Post by MikeVictor » Sat Oct 14, 2017 3:04 pm

I tried a heat gun, it got rid of some og the blushing, but added some more.. ??

I ordered some blush eraser spray, will try that next week.

OldPotter
Posts: 1754
Joined: Thu Dec 06, 2007 7:31 pm
Location: Channel Islands

Re: Lucida Clear Coat Finish Blushing

Post by OldPotter » Sat Oct 14, 2017 3:39 pm

The more you mess about with it the more likely you are to mess up the finish in one area and then have more problems to deal with. I have a feeling that you already know this
"When I was younger, I could remember almost everything, whether it happened or not." Mark Twain

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