# Baffled, I have salt crystals forming on the end grain of my finished cedar boxes



## Blackie_ (Jul 10, 2011)

I have something happening that I've never seen before, On one of my red cedar boxes (bandsaw box Santa Sleigh) I had left the inside of all drawers unfinished for the cedar aroma and had a lacquer finish on the exterior walls and everywhere else, only the inside of the drawers were left unfinished, the box had been left on the shelf for over a year, today I took it down and was inspecting and found tiny clusters of what looked like salt crystals formed on the exterior of the drawer walls on top of the lacquer finish, when I took #600 sand paper to it they all just powered to a white substance.

I'm wondering if it could be a chemical reaction from the oil in the red cedar and the dried cured lacquer? baffled.

Was hoping someone might be able to bring light to this phenomenon?

Thanks


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## CharlesNeil (Oct 21, 2007)

The oil in cedar can be further softened by some finishes , lacquer is one of them , the oil will actually inter mix . As the finish cures it will migrate out and harden forming the crystals. Typically its not an issue because the oil is cleaned off just in everyday use and goes unnoticed , in your case where it sit ,it hardened. I have seen it do the same on alot of unfinished cedar, however it does seem like a hot solvent product like lacquer makes it worse.

The best "first coat" of finish on cedar is shellac, it will seal it down.

Spanish cedar is much the same the resin is liquified by the solvent and it can cause it to bleed sap . The diffference is the spanish cedar will just yield up a gooey mess, shellac as a first coat is a good solution


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## HillbillyShooter (Feb 15, 2012)

If I knew, I'd share. If no one comes up with an answer, I've got a good friend that is an arborist and he might know. I'll put this on my watch list (along with Roger's crib blog).

P.S. Never mind. As I was typing I see someone knew the answer and that answer was posted when I pressed the button. Thanks Charles!


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## Jim Jakosh (Nov 24, 2009)

I'll bet is is powered lacquer. Cedar does not like any top coating! I just finished scraping all the poly off a cedar lounge chair I made about 10 years ago. I found out the hard way! That oil in cedar sheds finishes.


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## CharlesNeil (Oct 21, 2007)

Jim, your right thats why shellac needs to be the seal coat, it works . Been here done it, got the hat and "T" shirt .


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## Blackie_ (Jul 10, 2011)

Charles thanks a lot!

I normally do a beginning first coat of tung oil and have since changed my finishing method to wipe on poly, I no longer use lacquer, would this help resolve this problem or is Shellac the only option? Or What about a final coat of paste wax, would this help prevent it?

Thanks


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## CharlesNeil (Oct 21, 2007)

I have not tried the tung oil, or the wax, I always use shellac, sorry not alot of help on that one


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## bannerpond1 (Mar 15, 2013)

Use Zinsser CLEAR shellac for a first coat. It is UNWAXED and the only one you can buy already mixed. You can put anything on top of it.


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## Blackie_ (Jul 10, 2011)

Great, thanks Dale.


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## DocSavage45 (Aug 14, 2010)

Good question Randy! Great answer Charles!


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