Turning Archive 2008

Subject:
Shellac Sanding Sealer Question

dan oliphant
>I have a question for those of you that understand how wood reacts with alcohol.
First some background. I do my turning in the following sequence;
Rough turn green wood, DNA soak for 4 to 5 days (because I'm not in a hurry), double bag (brown paper bags) ends sealed, allow to set on shelf for 40/45 days. The Rh in my area averages about 15%, remove from bags and allow to set in the open until I'm ready to finish turn. I then allow the sanded piece to set for a few days prior to applying a finish. In my mind the piece should be pretty well stabilized when it comes to wood movement.
On two separate pieces, one Juniper, the other an unknown species of conifer, when I applied a 2# cut shellac sealer to the inside surface (both hollow forms) as the first step, the piece will start to crack like a hard boiled egg within seconds.
Is this cracking caused because the cells in the wood re-expand too fast when exposed to alcohol? Is shellac the wrong sealer for HF pieces?

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