Probably should ask in .home.repair but I'm not sure they'd have much knowledge of shellac - so . . .
My neighbor, a single mother with three young daughters, had a fire in her home. No one was in the house at the time but they did lose a bird and two house cats required lots of cleaning. The structural damage was negligible, done by firemen, not the fire itself, which neighbors had put out with garden hoses prior to the firemen's arrival. Firemen ripped open a wall, tore down celing dry wall - dropping borax treated paper insulation into the 100+ gallons of water they used "just to make sure the fire was REALLY out - to make paper mache, and cut a hole in the roof - right next to a large whirly gig - "have to vent the smoke out of the attic you know. The smoke was all generated by the burning plastic of - wait for it - their computer (and printer). The power strip, which had a reset button circuit breaker, somehow shorted and caught the computer on fire - on an oak desk.
Anyway the smoke damage was major. Gritty thick black crud went everywhere - even in drawers and cabinets. ALL the interior dry wall must be removed and all the structural wood above the floor must be sealed prior to re-dry walling. Apparently the smokey smell even gets into the wood behind dry wall, and if not sealed off, will get back into the living area over time. Since the middle daughter is asthmatic, that wouldn't be a good thing.
The question is - would a one pound cut of shellac seal the would enough to stop future smokey smells? The wood in question is 50+ year old douglas fir which, today, would be considered furniture grade as it's mainly close to all quarter sawn, tight grown ringed stuff that's hard as a rock.
If there's another, less expensive way to seal the smoke in please feel free to provide that as well - specific product name if you can
Thanks
charlie b
If it weren't for bad luck, this poor family wouldn't have any luch at all. But, with help from friends a neigbors they'll get through this.