I would like to wood burn some designs into a nightstand but may want to add more burning down the road, after I coat it with shellac. From what I could gather, people mentioned to only burn and then seal, otherwise the burning after the shellac could cause issues, like releasing inhalants. Is that really an issue with shellac since it is “natural”?
you can use denatured alcohol as a solvent to strip the shellac later. might be a better option than trying to burn through the shellac
it is definitely still a problem, the “naturalness” of the finish is irrelevant
even burning wood itself releases compounds that can be harmful (hence why we advise against breathing in smoke)
I second the idea from a separate poster that if you want to burn, seal, and add more burns-- just use a solvent to remove the seal before you do the second set of burns. Or burn it all at once before sealing
I’ve done wood burning stuff a lot and you should burn first, seal after. Even if your finish isn’t flammable (and most I know of are), you’d still want to finish again the burned areas anyway, so you may as well save time burning then sealing/staining/etc.
Shellac is natural, but it needs to be mixed with denatured alcohol to become a wood finish. I don’t feel like going down to my shop, but I would imagine commercial shellac in the can, like Zinsser’s, could potentially have other chemicals mixed in to help its shelf life or speed up its drying process. But even then, it still uses denatured alcohol, and alcohol and fire aren’t a good combo.
You could make your own, which would just be shellac flakes and denatured alcohol, but it’d still be alcohol based. I’d burn first, then apply your finish.
