Hey Jimbo. I cannot see why you are getting this brittleness. Do you mean that just touching the surface with anything leaves an ugly scratch? Seems like the wax on top should help protect the shellac. Could it be the wax that is scratched?

There are a couple of things to know about shellac. First, it has a shelf life. I’ve read that after it is mixed (if it is made from dry shellac flakes), it should be used within a few months. I’ve only ever bought pre-made shellac. And I’ve used it for a couple of years without issues. Although, I did have some once that seemed a little gummy (not brittle) and I thought that could be from getting old.

Many shellac products come somewhat concentrated. The product I get in the US is Zinsser’s Sealcoat. It is a 2 pound cut, meaning it was mixed in a ratio of two pounds of dry shellac flakes to one gallon alcohol. I thin it to approximately a 1 pound cut (1 for 1 Sealcoat and alcohol) before using it and I typically apply three coats. I know some people use heavier cut shellac for sealing wood or knots. I don’t know if using the heavier cuts make it more brittle.

Not sure if this helps. Maybe others will add some thoughts.

That’s what I’m thinking, Ben. And maybe Jimbo is right about just having a bad batch of shellac. Normally works for me.

Jimbo, if you’re looking for something else very hard-wearing, then I’d go with a polyurethane (which is a varnish). There have been times in the past when I’ve mixed 1/3 poly, 1/3 BLO and 1/3 mineral spirits. You need to be patient with it while applying. Don’t slop it on, because runs can be a problem. Maybe even thin it a little more with min. spirits and apply several thin coats.

Shellac is not really good around water. I think Matt’s suggestion to use polyurethane is a good one.