I think any of the colored shellacs are the hardest finish I’ve ever applied, especially on open-grained woods like oak. The alcohol dries so fast on the outside of the coat that it pulls the finish up around the pores leaving ridges and also lap marks from the edges where the brush ended. Any edge always gets darker and reflects the light to make it even more noticeable. I have bought products that were suppose to increase the open time for shellac before it dries but they didn’t help much. The only thing was to fill the pores and sand the ridges. But sanding a colored shellac can leave light and dark areas unless you are perfect.
I came across some antique literature that used ammonia in some recipes for shellac. The ammonia is suppose to stop the ridging. Just add a few drops in your shellac/denatured alcohol mixture to help prevent the ridging. I carried it a bit further and did a little experimenting myself.
I did some experiments and some were failures. I think the failures (which was that the shellac bubbled off or flaked off) were caused by the mix being stored too long, like 2 to 3 days old. I had no trouble with the mix when it was fresh, meaning using it the same day. Even the literature said to only use fresh mixtures. It is also possible there was some left over wax on the wood from a stripper that wasn’t cleaned off good enough or my mix had too much ammonia in it.
To be sure that my shellac mix (below) had good bonding, I put some on my counter top. Actually, I spilled it but left it to see how hard it was to remove. With the regular shellac, when dry I can chip it off with a razor blade or just use ammonia on a sponge to wipe it off. When this mixture dried, it was just as hard to remove as regular shellac is on my counter top. So I’m pretty confident there won’t be a problem. *I should note that I used dewaxed garnet shellac. If the shellac is not dewaxed, I can’t say it would work.
What I did: (disclaimer: it worked for me but you do your own experiments as the results may not hold true under different circumstances.)
- Shellac mixed with denatured alcohol – 3 pound cut (you can find garnet shellac flakes on the internet and add denatured alcohol to make your own mix or buy it premixed on the internet.)
- Household Ammonia (not diluted)
I took just enough of the shellac/alcohol mixture that I would be using that day and put it in another container.
I dribbled a very small amount of ammonia into the shellac and stirred.
I took the spoon out and let some of the shellac drip from the spoon into the bowl of water to see if it coagulated or dissolved in the water. (You shouldn’t add so much it dissolves the first time or you may have added too much.)
If it coagulated, I dribbled a little bit more ammonia in the shellac mixture and stirred. I repeated this until the drops dispersed/dissolved in the bowl of water. (afterward you can clean your bowl with ammonia if you need to) You want the least amount of ammonia in the mix that it takes to get it to dissolve in water. Too much ammonia in the mix can bring up the shellac from previous coats when you brush it on. After all, ammonia will strip shellac off of wood when used full strength.
When the mixture has enough ammonia to dissolve in water, the mixture can be thinned with a little water. Too much water will make the finish blush white when you apply it (but it does evaporate out.) The water made the application smoother but also made it dry a lot slower and would cause drips on the vertical surfaces.
It takes longer to dry and will take more coats to build up color but I think it gave a better, more even finish. Your brush will also clean up with water unless it has started to dry in which you’d need ammonia to clean it. I haven’t tried it yet but I imagine this mix would mix well with water-based dyes.
Have fun experimenting and test small amounts so you don’t waste your shellac! See my results on my front stairs here.