I have a question about , how many coats?
Or perhaps a better question is how do you know when you are there? Since there can be many variables, cut of shellac, how much or well the surface was filled before finishing, and how light or heavy handed you are.
I am finishing a mahogany top, which I filled after the first coat of shellac. ( I’m not sure the fill job was all that great) I have since put on approx 6-8 coats , yea , I didnt really pay attention to exactly how many, after the fourth coat I was more interested in how it looks than the number. In between coats I either rubbed with a grey pad, or if there were brush marks sanded lightly with 320 to remove them. It now looks “almost there” I think, I can see a light orange peel , which is really what promted this post, could that still be remnants of the finish trying to fill the grain? or just the finish itself not flowing out completely and this is where you start to wet sand and rub out. I am obviously new to using shellac, and would appreciate any help.
Thanx
Eric
Replies
Here is the best shellac advise I have seen. It's from a craftsman who specializes in making and restoring antique furniture.
QUOTE
Applying a shellac finish is one part reading how (or watching a video demonstration) and ten parts practice. It is one of those processes in which you will one day reach what I call the "A-Ha" point in your journey and it will all simply fall into place. I would urge you to stick with the process and finish lots of test boards before you take the technique to a real project.
I can give you this simple pointer as a place to start. Forget everything that you know about applying other finishes. In particular, that means forget about the concept of "coats"! Every time you apply another coat of shellac to an existing shellac film you significantly increase the probability of failure, both near and long term. This is especially true if you are attempting to pad on a shellac-only finish. Padding (in my view, the best way to achieve a high quality shellac finish) is actually a continuous process in which a single coat is applied in steps until the finish is refined to a very hard film and a high luster.
I would also add (along the lines of changing your focus from "coats") that you need to change your view of what constitutes a good finish film. When we apply varnish, lacquer, or even water-borne finishes we think in terms of "building" the finish film. The best shellac finish is the thinnest film that you can apply consistent with good coverage and an even-depth film. One of my visualizations when I teach a class on shellac is to hold up a single flake of shellac (about the size of a quarter) and suggest that our objective is to dissolve this flake and then spread it evenly over the surface of our test board. Clearly, that is not possible; however, the image helps to reinforce the idea of a thin film. It helps students to think shellac and to loose the varnish or lacquer coat-building mind set.
As further evidence of this "think thin" approach I will simply hold up the shellac finish on 200-year-old antiques. Those on which the shellac finish has remained largely intact (and there are many) are those on which the shellac film is quite thin. The ones that have alligatored are those on which the finisher built up a thick shellac film. In using shellac, you increase the amount of resin by mixing a heavier cut, not applying more coats.
END QUOTE.
Every time you apply another coat of shellac to an existing shellac film you significantly increase the probability of failure..LOL.. LOL.. I just did that!Sure wish I knew how to prevent build-up at the joints..
Back to the Alcohol can... Dang!
I've found that to be true of every finish I've used!
Since the house is on fire let us warm ourselves. ~Italian Proverb
Ejc,
I stop brushing on the shellac when it achieves a full luster, in other words, when more coats do not leave the surface with more gloss. On filled mahogany, this would be 4-5 coats. When I brush on shellac it is a very thin cut ( but I don’t know the actual “cut”) so the resulting film is very thin. Until the shellac is rubbed out, it will look poor, so you can’t use the from the brush appearance to judge when to stop.
Rob Millard
This forum post is now archived. Commenting has been disabled