Sticky Shellac!

[jonathan snyder]

Hi Folks,

I used some shellac for the first time today. I bought a can of clear Zinsser at the borg. I thinned it down to a 2lb cut in a glass fruit jar. I brushed a coat on some wormy maple picture frames. While in the process LOML called and asked me to take some salmon out the the freezer, I put the lid on the jar, not thinking to wipe off the theads with aocohol! I had to use a pipe wrench to get the top lid off!!

Seriously, I have a question. My first coat came out a bit rough, almost like air bubbles. Is this a result of using the wrong kind of brush? I used a Purdy paint brush, as that is what I had on hand. I cant find any of those takalon brushed locally. Is my cut too heavy? or is it my brushing technique. I tried not to over brush.

I lightly sanded with fine steel wool and hit it with another cost. I think it will be ok. I like the way the finish loooks so far.

Thanks
Jonathan

[Rob Millard]

I think your "cut" was too thick. I have my shellac as thin as water. The brush is important too; it should be fairly small and have very fine bristles. The Taklons are best, and I have them in a 1 and 2 inch sizes, plus a 1/2" filbert for detailed areas. Dick Blick has them on thier website for a good price (I'm not sure if they have the 2" size though). Lacking a Taklon, any artist water color brush would work okay. In my area, Michael's, Hobby Lobby, sell excellent brushes, and Wal-Mart and Meijer's sell acceptable one.
Rob Millard

[Howard Acheson]

First coats are always rough as any finish will, to some extent, cause wood fibers to swell up and stand up. All you need to do it to let the first coat fully dry and then sand the surface with 320 paper on a sanding block. That will smooth it.

As to thinning, a 1 1/2 to 2# cut is fine for brushing but I would tend more toward the 1 1/2#. Shellac needs to be flowed on with minimal back and forth brushing. Brush in long, slow strokes. As it dries fast, don't go back over prior areas for an hour or so.

Finally, for the best finish, padding the shellac on is recommended. Here is something written by a friend on another forum.

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. Never, never, never let a real project be your learning experience.

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.

Steve

[Jim Hinze]

I agree with Rob.. I like Shellac for various woods, but have found through trial and error that a 2lb cut is a little too thick for me to work wiht. A 1# to 1.5# cut with a very fine brush will give a nice, even, bubble free finish that takes minimal rubbing...

I think I prefer 600g automotive paper as opposed to steel wool...

[jonathan snyder]

Thanks for the advice Folks,

I bought some muslin today, I will try padding. I have several more frames to finish. What do you guys usie inside your pad. I have read that lint free medical gauze or wool works well. Any thoughts?

I did some reading today including Howards post and see that folks say not to build coats, but use a thin even finish. I have also read of folks layering different colors of shellac to build depth. Whats the scoop?

Thanks
Jonathan