I am using shellac (dewaxed) flakes dissolved in denatured alcohol. I am not sure of the cut as I just eyeballed it when I mixed it up. I am not really sure how to make a certain cut, thats why I just eyeballed it. (around 40% flakes and 60% alcohol. I am using it on oak and using 2 different colors, Garnet and Blond.
1. How many coats of shellac do I need to put on?
2. I feel the wood fibers sticking up as soon as it dries(just a couple minutes) so I used a 220 grit sand paper (orbital sander). Should I sand between each coat or only after all the wood fibers are removed?
3. Should I leave the shellac finish alone or do I need to put something over it, maybe a poly finish or something? Does shellac work well with other finish products?
I am making a couple shadow type boxes and they will be indoors. Any help will be greatly appreciated.
Cut is the term used to designate how many pounds of shellac are solved in alcohol. 1 lb. of shellac solved in 1 gal. alcohol is referred to as a 1 lb. cut. This continues with every pound over the first additional pound. [3 lbs. of shellac to 1 gal. of alcohol = 3 lb. cut] If your looking to make smaller batches then just reduce the amount of each ok - 1/4 lb. of shellac to a qt. of alcohol is still a 1 lb. cut. !/8th lb - pint, the same etc.. Just keep in mind that the solvent [alcohol normally] portion always remains the same no matter how many lbs. of shellac is added.
Shellac, as a first coat is meant to raise the grain and stiffen the fibers that can then be cut off by sanding. This is best accomplished by hand sanding with a flat hard block at a biased angle with fine paper [320/400/600] that is fresh and sharp, not old used sandpaper.
Though you can use a sanding machine to accomplish this, it has more of a tendency to push some of the fibers back down and it may be necessary to repeat the operation again, which if working on a piece that has been stained may lead to cutting through the first thin coat of shellac and ruining the color-work. That is why light passes with the sharp fresh sandpaper at a bias angle work best.
As to the number of coats, it is necessary to know the intended use of the object being coated. This would also help determine if it can or should have some other type of coating applied over it ok? since your using dewaxed but not wax free shellac, your choices are limited to those who are not sensitive to minor amounts of wax as to adhesion problems, which would be nitrocellulose, acrylic, oil varnishes, or other natural resin finishes.
If simply a decorative object not being subjected to water and cleaning with ammoniated cleaners or other harmful ingredients, and only being polished or dusted, 3-4 1lb coats is plenty. after the first coat sanding is not necessary since the surfaces remelt into one another ok?
If desiring or wanting to coat with another listed coating you should only use 1 coat of shellac, sand smooth, and then apply ok? Of the ones listed you can build as many coats as you like within reason.
hope this helps.