I recently bought a gallon of Zinser “clear” shellac. I want to be able to put a top coat over it, so I want it dewaxed.
Right out of the gallon, I was able to split the shellac into 4 one-quart jars. The first two jars are dewaxed because the gallon had been sitting around for a while. The last two jars are very cloudy and the wax won’t settle to the bottom.
How long will this process take?
Out of a gallon of waxed shellac, how much of the gallon will be wax?
Replies
You can put any topcoat over it you want (the waxed) EXCEPT poly.
It can take quite a while. Zinsser uses a process to increase the shelf life of their shellacs. A side effect of this processing is that it takes a long time for the wax to settle out.
I had some a couple of years ago that took a month and then I only got about half separated. The fact that the can you purchased had sat around for a while and you were only able to decant about half as dewaxed is an indication that you will probably not get much more separation.
If you want dewaxed shellac, it is best to purchase the Zinsser SealCoat which is a 100% dewaxed, 2# cut, blond shellac.
In my experience, anywhere from approximately 1/3 to 1/2 of the gallon may be wax.
To (quickly) dewax shellac, here are 2 mthods:
1. Pour the shellac through a "paint strainer" (available at any paint store or the paint counter at Home Depot or Lowes). A paint strainer is a paper and nylon mesh filtering cone with the nylon mesh occupying the apex. You'll need several cones for a quart of shellac.
The wax will adhere to the paper and nylon mesh portions of the cone (and quickly clog it). Several passes will result in de-waxed shellac (good enough for just about any need for de-waxed)
2. If you are really compulsive about getting the wax out, like me, for 99.999+ dewaxed shellac, mix the shellac with mineral spirits or naphtha. Use a plastic squeeze bottle with a pointy spout closed with a small tip.
A volume of mineral spriits about 25% again in volume to the shellac is about right. Shake the mixture vigorously. The mixture will turn milky white with wax trapped in nicels of oil homogenized in alcohol.
Store the bottle overnight, pointy tip down. The clear alcohol/shellac will separate into the lower layer from the upper, milky, oil/wax phase with a sharp demarcation between.
Pull the tip off the pointy spout and squeeze the clear shellac out until the wax phase enters the spout almost down to the tip, then stop.
Rich
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