If you search for Shellac Flakes on the internet, there are a lot of articles mixed in with the web sales sites that explain about shellac and the advantages and dis-advantages to shellac. You can also search french polish techniques as well.
Mack; I do this on the lathe at about 1800 RPM, the friction heat does dry the the outer coat of the shellac/Tung mixture (same process as shellawax and Crystal Coat)but since I use a heavier mixture content than they do, I leave it alone for the two hours for it to harden and seal into the wood itself (allows for pentration of tung oil and stabilizes the finish (not tacky). I use a lint free cotton cloth to apply the finish. I soak the cloth before using for about 10 minutes and then put more mixture on the cloth before applying, the friction causes the finish to draw from the cloth for a more even coat. Some people use a French polish method which in itself is a art form to applying shellac.
One of the main reasons why I use the shellac method is the easy repair to the finish if damaged. Man made finishes have to be sanded down to re apply finish to varying degrees. The CA finish which is beautiful when finished properly cannot be repaired unless you completely go back to the base of the finish itself, meaning you have to disassemble the pen and sand back down to the wood itself and then reapply CA to get the look consistency you orginally had. The same applies for laquer, poly and varnish finishes as well. The shellac finish allows you to melt shellac into the spot that is damage, thus less work and after building back up your shellac in the damaged spot, you cannot tell where it was damaged (again time consuming). The main dis-advantage to shellac is with alcohol (any kind), alcohol will damage a shellac finish, I use a renaissance wax that is a micro-crystalline wax that provides good protection against harmful chemicals that damage finishes. Museums use this type of wax to protect their wood antiques. Also another tip on shellac finishes, keep in mind that ambient temperatures and humidity affect the finishing times of shellac. You can compensate for this a little with your mixture but not totally, high humidity areas use less Tung oil more shellac, low humidity and dry areas use more tung oil than shellac, you just have to experiment with it and its easier than it sounds. Rainy days in KC with temps in the mid 80's, I add 1 1/2 parts of shellac to the mixture. KC doesnt have low humidity, so I have never had to add more Tung oil, but I have relatives who live in Southern Arizona that do add more tung oil to the mixture (yep, they like it too and are flatworkers like me). I hope this helps and again I want to stress, this is only one finishing method out of a group of great finishes.