Sealing the Blow Hole and SAC
To protect the wood in the blow hole and SAC two coats of polyurethane coats are applied. I simply use some blue tape to close the SAC-Exit hole and fill some wipe-on-poly into the blow hole and SAC. After a few shakes I pour it out and let it dry for some hours. To make sure it is really sealed I apply a second coat.
This area will get really moist when playing and can end up very nasty if the wood is not properly protected. Other people use oils or shellac but poly is the better choice in my opinion. There is some dispute about chemicals getting close to your mouth but completely cured, I don’t see a major risk. Please inform yourself on this issue.
Final Sanding
I use sanding paper to smooth the complete flute starting from 320 to 800 grit. I pay special attention to the mouth piece, end piece and sound area. All edges and ramps need to be as smooth as possible. This is also the last chance to get rid of some dents, marks, scratches etc. Make sure to take some time for this step.
The Finish
As the first step in finishing my flute I use one coat of Danish-Oil (see tools) to preserve the wood and fire up the grain. Simply apply one coat with a soft cloth, wipe off the excess after a few minutes and let it dry for 4-6 hours. At this stage the flute should look beautiful and is ready for the final step.
To create a hard, durable. shiny and water protective surface, I apply melamine spray lacquer by Chestnut (see tools). I can not recommend this lacquer enough. It is fast drying (about 10 minutes), very hard and durable, water resistant and creates a beautiful shiny surface.
If you like a “natural” look and feel, this will not be the right choice for you. Look for an oil based finish like e.g. boiled linseed oil or others.
Back to “my” melamine spray: About 10 coats with 10-20 minutes drying time in between make a perfect surface that dries hard after 24 hours.
Polishing
I like very shiny surfaces. Therefore I am using micro-mesh (see tools) starting from 800 to 12000 grit to polish the lacquer to a very nice and glass/mirror like shine. The sanding works best on the lathe at a lower speed and some horizontal sanding in between (without a turning lathe). This will make sure that there are no vertical streaks in the surface.
As the final step I am applying friction polish (see tools) to polish it up with a cloth on the turning lathe.
If you like a more natural look with a satin surface finish you could try different types of oil like danish oil, boiled linseed oil, etc. and finish with a wax coating.
DONE! A new flute was born (see birth-certificate)!
