This is the fifteenth entry in a nineteen part series that covers the construction of one of my saws from start to finish. For links to the other entries, please see the full chronological index. -Ed.
Debluing & deburring the blade
The spring steel I use is blued to help prevent rust. While I think that a blued blade would look very attractive on the right saw, the bluing is not abrasion resistant and would highlight every scratch and scuff acquired over its lifetime. For this reason, I choose to deblue the blade.
My first efforts at debluing included the use of citric acid and vinegar. Soaking the blade in either one of these for 10 or 15 minutes removes most of the bluing, leaving a thin film that I removed with a Scotch-Brite pad or a deburring wheel.*
Then, one day while soldering some parts, I noticed the flux that I was using had dripped onto some blued steel, leaving it shiny. A little research revealed that the flux contained hydrochloric acid. Thinking this might be a better way of debluing the blades, I bought a bottle of muriatic acid from the hardware store.
The results were spectacular. Simply wiping the blade with a rag dampened with muriatic acid was enough to completely remove every trace of bluing and leave a bright finish. The steel does need to be rinsed in water (within seconds) and oiled immediately afterwards to prevent rust and corrosion from forming. This, to me, is a small price to pay for the time and mess that were associated with using vinegar.
I have since learned that others use phosphoric acid, and with similar results. If you decide to try either of these methods, please do so with great caution. Use them only in a well-ventilated area, and with the proper personal protection (gloves, goggles, old clothes, etc.).
For a more consistent satin finish, I turn once more to the deburring wheel.
*If you use vinegar or citric acid to deblue steel, first wash off any oil with dish soap. Failure to do so will result in uneven removal of the bluing. -Ed.
Naval jelly works spectacularly as well to remove bluing.
I’ve never used it, but that makes sense. I think just about any acid will do, and naval jelly has several of those.