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View Full Version : Can I use bluing to rust proof a back saw?



Harlan Barnhart
09-09-2009, 5:28 PM
I bought a matched set of rusty 60's era back saws with square blocky handles. I am in the process of making replacement handles and cleaning up the rust. Can I use gun bluing as a rust preventative? Where can I buy it?

Ryan Cathey
09-09-2009, 6:23 PM
I don't see why not!! http://www.brownells.com/.aspx/pid=1072/Product/OXPHO_BLUE_reg_

Bob Strawn
09-09-2009, 6:31 PM
Bob Smalser has good advice on that! (http://www.wkfinetools.com/contrib/bSmalser/art/rustproofing/rustproofing1.asp)

Before I use the phosphoric acid to parkerize (http://en.wikipedia.org/wiki/Parkerizing) the steel, I use it to remove zinc from steel that I am going to use on the forge. This gives a better rust resistance to the parkerized steel, and protects me from zinc fever.


Bob

george wilson
09-09-2009, 9:55 PM
Bluing itself is no guarantee of preventing rust. I use Oxpho Blue myself on guns. Years ago,I did blue an early acquisition small back saw to cover the previous "freckles",etc caused by rust in an earlier life. The blade succeeded in rusting a bit more,anyway.

I really don't like the looks of Parkerizing,but it might offer better protection,which is why the government used it.

Bob Strawn
09-09-2009, 10:27 PM
These Knives where first parkerized, and then treated with oxpho blue. Pretty much using Bob Smalsers method, with the only real change being the use of zinc in the phosphoric acid.

http://battlering.com/woodworking/images/Marking%20Knives/Marking%20Knives%20Oxpho%201.JPG

They have shown very good resistance to wear and rust. These are O1 steel and they have shown more resistance to rust than some of the less stainless, stainless steel that I have.

Bob

jim hedgpeth
09-13-2009, 10:09 AM
Off subject, but where did you get that knife Bob??

Jim

Bob Strawn
09-13-2009, 4:13 PM
Off subject, but where did you get that knife Bob??

Jim

I got the blanks from Bob Zajicek at http://czeckedge.com/ (http://czeckedge.com/)When he was discontinuing the model. They came tempered with no bevel, so I had to grind carefully to keep from removing the temper. I got a bunch from him at a very nice price. In the picture, you can see the extra one, labeled practice, that he threw in!
http://battlering.com/woodworking/images/Marking%20Knives/blades.JPG

They were worth it, but never again. I probably spent 2 hours each shaping the bevels on these guys, holding them in hand to make sure the temperature stayed low on them. Now I work annealed steel, shape my own and will often anneal half way through a project to restore workability. After I discovered that painting the steel in a mix of water, boric acid and iron oxide would prevent all oxidation and discoloration, I have been pretty happy with reheating regularly to restore softness for working.

Bob Z. also sells kits (http://czeckedge.com/kits.html), and I have never heard anyone give anything but praise for his product. Sadly this lovely form is discontinued, I suspect because they are quite a bit of work to finish up. His kits come with all the grinding done, (worth the price, just for that) and will take an edge like few other tools. The dark blade makes it all the more appealing to me, somehow. Fortunately they keep their edge practically forever, because I don't want to put a secondary bevel on them and will have to blue them again after sharpening. Properly done, the parkerization and the blueing sharpen the edge and case harden the steel, so they are wicked sharp like the O1 they are made with, but hold an edge like they were D2. Best of all worlds, until they finally get dull.

Bob

Joe Close
09-14-2009, 6:31 AM
I don't see that bluing will stop rust. I've never seen a firearm, not rust, from finger prints, humidity, etc, unless it is kept oiled. A heavy parkarization might help, but bluing I would say not.

Bob Strawn
09-14-2009, 9:05 AM
I don't see that bluing will stop rust. I've never seen a firearm, not rust, from finger prints, humidity, etc, unless it is kept oiled. A heavy parkarization might help, but bluing I would say not.

In my experimentation, bluing does not do wonders by itself. Nor am I real impressed with parkerization by itself although it is better than bluing. All of the bluings that I have used apart from oxpho are entirely useless. Salted vinegar puts a better rust resistance on a tool than any bluing does. It has also done better than parkerization in some of my tests.

However with O1 steel (rust bait) parkerizing until the bubbles stop coming up followed by Oxpho Blue rubbed in with very fine steel wool, does impart a level of rust resistance that I find superior to some of the less rust resistant metals that pass as stainless steel. It is certainly more rust resistant than D2.

With a touch of Ren Wax or Ballistol, I can pretty much trust a tool treated this way to remain rust free.

Bob

Steve Hamlin
09-14-2009, 11:40 AM
Does bluing reduce reflectiveness? I wouldn't use an HCl bath (acetic (or citric) acid and salt) because of this. I use the reflection of the stock edge in the blade to help gauge square and plumb.

Bob Strawn
09-14-2009, 12:03 PM
Any time you darken a tool, you reduce light. While you can see some reflection in a polished and blued tool, it will not be as as visible. So bluing is probably not the right choice for you with this application.

Bob Smalser, who lives in pretty much the highest rainfall area in the US, came up with this method. My conditions are not as bad as his, but for months at a time they can be close. What is a necessity for some of his tools, may not be the right choice for yours.

Sometimes I keep differently treated tools so that the contrast makes life easy. Dark for light wood, light for dark wood.

http://toolmakingart.battlering.com/images/WaxandDye/Finished%20Awls.JPG