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tool blackening

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  • tool blackening

    Im hoping to be making some tool holders soon, and would like to protect the metal from rusting as well as give them the professional look that I think the blackening does.

    After doing some searching I ony found 2 companies selling the kits at what I thought were extremely high prices.

    What is your experience with tool blackening and what products do you recommend?

    Are there reasonably priced kit available?

    Thanks in advance,
    Ken J

  • #2
    I've used touch-up cold gun bluing from

    1. Not black
    2. Not particularly durable
    3. Cheap

    #3 is what drew my attention to it.

    Assuming you do a good surface prep (i.e. really clean and degreased) the stuff does a reasonable job, and it looks pretty good, but I don't know how it compares to the cold blacking kits.

    N.b. none of the "cold" solutions are going to be as good as the professional hot-tank processes.
    Try to make a living, not a killing. -- Utah Phillips
    Don't believe everything you know. -- Bumper sticker
    Everybody is ignorant, only on different subjects. -- Will Rogers
    There are lots of people who mistake their imagination for their memory. - Josh Billings
    Law of Logical Argument - Anything is possible if you don't know what you are talking about.
    Don't own anything you have to feed or paint. - Hood River Blackie


    • #3
      Birchwood Casey makes kits for both aluminum and steel. I have used both and will say that the Alumablack process is pretty simple and effective. The steel blackener they make is not as good. It will produce a black finish that will fade to an olive/brown over time. The finish for aluminum is not as durable as anodize but quite useable on stuff that does not get a lot of handling. The steel black, although not as black as I would have liked is pretty durable and takes handling wear well.
      Jim (KB4IVH)

      Only fools abuse their tools.


      • #4
        I have Birchwood Casey steel blackening, which is better then nothing but most offer little actual rust protection in and of them selves, they have a new product out for a replacement.


        • #5
          I've used the touch-up bluing that I got in the Gun Dept. at Wal-Mart. I had some of the old formula (acid based, I think) and it worked great. I cleaned the parts really well and gave them several "coats" of the solution with a q-tip and then rsined them in HOT water followed by a coat of WD40 and then wiped off the excess. I have some tools that I did over 10 years ago and they still look good.

          They changed the formula and the new stuff ( supposed to be safer) doesn't work quite as well (slower - more coats) but its acceptable. Used the same process with both.



          • #6
            Depending on the material Oil Blacking might be the easiest thing.
            This is not a good photo, in real life this clamp is a nice even black:

            And this captive nut holder is also a nice even black.

            Dead simple to do: (Do it outsde, and away from the house - its quite smelly)
            Get a METAL bucket / pan, large enough to take about 5 litres of the cheapest motor oil you can find.
            I use new motor oil as used has all sorts of potentially nasty things in it.
            Fill pan with motor oil.
            Heat parts until a dull red colour.
            Dunk in motor oil (see why we use metal now )

            Its best to keep them moving whilst they cool, and keeping them under the surface helps to minimise the smoke produced.
            Once cooled leave them to drain off, I usually just hang them over the bucket for an hour of so, and then move them inside to sit on some paper roll.

            If the black isnt deep enough then repeat...
            A little experimentation may be called for, but I can get things to an even colour now quite easily.

            Note that this will effect any heat treat, I use it purely for blacking/rustproofing mild steel parts, not anything critical with respect to heat treatment.



            • #7
              Potassium nitrate and lye can be used with distilled water to make hot bluing salts.

              PS Do it outside! The fumes will rust everything in you shop if you do it inside.
              Last edited by deltaenterprizes; 02-09-2010, 04:13 PM.


              • #8
                I used cold bluing. Cold blued steel will rust.


                • #9
                  Just heating steel into the tempering range will turn it to whatever color you wish, as long as it's on the tempering chart. Then oil to make it prettier and prevent rust.

                  If it's a small enough part, an old toaster oven will do it.


                  • #10
                    The cold gun blues and cold tool blackening chemicals are all related...all are based on selenium acid compounds. None of them do a particularly great job, though with some experimentation and work, they can be made to look somewhat "presentable". If you have a gun shop near you that does hot caustic bluing on site, ask about their doing "dunk" bluing on your parts, where you do all the prep work, cleaning, polishing, bead blasting or wire brushing, and degreasing. No cadmium plated parts, no aluminum, and no galvanized or stainless parts. All they would do is the final degreasing, immersion in the hot salts bath, rinse and oil. Most shops doing bluing just charge a nominal fee for this type of work, and unless you're going to set up to do gun work or build an awful lot of tools, it isn't worth the expense to do it yourself.

                    David Kaiser
                    “You can have peace. Or you can have freedom. Don't ever count on having both at once.”
                    ― Robert A. Heinlein


                    • #11
                      All you need is some cold blue for guns. Brownell's gunsmith supply has it online or you can go to your local gun shop and get some. My favorite kinds are Formula 44-40 and Oxpho-blue. Birchwood Casey also makes gun blue, aluminum black, brass black, black oxide and several other chemical metal finishes.

                      To use the gun blue, first clean the metal with a good solvent that evaporates leaving no residue. Ketone, Acetone and Brake Parts cleaner all work. Pick one.
                      Keep fingerprints off the project. Apply cold blue or black oxide generously using a clean cloth, paper towel, q-tip, etc. Let dry completely. You may heat the part with a heat gun before or after application to speed up the process and make the finish more durable. Once it's dry, coat with a thin film of oil. Let cure undisturbed for a week if possible. Wipe off excess oil and use.

                      There are no cheap kits. They are all overpriced.
                      Last edited by Toolguy; 02-09-2010, 03:49 PM.


                      • #12
                        This was a good thread with equally good results.........


                        Unfortunately looks like the pics are gone.........frown, I guess you'll just have to go by the results by the comments made.
                        Last edited by hardtail; 02-09-2010, 03:37 PM.
                        Opportunity knocks once, temptation leans on the doorbell.....


                        • #13
                          I like the cold bluing products already mentioned. I've used Dicropan T-4 and Oxpho Blue, both purchased from Midway or Brownell. They seem equivalently easy to use. Dicropan left a darker more even finish. Oxpho was a prettier blue that had some interesting highlights but was a bit less even.

                          I would also look at Parkerizing. A hot plate and a big glass beaker (old drip coffee pot) would do the trick of heating the solution. A gallon of solution from Lauer Custom Weaponry is $29 and would last a long long time for tooling projects.

                          I had a pro machinist tell me that's what they use for their tooling.



                          Try G-Wizard Machinist's Calculator for free:


                          • #14
                            Something to note:
                            All my (store bought) holders while blankened on the outside, the entire dovetail area is bare, meaning machined after blackening (or masked off)

                            Soo.. you gotta keep em oiled anyway. (liberal use of cutting oil sure helps..)
                            And generaly avoid touching them except by the depth set screw (at least, thats how I handle them)

                            And since you need to oil them anyway, and keep clean hands to avoid rusting.. well, everything *hides flash rush stained chuck and goes back to inventing oil based hand prewash for machinists*, don't worry about blueing them too much..
                            Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.


                            • #15
                              The best corrosion protection.

                              I have used Brownells Baked on Teflon-Moly type finish. You can buy it in a spray can, but it is better to buy the liquid and use an air brush to apply it. Then you bake it at like 350°F for 30 min. Do the prep right and this is a very nice looking and very durable finish. The spray cans tend to stop up and go bad if you don't use it frequently. This is the best corrosion protection that I have found for shop made tools. It is also a good way to blacken a stainless gunbarrel. A light bead blast prep produces an excellent bond.
                              Byron Boucher
                              Burnet, TX