Re: Follow-up: Cold blue....

Here we have hydrochloric acid substitue. Active ingredient is muratic
acid. So now a gallon of diluted hydrochloric acid costs twice at much
as a gallon of concentrated hydrochloric acid used to. The acidic
toliet bowl cleaner at Home Depot contains HCl and some other stuff
but would prbably do what you want too.
Karl

On May 14, 2:18 pm, "Al A." <alanga...@xxxxxxxxxxx> wrote:
Hi All,
Just a follow up on the cold blueing I had asked about here a week or
so ago. I decided based on the recommendations I got here, and because
it was easy to do so, on trying the Brownells Oxpho cold blue solution.
A (I think) 16 Oz bottle cost about 20 bucks, and was small enough not
to incur haz-mat shipping charges.

One of the objects to be blued is an A.R.M.S. H&K style claw scope
mount that my son has. He wire-wheeled it with a fine wheel and got most
of the old stuff off. I was going to do the preclean in dilute muriatic
acid, as Randy O. suggested, but it turned out that I had none (thought
I had some around here)*. Unable to get some that night, and being
impaitent, I wiped it down with some acetone and then dunked it for a
few minutes in a container of near-boiling water with dishwashing
machine detergent in it (Cascade brand, IIRC. Very aggressive degreaser,
don't use on aluminum!). Took it out, dunked it directly into boiling
plain water a few times to get the detergent off, and then blew off any
water with dry air. As the mount was hot by now, it dried itself
quickly. It was very clean, as evidenced by the fact that flash rust
appeared almost instantly on a few spots. Went right to the Oxpho,
applying it with a small acid brush, as we did not have quite enough to
dunk the part. It blued up very nicely. We steel wooled, and re-applied
several times. The thing looks great, deep blue, almost black. Precisely
the effect he was after.

You can see the result here:

http://img.photobucket.com/albums/v479/alanganes/IMG_6309-crop.jpg

(Sorry for the slightly blury picture, it is a crop from a shot of the
whole gun.)

Thanks for all the great info. Much appreciated, thought some of you
might like to see the results.

Thanks again!

-AL A.

*Side story: All the decent local hardware stores around here were
closed, so I tried Home Despot for the muriatic acid. I know, dumb.
Looked in all of the areas where they would typically have such stuff. I
could not find any, so I asked one of the guys there. He said that no,
they do not carry it any more, because it is a "dangerous chemical". Out
of morbid curiosity, I asked what they would sell me if I wanted to
clean up some grouting haze from a tile floor. He says, "Oh, we have
this stuff for that!" and points me to a plastic bottle labeled
something like "ACIDIC TILE CLEANER SOLUTION". I turned it around and
read the label:

CAUTION! CONTAINS SULPHURIC ACID, blah, blah, blah...

Yeah, much safer, and only 10+ bucks a bottle. Sheesh!


.

Relevant Pages

  • Re: Follow-up: Cold blue....
    ... but the Muriatic is for pools and metal. ... Hydrochloric acid is for chemistry and medicine and pure stuff. ... There are trace elements in Muriatic if pure it would be Hydrochloric. ...
    (rec.crafts.metalworking)
  • Re: Follow-up: Cold blue....
    ... Muratic acid is hydrochloric acid. ... So now a gallon of diluted hydrochloric acid costs twice at much ...
    (rec.crafts.metalworking)
  • Re: muriatic acid on table saw
    ... Muratic acid (which is diluted hydrochloric acid) will damage iron and ... >>> so I assume aluminum. ... > scale and mineral buildup in iron pipes. ...
    (rec.woodworking)
  • Re: Low-cost retail CO2 bottles?
    ... > Buy a Kipps generator and use it with marble ... > chips and dilute sulphuric or hydrochloric acid*. ... Calcium sulfate, which is not very soluble, and very dilute residual ...
    (sci.optics)
Loading