Cold bluing or cold blackening seems to be an accepted method of
protecting steel parts in the shop. Add on a sealant or keep the part
oiled and supposedly it will resist rust and corrosion indefinitely.

I have done cold bluing in the ancient past using the gunsmith supplies.
When I was a kid I stripped and refinished and old Sears .22 rifle,
and I built 4 different black powder kit guns that came in the white.

The quantity in gunsmith supplies is rather stingy. The amount in a
bottle is enough to do a fair to good job on one complete firearm and
maybe do some touch up work if you know how to make it blend. Two guns
if you don't make any mistakes.

More recently I've started making tools in my own shop. Many were
intended to be a single use or short run tool. Long reach clamp to hold
a slide bar in a mold until it could be match machined and clamped in
other ways. Long reach tool holder for deep milling. Half round tool
for work stop in the spindle and work positioning. Lots of stuff
really. Mostly I have left them in the white (fine for carbide tools
and some I've made in stainless) because they were made to do a single
job. I didn't throw them away, but I didn't plan for them to be likely
to see future use. It turns out nearly all of them have been much more
useful than I originally planned. I need to blacken and oil them I think.

Not wanting to go with a stingy little bottle from a gunsmith supply I
looked at McMaster and MSC. They both stock some form of steel tool
black. It seems expensive, but its a larger quantity than your local
retail bottle of gun blue. How long does it really last? Is the
"sealant" in some of those kits better than just oiling the part? Is it
just oil? I don't mind spending the money. I just want to know its
worth it.

--
This email has been checked for viruses by AVG.
https://www.avg.com

Bob La Londe <none@none.com99> wrote:
> Cold bluing or cold blackening seems to be an accepted method of
> protecting steel parts in the shop. Add on a sealant or keep the part
> oiled and supposedly it will resist rust and corrosion indefinitely.
>
> I have done cold bluing in the ancient past using the gunsmith supplies.
> When I was a kid I stripped and refinished and old Sears .22 rifle,
> and I built 4 different black powder kit guns that came in the white.
>
> The quantity in gunsmith supplies is rather stingy. The amount in a
> bottle is enough to do a fair to good job on one complete firearm and
> maybe do some touch up work if you know how to make it blend. Two guns
> if you don't make any mistakes.
>
> More recently I've started making tools in my own shop. Many were
> intended to be a single use or short run tool. Long reach clamp to hold
> a slide bar in a mold until it could be match machined and clamped in
> other ways. Long reach tool holder for deep milling. Half round tool
> for work stop in the spindle and work positioning. Lots of stuff
> really. Mostly I have left them in the white (fine for carbide tools
> and some I've made in stainless) because they were made to do a single
> job. I didn't throw them away, but I didn't plan for them to be likely
> to see future use. It turns out nearly all of them have been much more
> useful than I originally planned. I need to blacken and oil them I think.
>
> Not wanting to go with a stingy little bottle from a gunsmith supply I
> looked at McMaster and MSC. They both stock some form of steel tool
> black. It seems expensive, but its a larger quantity than your local
> retail bottle of gun blue. How long does it really last? Is the
> "sealant" in some of those kits better than just oiling the part? Is it
> just oil? I don't mind spending the money. I just want to know its
> worth it.

I wonder the same. There appear to be something like 3 classes of bluing.

1) the room temperature selnium stuff, like Hoppe's gun blue. Works fine
to make parts dark. Durability is questionable. The stuff is heavy
metal toxic so beware and wear gloves. You can't wash it out of your
body once absorbed. It's more of a coating of a dark selniumcompound
than real oxide layer.

2) high temperature oxide kits, seems to require some weird solutions and
you the seal it all with some snake-oil like sealant. Kits come with
and require special cleaning steps. Expensive

3) low temperature kits that don't need the 300F solutions or whatever
they are. Same special cleaners and magic sealant involved. Expensive

THe last bottle of Hoppes I bought was $3.79, I really don't care if I
have to reapply it to stuff. Coat with your favorite rust preventer oil
and you're golden.

EPI (epi.com) makes sample kits of #2 and #3. Haven't tried them yet
though.

None of it will be as durable as real steam oxide coating you'd get on
even cheap chinese tools, but it's all better than metal that gets rusty
fingerprints when you handle it.

to prevent rust, my favorites are LPS-2 and even better, gun-coat from
Fluoramics. It has some additives with an affinity for iron, so the
protection is superior to a smear of some random lubricating oils. Any
TRUE corrosion inhibitor should have those extra ingredients.

"Bob La Londe" wrote in message news:smjtg6$nsd$1@dont-email.me...

Cold bluing or cold blackening seems to be an accepted method of
protecting steel parts in the shop. Add on a sealant or keep the part
oiled and supposedly it will resist rust and corrosion indefinitely.

--------------------

I was surprised by how long a knurled sawmill adjusting knob I made from
12L14 and blackened by boiling in sodium thiosulfate (photographer's hypo)
lasted without rusting.

On Thu, 11 Nov 2021 13:12:54 -0700
Bob La Londe <none@none.com99> wrote:

<snip>
>Not wanting to go with a stingy little bottle from a gunsmith supply I
>looked at McMaster and MSC. They both stock some form of steel tool
>black. It seems expensive, but its a larger quantity than your local
>retail bottle of gun blue. How long does it really last? Is the
>"sealant" in some of those kits better than just oiling the part? Is it
>just oil? I don't mind spending the money. I just want to know its
>worth it.

A bit of a mess... but a bunch of really old posts I saved on this
subject you can peruse...

I couldn't remember the name till I looked through this, but

https://caswellplating.com

might be worth looking at for ideas and supplies.

========
Newsgroups: rec.crafts.metalworking
Subject: Re: cold blueing chemicals...
From: Ecnerwal <LawrenceSMITH@SOuthernVERmont.NyET>
Date: Sun, 29 Apr 2007 23:52:17 GMT
--------
In article <wMGdnZobiad3uqjbnZ2dnUVZ_gCdnZ2d@comcast.com>,
"Al A." <alanganes@comcast.net> wrote:

> Any ideas or alternatives?

Go hot and Parkerize (phospate) it? My understanding is that it's far
more effective against rust, and given "small parts" cooking should not
be a big deal - perhaps an old coffee can and a hot plate with a pot of
water to set the coffee can in?

--
Cats, coffee, chocolate...vices to live by

========
Newsgroups: rec.crafts.metalworking
Subject: Re: cold blueing chemicals...
From: "Randal O'Brian" <ROBRIAN1@austin.rr.com>
Date: Mon, 30 Apr 2007 12:56:39 -0500
--------

"Diamond Jim" <jbanks2@ec.rr.com> wrote in message
news:463550ec$0$8986$4c368faf@roadrunner.com...
>
> <stans4@prolynx.com> wrote in message
> news:1177891193.017361.100830@y80g2000hsf.googlegroups.com...
>> On Apr 29, 5:17 pm, "Al A." <alanga...@comcast.net> wrote:
>>> Hi All,
>>> I am looking to blue some small parts (a flash hider, "claw" type
>>> scope mount, and misc small tools & doo-dads, etc.) and was wondering
>>> what the collective RCM wisdom on cold blueing chemicals is. It is not
>>> necessary that these have a deep polished show-grade finish, these
>>> aren't show-pieces. Mostly looking to have stuff look "finished" and not
>>> have rust develop on everything. This is on steel and for occasional
>>> (few times/year) use. I would like a black finish or something close to
>>> it.
>>>
>>> A perusal of the Brownells catalog and website reveals a number of
>>> different brands and formulations. Any favorites?
>>>
>>> Quite a few years ago, I used some of the Birchwood-Casey
>>> bought-it-at-K-Mart stuff, mostly with pretty incosistent and sort of
>>> blah results. Is that about what I can expect from any cold blue?
>>>
>>> Any ideas or alternatives?
>>>
>>> Thanks for any ideas,
>>> AL A.
>>
>> Oxpho Blue has been good stuff, it's almost as tough as a hot-salts
>> job. Downside is that it's miserable to apply evenly over large
>> surfaces with no practice. If your parts are small enough to dunk, do
>> that. Works better if the parts are warmed. Parts have to be CLEAN,
>> no fingerprints. Bronze wool works well to get the smut off
>> afterwards.
>>
>> Alternatives, Dicropan IM or the old Herter's Belgian Blue. Both are
>> kind of pricey to order with HazMat charges. Dicropan gives you a
>> black finish, the Herter's gives you a real blue. Both take nothing
>> more than a tank of boiling water and CLEAN parts. You need some way
>> to card off the deposit, steel wool, bronze wool, rotary brush,
>> whatever. You can do a whole rifle action in an afternoon. Both are
>> a lot more resistant to wear than cold blues.
>>
>> Did I mention you have to have CLEAN parts? Brake cleaner, boiling
>> TSP, acetone, MEK, TCE, freon head cleaner, carbon tet and dry
>> cleaning fluid have all been used. Alcohol doesn't cut it for
>> degreasing, isopropyl or rubbing. If you get spots that won't take,
>> grease is the culprit. With Oxpho Blue, you can "rub it in" with the
>> wool to shift the grease, but chances are the surface will be mottled.
>>
>> Stan
>>
>
> Go with the Oxpho blue, it is about the best cold blue around.
>
Oxpho Blue works exceptionally well if you pickle the degreased part in
HCL before bluing. I use hardware store muriatic acid cut 50-50 with
water. Dip the clean parts in the acid for about 30 sec, rinse off with
clean water and then apply the blue, dipping if possible.

Randy
========
Newsgroups: rec.crafts.metalworking
Subject: Re: cold blueing chemicals...
From: "Shaun Van Poecke" <shaunvanpoecke@bigpond.com>
Date: Mon, 30 Apr 2007 10:23:45 GMT
--------

"Al A." <alanganes@comcast.net> wrote in message
news:wMGdnZobiad3uqjbnZ2dnUVZ_gCdnZ2d@comcast.com...
> Hi All,
> Any ideas or alternatives?
>
> Thanks for any ideas,
> AL A.

As an alternative you may like to consider "gun kote". Its gained
quite a bit of popularity in many areas, used by navy seals on all
their guns if i recall correctly. Lots of gun guys use it for all
sorts of things. Comes in about a dozen colors from memory, mostly
differnt shades of black, and different shades of silver.

I bought a small tin of both the gloss black and some sort of stainless
steel color about 4 years ago to paint the cylinder heads on a bike.
According to their data (believe it if you will) its one of the only
finishes that wont reduce heat transfer. Paint and anodizing both
reduce heat transfer. They claim gun kote actually increases it by a
very small amount. They have extensive data on resistance to heat,
chemicals and salt water.

Application is supposed to involve pre-heating the part (I put it in
the oven, or for the larger stuff sat it on top of an inverted
household electric heater) then spray on to apply. I didnt have a
spary gun, so i used a brush... while the results probably werent good
enough for the fine tolerances on a gun, the finish was excellent and
durable. I washed my bike with a high pressure hose every week for
about 2 years afterwards until i sold it, never had to re-apply.

I think it was about middle expensive from memory, but not ludicous.

as usual, no affiliation with company etc blah blah blah

Shaun
========
Newsgroups: rec.crafts.metalworking
Subject: Re: cold blueing chemicals...
From: Rex <burkheimer@gmail.com>
Date: Mon, 30 Apr 2007 19:12:26 GMT
--------
Al A. wrote:
> Hi All,
> I am looking to blue some small parts (a flash hider, "claw" type scope
> mount, and misc small tools & doo-dads, etc.) and was wondering what the
> collective RCM wisdom on cold blueing chemicals is. It is not necessary
> that these have a deep polished show-grade finish, these aren't
> show-pieces. Mostly looking to have stuff look "finished" and not have
> rust develop on everything. This is on steel and for occasional (few
> times/year) use. I would like a black finish or something close to it.
>
> A perusal of the Brownells catalog and website reveals a number of
> different brands and formulations. Any favorites?
>
> Quite a few years ago, I used some of the Birchwood-Casey
> bought-it-at-K-Mart stuff, mostly with pretty incosistent and sort of
> blah results. Is that about what I can expect from any cold blue?
>
> Any ideas or alternatives?

I used some BC cold blue on a beater S&W a few months ago.
It already looks beat up, with minimal handling and no shooting or
cleaning since.

I did some research on cold blues. While many recommended Oxpho Blue
from Brownells. several people who seemed to know what they ere doing
(i.e. gunsmiths) recommended the Wheeler product over Oxpho.
So I ordered a bottle, and will try it on a 1911 frame shortly.

Also bought a serving of Gunkote, and will sample that on a similar
project.
=====
=====
Newsgroups: rec.crafts.metalworking
Subject: Re: Blueing products
From: Don Foreman <dforeman@NOSPAMgoldengate.net>
Date: Thu, 05 Jan 2006 11:11:45 -0600
--------
On Wed, 4 Jan 2006 17:47:17 -0700, "JensenC" <farview at frontier dot
net> wrote:

>I'm about to make some welded square tube picture frames and have been
>looking into various blueing products. 44/40 runs about $8.50 for 2 oz.
>Oxpho-blue runs about $9.50 for 4 oz. Van's Instant is about $10 for 4 oz.
>Hoppes runs about 9$ for 4 oz.
>
>I'm wondering what folks here have found to work best on mild steel. Any
>hints or tricks?

"Leon Fisk" wrote in message news:smlnfe$vst$1@dont-email.me...

Go hot and Parkerize (phospate) it? My understanding is that it's far
more effective against rust, and given "small parts" cooking should not
be a big deal - perhaps an old coffee can and a hot plate with a pot of
water to set the coffee can in?

----------------

Parkerizing undoubtedly gives a more durable finish but the
thiosulfate-blackened blade guide adjuster I made in the 90's still shows no
rust, unlike the 12L14 rod it was made from. I probably wiped it with LPS-3.
https://www.polytechforum.com/metalworking/rust-protecting-12l14-491661-.htm