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David Axt, AIA, CCS, CSI
Senior Member
Username: david_axt

Post Number: 699
Registered: 03-2002
Posted on Friday, August 11, 2006 - 04:29 pm:   Edit PostDelete PostPrint Post

Does anybody have a source for information on this finish? The architect wants to have black interior handrails but not paint them.
Lynn Javoroski CSI CCS LEED AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 407
Registered: 07-2002
Posted on Friday, August 11, 2006 - 05:35 pm:   Edit PostDelete PostPrint Post

Does he mean blackened steel? There may be a thread on that here...otherwise, I did considerable research on it for another project. I wouldn't recommend it for handrails. It's not a stable finish unless you coat it - it's easier to use a good coating (Tnemec, Ameron, etc.)
David Axt, AIA, CCS, CSI
Senior Member
Username: david_axt

Post Number: 702
Registered: 03-2002
Posted on Friday, August 11, 2006 - 06:06 pm:   Edit PostDelete PostPrint Post

Currently in my building the lobby floor and elevator cab is blackened steel (I think). So far it has held up well.
Vivian Volz, RA, CSI, CCS
Senior Member
Username: vivianvolz

Post Number: 75
Registered: 06-2004
Posted on Monday, August 14, 2006 - 01:41 pm:   Edit PostDelete PostPrint Post

We did do a thread on this, but now I can't find it.

To recap that thread, the black finish comes from a conversion wash, also commonly called bluing in the gun industry. In architectural uses it should be coated. For a matte finish, see if a sample of many thin passes of a urethane coating achieves the desired effect.

Perhaps the architect would do black non-touch surfaces and a stainless (or other stable metal) gripping surface?

What I don't understand about all this is all the black wrought iron that seems to have lasted forever.
George A. Everding, AIA, CSI, CCS, CCCA
Senior Member
Username: geverding

Post Number: 207
Registered: 11-2004
Posted on Monday, August 14, 2006 - 01:47 pm:   Edit PostDelete PostPrint Post

Was it this thread?
Black steel

http://discus.4specs.com/discus/messages/2196/1027.html
Vivian Volz, RA, CSI, CCS
Senior Member
Username: vivianvolz

Post Number: 76
Registered: 06-2004
Posted on Monday, August 14, 2006 - 01:49 pm:   Edit PostDelete PostPrint Post

That's the one. Thanks.
Lynn Javoroski CSI CCS LEED AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 412
Registered: 07-2002
Posted on Monday, August 14, 2006 - 01:53 pm:   Edit PostDelete PostPrint Post

Here's additional information I collected:
Blued: This is probably the oldest finish to be found on a gun. Some even say it's the most attractive finish. What this finish really is, is a carefully controlled oxidation of the surface of the metal. Salts and other chemicals are used to "blue" the gun. Mostly the results are a blackened finish and not actually the color blue by any means... There are two ways of doing this, hot and cold. Professional grade bluing uses the hot methods as it's a more effective method and cold Bluing is something you can actually do a home to touch up a warn blued finish. The biggest downside to blued is that it offers very little in terms of corrosion protection. The blued finishes that are highly polished are better for that as there is less surface imperfection for moisture to adhere to and take root. This is why you must always wipe a blued gun down with an oil to displace moisture and O2 and provide a barrier against the same. I've seen neglected blued guns rust completely on a humid Virginian summer night. It also offers little abrasion protection. Old duty guns with blued finishes often look like hell. With scratches and areas where the finish is worn down to the bare metal.. But then again there is a certain nobility in the worn looking gun that I cannot explain. If the gun is free of corrosion and operates smoothly... The wear can be a sign that the owner has been there and done that with this dependable sidearm. You can always tell the new GI's from a distance... The are the ones wearing the BDU's that look like they just came out of the packet. Same thing with a blued gun, really. This is why a blued gun can still be considered in good condition with only 60% of it's finish left. But that's another article for another day.

Blued Regular Duty Steel Strapping, Blued & Waxed:
A mild carbon product for most general applications. The surface finish is blued by a flame process rather than painted. Bluing the steel burns off foreign material from the steel. Blued strap is an economical alternative that offers similar characteristics as painted strap with less cost. Please contact us for more information

You need to dry and seal the work right after you blue it. You can't just leave it sitting around to rust. I've blued hundreds of things, large and small, with no rust problems.
Once you finish blueing a piece, immediately dry it with towels, rags, whatever is absorbant, then slowly heat the piece with a torch until you see the moisture in the metal come to the surface and then evaporate. While it is still hot, wax the piece. Or, if you want a clear paint finish, wait until it has cooled enough to comfortably leave your hand on the piece, then immediately paint it.
Gun blue is by far the easiest way to get a natural blackened finish. If you are not willing to take the trouble necessary to do a blueing job properly, I suggest you just stick to paint finishes

Bluing
Subjecting the scale-free surface of a ferrous alloy to the action of air, steam, or other agents at a suitable temperature, thus forming a thin blue film of oxide and improving the appearance and resistance to corrosion. This term is ordinarily applied to sheet, strip, or finished parts. It is used also to denote the heating of springs after fabrication in order to improve their properties.

Blued – Degreased and heat-cleaned to form thin blue oxide film required by lathers.

The blueing solution is very simple: 60..70 % NaOH and the rest NaNO3 (sodium nitrate). This mixture is added to boiling water until the boiling point of the solution reaches 140..145 oC. Note, that the total water content of the solution will be about 40 %, so relatively little water should be used. The parts to be blued are immersed in the boiling solution for 5 to 10 minutes (no more or the finish will become reddish). The temperature must not exceed 150 oC or the parts will immediately become red or rusty. Below 135 oC the bath won't work either. The parts must also be free of any grease or other impurities or the finish will be uneven (spots of different color).

Certain ``blued steel'' coil (also know as ``steamed blue steel'' or ``blue oxide'') with a thickness and size of 0.38 mm x 940 mm x coil, and with a bright finish; Certain cold-rolled steel sheet, which meets the following
Certain "blued steel" coil (also know as "steamed blue steel" or "blue oxide") with a thickness
and size of 0.30 mm x 0.42 mm and width of 609 mm to 1219 mm, in coil form.

1. The metal must be clean. No finger prints etc. so you get even reaction.
2. Use gun blacking (a form of bluing) Coat evenly and quickly as multiple coats give slightly different colors
Different acids get different colors phosphoric acid with selenium will give you black. The ones you mentioned may result in the blue color.
3. Neutralize surface with water (yes, water,) this is critical for any further coating or finish. pH as required by coating mfr. Usu 7.0 = to water
4. After you’re sure its neutral then coat it with something. Remember you have just made "rust." Black or blue rust but still rust.
Gunsmiths make the special rust to "fluff up" the surface of the metal so that it has a patina that protects the metal and (I believe can hold oil that then protects the metal and allows no more Oxygen in so the rust stops growing and your gun stays shiny)
I have speced clear coat urethanes with varying success and waxes.
The final finish has always been in the field between the architect and the contractor. One job still looks good with no finish but it’s interior, and dry. But I don’t trust it forever.

Any typos are original from the source.
Lynn Javoroski CSI CCS LEED AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 413
Registered: 07-2002
Posted on Monday, August 14, 2006 - 01:56 pm:   Edit PostDelete PostPrint Post

Also this:

SECTION 05500
STEEL BLUEING PROCESS
PART 1 - GENERAL
1.1 SUMMARY
A. Metal must be clean and free of rust.
B. Clean metal parts to be blued with denatured alcohol and rinse with cold water.
C. Apply BIRCHWOOD CASEY Perma Blue with saturated swab or sponge.
D. Allow to work *minute; rinse with cold water and wipe dry.
E. Repeat steps 2-5 for second application.
1.2 PROTECTION FOR BLUED METAL
A. Apply a thin even coat of Johnson Paste Wax (The Original Formula) with dry soft cloth.
B. Allow to dry to a haze (approximately 20-30 minutes).
C. Buff when soft cloth.
D. Repeat steps 1-3 for second application and for reconditioning when necessary.
END OF SECTION
Anonymous
 
Posted on Monday, August 14, 2006 - 04:36 pm:   Edit PostDelete PostPrint Post

Based on an interior designer's requirement, I researched and ended up specifying this company's products for chemical colored steel stairs railings:

Triple-S Chemical Products, Inc. (800/862-5958)

It requires a transparent finish coat, and I spec an epoxy system by Devoe.

Of course, the Contractor had a fit and we ended up using a black tinted lacquer instead (from the same company, I believe).

You need to ask yourself whether or not this is really what you want to do. Anything large scale is extremely difficult to do with chemical coloring... You would be better advised to go with a coating system instead.
Lynn Javoroski CSI CCS LEED AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 418
Registered: 07-2002
Posted on Tuesday, August 15, 2006 - 10:57 am:   Edit PostDelete PostPrint Post

Serendipity. Just got this from an interior designer I'm working with:

http://www.birchwoodcasey.com/metal/index.html

But I still think a good coating will yield better results.
Anonymous
 
Posted on Tuesday, August 15, 2006 - 02:05 pm:   Edit PostDelete PostPrint Post

I would not use any kind of a bluing process on a handrail, or anything else which comes into regular contact with human skin. Having been a competitive shooter for over 20 years, I have quite a bit of experience in maintaining blued finishes.

One of the worst things for bluing (besides humidity) is human perspiration and skin oils. These will spot and deteriorate bluing faster than just about anything. Wax helps a lot, but is that a maintenance issue you want to burden the Owner with because a designer wants a black handrail?

The process does not lend itself to large-scale pieces, either. Blued parts must be evenly and consistently immersed in a tank for a specific period of time. I don't know how the solution would react to welds, either (unless you welded it up afterwards and touched everything up with cold blue.)
Another downside to bluing is that it uses some really nasty chemicals, particularly selenium. The cost of the applicator's procedures to mitigate the environmental hazards and dispose of the chemicals will be reflected in the price. In after-market gunsmithing work today, it now costs more to re-blue a gun than it does to apply something like Black-T or hard chrome, which are higher quality finishes, and used to cost much more than bluing did.

I'd stick with high-performance coatings of one type or another for any application like this. Some type of automotive finish with a protective clear coat would work, too.

Sorry if I've rambled on-I'm interested in metal finishes in general, and it's not very often than work and hobbies cross paths.

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