When I first read this thread, I was certain that I would never have to use this particular bit of archane trivia… not so.
I have a designer who is set on having a blued finish on a limited number of exposed structural steel columns. I forwarded the link to this thread to him for his information, and he is still set on it. Am all but certain that it will be VE’d out before the end of the day.
Have developed a specification more appropriate to public work, and if anyone is interested, I will share. The information here has probably saved me a day (or more) of research. Thanks to everyone who provide input.
Last December, I, too, had a designer who thought blued steel looked cool. I didn’t remember this thread (seemed irrelevant at the time) and started another. Maybe specifiers do serve a purpose… 
I have also had blackened steel finish requested on two or three recent projects. It always goes away, probably when the Contractor says WTF!! in front of the Owner.
I think the recent interest stems from a Kieran Timberlake project at Wellesley College. You can read more about their finish research here: http://kierantimberlake.com/research/steel_finishes_study_1.html
I don’t know who prepares specifications for Kieran Timberlake, perhaps she is listening in and could tell us more.
It’s amazing what you can accomplish with enough fame and enough money…we should thank Mr. Timberlake for sharing his research.
You may be safe – I specified blued steel a few years ago and it was so expensive that we ended up going to a more typical finish. Since the fabricators will all have their own version of this, I think the way to specify this is by use of samples that are approved and matched. (of course on public work this won’t work…)
ps: Keiren Timberlake is two guys – Stephan Keiran, and James Timberlake. and they probably do all their stuff by matching samples.
Oops - thanks for the correct information, Anne (my bad).
I think you’re right, especially with something like this. There’s no way to get the desired results without approved samples to match. From all I found out, this process is more of an art than a science, in spite of the carefully prepared chemicals involved, and should be treated and specified as such.
This sounds akin to specifying a verdigre patina finish for bronze. We’ve used wording along the lines of “Chemicals, proportions, and procedures specified are suggestive only. Vary as may be recommended by fabricator and finisher to achieve appearance and finish of Architect’s samples.”
These finishes get tricky. I try to specify performance very specifically; appearance to match samples, and if the performance affects the appearance, then it has to get very specific.
For blued handrails, you probably don’t want the bluing on the rail that anyone touches – only for the supports and accessory rails. You’ll want stainless steel for the actual handrail.
another option is that there are some stainless steels that have color added to them – they don’t look blued, but you can get a dull dark gray that is really attractive (and very expensive as well). Japan has some of the prettiest colored steels with lovely finishes.
Can’t we just buy these guys a nice gun so they can admire the bluing, and put urethane on the railing?
I write specs for KieranTimberlake, and can fill you in on the process spec’d for the Wellesley Chapel project. Based on the research & test applications outlined in the link cited above, a lacquer finish was selected, using Permalac, w/ black color & satin finish to match architect’s sample.
The spec went into some detail for surface prep, including provisions for degreasing & cleaning; abrading; dressing using silicon carbide pads w/ a suspension of powdered pumice in thinner; and specific processes for cleaning.
There were also specific provisions for the lacquer application process, which involved wiping the surfaces; thinning the lacquer product; and requirements for dry-film thickness, adhesion, hardness & flexibility.
I couldn’t have written all of this, of course, without the materials research & in-house sampling prepared by KT – which as you might guess is top-notch and extraordinarily detailed.
Jeff Wilson
Wilson Consulting Inc
Narberth PA
Jeff, Thanks for your input. Very helpful.