Blackened Steel

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Author Message mcc351 (Unregistered Guest) Unregistered guest Posted on Thursday, June 11, 2015 - 01:14 pm:    Blackened steel seems to be used a lot more frequently in our office but there doesn't appear to be a lot of resources out there. does anyone have any tips on specifying? ASTM type references? standards? Lynn Javoroski FCSI CCS LEED® AP SCIP Affiliate Senior Member Username: lynn_javoroski Post Number: 2027 Registered: 07-2002 Posted on Thursday, June 11, 2015 - 03:38 pm:    Are you referring to blued steel? A couple of years ago, I did research on this; There's another thread on 4specs about it: http://discus.4specs.com/discus/messages/2196/1027.html It's a craft; I don't believe there are standards (but I could be wrong). You'd want samples and mock-ups. Ronald L. Geren, FCSI, AIA, CCS, CCCA, SCIP Senior Member Username: specman Post Number: 1313 Registered: 03-2003 Posted on Thursday, June 11, 2015 - 03:43 pm:    This is what I've done: In PART 1 in "Quality Assurance" Article: "A. Blacken Finisher Qualifications: A firm experienced in successfully applying black oxide finishes." In PART 2 within "Steel Finishes" Article: "A. Surface Preparation: Clean surfaces to comply with SSPC-SP 1, "Solvent Cleaning," to remove dirt, oil, grease, or other contaminants that could impair paint bond. Remove mill scale and rust, if present, from uncoated steel, complying with SSPC-SP 5/NACE No. 1, 'White Metal Blast Cleaning,' or with SSPC-SP 8, 'Pickling.' "B. Pretreatment: Immediately after cleaning, apply a coating of petroleum-based penetrating oil. "C. Blackened Finish: Immediately after cleaning and pretreating, create a black oxide finish over exposed surfaces using heat and penetrating oil treatments. Repeat treatments until black oxide finish matches Architect’s sample." Ron Geren, FCSI, AIA, CCS, CCCA, SCIP www.specsandcodes.com J. Peter Jordan Senior Member Username: jpjordan Post Number: 845 Registered: 05-2004 Posted on Thursday, June 11, 2015 - 06:16 pm:    Ron; you should have added: "Wait until it rusts" or maybe you don't have that problem in Aridzona. Chris Thomas (Unregistered Guest) Unregistered guest Posted on Wednesday, July 01, 2015 - 04:28 pm:    In reference to your asking about which ASTM standards to specify, I don't believe there are any that specifically reference a black oxide finish. Since it is a finish or a coating, it should not effect the material characteristics of the steel, so you can use the base ASTM for metal such as E8 or similar when specifying these sorts of materials. I read hundreds of pages worth of ASTM standards a month and have not found any topical instances of blackened steel. We regularly publish articles which summarize ASTM tests that pertain to physical testing. If I find anything, I will be sure to post it on our website www.universalgripco.com Are you sure that you are not referencing hardened or heat treated steel? This would change the nature of your question and there are in fact different ASTM specifications for these types of materials. Hope this helps. - Chris RH (Hank) Sweers II RA CSI CCS Senior Member Username: rhsweers2 Post Number: 10 Registered: 08-2005 Posted on Sunday, September 20, 2015 - 10:32 am:    I do specs for a high-end design/build firm that also has their own metal shop - and blackened steel is a big design deal. They have experimented a lot with it, and though it is a proprietry process, I pointed out it would be best to spec the process, so they would be competitive with others when bidding/proposing their services (showing all processes required). You should know though that this is not a "final" finish - as it still requires periodic maintenance with furniture polish, to remove minute rusting that continues. We also use a powder-coated blackened finish when this is not feasible. I'm still pushing them to get a more permanent final coat - the referenced manufacturer has a laquer coating, but when they used that, it degraded the "natural" look of the steel too much - which is why they only use a wax finishing: BLACKENED FINISH (BLACK OXIDE): Where indicated in the Drawings as “blackened” or blackened steel finish, provide the following shop-applied finish on steel sheet or steel shapes to match the Architect’s blackened steel finish sample, including color, surface sheen and texture. Note that residual waste materials from this application must be disposed of legally, and cannot be drained to plumbing or drainage systems. BLACKENING MATERIALS: ABRASIVE PADS: general purpose pad equal to Scotch-Brite # 7447 - “Maroon” colored BLACKENING TREATMENT: “Insta-Blak 33 - Gel” by Electrochemical Products Inc. (www.epi.com) BLACKENING FINISH WAX: Clear, “Metal Wax” by Sculpt Nouveau” (www.sculptnouveau.com) SURFACE PREPARATION: After cutting, forming, welding and other fabrication is complete, and welds have been ground smooth, degrease residual mill oil or grease, cutting compounds and other soluble contaminates with denatured alcohol per SSPC-SP1 “solvent cleaning” requirements. After degreasing, hand sand with pad to remove loose mill scale, loose rust, paint and other detrimental foreign material per SSPC-SP2 “Hand Tool Cleaning” requirements. Repeat until residual rust is completely removed. APPLY BLACKENING treatment with abrasive pad evenly over the surface until a consistent darkened patina is achieved. Rinse with clean water, and re-apply blackening treatment and re-wash with water until required level of blackening color is achieved. TORCH SURFACES after application and cleaning to remove all residual moisture from the surface. WAX FINISH: Apply two (2) coats minimum of wax, and burnish surfaces when wax is dry (usually 1 0 2 hours). Any comments are welcome. Especial any ideas for a final coat that would work better. anon (Unregistered Guest) Unregistered guest Posted on Monday, September 21, 2015 - 12:48 pm:    Hank, I have many year's experience with this. Our interior designers call anything that looks like black metal "blackened steel." The finish you describe is legendary in the firm I work for. Often brought up as something we have always done, project after project, but legend it remains, because this finish is rarely, if ever, actually used on any project. Here are the facts about this finish: 1. It is fine for small items - items that can be immersed in bucket after bucket. Most teams want this finish for large items - stairs, typically - including railings. It is IMPOSSIBLE to get a uniform finish with this process for anything field finished that cannot be fully immersed bucket to bucket. When attempted, the results are usually rejected by the designer... 2. This finish is not durable - it requires a transparent coating to protect it. If not protected, the "blackening" will come off very quickly when/if subject to human contact (railings, metal base, wall panels. etc.). Transparent finish over this finish changes the appearance, and usually unacceptable to the designer. 3. Most finishes described by designers as "blackened steel" are, in fact, simply black coatings - often cheap lacquers or just paint. I have been given countless samples of what was described as "blackened steel" only to find that the sample is some kind of proprietary coating - typically something that the originator of the finish regards as a trade secret, no disclosure possible. But they are coatings. Before I blindly drop in the Insta-Blak into a specification (my spec for this looks almost identical to what you have come up with) I ask for a sample. 99% of the time the sample is not as described, not this finish. I then work with the designer to try and identify the coating and specify an equivalent. A designer on one of my current projects insisted at the outset that the finish he wanted was "blackened steel", insisted that I specify it, and ultimately - after months of back and forth with the Contractor - realized/admitted that, no, in fact what we need is a transparent coating over steel - no way to get the "blackened steel" finish over all of the items scheduled for it that was aesthetically acceptable within budget. We ended up using a coating to get the uniformity, durability, and cost required for the project. Per usual! Hope this helps you. Jeffrey Wilson CSI CCS SCIP Senior Member Username: wilsonconsulting Post Number: 180 Registered: 03-2006 Posted on Monday, September 21, 2015 - 03:08 pm:    There have been other discussions on this forum about blackened steel finishes. For example: http://discus.4specs.com/discus/messages/7464/2642.html?1276547487 A link to a study referenced by one poster is no longer valid, but here is a blog post on the same subject, by one of my clients that has done extensive research to identify relatively simple, repeatable, non-toxic methods for producing this type of finish. It's an interesting read: http://www.kierantimberlake.com/posts/view/100 Jeffrey Wilson CCS CSI SCIP Wilson Consulting Inc Ardmore PA RH (Hank) Sweers II RA CSI CCS Senior Member Username: rhsweers2 Post Number: 12 Registered: 08-2005 Posted on Wednesday, September 23, 2015 - 09:33 am:    We're aware of the not-so-permanent nature of blackened steel finishing - why we also have a powder-coat version, and what I call a "natural steel" version with a clear, laquer coating that IS more rust resistant and less of a maintenance issue. The process doesn't involve dipping anything (cold process, not hot) - and we use it on large furniture pieces - in the office (for large, mobile display panels) and at the Owner's own show-home where they try-out things. The referenced study for Houghton Memorial Chapel at Wellesley College is very interesting, and we will be trying out their recommendations, I'm sure. We would like to have less hazardous chemicals used . . . just saying its done "off-site" but still in our shop is not really great! Phil Babinec Senior Member Username: pbabinec Post Number: 10 Registered: 09-2004 Posted on Wednesday, February 24, 2016 - 07:34 am:    We are using the black permalac finish referenced in the kierentimberlake article. Ok we read the same article before hand. We tested it in the office with good results. I'll keep you posted.