Red Oxide Primer

Archive of Older Topics Archive - Product Discussions #2
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Recently, we had a contractor come back to us with a substitution request for shop-applied red-oxide primer on structural steel, stating that it was banned for use. I immediately new something was not right, I know zinc chromate is a carcinogen and is not allowed in some instances, but had not heard this about red oxide.

Needless to say there was some confusion on the contractors part. We straightened it out, but in my research I found that we were specifying an SSPC - Paint 13 primer. When I looked that up, there is no such thing, I guess anymore. Closest I could find was an SSPC - Paint 11, Red Iron Oxide, Zinc Chromate, Raw Linseed Oil, and Alkyd Primer. Since that didnt seem like much help, I went to SpecText. They had Paint 15, Type 1, red oxide listed. It is an old copy of SpecText, but Paint 15 is for Steel Joist Shop Primer. Then I found in MasterSpec that they deleted Paint 15, Type 1, red oxide from their primer spec.

Now I really am cornfused. Anyone tell me what the correct SSPC designation for shop applied red oxide primer on structural steel? And why is there so much contradictory information in the industry? Who can you trust? It also shows how diligent one must be to keep up with the changes.

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Horse’s Mouth: http://www.sspc.org/

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Dead horse, at that.

I tried that. I can only find the list, can’t access the explanation. Seems these guys aren’t willing to share without payment. I guess I will if I must. I’d go broke if I had to join every society and association available just to do my job.

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Here is my paint resource guy-- great, reliable, straight-forward information and timely. A corrosion engineer located in Indianpolis,IN

tippoliti@sherwin.com
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They shoot horses, don’t they? If that’s a dead-end (pun intended), I’d contact my coating resource guy; he’s with Tenemec (cerickson@tnemec.com and you can mention my name) or you can contact your own Tenemec rep. And I like Ralph’s idea, too. These guys deal with preparation of surface all the time and should have the information - and be willing to share.
Did you try just asking SSPC a question? You’d think they’d be willing to share such important information!

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Thanks, Ralph. And Lynn, yes, pun intended. I was hoping you didn’t take that wrong.

Still, anybody care to comment why two of the guide specs don’t seem to agree?

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Brett: here is the current text from Masterspec, section 05120, revised May of 2004:

“A. Primer: SSPC-Paint 25, Type [I] [II], iron oxide, zinc oxide, raw linseed oil, and alkyd.”

you don’t mention the date for the SpecText section.

if you go to www.sspc.org site, and their listing of standards, you get:
"SSPC-Paint 25, Zinc Oxide, Alkyd, Linseed Oil Primer for Use Over Hand Cleaned Steel, Type I and Type II
May 1, 1997
Editorial Revisions November 1, 2004

This specification covers a slow drying French process zinc oxide, raw linseed oil and alkyd primer suitable for use over hand-cleaned steel.

This primer is suitable for exposures in Environmental Zones 1A (interior, normally dry) and 1B (exterior, normally dry), and is intended for brush, roller or spray application over steel surfaces prepared in accordance with SSPC-SP 2, Hand Tool Cleaning, or better.Within the limitation stated, it is suitable as a shop primer, field primer, maintenance primer, or intermediate coat, and is to be applied in accordance with SSPC-PA 1, Shop, Field, and Maintenance Painting of Steel. If the primed part of the structure is to be exposed to the weather, it should be topcoated as soon as practical."

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SpecText, Winter 2004

Actually, I did find access to SSPC at: http://www.sspc.org/standards/scopes.html

Now I’m trying to find out what the differnce is between red (iron) oxide and zinc oxide.

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Info from my Tnemec rep (he tried to post here, but something happened): “SSPC Paint 13 was discontinued in 1995. Paint 11 calls for a zinc chromate as a rust inhibitive pigment and you do not want to use that or Paint 15 which is for joists. Use SSPC Paint 25. (Tnemec) Series 10-99 or 88HS will be performance equals. And (Tenemec) Series 10-99 is outstanding among primers. Really.”

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SSPC Paint 25 Type I or II? MasterSpec’s hidden text tells me that the Type II has lower VOC. So should I plan on using that on my environmentally sensitive project in California? Anybody know how low is “lower VOC?” Following Lynn’s lead, I have the VOCs for the Tnemec products, but not the limit, if any, imposed by SSPC’s standard.

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Vivian: if you require everything shop primed, then it does’t matter what the VOCS are. just do it that way and save the headache.

Anne

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Anne,

I am not sure I understand about shop priming and VOCs. Can you please explain further?

Thanks.

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The limitations on VOC content of paints are for field-applied coatings. Emissions of VOCs for shop-applied coatings are under the control of the facility where the coating is applied, which may even be in a different jurisdiction than the project. Also, emissions from “factory” or shop facilities is regulated differently (I think), and since the facility is a controlled environment there are more options in how to comply.

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Anne, I take your point. It’s a shop coatings spec I’m writing right now, actually, so the VOC question was more about curiosity than actual need. Just wondering if the 350ish g/L that the Tnemec products contain is typical.

David, Anne’s referring to the fact that the most restrictive VOC regulations are for field-applied coatings, not shop coatings. (What John just said.)

http://www.paintcenter.org/newcalc.cfm has a wealth of information on VOC compliance, probably more than you wanted to know, but also a reasonable introduction to the whys and wherefores of VOC regulations.

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Are you sure that field-applied coatings are held to higher standards than shop- or factory-applied? The California regulations I’ve read do not distinguish. Try www.baaqmd.gov (for Bay Area) and www.aqmd.gov (for South Coast).

On the other hand, these are regulations that the shop-applicator must know about, because he is fined if he doesn’t comply, so it may not matter what you specify - although it would be good not to explicitly flout the law or open yourself to a change order that could have been avoided.

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Susan - both field and shop applied coating products and operations are regulated, and I wouldn’t say one was any more or less restrictive than the other - because the regulations are different. It’s important to ‘follow the money’ - there are lobbying entities for both the field application and shop application of coatings.

For our purposes generally we want to instruct the field applicator more so in my opinion than the shop applicator. The shop applicator generally has a fixed place of business that numerous agencies can utilize in a process of tracking macro/micro compliance. The guy on a jobsite however is much less ‘trackable’.

Generally I think specs that get into issues with air quality regs applicable to shop applicators are questionable from an enforceability perspective. I think we all want cleaner air, but let’s face it, the last I checked, the dry cleaning fluids remain legally acceptable in many coating products despite the high VOCs. Those who have money probably are not subject to the highest levels of enforcement.

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Factory emissions are considered point-source, which makes them subject to different methods of regulation, at least in some places. An interesting aside: Here in Boston when they were permitting the famous “Big Dig” project, there was a huge issue over the tunnel ventilation systems. (For those who don’t know, we put the main interstate highway through town into several miles of tunnels. Yes, after more than 13 years of huge holes in the ground, it’s virtually finished, with landscaping and surface improvements to finish this spring.) There were some who claimed that the exhaust coming from ventilation structures was a point-source of pollution, regulated like a factory. Of course, the same amount of pollution was pouring out of the tailpipes every day on the elevated highway, but it could not be regulated in that “form”.

It is plausible for the applicator of a shop-applied coating to use technology to remove VOCs from exhaust streams to the outside environment, though they probably wouldn’t do that. They can also use powder-coating, which cannot be done in the field. Of course, structural steel cannot be efficiently powder-coated due to its size. (I may be wrong about that, anyone know?) As a practical matter, I’m guessing that an applicator of a shop-applied coating on structural steel is probably complying pretty much with the same VOC issues as in the field. It is also true that specifiers are more interested in trying to control what happens in the field. We are also required by law to specify the right products–technically, we could be charged with a crime for specifying a non-compliant coating. I don’t know if any architect or specifier was ever charged this way.

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I learned yesterday at a coating seminar that you want to be careful about what you specify as “shop” coated. You cannot simply leave it to the sub-contractor to give you a quality shop primer, for instance. You do need to specify what you want, or you may get red water that cost the shop about $5 a gallon.

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This has all been very interesting. I would be interested in opinions as to to the best approach to specifying shop coatings. Which things absolutely need shop coating? Whether to specify by characteristics (either by referencing a standard or explicitly), or by brand names? Should the specifier specify limits on VOC content?

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My opinions -
Absolutely need: Any 25 year finishes.
Brand names: no. Suggest identifying classes of coating polymers (not brands) be shop applied.
Specify VOC content: No, not for shop applied coatings. However, review with your LEED consultant about whether you seek to reform the coatings world with your project as the leverage.

Incidentally, it is possible and even preferable to coat very large structural steel elements prior to shipping, assembly, and erection. This is reasonable when steel is being ASSEMBLED then erected (a special case). If erection and assemply occurs simultaneously (the case with most building steel), in that case the advantage of shop coating may have been lost. Generally, structural steel indicated to recieve coatings should be finished in place for convenience, thus the VOC content is “our business” as specifiers.