# Clear Finish for Exposed Structural Steel Columns **URL:** \ **Category:** Archive - Product Discussions #3\ **Created:** [June 12, 2007, 4:10pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827 "2007-06-12T16:10:40Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![dhassloch](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dhassloch](https://forum.4specs.com/u/dhassloch)\ **Post date:** [June 12, 2007, 4:10pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/1 "2007-06-12T16:10:40Z")
We have a LEED project team wanting a clear finish on an interior exposed steel column. Therefore, the VOC content must be 50 g/L or less. Has anyone had success with a product for this application? Tnemec has several options, but they are epoxies, and this application will be exposed to UV. Thank you for any assistance. ---
**Author:** ![lynn\_javoroski](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.4specs.com/lynn_javoroski/32/188_2.png) [@lynn\_javoroski](https://forum.4specs.com/u/lynn_javoroski)\ **Post date:** [June 12, 2007, 4:17pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/2 "2007-06-12T16:17:53Z")
Is the steel galvanized? ---
**Author:** ![dhassloch](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dhassloch](https://forum.4specs.com/u/dhassloch)\ **Post date:** [June 12, 2007, 4:55pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/3 "2007-06-12T16:55:16Z")
It has not been erected yet, so can still go either way, but it has been specified to be galvanized. ---
**Author:** ![Anonymous](https://avatars.discourse-cdn.com/v4/letter/a/8491ac/32.png) [@Anonymous](https://forum.4specs.com/u/Anonymous)\ **Post date:** [June 12, 2007, 6:04pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/4 "2007-06-12T18:04:20Z")
Shop coat the steel with whatever you need, and the LEED requirements do not apply. ---
**Author:** ![dhassloch](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dhassloch](https://forum.4specs.com/u/dhassloch)\ **Post date:** [June 12, 2007, 6:40pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/5 "2007-06-12T18:40:52Z")
That would be preferable, but they need to do sand blasting and welding in the field, and want to maintain the industrial look. ---
**Author:** ![redseca2](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.4specs.com/redseca2/32/50_2.png) [@redseca2](https://forum.4specs.com/u/redseca2)\ **Post date:** [June 12, 2007, 7:18pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/6 "2007-06-12T19:18:22Z")
Here is a link to an article about the exposed steel at Pixar Movie Studios (hope you can make it work): [http://www.aisc.org/MSCTemplate.cfm?Section=Back\_Issues1&template=/ContentManagement/ContentDisplay.cfm&ContentID=21946](http://www.aisc.org/MSCTemplate.cfm?Section=Back_Issues1&template=/ContentManagement/ContentDisplay.cfm&ContentID=21946) This is a look, clear coated steel with warts and blemishes, I have been asked to try to match in the past. ---
**Author:** ![lynn\_javoroski](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.4specs.com/lynn_javoroski/32/188_2.png) [@lynn\_javoroski](https://forum.4specs.com/u/lynn_javoroski)\ **Post date:** [June 12, 2007, 8:01pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/7 "2007-06-12T20:01:21Z")
Try searching for what you need here: [http://www.ppgpmc.com/](http://www.ppgpmc.com/) ---
**Author:** ![randy\_cox](https://avatars.discourse-cdn.com/v4/letter/r/ebca7d/32.png) [@randy\_cox](https://forum.4specs.com/u/randy_cox)\ **Post date:** [June 13, 2007, 12:01pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/8 "2007-06-13T12:01:56Z")
does the column need to be fire rated? ---
**Author:** ![dhassloch](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dhassloch](https://forum.4specs.com/u/dhassloch)\ **Post date:** [June 13, 2007, 6:15pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/9 "2007-06-13T18:15:14Z")
It does not have to be fire-rated, and it has been specified to be shop primed, sandblasted in the field to remove all primer, and then to be clear-coated to maintain the steel look. ---
**Author:** ![Anonymous](https://avatars.discourse-cdn.com/v4/letter/a/8491ac/32.png) [@Anonymous](https://forum.4specs.com/u/Anonymous)\ **Post date:** [June 13, 2007, 7:21pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/10 "2007-06-13T19:21:44Z")
Yesterday it was specified to be galvanized. Your designers must be worse than mine. ---
**Author:** ![dhassloch](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dhassloch](https://forum.4specs.com/u/dhassloch)\ **Post date:** [June 13, 2007, 11:58pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/11 "2007-06-13T23:58:01Z")
Two different projects, two different structural engineers. PPG has declined to offer any products for this use. I found the article on Pixar, but without any product information. Thank you all for your assistance. It looks like we’ll be painting. ---
**Author:** ![Rliebing](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@Rliebing](https://forum.4specs.com/u/Rliebing)\ **Post date:** [June 14, 2007, 11:05am UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/12 "2007-06-14T11:05:18Z")
Try e-mail to [tippoliti@sherwin.com](mailto:tippoliti@sherwin.com) Tony is a corrosion engineer who is a wealth of information on sophisticated coatings. I would think such a person might be a better source than just a paint rep. ---
**Author:** ![bunzick](https://avatars.discourse-cdn.com/v4/letter/b/a587f6/32.png) [@bunzick](https://forum.4specs.com/u/bunzick)\ **Post date:** [June 14, 2007, 1:06pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/13 "2007-06-14T13:06:11Z")
If the column is indoors, glass will filter out some of the UV that would be detrimental to epoxies. You may want to look at your glazing system to see how much filtering of UV it would have, and then check with Tnemec again. Some coatings, and PVB interlayers especially, block UV. PPG says 6mm clear glass filters 50% of UV, but I don’t know what wavelength cutoff they’re using. It seems to me that this would probably be acceptable in an indoor environment. Also, consider that minor yellowing or chalking may not be noticable with the particular application you have. ---
**Author:** ![redseca2](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.4specs.com/redseca2/32/50_2.png) [@redseca2](https://forum.4specs.com/u/redseca2)\ **Post date:** [June 14, 2007, 4:23pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/14 "2007-06-14T16:23:53Z")
Regarding a clear finish on interior steel: I found this from a project in Utah (VOC’s are not recorded because they were not an issue at this time and place): Interior Work: Provide clear aliphatic acrylic-polyester polyurethane high-build coating system. 1. First Base Coat: Clear satin formulation of “Carbothane 133-HB” as manufactured by Carboline, or equal; not less than 4.0 mils dry film thickness. 2. Second Base Coat: Clear satin formulation of “Carbothane 133-HB” as manufactured by Carboline, or equal; not less than 4.0 mils dry film thickness. 3. Topcoat: Satin formulation of “Carbothane Clear-Coat AG” as manufactured by Carboline, or equal; not less than 2.0 mils dry film thickness. ---
**Author:** ![rlmat](https://avatars.discourse-cdn.com/v4/letter/r/eb9ed0/32.png) [@rlmat](https://forum.4specs.com/u/rlmat)\ **Post date:** [June 14, 2007, 4:52pm UTC](https://forum.4specs.com/t/clear-finish-for-exposed-structural-steel-columns/827/15 "2007-06-14T16:52:45Z")
Carboline is an excellent choice as far as product goes, but I would check with your local rep as to VOC compliance in your area. However, the HB has a VOC content of 383 g/l and the AG has a VOC content of 335 g/l 133VOC is the best at 157 g/l I think you’re going to have a difficult time finding anything at or below 50 g/l Even here in California, where we have some of the toughest VOC standards, we are at 100 g/l