Galvanized Steel & Penetrol

January 16, 2009 4:00 AM

Is Penetrol a good coating for galvanized steel?

I live in an old tobacco warehouse and the HOA is having the entranceways replaced, with steel railings, which will be exposed to the elements. After seeing some local steel sculpture with a transparent finish, I researched it and found that the finish was called Penetrol. We have gotten bids for our entranceways, for galvanized steel, not just the standard steel. My thinking is that the galvanized is already finished and will the Penetrol actually work (i.e. penetrate the galvanized finish). The alternatives are painted or powdercoated steel but the HOA wanted a more industrial look. Does anyone have any experience with this? Thanks.
Philmas

posted by philmas to grab bag (5 comments total)

When I google Penetrol I get a medicine of some sort, and a paint conditioner. The website says you add it to your paint to make it go on nicely. Is this the finish you're thinking of?

Secondly, you're talking about putting a transparent finish on top of a galvanized coating. Won't that be a lot like the same part without the transparent finish, and if not, what differences are you hoping to achieve?
posted by Mike1024 at 4:33 AM on January 16

If you've got the galvanic coating, you don't need the penetrol.
posted by notsnot at 4:34 AM on January 16 [1 favorite has favorites]

If all you want to achieve is rust/weatherproofing then galvanizing is just about all you need; galvanizing is one of the best anti-rust coatings for steel, in terms of durability. If the people installing it bolt it into place, make sure they use bolts that won't rust either.

If you're hoping to achieve a visual appearance resembling the sculpture, well, that's why I asked those questions above.
posted by Mike1024 at 4:51 AM on January 16 [1 favorite has favorites]

Galvanized steel, as indicated above, is finished.

Additional things to consider, prompted by Mike1024 -- be careful what bolts/screws are used, and also be careful what washers are used. I cannot tell you how many times I find rusting washers on a nicely galvanized structure. That's usually not a serviceability concern (although it could be in some cases), but it is ugly (well, once or twice it actually looked kinda cool, but those were designed that way). Personally, I'd recommend using galvanized fastener assemblies NOT electroplated fasteners. There is a difference.

You may want to read through the AGA's website, as they've got quite a lot of useful information.
posted by aramaic at 6:45 AM on January 16

I have since learned from someone who does lots of outdoor steel sculpture that penetrol is a great protective coating for raw steel but that you would not use it on galvanized steel, as galvanized is already a protective coating. Thanks very much to all for your responses and sorry for not getting back sooner.
philmas
posted by philmas at 11:05 AM on January 30