Paint as good as hot dip galvanize
Paint as good as hot dip galvanize
(OP)
Is there a paint as good as hot dipped galvanizing out there ? I have some existing painted steel which is at present inside that will be exposed to the outside atmosphere and must be painted to a standard as good as hot dipped galvanize.






RE: Paint as good as hot dip galvanize
RE: Paint as good as hot dip galvanize
Try a zinc rich paint, these straddle the line between the two.
RE: Paint as good as hot dip galvanize
RE: Paint as good as hot dip galvanize
I think the OP was mentioning that the steel was existing already in place. Also, that seems like an idea that came from the department of redundancy department. ;)
RC
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RE: Paint as good as hot dip galvanize
RE: Paint as good as hot dip galvanize
To answer your specific question (as I interpret it), yes you can find a paint system which will give similar protection as galvanising, IF it is not possible HDG the existing items you have.
If you can HDG it then do that, as it will be more robust and probably cheaper.
RE: Paint as good as hot dip galvanize
A properly applied zinc-rich paint system can last a good long time. Best is inorganic zinc with no topcoat, if you don't care about color--there are test panels out there that have been up for decades and are doing fine. You need to make sure that the surface is cleaned to bright metal before you apply the paint.
Hg
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RE: Paint as good as hot dip galvanize
RE: Paint as good as hot dip galvanize
I think you have the sense of comments here that no paint system is actually as good as HDG, which was your question. But if you have to provide a durable paint system to an existing structure, the most important thing is the preparation. As the existing steel is interior, it probably has only been painted with an architectural coating not designed for exposure. To get a durable coating, the existing coating would have to be removed. I would consult with one of the industrial coatings manufacturers for a suitable system. It will likely involve an epoxy zinc rich primer (not inorganic zinc, which is only for shop work), and top coats to complete the system.
RE: Paint as good as hot dip galvanize
RE: Paint as good as hot dip galvanize
IOZ is difficult to apply in a field environment, but that does not mean it is not appropriate for field exposure. If you can get it on right, it's better than a multi-coat epoxy zinc system.
On the other hand, hokie66 is right in that if you have any doubts about how good a job they will do with surface preparation and paint application, you're better off with an epoxy zinc system (typically zinc primer, epoxy intermediate coat, and then urethane topcoat). Epoxy zinc is a rather forgiving coating.
Hg
Eng-Tips policies: FAQ731-376: Eng-Tips.com Forum Policies
RE: Paint as good as hot dip galvanize
Hg
Eng-Tips policies: FAQ731-376: Eng-Tips.com Forum Policies
RE: Paint as good as hot dip galvanize
Hokie66 epoxy rich zinc top coat with top coats sounds like the way to go with the existing steel (UBs) and hot dip galvanize the new steel which will be bolted onto the existing steel columns.
Many thanks.
Its great to be part of this group.
Cheers !
RE: Paint as good as hot dip galvanize
RE: Paint as good as hot dip galvanize
RE: Paint as good as hot dip galvanize
I have personally done work on these towers. Some are quite old and still in very good condition. Some areas, which may have been more prone to standing water or poor drying, have shown some corrosion damage, though proper periodic maintenance could have helped these areas.
IO Zinc can be field applied, and touched up in the field. The critical step is proper sand blasting and time after blasting until painting. The steel needs to be blasted near white, and then painted immediately. This can be tricky for large areas in the field.
If I could not HDG steel, I would use IO zinc.
RE: Paint as good as hot dip galvanize