galvanized, weathering, painted steel
galvanized, weathering, painted steel
(OP)
almost all steel i work on uses galvanized steel.
am interested when weathering, painted, etc.. are used.
can someone link me to this.
my online search hasnt really helped me.
thanks,
am interested when weathering, painted, etc.. are used.
can someone link me to this.
my online search hasnt really helped me.
thanks,






RE: galvanized, weathering, painted steel
As far as your ohter question, I'm not sure what you're driving at. Painted steel (or at least primed) should be used everywhere. Unless steel is not exposed to oxygen or water, it will corrode.
RE: galvanized, weathering, painted steel
i only have experience designing galvanized steel. i have not designed any steel that is painted.
RE: galvanized, weathering, painted steel
In general the decision of using weathering, painted or galvanized steel will come from analyzing a number of factors, such as location of the structure, use, environmental conditions, expected use and maintenance, design life...
The three systems provide different levels of protection at different costs.
It is very difficult to summarize it but in a couple of lines, paint is cheap, OK for most applications but requires maintenance. Galvanized gives the best protection with less maintenance required at a price. Weathering steel is supposed to be maintenance free but requires dry/wet cycles to develop the proper patina and has other issues such as staining.
RE: galvanized, weathering, painted steel
See you into Structural design....
I do not know where in the world you come from but,
I work in South Africa in the cheaper residential structures and galvanizing are often prompted to be expensive and "the ordering of it" time consuming, therefore we paint most of our structural steel work,
that is often not the case with bigger projects thou,
however, the Galvanizing society had a huge marketing thing going on and they have compared the two systems and therefore I think I understand the differences,
Painted methods need more maintenance and application is important.
Galvanizing need lessor maintenance IF DONE AND INSTALLED CORRECTLY and therefore is cheaper over time,
Galvanizing is a chemical method while painting is a mechanical method – the paint get "sucked" to the steel,
Preparation for paint is done by sandblasting to remove slag - that is never done over here anyway, and the slag is burned automatically when galvanised
The design calcs is the same as strength are not influanced (I do not know if this is true with all grades of steel)
Tx for giving my 2 cents
RE: galvanized, weathering, painted steel
http://www.FerrellEngineering.com
RE: galvanized, weathering, painted steel
RE: galvanized, weathering, painted steel
http
There is a good discussion of the relative costs of different levels of painted protection and various surface prep methods..
RE: galvanized, weathering, painted steel
RE: galvanized, weathering, painted steel
http://www.sspc.org/
Also, check NACE International...
http://n
RE: galvanized, weathering, painted steel
- electric/domestics appliances industry
- car manufacturing
- insulating panels used as roof and wall claddings
(mainy in preengineered steel buildings )
RE: galvanized, weathering, painted steel
Hg
Eng-Tips policies: FAQ731-376: Eng-Tips.com Forum Policies
RE: galvanized, weathering, painted steel
RE: galvanized, weathering, painted steel
RE: galvanized, weathering, painted steel
But "wind and rain" are not an issue for weathering steel. (And I'd be interested in seeing your source for that claim.) It's not good for splash zones or low-water crossings with frequent immersion, because with frequent rewetting the protective patina doesn't get a chance to form, but otherwise, it does well with ordinary weathering exposure ("wind and rain").
Hg
Eng-Tips policies: FAQ731-376: Eng-Tips.com Forum Policies
RE: galvanized, weathering, painted steel
The whole idea of weathering steel is that the protection is, for lack of a better term, "built in".. In other words, it is a material property of the steel itself that a protective coat forms on the steel to prevent further corrosion, much like aluminum.. It is not a "coating" in the traditional sense of the word.
RE: galvanized, weathering, painted steel
"The FHWA TA recommends caution in employing weathering steels in areas where the material could remain wet for extended periods of time due to high levels of rainfall, humidity or fog. The FHWA TA recommends evaluating these conditions using ASTM Test G 84 "Time of Wetness Determination (On Surfaces Exposed to Cyclic Atmospheric Conditions)." If the average time of wetness exceeds 60 percent, use of weathering steel is not recommended. No measurements of the time of wetness were taken at any of the bridge sites visited, so an assessment of the adequacy of the FJWA TA recommendation cannot be made. It has been reported by others that weathering steel in bridges located in the Northwest portion of the United States, west of the Cascade Mountain range, and southeastern Alaska, has not performed satisfactorily and required painting...."
However, contrary to what I said before, most of the experiences have been satisfactory. Read the whole report.
http://www
RE: galvanized, weathering, painted steel
On the other hand, in my country weathering steel ( CORTEN ) is mainly used in Electric Power Authority's projects and in train manufacturing.
RE: galvanized, weathering, painted steel
But for applications where it will work (which is most bridge applications in my opinion), I'm a fan.
Hg
Eng-Tips policies: FAQ731-376: Eng-Tips.com Forum Policies