Everyone,
We have a structural project coming that will require W- shapes to be Metalized for protection.
Other than read an article on it in the AWS monthly magazine, I'm not real familier with it. I believe its similar to a GMAW gun set up w/ a spool of wire, and the process using heat and the arc atomizes the wire and the gas propells onto the base material, then a cold jet of air/ gas comes directly after and cools the part.
What about surface prep? and film thickness? My spec. doesn't call it out directly. We have contacted a metalizing company that does this full time, and I plan on visiting their facility soon, but in the meantime I'm trying to gather as much info as I can. I searched this forum and there is very little on this topic.
Any infor would be appreciated,
Thanks Chris
Chris
You might find more info on it in some of the metal boat building forums. I know it use to be done on the outside after sandblasting. Now days the paints are a lot better so a lot are using zinc rich primer then epoxy after sandblasting.
Tom
I've inspected it before. What I suggest you do is contact the wind tower manufactures. Most of them do it.
There are generally two or three processes: high velocity oxy-fuel (HVOF), oxy-fuel flame spray, and then plasma flame spray.
If you Google on those processes you will find a lot of info. The advantages and disadvantages of each depend on the type of coating you plan to apply.
They can all be highly automated and done in a lathe or even with a robot.
I don't know that much about the process, but a 3rd party NACE inspector was here looking over our steel and was telling me that the job he had just came from was using that process while restoring and refurbishing old bridges in FL. Sounded interesting. I'll have to read up on this.
We do plasma spray here.We don't do the wire type any more (the one you're referring to).It's basically metal powder (many different alloys) that is sprayed on with a carrier gas (usually Hydrogen and Argon).the part is preheated (in the CNC program),then the part or surface is sprayed usually a couple of thousanths a pass,then it's finish machined to a specific dimension.
Hello eekpod, a number of years ago I was working a structural job that required all the components to be hot-dip galvanized. In the event of any repairs or changes they additionally required a "hot" repair/recoat. Their solution or requirement to accomplish this required the area to be sand blasted and then they used a twin-wire spray system. Essentially there was a twin-wire feeder that fed the two wires through the gun at an angle to where they would cross one another and create an arc(one wire +, the other -), a blast of compressed air would propel this hot atomized material onto the parts. This might possibly be the system that you are referring to. A bit more food for thought. Best regards, Allan
This is what we do when we have to repair large areas of hot dipped galvanized items. 99 percent of everything we do gets galvanized. Your best bet is to get it galvanized, hot dipped.
Brian
Thanks everyone for your input.
I've had time to do a little researching into this. I have spoken to a company that does it and info is in the mail.
Now Ive come across info from both organisations, one where the galvanizers say why there process is better, and the other where the Metalizers say theirs is better than HDG.
Luckily thats not my decision, thats the customers call.
Keep you posted. Thanks Chris
Alan is spot on with his explaination (use to do it build up pump shafts) but what Alan didn't tell you was how noisy it is and its loud, more so than Arc gouging.
I have seen older equipment that used oxy/acetylene and spools of wire, it RAN on compressed air, lots of it, I think 35 CFM. I don't know if the air was used to cool the deposited metal.
I did meet a guy who has flame sprayed the 50' steel boat He built, He used aluminum, but said it could be done in zink as well.
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