Pin holes in powder coated wire mesh...
Pin holes in powder coated wire mesh...
(OP)
We are doing powder coating in wire mesh.The mesh is welded using resistance.Now after powder coating there is pinholes near in weld areas and some areas in bottom side of wire . Coating in the sheets found ok . What will be possible reasons for pinholes only in wire mesh ...?
RE: Pin holes in powder coated wire mesh...
RE: Pin holes in powder coated wire mesh...
As you said, After welding voids are created .. image attached. i think we cant do much change in our process of welding . So what precautions we should take to avoid pinholes in these welded areas
RE: Pin holes in powder coated wire mesh...
TTFN (ta ta for now)
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RE: Pin holes in powder coated wire mesh...
RE: Pin holes in powder coated wire mesh...
I don't think welds are supposed to look like that. and, likely a significant cause of your poor coating. Surface profile for successful powder coating is critical.
Dik
RE: Pin holes in powder coated wire mesh...
This could be caused by any number of problems with the setup of your WWF system- too much weld current or pressure causing the extrusion, an imbalance of conductivity causing one side of the weld to soften more than the other, etc.
See below for what a properly set up WWF joint looks like.
RE: Pin holes in powder coated wire mesh...
Yss . Its looking good .
We are using 4.5 mm dia wire only .
Due to the cavities created in the weld area , it results in pinholes after powder coating.
RE: Pin holes in powder coated wire mesh...
Dik
RE: Pin holes in powder coated wire mesh...
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm
RE: Pin holes in powder coated wire mesh...
The splatter at your weld sites is caused by either not enough contact pressure or too much current, either one can leave small holes under the weld.
B.E.
You are judged not by what you know, but by what you can do.
RE: Pin holes in powder coated wire mesh...
Ratheesh, you say there are pinholes in the wire away from the welds also? Could be a defect (cold shut or lap) in the wire, poorly drawn/descaled material?