Powder coating

[John MCParticipant @johnmc39344]

I want to fill some imperfections in a number of steel parts before having them powder coated.  My understanding of the process is that the part needs to be electrically conductive so the powder sticks.  Traditional body fillers, Isopon etc., are not conductive.

Also the heat involved, around 200deg C?   I can’t see body fillers liking that!

Is there a special filler available?  I’ve seen something called “Lab Metal”, good for ~170deg C, supposedly good for powder coating.  Conducting.  Very expensive though.

Solder might be a way forward, conducts and good for 300deg C.

Any thoughts?

 

[David Gibbons 1Participant @davidgibbons1]

all of the videos I have seen use car body filler or JB weld epoxy. seems to work for them

 

[duncan webster 1Participant @duncanwebster1]

Most lead/tin solders melt at a lot less than 300C (typically 180) even the lead free stuff is 217C. Comsol is higher, but I’d just ask the power coating man (unless you’re doing it yourself)

[mark costello 1Participant @markcostello1]

The people that I know that do that kind of stuff will braze up defects as a lasting fix.

[John MCParticipant @johnmc39344]

Thanks for the replies.

Brazing and soldering (HMP) both seem to be the common methods of dealing with the larger blemishes from the info I have gathered from recent investigations.

One recurring piece of advice is to use JB weld epoxy for the small blemishes, will probably do for the rust pits I need to fill.

As for conductivity, does seem to matter if the (non-conductive) filler is a thin layer.

[Mick DParticipant @mickd41895]

Hi

 

On the advice from my local powder coaters, I have successfully used alloy wheel filler, it is conductive and withstands the oven temperature they use, (206 degrees C). The brand I have used is Isopon Alloy Wheel Filler.

 

Regards   Mick

[bernard towersParticipant @bernardtowers37738]

Looking at isopons info it looks like it could be an alternative to jb weld.

[BazyleParticipant @bazyle]

Although it is probably an epoxy base be aware that some of the isopon range are actually designed to be soft (unlike JB Weld) so that they can be sanded back easily for car body repairs. I would expect the alloy wheel filler to contain powdered aluminium while JBW hopefully wouldn’t as it might promote corrosion when used on steel.

[Paul Mills 4Participant @paulmills4]

Used to work at a firm that made expensive one of f lighting, any small defects  in parts to be powder coated were filled with this

Superfast Steel Epoxy Putty Stick

easy to use and resistant to the temperatures in the coating process

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