Question DC welder connected to car while painting ?????

When picking up parts for my battery charger rust remover I was explaning what I was assembling a man entered into the conversation. He told us that his X son in law would paint cars and other things by hooking up a DC welder on low current and then spray the paint. It sounds unsafe but I think it would work. I am not going to do it but I would like to know about it. Thank You.

 

I dont get it. It makes the paint stick better or what?

why would you do it

 

I would think.. that you would have to charge both sides of the equation... i.e. the gun(or rather the paint in the gun) and the car... so that there is a magnetic draw.

I know that a similar technique is used w/ powdercoating and some ceramic coating to ensure a good uniform coating

Garth

 

makes the paint stick better, turn up the amps and you'll have a FLAMETHROWER!!!

 

If I remember correctly,the factories had done some commercial vehicle painting back when acrylic paint was first being used.They would electrostatically charge the vehicle either positive or negative(I don't remember which)and the paint the opposite.After the vehicle was coated(I think the process went very quickly)it would be sent through a,"reflow"booth where it was heated until the paint smoothed or flowed out.I don't know if this process is still used or not.

 

It must have something to do with static electricity and trying to eliminate dust from attracting to the car while spraying.
I just attatch a metal strap to the frame of the car and let it dangel to the floor to ground it. Helps dust from attracting do to static charge.

 

There are industrial electro-static painting systems that I have seen advertised for painting things like metal fences and already in place chain link fences. It supposedly cuts way down on overspray as the paint is attacted to the metal which has an electrical charge run through it.

 

So how does the atomised paint hold the charge?????

 

I've heard of this befor, but using a battery charger instead of a welder.I believe the theory is that the paint picks up an electrical charge caused from friction as the paint is forced thru the nozzle of the gun.the charger is set to the opposite polarity and thus the paint is attracted to the car (opposite charges attract)It also is supposed to have something to do with less dust getting on the freshly painted car, tho I can't remember what the reasoning was on this.
Doesn't make much difference in my case as I usually use a brush!
Ted

 

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If I remember correctly,the factories had done some commercial vehicle painting back when acrylic paint was first being used.They would electrostatically charge the vehicle either positive or negative(I don't remember which)and the paint the opposite.After the vehicle was coated(I think the process went very quickly)it would be sent through a,"reflow"booth where it was heated until the paint smoothed or flowed out.I don't know if this process is still used or not.

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I had a 77 silver Ford truck that was done at the factory this way, it worked decent but you could tell where the charge lost as the paint peeled on the sides of the cowl and left a nice coating like galvanizing almost.

 

Here's an interesting site that explains it well.

http://p2library.nfesc.navy.mil/P2_Opportunity_Handbook/4_2.html

They note that ES painting takes paints that will polarize.
The list of chemicals in the paint that work well seems to be the very chemicals used in most auto paints.

Bell Helmets used to paint their helmets with the ES process - and probably still do.
The finish was smooth and glossy.

If ... big word that 'if' ... the equipment was halfway reasonable in cost, the ES system would seem to be just the thing for the home garage.
Combine ES with an HVLP gun and home painting would be painless and not bothersome for the neighbors and safer for us.

 

Thank you to all who gave replys. C9 the link was very helpful.Thanks again.

 

Ted I agree. It makes the old sashtooth bristle brush look pretty good. Often wondered why a guy couldn't brush paint a car and then color sand like hell. Lots of labor but I don't pay myself much an hour. Got more time than money. Oh and don't forget the sashtooth to cut-in around the windows.

 

I remember my dad talking about an old boy who painted cars with a brush.
There was definitely a technique to it from what they said.
The finish was supposed to be quite good as well.
And no, I don't have a clue what technique the old boy used.
However ... I've seen more than a few wooden boats painted with marine enamel - usually white.
There's a few tricks there, but the biggest trick is the marine enamel proper.
Marine enamel is one of the best brushing paints I ever saw.
The handrails on the fence around the slips and down the ramp to the slip float/dock were like white plastic.
No brush marks, no nothing, just good smooth white paint.

When a boat was painted - and this could be the secret to brush painting a car - many times there would be three guys painting the same side of the hull.
First guy would flow on the paint, at the top and about 1/3 wide of the vertical area to be painted, but he was painting horizontally.
Once there was some room, the next guy would start in on the next 1/3 and so on.
With the painters overlapping each other it kept brush marks to a minimum and the better looking wooden boat paint jobs looked as good as did the dock rails around the slips.