Technical Can I Paint A Resistor?

This may seem like a stupid question (OK, it is a stupid question) but I've got a resistor that needs to be installed on my Dad's Model A and it's uglier than man-***. I'm going to mount it on the inside of the firewall to minimize the hideousness but it's still going to be semi-visible. Can I paint the ceramic or will that damage the effectiveness of the thing?

 

The ceramic is cooling area, I would think as long as you kept the paint light enough it wouldn't cause you a problem.

 

I don't know if it's a good idea. A resistor works by turning energy (electricity) into heat. While it would probably keep working, the resistance would probably be changed by the coating. Enough to make a difference? I'll leave that up to the electrical engineers. You could measure one, paint it, and measure it again and then use the results to go to a different value resistor that will work with the coating. Nahh, you really don't want to do that.

 

Resist painting it, Muttley...

 

Yeah, that's pretty much what I was expecting. I'll go with option two...................get my hands filthy as hell and dirty it up to camouflage it a little.

 

HAHA, I found that out years ago when I burnt the snot out of my fingers once.

 

Dont they make a little chrome cover for ballast resistors? you could paint that. Then throw it in the trash.

 

HAHA, apparently someone does. I just Googled it and it's even uglier than the resistor.

 

Great thread, wish I had the ballast to resist!

 

Wont change the resistance, but could change the wattage rating. As others have mentioned the surface of the resistor needs to dissipate thermal energy. If you paint it that would likely change the dissipation efficiency. You could always increase the wattage rating but that would increase the size which is probably self defeating for your purposes.

 

Oh, common now. Don't tell me you guys haven't seen painted ballast resistors before...along with the painted wiring harness, brake lines and everything else bolted to the firewall after a "spray can" restoration. They always still work!

 

The paint may burn off though, or stink when hot.

 

use a black sharpie on it

 

Or bolt it to one of these heatsinks and make a feature of it. Improves efficiency, and they come in all sorts of fancy profiles.

 

I have painted Ignition Ballast resistor's numerous times with VHT Black - been doing it for 40 years, have yet to have a problem.