Painting Cylinders?

tonyg · Post by **tonyg** » Wed Oct 24, 2001 6:05 pm

OK, here's the lowdown on Cylinder painting and I know from 25 years of doing it that it WORKS: Clean outside of cyls with paint solvent. Be meticulous. Do NOT polish the fins. Get a pressure pack of the cheapest flat black paint available. Squirt. Do it so its just covering, do not put on too thickly.The solvents in the paint are eventually burnt off, leaving a thin coating of pigment (I think carbon black) on the cyls. This does the trick resulting in significantly lower operating temps. While you're at it, do also cyl heads, valve covers, pushrod tubes and engine block, sump plate, etc. This is well known in a/c aircraft engine circles. There is also a dye process but am unsure of formula, I think it is done in heavily alkiline base and dye is etched into metal, similar to anodizing. best wishes for a Cool vw,
Tonyg

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Wed Oct 24, 2001 11:01 pm

Looks like another test for the DYNO. The candy thermometer placed in the fins should work fine for the true test....

Lycoming doesn't paint their cylinders, I turn wrenchs on those also.

James2 · Post by **James2** » Thu Oct 25, 2001 2:50 am

In any case I would not powder coat them! that would insulate them.

I paint mine just because they look better. I can't see where a light coat of black VS no paint would make a "big" difference in either case. you might be talking about 4 or 5 degrees one way or the other.

PapaG · Post by **PapaG** » Thu Oct 25, 2001 10:07 am

What about a black oxide coating?
Check out this stuff Eastwood sales.
http://www.eastwoodco.com/cgi-bin/sgin0 ... A=1&FNM=20

ray greenwood · Post by **ray greenwood** » Thu Oct 25, 2001 6:22 pm

A little about paint and coatings...black appears black because its pigments absorb the other spectrums so as not to reflect them as light you can see (color). The reason black surfaces tend to draw/attract heat is that they do not reflect one of the most important spectrums...infrared...which is slow in energy level...hence not having the energy to bounce..it is absorbed..heat. By the way, gloss black absorbs less heat than flat/matte black. The surface sheen/gloss...or reflective coating actually covers the pigment particles that make it black. It magnifys them like a lens...making them look blacker (see difference between gloss and matt photos) and also in turn reflecting away more infrared. This gloss also protects the actual pigment from coming in contact with moisture...so the gloss paint oxidizes slower...the point? Matt black paint has a higher coefficent of surface tension...and greater area. Crinkle coat...or hot jet applied aluminum/zinc...is even higher. And I would bet that Jake is correct....short of new high temp/high tech coatings...rust and bare metal probably had as much surface area as you can get...in those days. The problems with paint, are the metals they contain in the pigment. Chromium, cadmium, zinc, copper etc....are all in black paint in some level or another. These absorb heat, some radiate, some are insulators. For example, the application of chrome, traps heat in cylinder tin. Chrome is a heat reflector regardless if it is polished, or if it is the side you don't see, against the metal. By the same token, gloss surfaces, of any gloss level..reflect light...and heat in all directions. The gloss black paint would not absorb as much ambient heat...but would reflect it to adjacent fins...where it would be re-reflected and accelerated...until it was absorbed. Gloss is subjective...I have meters to read it. I would love to see what everyone learns from testing on this subject...until then, I don't paint cylinders or the aluminum block...mainly cause I have no idea whats best to paint them with. Ray

JohnConnolly · Post by **JohnConnolly** » Fri Oct 26, 2001 12:16 am

I found the semi-gloss spray can (rattle can, spray bomb, etc) called Plasticote works great. A light coating is all you need, plan on $6 at most FLAPS.

<BLOCKQUOTE>quote:<HR>Originally posted by Derrick from NC:
Any particular brand paint you recommend or should they be powder coated?<HR></BLOCKQUOTE>

vw_bug_owner · Post by **vw_bug_owner** » Fri Oct 26, 2001 8:22 am

Imagine walking around at noon in the open street... which way do you get hotter with a white shirt or a black one?

CPRcubed · Post by **CPRcubed** » Fri Oct 26, 2001 2:54 pm

The shirt analogy is not quite correct. In that case you are aborbing heat from an outside source. With the aircooled motor, you are trying to get rid of the heat from itself. Cheers!

------------------
1970 Bug (stock & rusted for now), 1994 F350 CC DRW PSD, 1971 Airstream. Life is good in Bear Valley Springs!

JohnConnolly · Post by **JohnConnolly** » Fri Oct 26, 2001 3:40 pm

but there is something to be gained by his point. Black absorbs and radiates heat well. Ever wonder why teapots are chrome on the top and sides? This minimizes their heat radiation, since we use em' to heat water.

If they made them black, they'd be way less efficient at heating water.

John
Aircooled.Net Inc.

<BLOCKQUOTE>quote:<HR>Originally posted by CPRcubed:
The shirt analogy is not quite correct. In that case you are aborbing heat from an outside source. With the aircooled motor, you are trying to get rid of the heat from itself. Cheers!

<HR></BLOCKQUOTE>

Airhead · Post by **Airhead** » Sun Oct 28, 2001 8:56 am

Anyone ever tried Kalgard Gun Kote ?
WWW.kalgard.com/
Gun Care Products