Turbobeaver

Hi all.Would like to find out what the general concensus is towards painting weed wacker motors.I know it's a personal choice as to whether one should do it or not and we're talking aesthetics here and nothing more but I was curious to know how many guy's bother to paint their engines(or parts of) during/after conversion?

What paints have you tried and how do they hold up to the heat?Is flaking a big problem after a while or is that more closely related to lack of preparation prior to painting or simply just a poor paint selection choice?I find they definitely look better after they are done and I usually only bother to paint the cylinder itself but it will be interesting to find out what others do to finalize their projects as well.Just because it's a weedie doesn't mean has has to always look like one does it?

av8tor1977

My Feedback: (6)

A thick coat of paint will make any engine run hotter, though the weedies tend to have plenty of cooling capacity so it may not be a problem. Studies show that a light coat of flat black paint actually helps cooling by a good percentage.

As far as adhesion, it is both surface prep and paint quality. The best deal would be glass beading, then painting with an automotive engine paint. If glass beading is not an option, then a thorough cleaning followed by a lacquer thinner or acetone bath works well.

Good luck,
AV8TOR

Turbobeaver

Av8tor,would you happen to have a link to the flat black paint studies that you mentioned?I'd be very interested to find out why flat black disipates heat better than any other colour.I know that some glow engines have been painted with a matt black type finish such as the Skyward .40's and .60's and they referred to this material as "Thermex" which was suppose to help keep the engine cool.Fact or fiction,who knows but it is directly along the same lines of what you were saying.

Has anyone tried BarBQ paint or gas fireplace paint on their engines and had any degree of success with it?Other than high heat automotive paint,the only other high heat paints that come immediately to mind are the ones sold by Tremclad.They have a flat black and I think also a gloss black unless they discontinued manufacturing it.I would think that any other colour other than black wouldn't stay that colour for long once the engine has been run up a time or two.Mind you,the guy's making chainsaws and painting them perdy shades of yellow and green etc. don't seem to have too many problems with paint discolouration do they?Or is it because the engine is buried underneath all that shrouding and you just don't notice.

SilverEagleBW

My Feedback: (1)

I used Dupli Colors Anodized engine paint on a Ryobi i am converting,works great!.I did a trim job to the front fins of the cylinder,left the back alone around the muffler.Pretty cool looking on what i have done.This is a two ring engine and i am going to use an electronic ignition as soon as funds are avilable,also i removed all the junk on the lower case.I did take some pictures of this engine and will post them when i develop the roll of film,This engine does not look like a Ryobi anymore!

Flypaper 2

I have painted a few with stove paint. Covers well so you only need one light coat. Some earlier Quadras came painted black.Black radiates heat better than any other colour and why car rads are black.

av8tor1977

My Feedback: (6)

Hi,

Sorry I don't have any copies of those studies. (I have read several over the years.) Recently an engineer and I were chatting about it. He said he tried an experiement once. He filled a bare metal can with cooking oil, and another identical can with cooking oil, the only difference being the second can was painted flat black. Then he heated the two cans and measured the cooling rates. The oil in the black can cooled an astounding 40% faster.

The flat black barbeque paints are a good choice, except that the one I used wasn't fuel proof. Sorry, it's been a while and I can't remember which brand it was; I have since switched to engine paint.

Good luck
AV8TOR

RunningMan

It's strictly Physics, some objects (paint pigments in this case) only absorb some of the wavelenghts of light that impinges on it, the reflected light gives the object its color. Black on the other hand absorbs all the wavelenghts and reflect none (in real life very little). Since heat is Infrared Radiation it is absorbed by the paint very well, and reradiated into the cooler space beyond it, much more efficently then a coating of alumium oxide will. It's one of those particle/wave duality things.

Steve

Turbobeaver

Thanks for the replies guy's.I was over at the local hardware store looking at their selection of high heat paints and I found another type of high heat paint.It is used on car brake calipers to jazz them up.I found bright red and Piper Cub yellow in this type of paint.

Looking at the other black paints in various gloss shades,the flat black is indeed rated the highest for temperature.Somewhere around 900-1200 degrees fahrenheit.The other gloss blacks were only rated up to around 500 degrees as were all of the automotive high heat paints that I looked at.

Deadeye

Get it powder coated. That finish will be bulletproof.