ive seen A LOT of posts about prepping and painting engines but i havent really seen anything in them about priming the engine or anything before the actual painting process. is it really not necessary or what? but yea, i have a good bit of other questions anyways

1. sandblasting/beadblasting (cause my dad has them) or just clean everything really good before painting?
2. leave the housings and ends just cleaned aluminum or paint them that color...which would be better?
3. how many coats of paint do u guys put on your engines?

and then this is a little off the subject but still related. i havent really read to much about people priming their calipers either...so do u not have to not have to prime those or what? thanks

 

it is due to the type of paint used...the ceramic paints do not really require a primer, and more importantly, high temp primer is hard to find. if you use regular primer underneath high temp paint, it will burn up and ruin your paint alng with it.

pat

 

primer is susceptible to heat and may cause the paint to peel off, your best bet is to clean the housings with dish soap and dry them then use a high temp engine paint preferably 800+ degree paint. most people sandblast the aluminum housings, i did and it looked great or you can paint them with an aluminum colored high temp engine paint. you dont need to bead blast the iron housings, in fact bead blast the least necessary because it gets in all of the holes/ports/crevisces in the engine and could come loose inside the motor and do damage, the rotor housings do not have many spots that bead blasting media will hide and likely wont bite you in the *** if you bead blast them. if you do bead blast other pieces be sure to clean them up as best possible with compressed air.

here is how my engine turned out with bead blasted housings and non primered just painted irons.




1000 miles now and the paint is just as clean.


the front cover you can paint a aluminum color as mine was, it matches the aluminum housings well.

 

i've heard alot of people say its not wise to paint the housings because it retains more heat.

 

false info, the heat retention is so minor that it hardly would be noticeable. how many pics of a rotary engine have you seen on these forums that have been unpainted?

 

Yea the high heat paints do not need a primer, and you must use a high heat paint or else if you use regular paint and primer, it'll stink up a storm and get ruined.

I wouldn't mind powdercoating the outside of the housings! if thats even possible without getting the powdercoated paint into the water jackets, sides, etc.
Also im curious to know if powdercoating acts as an insulator for heat also, or is it like karack said, it is hardly noticable?

 

oh....one more thing that i just thought of. has anyone tried to just clear coat or somethin the housings after beadblasting or cleaning like hell?

 

I don't think it would look to good. Last time I tried clear coating bare metal as an experiment, it made all the flaws show up twice as good. Not only that, but certain parts of the clear coat sort of "stained" the metal, while other parts did not. In other words, it looked like complete ****. Its also not heat resistant.
Paint first, then clearcoat.

 

they make high temp clearcoat. i was gonna use it on my housings, but decided to just paint em instead.

pat

 

well, i got all my answers i need for now except how many coats of paint to spray onto the engine. so how many coats of paint does everyone put onto your engines. (light coats...heavy coats?)

 

i use a light coat, and then 2-4 heavy coats. not really heavy so it deosnt run, but the ceramic paints sticvk really well, so you can coat much thicker than normal.

 

Yea, I've tried painting a few engine pieces. For metal pieces, the best way to go is to just use high temp paint and high temp clear coat. I sanded and primed a valve cover for my 92 Cavalier, and a week later, the primer was cracked and looked like crap. Also, from what I could tell, there was no difference between using primer and using primer then paint besides that when I used primer, it ruined my paint. High temp primer is expensive, and hard to find. In fact, I've never found it before in my life. High temp ceramic paint doesn't need primer, it sticks plenty good. Basically, that's all primer is used for when painting things. Make sure the clear coat is high temp, or it will basically do the same thing as what the primer does. I've also tried clear coating unpainted metal parts. It does look cool because it makes the part look glossy and wet, but it also does show flaws really badly and also it will sometimes make the metal look stained. I've also used a sandblaster to clean parts up. It helps to prep the metal and remove any contaminants that are on the surface that will prevent the paint from sticking right. Make sure that if you do sandblast the part, you clean it really well with compressed air and water afterwards. Also, let the part dry thoroughly for best results. When you're ready for paint, lay down a light coat first so that the paint has a chance to stick well, then apply a little thicker coat so that all the bare metal is covered, then after that you can start putting on your heavier coats. Repeat until you have a nice even spray on the piece. Painting things is a very involved process. Experiment a little and try to find what you think works best. That's how I figured out how to paint. Try to stay away from cleaning solvents. Usually, they will make it so the paint doesn't stick as well to the surface. I used to use deglosser to clean my parts off, but decided that it made the paint not stick as well and take a lot longer to dry. You've better off with just plain water and a clean rag. Also, don't go overboard and get that primer sealer and extra crap. Just stick with the basics.

 

what type of paint, so far i've seen dupli color selling 2 types of high heat paint, any others? i wanna paint my housings on my project motor.

-Andrew