Painting engine casings

[trib]

Just received my kit ECi engine O360. For prep I need to paint the engine casings. Does anyone have any advice on prepping and painting the casings? I have brian76's notes on assembling the engine, which has good pictures of masking. I'm primarily looking for advice on any cleaning/etching and the like. I am planning on using Duplicolor engine primer and paint.

thanks,
Tim Ribble

[RV7Guy]

I have an ECI I0360 that was built at my place. The only prep I did before painting was scrubbing everything with a degreaser, then lacquer thinner.

Masking was very tedious, 10 hours!!! After masking I wiped everything down again and sprayed with zinc chromate from a rattle can. The color was Dupont single stage Viper Red. I used three coats. 2.5 hours to remove all the masking tape!!!

You can see my engine at www.attawayair.com. Look under "Recently built engines."

No special prep is needed other than protecting the mating surfaces.

[gbrasch]

Originally Posted by trib

J I have brian76's notes on assembling the engine, which has good pictures of masking.
thanks,
Tim Ribble

Are Brians notes published somewhere on the web? And if so can you pass on the link. Thanks in advance.

[trib]

Notes are at

http://brian76.mystarband.net/superiortextpics.htm

[G-force]

10 hours, yikes. Why not paint it after the case halfs are assembled?

[Sam Buchanan]

Why not paint it after the case halfs are assembled?

That's what I did when the engine in my RV-6 was rebuilt. The case was painted after the accessory case was installed and just prior to the cylinders being bolted on. The only advantage to painting the cases prior to assembly is that the hardware won't be painted. But as has been noted, that will require very time-consuming masking.

If you decide to paint after the case has been assembled (I think this is the way Lycoming does it) borrow a set of junk cylinders to slip on the case temporarily while painting. This will allow you to skip masking the cylinder mating area. I found aerosol PlastiKote engine enamel from the aviation aisle of a local auto parts store to work very nicely and it still looks great after being in service six years.

[DanH]

I've been real pleased with VHT High Temp Engine Enamel. I paint before assembly. Scrub the degreased cases inside and out with hot soapy water, rinse, dry, mask, spray, then bake at 200 to 250F for about 30 minutes.

Not a lot of color choices, but it sure is tough.

Dan Horton

[rv969wf]

Question Tim, not to be negative, but why are you painting the case? For appearance, showplane, looks or just because. Not to be outcast or saying it's good or bad. Reason I'm asking is because if the Aluminum Case is Alodined correctly, there should not be any issues with corrosion. Another thing to think about is heat transfer. Several coats of paint acts as a barrier and will not be the best for cooling. Were not talking about much on cooling effect, but every little bit helps in keeping these Lycomings cool. The crankcase is not that important if painted or not but the Cylinder Heads and Cylinder fins are the most critical areas for heat transfer. The Cylinder head and Cyl fins will cool the best if they have a very lite coating of .0015" thick coating of Techline coatings black heat dispersent coating applied then baked on OR leave them bare in the rough casting. I like things to look nice and pretty myself, but painting some things like an air cooled engine can bring your oil and CHT's a little higher if painted. I myself have painted some engines and have made them look very nice,,,,, but I'm more into keeping things on the cool side and not putting an insulator like primer then several coats of paint in some areas. Think of it like this. Winter time, you put more cloths on to stay warm right???? Summer time you take them off to cool down. Think of your air cooled engine like this. Keep the cloths or paint off your engine and she runs cooler. Were not talking about much temp reduction here but it's just something to think about. Painting the case is a pain in the butt and it takes alot of time to mask everything off. I've done it on a few aircraft engines as well as many other non aircraft related engines and it is more for show than anything else. I've got a plenum on top of my engine so nobody can see the case anyway. Main thing, if you do paint the case, clean it very good like the others have posted on here, no oil or things like that on any of the surfaces. AJ

[trib]

I'm painting for corrosion resistance and also for appearance. The lycoming overhaul manual says you should, so that probably was the start. The cylinders are painted by ECi already, standard blue, and that's good enough such that I'm not going to add any more. I'm painting the cases red and the masking time really doesn't scare me. It's the same with any painting chore, the actual painting only takes a couple of minutes, but the clean, prep and mask takes forever !