Topic: Started painting my engine

[killersoundz]

Started painting my engine with duplicolor engine paint semi-gloss black. I prepped the top end by cleaning it up with scotch brite pads and then spraying it with mineral spirits and hosing it off, yes literally hosed them off. Since it was a hot sunny day everything dried quick and was left with a oil-free surface ready for paint.

The rattle can states recoat within 1 hour, 10 minutes apart, but after that if you want to recoat you have to wait 7 days. This stuff was drying REALLY fast probably because I had it sitting directly in the sun and the parts were heated up quite a bit.

Also I've seen some people individually tape off the valve cover, head and jugs to paint separately. I just decided to make it quick and assemble them and paint it all together. Even without gaskets no paint gets inside.

[Joe]

bummer.

[killersoundz]

What's a bummer?

[phil71]

Don't worry joe , with that type of paint , that top end will be aluminum color again after a few hot/cold cycles.

[Terry in Australia]

Looks nice mate, but as you didn't etch prime the bare aluminum, like Phil says, it'll be silver again before long. Cheers, Terry. 

[matt mattison]

Mineral spirits or any oil based solvent really does not work too well for paint prep. It leaves an oil residue behind that you can't see or feel,but it's there. I hope it works out for you, but if you have to do it over, use lacquer thinner only.

[killersoundz]

It seems to have adhered well. Even after a couple hours after applying I could not scratch it off with my finger nail. This is good quality paint without a doubt. Much better than the rustoleum "high performance enamel" I painted my frame with, that stuff is chipping right off!

[cgswss]

I know nothing about the paint you are using so I'm asking... Dose it indicate it will stand up to the heat of AIR COOLED engines?  I would like to do something similar to my bike some day.  My grand plan is to bead blast the engine then paint it.  the PO on my bike painted it with "something" and it has pealed off in a lot of places making the engine look real ratty.

[killersoundz]

It's dupli-color engine enamel. about $10 a can. It is rated upto 500 degrees, which if my 750 hit that well it wouldn't because it would be seized up lol.

http://www.amazon.com/Dupli-Color-DE1635-Ceramic-Semi-Gloss-Engine/dp/B000GKEXVQ/ref=sr_1_2?ie=UTF8&qid=1337524727&sr=8-2

These engines are painted silver from the factory they are not bare aluminum. Most people repaint them silver in this duplicolor paint. They have a 'brushed aluminum' color that is a dead ringer for the stock color.

[Terry in Australia]

Duplicolor paint is fine, but no matter how good the paint is, it won't stick to bare aluminum. The cases were painted silver but the head and cylinder block weren't. Bare aluminum needs to be "etch primed" to create a chemical bond between the bare aluminum and the paint, or eventually, it'll peel.

Trust me, I've had more CB750's than you've had blowjobs (hell, more CB750's than I'VE had blowjobs!) and I've literally spent weeks removing the remains of "Good Quality" engine paint from engines that weren't etch primed. It's not a matter of "if", it's a matter of "when". Cheers, Terry.

[killersoundz]

How do I 'etch prime' it then? By the way, my entire engine was clearly painted, head, jugs, case. I could see it chipping off in some spots.

[matt mattison]

Strip off all the old paint, you might need to use "aircraft stripper" in some areas. I would use a stiff nylon or a brass brush in some areas, or scotch brite in others. Then use warm soapy water and a brush to clean. Blow everything with compressed air. Next, apply lacquer thinner via spray gun or use a clean brush, and get the thinner in everywhere as this is your final metal prep step. Let the thinner evap off. Now this is as clean as your gonna get, so apply your self etching primer ASAP. Make sure the primer is recommended for engine heat and apply it according to the primer instructions.

[Terry in Australia]

Yep, I agree with everything Matt says except I wouldn't allow the thinner to evaporate off, because if there's any contaminants that the thinner has lifted (oil, wax, tar, dead bugs, gasket adhesive, silicon etc etc) they'll just dry back on to the bare metal, so I'd remove as much of the wet thinner as I could with a clean lint-free cloth, and use compressed air to dry it completely.

Any good zinc-rich etch primer will work fine, you don't need a whole lot of it, just enough to spray a light "mist coat" over everything. With etch primer, "less is more". Cheers, Terry.

[bollingball]

Yep, I agree with everything Matt says except I wouldn't allow the thinner to evaporate off, because if there's any contaminants that the thinner has lifted (oil, wax, tar, dead bugs, gasket adhesive, silicon etc etc) they'll just dry back on to the bare metal, so I'd remove as much of the wet thinner as I could with a clean lint-free cloth, and use compressed air to dry it completely.

Any good zinc-rich etch primer will work fine, you don't need a whole lot of it, just enough to spray a light "mist coat" over everything. With etch primer, "less is more". Cheers, Terry.

Make sure your air compressor has a good dryer/filter don't want oil or water in the air