Topic: Engine paint

[cobra2411]

Ok so I searched and everything came back talking about rattle can paint jobs or powder coat.

Are there any sprayable solutions that work? Can you use a single state urethane paint on the engine? Will the heat kill it?

TIA

[camelman]

Are you not interested in the rattle can options?  I've done a fair bit of painting and I swear by those engine paint rattle cans. If done right, then it looks great and is very durable. I don't know if it will hold up to a gasoline bath, but splashing gas on it doesn't seem to bother it and engine oil has no effect on it. Heck, brakleen won't bother it either. It lays down very nicely too.

I can't comment on a single stage urethane on an engine. Will it hold up to oil and gas?

Camelman

[cobra2411]

I've heard good and bad things about the rattle can paint and I don't want to have to do it twice. The engine is out but I'm not taking it apart and I know some engine paints want to be baked to fully cure. Not sure how I can do that.

Single Stage Urethane holds up pretty well to gas but you have to clean it up pretty quick.

[boatsdickson]

Just dont heat cure it after yu spray it. Hell i did my cases with the motor all disassembled, put it back together, framed it, and let it cure on the road as i road. No problems what so ever. Very durable if yur careful while framing it once again. I used duplicolor engine enamel ceramic, de1615 aluminum. Very nice for my first try. 

[Magpie]

I've done the same as boatsdickson using dupicolor engine paint. It's lasted well without any problems. No baking, just let it cure for awhile before handling.
Cliff.

[boatsdickson]

Yeah as magpie states, and i forgot to, once i painted my motor and reassembled the lower end, the motor sat on the stand for probably a month before i got the upper end finished. Plenty of cure time i guess. Good point MP.

[Kong]

I've been asking around for about a year now trying to find a sprayable VHT without any luck.  I'm sure that standard single stage or BC/CC systems won't hold up to the heat, at least not on the cylinders.  I'd call it a toss up if the stuff would hold up on the cases or not, but I think it might.

I just have this aversion to rattle can paints myself.  My problem with the rattle can stuff is how easily it chips.  So you've got the engine out and you paint it but then in putting it back in the the bike and putting the rest of the bike back together you find yourself having to re-mask it, and the frame, and goodness knows what else, and then do touch ups before you even get to start it - and the self curing process.  I am sure of one thing though, and this applies to rattle-can too, you have to find a good primer for the paint you're using or nothing put on top is going to stick to that aluminum.  This is one of the few places where I think "etch primer" is probably the best stuff to use first, providing the manufacturer recommends it for use along with their VHT.

[camelman]

Kong, I've noticed that keeping the paint layers thin really helps the chipping issues with this VHT paint. Two layers of light dusting with one complete layer gives good coverage and is very resilient. One week of curing seems to result in some solid paint without baking. Scratching during install is an issue although I've not had any issues with the 350f and 350 twin I recently installed. The engines took a few whacks during install but did not lose any paint.

I know others have had chipping issues, so there might be more to it than I mentioned.

Camelman

[Silverback]

I think that bumping a 175 lb. motor into anything would chip any paint you have. Hell, it even chips powdercoat on the frame. I have seen some companies offer an engine enamel for use in a spray gun. I'm sure a search would find it; try Eastwood. I have also seen custom auto builders use automotive paints on blocks before, you know, to match the color of the car. Can't speak about the durability, though.

I was even thinking about using Gun Coat on some motor parts. I think it's rated up to 500^oF. It is a bake-on product and is actually pretty thin, but supposedly durable.

[Kong]

You can wrap the tubes with pipe insulation during installation and be awfully careful.  The real problem comes later when I drop the pointy end of the test-light while I'm wiring, or drop a screw-driver when tuning the carbs.  That's when I screw them up.

When I did my hubs I used rattle can (Duplicolor) HT engine paint on the centers.  I did them with it because I want a color match for my cylinders and a couple of other parts.  I primed them and painted them using the normal application, just what Camelman suggested; two light and one heavier.  I also came back a half hour later and used their Clear on them.  Same routine, two light and one just wet enough to lay down.  Not having an oven available I just stood them up in front of a 450(F) wood-burner and kept turning them for an hour.  I suspect their temperature approached 200 degrees; they had to be handled quickly with heavy gloves.

Now here's the odd thing, one hub came up indestructible and the other chipped anywhere a spoke end touched it - not such a good thing with its my monkey-thumbs lacing the wheel.

So I sanded all the paint off the one that chipped, re-polished the aluminum, acetone cleaned it again, and re-did it, but used Duplicolor's "Etch" primer the second time around.  I do not recall that I heated the hub the second time around, it just sat for about a week.  The second time around it did not suffer any chips at all when I laced it.  I'd like to tell you that was because of great care, but it was not - I banged spokes into the paint just about like the first time around, but this time it didn't chip at all.

Go figure.  The only thing notably different was the primer, but then the first time around the rear hub didn't chip a bit, and it had the other primer on it. So, I just report, you decide.

[camelman]

Kong, that is interesting. I have preheated everything I've painted to get any residual oil out (except the cases) and did not have any chipping problems. When I've powdercoated, I've baked everything too, with the exception of one set of spokes that bubbled like mad. I had cleaned those spokes very well too, just not baked them. I wonder if you still had residual oils on that hub you had to redo.

Could you use the etching primer on high heat zones such as the cylinders?

By the way, sorry for hijacking this thread. I think it started life as a single stage paint question.

Camelman

[Kong]

Well, once its hijacked we all fly together.

You ask the question that is on my mind.  Can I use the green primer on the cylinders?  I do not know, but I know I'm going to try it.  I'd like to hear from anyone who used it with either success or failure.  The only alternative I can see is to take the top end off the engine and have the cylinders coated.

[Ernest T]

Eastwood makes a urathane engine paint you can shoot as a one part or two part paint.  Use the activator and it cures quicker and harder.  Its a little darker than OEM paint, but its resistant to gas and oil.





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