painting block: proper prepwork? +subjective color advice? :-)

[BerniniCaCO3]

Hi!

Painting my block, possibly even tomorrow but more likely next week.

I don't really have the facilities, and I'd be nervous anyway to do a proper sandblasting (lest I hit a machined surface) so I'm just scrubbing it down with a steel bristle brush. I'm not even sure if a wire wheel on an angle grinder could do damage?

So, I'm wondering... how clean is clean enough to be sure the paint won't just flake off? I don't think I can get it all down to shiny iron, a lot is still red and scaley even after a good manual scrubbing. Will the paint stick? Are there primers that are good to use first, or maybe naval jelly, or should I make a greater effort with the bristle brush?

And, while I'll try to take everything off... is a bit of paint on a machined surface the end of the world as we know it?


Finally, colors Ford blue? Or maybe even white, to better show where future fluid leaks are coming from? Or cold,steely, professional but dull gunmetal grey?

[1990LTD]

Ford blue?

ford blue.

[zoomie]

honestly the best way to do it is to take it to a machine shop and have it cleaned, but you can clean it using a pressure washer and engine degreaser, just make sure you have a good shopvac and a compressed air handy to blow dry and suck up water and what not. roloc disks work fairly well at cleaning iron too

[87gtVIC]

Pressure washing with degreaser or even easier pick up a couple cans of brake clean or equivalent and spray everything you want painted down good and use a stiff bristle brush to clean everywhere. Make sure nothing is shiny...you want everything dull so stuff sticks. Shiny means slick, dull means rough.

I haven't painted a block but I painted intakes and valve covers and the like. I cleaned them up really good and sanded them down with some coarse paper then laid down engine primer on them....let them flash off (loose the glossy look) then went back with paint. The pieces I did still look good.

Definitely get high high heat paint because you want to do this once. I'd primer it to for the same reason. Just do your best....Also if you are afraid you cannot get into all the nooks of the block and what not there are products (I believe i seen them in my local Lowe's) that is a surface scuffer in a bottle. Basically you pour the contents of teh bottle on a rag and with some water AI believe you rub the surface. It scuffs and preps everything.

[1987cp]

I used to use a machinist who tumbled the blocks, so they came back to me nice and shiny. I did goof rather badly on one and wiped it down with carb cleaner instead of brake cleaner - bad move. A gallon of lacquer thinner is better still, and since then I've always kept one on hand for various purposes.

Any media blasting should obviously be done before the machine work like honing and surfacing.

FWIW, I've had bad luck with Duplicolor as far as durability. I'd suggest getting something by RustOleum or maybe PlastiKote.

[P72Ford]

If you get all the grease and grime off, you should be good to go. Its hard to get all the old paint off, really.

A wire brush, or brushes, some lacquer thinner, and brake clean are really your best tools for this.

When its good and clean, I use a high temp primer, and have used everything from Dupli Color engine enamel, to Rust Oleum. Rust Oleum shines extremely well. Not sure how it holds up, because I've never used it on a DD.

Some people may flame me for this, but I paint an engine with it together. Some folks paint the heads and block/ timing cover, etc, seperately. I do not. Its one thing if you want them different colors.

I paint over all the bolt heads, excess gasket, etc. I always tape off head ports, crank snout, etc, and usually paint without the intake I'm using installed. Things like the accessories, balancer, brakets, etc, I always paint seperate. But I get the best results on an assembled engine. Pan on, heads on (as long as they aren't aluminum), timing cover on, and I use an old set of valve covers, and lay an old intake in palce, or tape the gasket surfaces and valley off.

I like the look of the bolt heads and everything being the same color.

My buddy has painted engines before assembly, but I showed him my method when we put the engine back in the Monte Carlo in November, and he now agrees that my way produces better results.

[1987cp]

RustOleum has been making engine paints for a while now.

+1 on painting stuff assembled. I've done it otherwise in the past, but always end up with nasty, gross bolt heads (I tried painstakingly bluing them, but used oil instead of wax to protect it, which didn't work). Painting assembled is also supposed to also help with crankcase sealing.

[rellik god]

this is the only way to clean a block http://www.youtube.com/watch?feature...&v=paUTGRdctpE

[rellik god]

http://www.youtube.com/watch?feature=player_detailpage&v=ScADnaomeDI

http://www.youtube.com/watch?feature=player_detailpage&v=u3K5vJxOiKw

[BerniniCaCO3]

How much does thermal cleaning cost?
I think I might be cheap and go with a wire wheel... though I do want to be sure, can a wire wheel do any damage to machined surfaces, or not really at all and I can just go to town and make the entire block shiny, inside and out?

[rellik god]

$100? a wire wheel can do damage to machined surfaces.other way of doing it is if your block is nasty i would use simple green on it and scrub it good when your down to painted surface use aircraft paint remover scrape paint off then simple green it again then use wax grease remover.surface has to be super clean or your new primer and paint wont last thats why thermal cleaning is the only way i think cause it bakes inpuritys off and it gets sand blasted.its up to you what you want to do but remember prep work is want you want to focus on

[1987cp]

You can always hit a machined surface hard with your intended wire wheel and see how much damage it causes!

I'd personally be afraid to use a wire wheel anywhere on the inside of an engine block.

This engine is already disassembled, right? If so, it might well be worth having your local machinist check it out, run his machine hone through it, and install new cam bearings so you don't have to. Then you can decide on other stuff like having the rod ends resized, crank checked and polished, and that sort of thing.

[1990LTD]

You can always hit a machined surface hard with your intended wire wheel and see how much damage it causes!

I'd personally be afraid to use a wire wheel anywhere on the inside of an engine block.

This engine is already disassembled, right? If so, it might well be worth having your local machinist check it out, run his machine hone through it, and install new cam bearings so you don't have to. Then you can decide on other stuff like having the rod ends resized, crank checked and polished, and that sort of thing.

+1 it's gotta go to the machine shop for it to be done "right."

I wouldn't put a wire wheel anywhere near surfaces intended to be in permanent contact with anything but air

[BerniniCaCO3]

Hey, I could always use a grinding wheel! Like whichever noob first attempted work on a 350 block one of my classmates bought and brought in. Luckily he found an affordable machinist and will have all the scarring milled off, but good god what a bad idea.

Yeah, on you guys advice I've just stayed away from the wire wheel altogether. The block really isn't all that bad, to risk hitting anything with a wire wheel.
The block is dead on, the heads are .002" shallower in the center, which is within spec. I'm just going to leave it.

Crank is .249", right where it should be; I might repolish it. For the money I just got new pushrods, cheap insurance.

But it's worrisome, a majority of my classmates ARE going to town with the wire wheel, even on aluminum head surfaces!!
...hopefully all of them are also planning on a visit to the machine shop.

I have gotten mixed messages on other things... for example one teacher takes his pistons and shoves them into the wire wheel to clean 'em up, and another advised me to stop when I touched my own pistons with a manual wire brush. I compromised and used a brass bristle brush and some acetone
We also heavily wire-wheeled all of our valves... but we did follow up by regrinding the seat! So all should be well there?

[1990LTD]

I should mention that I didn't say you can't, just that I wouldn't.