I'd be wary of sandblasting an assembled engine. That grit and dust gets everwhere. I'd be more inclined to use a sodium hydroxide based caustic cleaner (oven cleaner or people talk of something called "simple green", wear goggles) and a pressure washer. Water may get places it shouldn't, but at least it evaporates. Personally I don't think the rust is a big deal, the pain may stick better to the rust than fresh metal.

 

What Tim said. If it really bothers you, use Naval Jelly, a caustic that will remove rust, or a rust converter which will turn red-brown rust to a hard, black oxide that's very tough. Simple Green is mainly a degreasing detergent concentrate. I don't think it will do anything to rust, but it's a good prep cleaner.

But all you really need to do is use a wire brush to get the loose stuff off, apply primer and then the finish color.

 

Don't sandblast for the above reasons. It's a great way to ruin an otherwise good engine. When I clean up an engine for painting I use oven cleaner, followed up by simple green and then carb spray. Works every time. /ubbthreads/images/graemlins/wink.gif

If you want to remove the valve covers and the oil pan, and front engine cover, go ahead. Then you can paint them separately. But beware of leaks when you put it back together. You're trying to minimize work, not make more.

As for taking other stuff off the engine... that's up to you. If you don't want it painted, mask it, or take it off.

 

Ok, hear is what I did. Though I hate rust I left it there...untill my valve cover gasket started to leak, removed it and sanded it and painted it. The next leak was the oil pan...same process. I did that all through the engine. Its not a show engine but it runs and dosent leak. My dad always told me "Id rater have a ugly car the runs than a pretty one that dosen't." The process that I did ensured that it was a slow project that made sure all worked and didnt leak. Also no-brainer paint all the parts that you replace befor instalation. Do it this way and before long it will be a freshly painted engine. Good luck.

 

I think oven cleaner is probably close chemically to Naval Jelly, and neither should be used on aluminum or magnesium. Caustic chemicals will eat them up.

 

True, it does remove anodizing. But then that returns, so I've never had a problem with it.

 

Left on too long it will eat and pit the heck out of it. Maybe some alloys are less sensitive than others, but it will eat a lot of them. I play it safe by keeping caustics off of all metals but stainless, steel and cast iron.

 

So if I have some 6061-T6 that has been anodized, color not hard, I can just hit it with oven cleaner to remove it?
I usually sand blast it, but that doesn't leave the best finish.
Good to know.

 

Yes, my son has actually sandblasted an engine in order to remove the rust prior to painting. It was a 4 cylinder from an 84 xj. Engine looked brand new when he was done. The only extra work involved was a complete tear down to remove all of the black beauty from inside. It was packed full. Personally I think that I will stick with chemical cleaners.

 

Re: painting engine what color ?

thanks all for the replys

i know how to paint, but all the parts we paint at the shop are either brand new or sandblasted , so the cleaning of a 26 year old engine with oil and rust, and old paint flakes all over is another issue, i think i will try some enginewash and pressurewash, and see how far that gets me.
Then i can always remove minor parts for sandblasting and painting.

what color is you engines and trannys; PICS please !! i need ideas i have already powdercoated the airfilter,fan: red and the batterybox and brakeMC: black

 

Re: painting engine what color ?

I've been tempted on many occasions to paint my block white, just to pick out leaks quicker and easier, and paint the headers, pan, and valve covers aqua or green as a contrast. But that's just me, and anyone will tell you that I'm just plain strange.

 

Hello Maddane

Can't give you any advice on this one.
But....I'm a Dane too! Can't remember if we have spoken before. Do you attend Jeep events here in Denmark? I'm writing in English so all the "others" understand it /ubbthreads/images/graemlins/smile.gif

Maybe we know each other. I live in Ikast and own www.jeepster.dk

 

Re: painting engine what color ?

Just attached some pics for you
If you come to Ikast anytime soon, you can see it live
The paint is "chevy orange". Natural choice for a cheyv 350 /ubbthreads/images/graemlins/smile.gif

Pics below are from an AMC 360 I had
The color is "Ford dark blue"

I hope this inspires you /ubbthreads/images/graemlins/smile.gif

 

Re: painting engine what color ?

this i what i did to the engine today
now i need to remove the rust so pain can be applyed

before

after

now you can see that the transmission is aluminium, i also found out that the inlet manifoldgasket was replased with somthing else because i was leakin oil all over the end of the engine and out over the transmission.

 

Re: painting engine what color ?

i went with a chrysler blue of '70s era IIRC, the job started as a simple intake/exhaust gasket replacement/ubbthreads/images/graemlins/grin.gif, degreased it, sandblasted the intake while it was off, wiped down with acetone, and spray bombed it.

held up fair....needs a redo next spring