Speedtoys

My intake parts on the 85 are in good shape, but the metal oil filler neck has been w/o it's paint for some time, and is clearly dark and soaked.

What will deep clean this enough so that a good paint will stick nicely?

I'm considering once these are blasted, using this down at the airport to really clean and pull out the oil from the surface the blasting may miss:

http://www.chemical-supermarket.com/...?productid=365

And then alodine the parts to seal em.

terry gt

a oven . out gassing

Speedtoys

The oven...would clean them? Lost me there.

Ladybug83

Clean them with solvent or your favorite cleaner, then you bake them in the oven to "off gas" the residue out of the metal. Seems like the approved practice before painting or powder coating

85euro928

Do this multiple times if you can. I did mine 4 or so years ago and it still looks like new.

Petza914

I've had good results using Piston-Kleen which is an aluminum safe cleaner.

http://www.orisonmarketing.com/pistonkleen.html

Lizard928

It has turned black due to the magnesium in the filler neck.

Either sandblast and powdercoat, or sand and paint.

karl ruiter

I sanded and painted, with degreaser and mineral spirits in there to degrease. But still I felt like I did not get the oil off. It seemed like oil had actually impregnated the material. So, clean, degrease, sand, bake, and sand again.

karl ruiter

Wait. '85?

Speedtoys

Yes, 85 32v.

BPG_Austin

Sorry, I'm late to the party.
I believe the metal oil filler necks are pure aluminum. I've refinished a lot of them. They're more durable than the cast mag alloy parts and don't corrode the way the mag alloy castings do. And, they don't get off-gassing pineholes when coating. That's the tell-all.
That being said, they are cast, so they will absorb dirt and oil. I agree with what's been said above. Give it a good media blast, then off-gas in an oven if you are able. (and WASH, SCRUB etc.. of course) Otherwise use a degreaser of your choice prior to painting. The deaply trapped oils will only surface through the application of prolonged exposure to heat. (much higher temps than the filler will ever see in the engine compartment) So, you should be fine to paint.

Jerry Feather

Jeff, I think that if it were me, and probably will be at some point soon, I would first clean the part by blasting with something not too abrasive, but enough to open up the surface of the metal, then soak the part in lacquer thinner or MEK for about 3 days. Then I would put the part in the oven for several hours at about 300 degrees and bake it. Then, depending on what shows up on the surface, I would blast it again then paint or powder coat it. Don't use your kitchen oven.

Both magnesium and aluminum, especially cast, are very porous. A friend of mine who was teaching me about mold making for investment casting told me about one of his projects that he tried to do with sand casting for a motorcycle engine cover of some sort that, after being cast, was so porous that the oil literally seeped through it. I think that is what got him interested in mold making for investment casting.

I think this is why alloy wheels are commonly painted on the tire side surface, to seal the air in.

Speedtoys

"Don't use your kitchen oven."

You are no fun.