Can i use either mineral spirits or paint thinner to take off paint from the plenum? If So which one is preferred?

------------------
Fieros......Gotta Love Em!

https://www.fiero.nl/forum/Forum1/HTML/087369.html

I am unsure if thinner will work, Aircraft Remover may work well however.

I am sure that chemicals won't hurt the aluminum. However I generally media blast the upper plenum when I repaint, gets rid of all the corrosion in the hard to reach spots, so the paint sticks well.

If you have no access to a media blaster, chemicals will work, but Lacquer thinner wont work because the paint is cured. However I may be wrong!

relax.....you are right. Aircraft paint stripper in a spray can is about the only chemical. the other ones are good cleaners, but won't remove any paint.

[This message has been edited by Gall757 (edited 12-20-2011).]

Easiest, cheapest and most complete way to remove the paint including in all the nooks and crannies s to take the throttle body off, take the plenum to an automotive machine shop. They'll have a hot tank to dip it into. Cleans the inside and outside. Usually around $20-30.

Agreed. Thinner wont work on cured paint. Just use a paint stripper. Apply, wait until it wrinkles up the paint, and strip it off. Wait too long and it will harden again. Don't wait long enough and you'll make more work for yourself. Be sure to use gloves. The stuff will mess your hands up. When you go to paint it be sure to get the surface good and clean and use a self-etching high temp primer.

Take some paint stripper and pour it into a pan and just let the plenum soak. That worked best for me when I painted mine. I also used a wire brush wheel to get those stubborn areas.

The valve covers and the upper plenum on the V6 were not painted, they were powdercoated. Aircraft stripper will work, but it is a bit of a job to do - I've done it myself. The plenum is not really easy to strip with the aircraft stipper due to the rough surface of the casting. You have to apply, soak, scrub off, and repeat one or more times to get all the color out of the surface imperfections.

The easiest way to strip it is to take it to a media blasting shop and have them strip it. I just picked up a plenum yesterday from a shop in this area:

If you have it media blasted, tell the shop to only use fresh glass bead. Recycled glass bead, or crushed glass bead is too abrasive,and will pit the machined surfaces. Any type of silica sand, or any of the aluminum oxide media are much too abrasive and will severly pit the finished surface on top as well as the gasket surfaces. Many years ago I had another one of these media blasted and the shop used silica sand. The plenum was basically ruined because the machined surfaces were agregiously pitted.

I have read that Permatex gasket remover will strip powdercoating much the same way aircraft stripper will. I've never done it myself so I can't say if this method would work well.

quote Originally posted by lateFormula: The valve covers and the upper plenum on the V6 were not painted, they were powdercoated. Aircraft stripper will work, but it is a bit of a job to do - I've done it myself. The plenum is not really easy to strip with the aircraft stipper due to the rough surface of the casting. You have to apply, soak, scrub off, and repeat one or more times to get all the color out of the surface imperfections. The easiest way to strip it is to take it to a media blasting shop and have them strip it. I just picked up a plenum yesterday from a shop in this area: If you have it media blasted, tell the shop to only use fresh glass bead. Recycled glass bead, or crushed glass bead is too abrasive,and will pit the machined surfaces. Any type of silica sand, or any of the aluminum oxide media are much too abrasive and will severly pit the finished surface on top as well as the gasket surfaces. Many years ago I had another one of these media blasted and the shop used silica sand. The plenum was basically ruined because the machined surfaces were agregiously pitted. I have read that Permatex gasket remover will strip powdercoating much the same way aircraft stripper will. I've never done it myself so I can't say if this method would work well.

I generally use tape over the machined surfaces, and I have 2" Roloc Scotch Brite pads to remove and minor pitting from sand blasting, works like a charm. its a bit more labor intensive, but works! the 2" pads work on 2" sanders generally for gasket removal, but they shine up surfaces and take out imperfections nicely, as long as you are careful.

I used a wire wheel in a die grinder to remove around 90% of the old paint. About an hour. After priming and repainting it looks pretty darned good.

On plenums and valve covers I've refinished, after stripping, I wash them well with a good degreaser. After they're dry, I then wash them with pure white vinegar, rinse with hot water and handle them only by the surfaces that aren't to be painted. When they're dry, I prime them with Zinc Chromate primer, designed especially for use on aluminum aircraft panels.

I let the Zinc Chromate primer dry for 24 hours, then spray my color of choice. I always use a high temp engine paint. When the paint is dry, I remove paint from the polished surfaces, then put the part into an oven at 200-250 degrees for 30 minutes. A single-edge razor blade type window scraper works well for slicing paint off the ribbing and flat surfaces of the plenum and valve covers. Then polish with a sander using progressively finer sandpaper.

quote Originally posted by fierofool: A single-edge razor blade type window scraper works well for slicing paint off the ribbing and flat surfaces of the plenum and valve covers. Then polish with a sander using progressively finer sandpaper.

Here's a tip from someone who has done this several times. If you intend to polish the raised areas on the valve covers or upper plenum, do this before you paint or powdercoat the parts. Polish first, mask off the polished surfaces, then paint or P-coat the parts. The reason to polish first is because the steps invloved in polishing those surfaces can damage or discolor the paint/powdercoat. Once the parts are finished you can give them a touch up with Mother's Mag & Aluminum polish (or Wenol) or even clear coat them with Eastwood's "Diamond Clear"

lateFormula, I suppose you could do some damage. I use an electric pad sander. Since all the polished portions are the same height, it doesn't get down into the areas that are to remain painted. Using the razor blade scraper, I place the blade so it bridges across the raised ribs and slice everything off the raised areas before polishing with the sander. Because paint will not bond to a sharp edge, I tilt the razor at a 45 degree angle and run along the painted side of each polished portion, slicing a very thin strip of the paint off. This keeps the paint from peeling as the part ages.

I like the idea of polishing out with Mother's. Never tried that. Where do you get the Diamond Clear?

quote Originally posted by fierofool: Where do you get the Diamond Clear?

http://search.eastwood.com/search?w=diamond+clear

After a media blasting, if it turned out that good, Id seriously think about just putting Duplicolor Engine clear on it. When I bought my Magnum brand new, I drove it a few weeks then cleaned it good in the car wash. Then I sprayed the engine clear on everything. 4 years later all the alloy on brackets, block, heads, etc still looked showroom new. All my friends that didnt, had layers of white powder corrosion everywhere.