[mgarblik]

I thought the body and paint experts could help me on this one. I am working on an SD-455 car that has a fresh engine in it, never started. Problem 1: it was painted the wrong color. Problem #2 it was painted 41 years ago but never started. Back when it was rebuilt and painted in 1981, little was known about the slight color difference on the SD engines and frankly, I doubt anyone cared. It is painted regular 73 non-metallic Pontiac blue. I plan to remove the engine and re-paint it the correct SD color, which I have. I don't see any practical way to remove the paint that is on the engine and it looks to be fine, with no rust bleeding through. How would you body and paint experts proceed with this? Thanks for the input

[hobbygto65]

After 41 years wouldn't you want tear the motor down and relub everything and then paint?

[mgarblik]

I am going to open it up and inspect. Change the rear main seal. (I am sure it is a rope now). Put new gaskets in as needed. But still don't have a good way to remove the old paint ? Don't want to do a complete tear down and hot tank type thing. Then your talking new SD rod bolts, new rings and bearings again, new cam bearings. Want to avoid all that. I guess my better question should be: How would you body shop experts prepare this engine for a repaint or if a complete disassembly and strip is necessary, I may consider it. Thanks

[HoovDaddy]

41 years, never started? Does it rotate? Based on the value of it, I would take it out and remove the oil pan and give it a good visual inspection and remove a couple bearing caps. Then you can tell what kind of job the builder did, and go from there.

As far as paint, try to scrape some paint from a hidden area and see how easily it peels. If it's stuck good, you should have no problem painting over it. Otherwise use aircraft stripper and remove all the existing paint then repaint it.

[mgarblik]

Engine seems fine. It's been stored in a climate controlled environment all these years. Aircraft stripper? I had heard none of the strippers worked very well anymore because of all the new formulas. If the stripper residue has to be removed with water, that doesn't sound very practical on an assembled engine. I will try the scraping idea on some areas.

[Bruce Meyer]

If current paint doesn't easily chip off, I would get some lacquer thinner put in on a rag and wipe it down. It should soften the paint so a new coat will stick.

[Scott Thelander]

burnt it off with a propane torch wire brush
prime it with rustoleum
and paint the correct color

[Stuart]

I'd just scuff up the paint to give it some tooth, and shoot the new color.

[Greg Reid]

Originally Posted by mgarblik

Engine seems fine. It's been stored in a climate controlled environment all these years. Aircraft stripper? I had heard none of the strippers worked very well anymore because of all the new formulas. If the stripper residue has to be removed with water, that doesn't sound very practical on an assembled engine. I will try the scraping idea on some areas.

Funny, before reading this thread I was going to advise how NOT to do it, that being, using aircraft stripper. I did that once to an assembled engine and swore I would never do it again. It did work but it was a wrinkled mess. Once you put that stripper on and it starts lifting the paint you have to make sure you get every single bit of it out of every nook and cranny. You definitely don't want your new paint on top of any stripper residue
Like I said, it did work but there has to be a better way.
If I were doing it again I would just pressure wash it after a really strong degreaser (l like Easy Off in the yellow can) and the hottest water I could. The pressure washer should remove loose paint and if it's clean and degreased new paint should adhere.

[grandam1979]

Originally Posted by Stuart

I'd just scuff up the paint to give it some tooth, and shoot the new color.

Me too.

[b-man]

That engine really should be completely torn down after sitting over 40 years.

Who knows what dried up assembly lube is on the bearings and camshaft or what kind of job in general was done on the rebuild.

Get paid to take it all the way down and to build it back up. Strip off the old paint during the process.

Doing the job correctly isn’t the easy or cheap way out.

Good luck.

[400 4spd.]

Originally Posted by mgarblik

Engine seems fine. It's been stored in a climate controlled environment all these years. Aircraft stripper? I had heard none of the strippers worked very well anymore because of all the new formulas. If the stripper residue has to be removed with water, that doesn't sound very practical on an assembled engine. I will try the scraping idea on some areas.

HELL NO on the stripper! This isn't a slick piece of stamped steel, but a porous, cast assembly. If you use stripper on it, you will never get another paint to stick.
If you have a safe place to prevent the dangers and build up of fumes, you could try an enamel reducer and scotch brite pads or bristle brush to dissolve the paint. Next choice would be lacquer thinner.. If that works, get up with me and I'll tell you how to get it painted.

[yahooskidoo]

Read this.

[mgarblik]

Thanks for all the different ideas. I just wanted to make sure my thinking process was on the right track. The engine was built by A-Hines Racing Engines in IN in 1981. Have full documentation. Engine has always been inside in climate controlled environment, then installed but not completed. Problem with complete teardown and complete paint strip is the methods I use are too invasive. I have a thermal oven and blaster. Great for a needed rebuild, bad for this. Once the block has been run through, it requires a line hone, surfacing and cylinder hone job. Just too much for a already fresh engine. Customer would be into several thousand dollars for a paint color change. So I am going to try several suggestions from this thread. Scotch Brite/lacquer thinner/enamel reducer, scraper to check for loose paint, then try the color change and see how it looks. Engine is in the car now. Just planning for a weather break when I can pull it. Thanks for all the ideas. Painting the body of a car, I wouldn't even consider. But a job like this, I can handle. I will post some pics when I get it pulled.

[mgarblik]

Originally Posted by yahooskidoo

Read this.

Thank you for that interesting information. I will have to look at the EUN number on the block! Could I get lucky enough that this would have been a factory respray anyway? That would be just great. Then I can just do an overspray and it might not look the absolute greatest, but it will look correct. Have to go check. Not going to respray in the chassis no matter what. I can have the engine out in an hour or two. It's just sitting in the chassis, no transmission.

[Mike Davis]

Just did this with some SD parts that had been painted Pontiac blue and wanted to change them to SSD slate blue.. Lightly wiped with lacquer thinner, let dry out a day to make sure the base paint didn't craze, dusted a very light coat of Bulldog Adhesion Promoter and painted. After the paint tacked up I put them in an oven on 200F for about 20 minutes.

[tjs72lemans]

I have to agree with the scuff and clean process. Shoot with epoxy primer and color. Epoxy sticks very well and color will adhere to that. That's how I resprayed my 55 Chevy motor while it was out during my frame off restore and it had 7,000 miles on and was first sprayed rattle can orange 30 years earlier during motor rebuild. I resprayed it metallic graphite grey to match my interior. That was 10 years ago and it still looks like new.

[77 TRASHCAN]

The difficult part of this , is the amount of time needed....
I’d start with the least harmful method. Possibly using scotch brite. There’s all kinds and shapes of this stuff that can be attached to a drill or a die grinder. A car buddy and I were at a swap meet, sometime back. An individual was sell these scotch brite pads, we had never seen. They are were like 8 inches in diameter and 1 inch thick. Made to be on welding grinder. He used his to strip the inside of a pickup bed. .

If you stripped off as much as possible with scotch brite or sand paper, it would leave a lot less paint to remove to get to bare iron.

[Skidmark]

My engine was painted the wrong shade by the builder. When I installed it 7 years after it was built, I stipped it using a wire wheel. The paint came off pretty easy not much labor involved.