Removing Engine Paint for New Paint

[Tom Wesenberg]

I haven't used paint remover since 1970 when I used a gel to remove layers of paint. I don't recall the brand, and don't recall how I cleaned up the mess it made. I'm wondering if oven cleaner will do a job on this engine, or do I need something better to remove the paint. I'd also like to remove the rust without sandblasting it, as I won't be taking the engine apart. It runs great, but I'd like to paint it the right color.

I'm still wondering about the black painted area. I hope that isn't red paint that turned black from a bad overheat.

[Ed Saniewski]

Aircraft Paint Remover is the stuff I have used in the past and it works great. You must have good ventilation and wear rubber gloves. You paint it on and watch it attack the paint. Then wash it off with water.

[C26Pinelake]

[B][If you can power wash before and after it works wonders. Wayne/B]

[captndan]

I agree with the aircraft paint remover. Just one thing when the paint is loose wash it off with a gentle stream of water. The remover is still active and will attact anything it touchs. When it's off then hit the engine with high pressure. WEAR GLASSES!

[BILL WILLIAMSON]

Tom,
T.S.P, mixed to a pancake batter consistency, will remove paint. It's not fast, but it's not CAUSTIC.
Bill W.

[bunnyc]

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I just did this to my engine. I used Aircraft paint remover by Kleen Strip. Note: the directions contain a warning "do not use on aircraft". !!
I used a heat gun on the paste. Seemed to work better. Used an old pocket knife and various hand wire brushes to remove the softened paint.
Wiped the block with Purple Power, then acetone.

[Special Coupe Frank]

Tom,

That'd be one heckuva overheat to turn red paint that dark !

Hope the cause was something else !


Frank

[Russ/40]

My preferance would be mechanical methods. I just dont like dealing with harsh chemicals, and the mess to clean up. I have had great results by using air tools driving different types of wire wheels. You can get right down to bare cast iron rather easilly. What ever remains of prior paint, if any, will be well adheared and never be an issue. It also gives you the freedom of walking away from the task, to resume at your convenience without another cleanup.

[Tom Wesenberg]

Originally Posted by Special Coupe Frank

Tom,

That'd be one heckuva overheat to turn red paint that dark !

Hope the cause was something else !


Frank

A couple years ago I saw smoke coming from the hood of a Model AA truck. The fan had so much end play that it sliced the radiator tubes, then the engine got so hot it burned the paint off the rear of the block. The area of burned off paint looked quite similar to the black area in my picture.

I'll keep cleaning with the wire brush, then I might decide to make a small enclosure to sandblast the block. If I do that, then I'll have to wrap rope around the front seal to keep the grit out. And, I'll stay clear of the rear seal.

I should just leave the red paint on because I've heard red engines are faster.

[Tim Armstrong]

Oven cleaner...Easy Off works great.

[H. L. Chauvin]

Just one (1) way, for one (1) time engine painting:

I do it quickly to save valuable time and use vintage, toxic "Kud-zit" gel.

But, don't forget the vintage engine re-builders' selling points:

"Rebuilt Engine with a Fresh Coat of Paint." (Old time lead-oil paint worked over old caked dirt and grease ....... all engines guaranteed to run better with a fresh coat of paint.)

Old engines will take several coats of Kud-zit followed by several coats of POR 15 water based Marine Clean to go through several layers of paint/grease.

Finalize with POR 15 Marine Clean, POR Prep & Ready, (2) coats of POR 15, and (2) coats of POR 15 engine green ...... paint engine once in a life time ...... no rust ever forming around head gasket area for several centuries.

Just don't have time to waste removing old paint and re-painting.

[Dan Partain]

I've found that oven cleaner is good for grease but it didn't do much, if anything, for paint. It left the original black paint on oil tubes untouched after the grease was gone.

I scraped my block with a heavy putty knife type scraper to chip off the easy stuff, then used aircraft paint remover for the difficult to reach areas and pores in the block. Next I used a wire brush on a little side grinder tool I have. That cleaned up the block pretty well. Next I brushed on a degreaser and ragged it off until the rag didn't show black residue. Finally I masked off some areas and brushed on a couple coats (maybe 3) of engine paint. The paint flowed out well and showed no brush marks.

I wouldn't use a sandblaster anywhere near an engine. Seems like no matter how well you think you protect the engine the sand will find a way in there. Just my opinion.

[Charlie Stephens]

If it won't come off with a wire brush on the end of a power tool I think I would paint over it.

Charlie Stephens

[mshmodela]

Strypeeze Paint Remover

[Dollar Bill]

Have prepped several tractors for paint using oven cleaner followed by pressure washing. Feather any remaining paint edges with a powered wire brush. Treat any surface rust with phosphoric acid. Do a final wash with prep sol and you're ready to paint. I did my 8N this way 10 years ago and it looks as good as the day I painted it.

[Russ/40]

Originally Posted by Charlie Stephens

If it won't come off with a wire brush on the end of a power tool I think I would paint over it.

Charlie Stephens

Amen to that!

[ronn]

engine degreaser/oven cleaner and an old pickup-quick ride to the car wash and blast it there and come home with a clean engine!

[ursus]

Having seen the dramatic effect resulting from DOT-3 brake fluid spilled on a fender, I wonder if painting on some used brake fluid and hosing off the paint after it lifts off is an option?

[Big hammer]

Cast iron is porous, I think brake fluid soak in and be a problem.

[Neil Mylar LakewoodCA]

Can too many layers of engine paint (1/16 to 1/8 inch thick) have an effect on engine cooling?

[ian Simpson]

Originally Posted by captndan

I agree with the aircraft paint remover. Just one thing when the paint is loose wash it off with a gentle stream of water. The remover is still active and will attact anything it touchs. When it's off then hit the engine with high pressure. WEAR GLASSES!

I wear glasses full time. When using this sort of nasty stuff, I use a cheap Plexiglas mask to protect my good looking face, not just my eyes

[Mike]

This is a engine I detailed 2 weeks ago using high speed and multiple wire cup brushes. New timing gear and dropped the oil pan.

[Tom Wesenberg]

Mike, your engine sure looks nice.
It looks like you might have the tall water outlet, rather than the correct shorter 28-9 outlet.

Great news. It was way to hot and humid to be outside yesterday and today, but I worked on my engine anyway. I connected the garden hose to the hot water and had my air hose ready to blow dry the engine. I bought 2 cans of oven cleaner at Dollar Tree, and was really surprised at how well and quickly it worked.

Back in #1 you can see the engine after I spent a couple hours wire brushing the dirt and rust. A lot of work for little gain. Then I sprayed some oven cleaner on it and left it overnight. This morning I gave it a respray and used my new parts cleaning brush to work it. The first picture shows the engine right after spraying the oven cleaner, then it quickly turned brown as it lifted the dirt and some of the rust. After brushing it the red paint started coming off. I repeated this process, then had to quit due to the heat and humidity, but a third application probably would have removed all the red.

Anyway, it's really clean and ready for paint, but I'll still use some phosphoric acid and maybe wax and grease remover. I still think the black looks like red paint that turned black from too much heat, and I might hit that with my spot sandblaster. You can see what the oven cleaner did to my new parts cleaning brush, but it's now a better brush to use for cleaning out the driveshaft tube. I'll just cut the wood handle in the middle, then attach a long rod.

[Mike]

Tom,
Thank you ! If the engine is out of the car I use oven cleaner, most of my jobs the engines are in the car so I use degreasers and hot water to get the engine ready for paint.

mike

[marc silva]

Tom,
I use what is called a "needle scaler" I got it at Harbor freight. It is a bunch of 1/8 inch hardened rods in an air tool that vibrates kind of like an air hammer but will chip off paint and rust. It will maintain the texture of the casting finish. I actually used it to re texture a couple mold spots that I had on a Snyder head that were there from casting the head that I ground off. You cant tell where I did it. I took the paint off of a transmission and it looked like a brand new casting. Just clean it with prepsol or a wax and grease remover and paint. The ends of the rods eventually get rounded a bit so touch the ends to a grinder to make them flat again and you are back in business. I strongly recommend this tool. It is much easier than messy remover or wire wheels on cast iron.

Marc

[Mike]

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Please post pic of the tool

[marc silva]

How do I do that ?

[ronn]

Ian,
doing any modeling lately?

Mike,
your engine looks like one of those "rebuilt" engines so often spoke of on the barn. beautiful!

[marc silva]

i will do a test and post the photo


IMG_1820.JPGscaler.jpg

IMG_1819.Jpgscaler2.jpg

IMG_1818.JPGscaler3.jpg

[marc silva]

This took about 3 minutes and as you can see from the previous pictures the ends of the needles are rounded a bit. If I were to grind them flat again it gets a better bite and the metal would look more shiny.


IMG_1821.JPGhead 4.jpg

IMG_1822.JPGhead 1.jpg

IMG_1824.JPGhead 3.jpg

IMG_1823.JPGhead 2.jpg

[marc hildebrant]

Originally Posted by BILL WILLIAMSON

Tom,
T.S.P, mixed to a pancake batter consistency, will remove paint. It's not fast, but it's not CAUSTIC.
Bill W.

Bill,

Are you talking about real TSP or the fake stuff sold now.

Marc

[Mike]

Marc, Ronn,
Thank you !!
Mike

[Mitch//pa]

Mike that motor looks really great.. Very nice job I bet the owner is thrilled..

[Tom Wesenberg]

This morning I finally was able to make some progress on the engine from the deer hauler. I went to the store yesterday to find an assortment of rubber balls, but only found the two large ones, which will be good to block off the water pump hole and top hose hole.

At Fleet Farm I just happened to spot these rubber leg caps, and bought an assortment, as they are perfect for plugging holes. Since they are hollow they also work well to cap lines, and the tapered outside makes a perfect fitting plug.

When I was half way through sandblasting I'd wished I would have done one more round of oven cleaner and forgot about sandblasting. I made a tapered wood plug for the dipstick hole, and wrapped a lot of duct tape around the front pulley to keep the Black Blast out of the rope seal.

The third picture shows some large washers I cut out of aluminum plate with my hole saw. I also have some fairly stiff foam rubber behind them so seal the openings. Since this is an assembled running engine, I won't worry about the hardware finish at this time. Green paint on them will be fine.

I still need to drop the oil pan and also dial in the flywheel cover before this engine is ready to install.

[ronn]

I should just leave the red paint on because I've heard red engines are faster.

yeah, if your engine is a "fire" engine........................!

[ford31]

what about soda blasters

[Tom Wesenberg]

Originally Posted by ford31

what about soda blasters

Soda removes paint, but not so much for rust.

[Dollar Bill]

Looking good Tom!

Your next sand blasting project, you may consider using spray foam to plug up holes. Just lay in a piece of Saran Wrap to contain the foam and squirt with spray insulation. Easy, peasy!

I share your sand blasting sentiments. Ironic that my sand blaster rig is now rusty from lack of use - It's agonizingly slow and makes a terrific mess.

[Mike V. Florida]

Originally Posted by Tom Wesenberg

Soda removes paint, but not so much for rust.

Whenever I read about soda blasting the always mention that it will not remove "heavy" rust (Eastwoods site). I wonder how heavy the rust has to be?

[Tom Wesenberg]

Here's why you should ALWAYS remove the oil pan on an unknown engine. This engine ran so nice that I was thinking of installing it without painting and removing the oil pan. I'm glad I decided to remove the oil pan because I found a crack in one tooth on the cam gear. I might have even missed this had the engine not stopped in this exact position.

I also found a broken oil pump spring and homemade retainer, so they will get replaced. The rear cam lobe has some light pits, but this should be OK for now. I also found the distributor shaft is quite loose and needs to be rebuilt. The pan had only about 1/8" of soft sludge, so that was better than what I usually find.

The bad tooth is the third one from the crank gear. I'll install a new aluminum cam gear and will polish the crank gear.

[Tom Wesenberg]

I've got to stop taking things apart. Every time I remove something I find another problem. Yesterday I removed the broken 2 piece aluminum pulley and found someone had forced the sleeve into place without lining up the notch for the key. It forced the key to cut a new notch and also put a crack in the sleeve. I saw where someone had done this same thing to an original pulley a few years ago, but on that cast iron it broke out a chuck of the sleeve.

They also deformed the key by pushing it up and to the side, so now the oil slinger can't be removed. I'll try to straighten the key tomorrow.

[burner31]

Well, lets see, I work as a aircraft corrosion control supervisor. ie: paint stripping.

The best stuff is called "plane naked" it is eco-friendly and my #1 pick...if you can get it. The warmer the working temp and higher the humidity the better.

#2 would be "phenol", very harsh, very very eco-unfriendly, this shit will burn the hell out of you if you do not wear proper protection, makes a mess, but gets the job done quickly. Use lots of rags and lots of water, only use a water hose once you get 99% of the chemical wiped off. Cover yourself from head to toe. And don't splash it on anything you don't want stripped, stained or melted.

As for me...I used a good eco-friendly degreaser and a power washer, repeated several times, let fully dry, mask and paint.

[Tom Wesenberg]

Still making slow progress. If the crank was out of the engine then I'd install a new crank gear, but in this case I spent about 3 hours sanding on it. It seems the crank gears like to rust on engines that set unused for long periods of time. Look at replies 39 and 40 to see the rust. Also notice the left main bolt in the picture should be turned 90* for the cotter pin hole to line up better. The small bump on the head should face straight in or out. Notice the groove worn in the aluminum sleeve of the two part pulley. I've seen wear from the rope seals before, but never this much.

[Tom Wesenberg]

Well, once again it's one step forward and three steps backward. I saw this engine run for an hour two years ago. In fact I was the one that helped get it running. It ran strong and smooth and never leaked a drop of water. The water was drained after the run, and I bought the engine a few weeks later. The engine was down low on the wood engine stand I made when I sandblasted and painted it, so I never saw a problem.

I never saw these two water jacket cracks until I had it in the regular engine stand and turned it upside down yesterday. The red paint had covered them over when I bought the engine. Since it never leaked before I think I'll sandblast the cracks and use some JB Weld on them.

I did get the flywheel cleaned up today. It cleaned up fine for being the home to a family of mice. Since the wishbone ball hole was left open on the bellhousing, the mice had a nice opening to enter. When the engine first started, ground up mice came flying out the hole and a couple burned mice flew out the exhaust pipe.

[Tom Wesenberg]

Well, after putting this engine on hold for a while, I finally sandblasted the 2 cracks yesterday and applied slow set JB Weld by pressing it into the cracks as well as I could with a plastic credit card. after it set up for a couple hours I detailed it by using a small wire brush, then today I painted it. It was too hot and muggy and too many mosquitos to do any more work on it today, so hopefully tomorrow, if it doesn't rain again, I can get the covers back on.

Since the cracks never leaked when it ran 2 years ago, I hope the JB Weld will be a good secondary plug to keep it from leaking. Only time will tell, and I hope I can get it installed before it's too cold to work outside. I learned one thing from all this, the next time I buy an engine I'll have to look closer for cracks, and not pay more than good core price, unless I have real proof of the engine condition. Yes, they can sound good, but have many problems to be fixed.

[Dollar Bill]

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I think you'll be fine. Repaired a similar crack in the last 8N I restored using JBWeld - Hasn't leaked in 5 years.

[Tom Wesenberg]

Still making progress on the engine, then I spotted a void in the casting on the front of the block at the bottom of the cooling chamber. This area always looks like an old repair, but that must be from the factory grinding away the excess cast from the pour. Anyway the void looked deep, so I sandblasted it and filled it with JB Weld.

I bought a new cam plunger and spring because the oil grooves were almost worn away on the original part. I turned a thick piece of wood to 1 5/8" to use to pound in the new rope seal. I never soak them in oil, but I oil and grease them well after they are in place just before installing the cover.

The flywheel cover had no bolts nor shims in the top two mounting holes. After cleaning the threads and installing two bolts and one shim on each side, the cover was out by just over .010". By adding a second shim to the left side I was able to dial it in under .004".

I had to install a new timing gear due to a crack in one tooth on the original gear. Notice the timing dimple lines up to the right side of the keyway, not the left side as has been pictured in some books.

The valve chamber was cleaner than I expected, so the seller was probably telling the truth when he said his dad overhauled it shortly before he quit using it.

I had to make a new tool to pull the timing gear cover down enough to get all the bolts started.

[Dollar Bill]

Looking good Tom! You’ll be making smoke before long. I applaud your ingenuity - Those tools will make the onerous rope seal installation go a lot easier.

[PatrickGrant]

It is nice to see another place to mount the engine stand. The thing is I would like to get access to the valves and am leery about using the pan mounting threads and water inlet mount method. I have the flywheel cover off. I was wondering if I could use the top 2 bolt holes, above your indicator, and the two that hold the carb linkage on? I will make a new plate, pipe fixture and bolt it directly to those places. I would use a 2" longer pipe with spacer on it to get the crank to clear my stand. Question is, would this be a good location ? Also thanks for this thread.

[Tom Wesenberg]

Originally Posted by PatrickGrant

It is nice to see another place to mount the engine stand. The thing is I would like to get access to the valves and am leery about using the pan mounting threads and water inlet mount method. I have the flywheel cover off. I was wondering if I could use the top 2 bolt holes, above your indicator, and the two that hold the carb linkage on? I will make a new plate, pipe fixture and bolt it directly to those places. I would use a 2" longer pipe with spacer on it to get the crank to clear my stand. Question is, would this be a good location ? Also thanks for this thread.

I would only use the side mount. The water inlet bolts are large and with the two pan lip bolts your engine will be mounted solidly. You'll be able to assemble the whole thing except for the two pan bolts.

[captndan]

If you don't like using chemicals get a needle scalier. That's what the big equipment boys use.

[Tom Wesenberg]

I finally got the dog house made and my engine put away in it. I've had the engine stored outside next to my pine tree under 3 plastic tarps since the end of September. You can see the flywheel took on a little rust, which I'll have to remove again. I still need to paint the oil pan, then it will be ready to install in my 28 Phaeton as a better temporary engine.

[Dollar Bill]

I like your dog house Tom!

Knock the rust off of your flywheel with a maroon Scotch-Brite pad and then spray/wipe on a light coating of ATF.

I have ATF thinned about 25% with varsol in spray bottle to wipe down unplated tools to keep them from rusting. Cheap and very effective.

[Barry B./ Ma.]

Originally Posted by Charlie Stephens

If it won't come off with a wire brush on the end of a power tool I think I would paint over it.

Charlie Stephens

I agree with Charlie. Just don't paint over grease, no problem over another color.

[Ray64]

Im with Russ #8 Post did mine just like that Good results