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Red engine paint bubbling from carb cleaner -- Any way to remove it safely?

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DrewM Avatar
DrewM Silver Member Drew Maddock
74 MGB roadster, Southern California, USA   USA
A few years ago, my engine got pulled out out to have a "new" o/d transmission and heavy-duty B&B clutch installed. While it was out, the mechanic painted the engine with Moss red engine paint. It wasn't my choice of paint brands, and I soon found what I'd heard was true -- Moss red engine paint discolors easily. Coolant stains appeared on the valve cover and block as faded orange stripes. Not a good look. And clearly not the best paint.

Today, I was doing some minor work on the engine and grabbed a can of carb cleaner to remove some grease on the block. Itimmediately caused the red-orange striped paint on the block to start bubbling like it was paint remover. Who knew carb cleaner could remove paint? Now it looks terrible and the lousy paint (which I hate anyway) needs to be removed. The valve cover is fine. I only sprayed the block.

Is there a safe way to remove engine paint from a block with the engine still in place? I had the engine removed a second time a year ago for a minor engine rebuild, and I'm done with removing engines for the time being. Is there a safe way to remove paint from an engine block without removing the engine? I don't want to damage wires, hoses, etc. It can't be as simple as paint stripper, can it? Would that work if I removed what's removable and shielded everything with towels? Or is paint remover a disaster waiting to happen? What would paint remover do to wires, hoses, distributor, etc if it got on them???

My instinct tells me to just live with it. But I'd like to clean it up. Arrgh! sad smiley

Drew Maddock, So. Calif. USofA

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dohc281 Avatar
dohc281 Gold Member Ira Eckstein
Laurel Springs, NJ, USA   USA
If the carb cleaner made the paint bubble then you’ve found your paint remover.

If you hit your pony over the nose at the outset of your acquaintance, he may not love you, but he will take a deep interest in your movements ever afterwards.

Rudyard Kipling

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Tried wire brushing off all the loose and bubbled stuff and wiping it down with paint prep and shooting Duplicolor deep canyon red or whatever the stuff is called.

"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"

"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

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MGB engine and overdrive conversion 7-2013 002.JPG    53.7 KB
MGB engine and overdrive conversion  7-2013 002.JPG

little G Avatar
little G Charlie T
queensland, QLD, Australia   AUS
1964 MG MGB "Little G"
depends how far you are prepared to go apart from removing the engine ..

forget about band aiding it with patch ups !...there is obviously an issue across the board with the paint and what is underneath it ..
Paint stripping runs the risk of splatter onto engine bay etc and runs the risk of getting into and behind things when washed off , and it has to washed off ...probably even scrubbed

Me ?....remove all bolt on items ...even the distributor if you are confident ..expose as much area as possible with out pulling the motor ....block orifices and use one of those cheap hand held sand / bead blasters to start again ...but then again . that is just me ...

HiPowerShooter Avatar
HiPowerShooter Gold Member James Booker
Lake Winneconne, WI, USA   USA
1973 MG MGB
Live with it. Everything short of pulling and prepping will look like a dumpster fire.

"One test is worth a thousand expert opinions"--Alvin "Tex" Johnston...Boeing test pilot.

73 MGB. Tires: Round, black, hold air. Oil: Sometimes old, sometimes new...always slippery. Oil filter: Yellow, usually full of oil. Carbs: 2 SU HIF. Distributor: Yes. Headlights: Not that bright but bright enough. A bunch of other stuff most cars have but not really important enough to itemize. Oh, has a cool sounding exhaust with stickers on the chrome tips. Really slays the ladies...

Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
Mission creep is lurking in the shadows.... devil smiley

If paint removal is already tricky, repainting such a surface will be even more problematic and God knows you then may have to lift the engine after all sad smiley

barry s Avatar
barry s Silver Member Barry Stoll
Alexandria, VA, USA   USA
1972 MG MGB GT
1974 MG MGB
1976 Triumph TR6
1980 MG MGB
If the paint bubbled that rapidly, it is not well adhered to the block, likely due to poor preparation of the block prior to painting. It would be hard enough to remove the paint with it in-situ mush less clean whatever residue is on the block.

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Gremlin Steve G
Antioch, IL, USA   USA
I just used the Por 15 engine paint kit to paint my engine on a stand. It is brushable so that might make it easier to apply in the car without too much trouble. Hopefully the Moss paint adhered to the block ok and is just failing when exposed to solvents or other fluids. Perhaps the Por 15 can lock it down

barry s Avatar
barry s Silver Member Barry Stoll
Alexandria, VA, USA   USA
1972 MG MGB GT
1974 MG MGB
1976 Triumph TR6
1980 MG MGB
I would not suggest trying POR15 over other paint, certainly not of questionable condition.

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OldDuffer Avatar
OldDuffer Silver Member John S
Eugene, OR, USA   USA
1970 MG MGB "Ella B"
1979 MG MGB "Mae B *SOLD*"
Ugh. I feel your pain. My engine is on an engine stand as we speak and freshly painted with Duplcolor Deep Canyon Red. I thought I had the block clean as it was down to bare metal but have noticed a few places where the paint didn’t adhere. It absolutely needs to be prepped properly and painted properly. Light coats, multiple passes or it probably won’t hold up. Short of doing that, it won’t result in a good looking, long lasting finish. My advice would be to close the hood/bonnet and drive on. Worry about the engine paint when the time comes to pull it again. Hopefully that won’t happen for a long time because then you’ll wind up like me because of all the might-as-well jobs that delay completion of projects...
Good luck!

I was addicted to the hokey pokey but I turned myself around.

mgbanthony Avatar
mgbanthony Platinum Member Anthony Henderson
Gananoque, ON, Canada   CAN
1962 MG MGB
1962 MG MGB
1970 MG MGB GT
1974 MG MGB
If you do use Moss engine paint again, it needs a clear coat over it. It reacts poorly to coolant, oil and brake fluid on its own.

DrewM Avatar
DrewM Silver Member Drew Maddock
74 MGB roadster, Southern California, USA   USA
Thanks for the suggestions. I doubt I'll try to repaint it. I'm not going to start removing engine parts (distributor, etc.) since I'll screw that up. And I'm not going to remove the engine again. So my options are to leave it "as is" and cringe whenever I look at the engine or remove whatever bubbled paint I can easily remove so I don't have to see as much of it.

I think I'll try the second option since a lot of the paint is already pretty much removed. I'll remove spark plug wires and anything else easy to remove. Not sure I want to remove the carbs (again). Mask off the valve cover and other parts like the distributor with plastic bags,masking tape, etc. to keep dried paint out of them. Then I'll try a small wire brush (maybe preceded by another does of carb cleaner since it works so well!). The paint should mostly fall to the garage floor. Maybe try using a vacuum cleaner to try to suck some of it up as I go. The things I have to do to keep this car looking spiffy. At least it'll be fun. eye rolling smiley

Yes, I'd say the prep that went into painting this engine some years ago was a little deficient. Probably just a wipe down followed by a quick rattle can spray job. I sure wish they hadn't done it that way. Don't do it that way.

Drew Maddock, So. Calif. USofA

Speedracer Avatar
Speedracer Platinum Member Hap Waldrop
Greenville, SC, USA   USA
1967 MG MGB Racecar "The Biscuit"
You could use scotchbrite, and sand paper to clean up and prep the affected areas, then get some matching paint, preferably engine paint, I find that Duplicolor reacts well to almost any type of paint without a chemical reaction. So if the engine is black or any color Duplicolor engine paints come in, use that. As far as antifreeze bleaching paint, almost all paints falls victim to this and the Dark Canyon Red, can flake off in big chunks over time, so it would be my last choice. Once you have sanded a given area, then you can brush touch it up, use a cheap horse hair brush, if the paint you are using come in a rattle can, no biggie, spray some into the cap and let it thicken up for about 30 minutes, then brush it on, use a small container of solvent, like laquer thinner to keep your brush thinned out and you will get good flow results. Good luck.

Hap Waldrop
Acme Speed Shop

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mgbjones Avatar
mgbjones Jim Jones
Liberty, NC, USA   USA
1966 MG MGB
1980 MG MGB "Orange Crush"
2012 Ford Fusion
I did mine while in the engine bay several years ago. I just removed everything from the engine I did not want paint to get on. Did a complete cleaning with mean green and wash it off with a sprayer, rubnedbit down with scotch brited pad. Let it dry and repainted. It took a few days but well worth it. It's doable.

DrewM Avatar
DrewM Silver Member Drew Maddock
74 MGB roadster, Southern California, USA   USA
Thanks again. I like Hap's and Jim's cleaning and repainting suggestions which I might try. After I remove the ugly bubbling paint. Keep the carb cleaner spray off your engine.

Drew Maddock, So. Calif. USofA

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