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Engine painting (Ospho)

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When I was changing the spark plugs I noticed a lot of rust on the lower block on both engines, out of sight unless you are very low. A friend told me about Ospho and I just read some info about using it. What I an thinking is to brush off as much rust as I can, then apply Ospho with a rag or spray bottle for hard to reach places. 24 hours later wipe down the engines and paint with the blue engine paint I got a Autozone, it is close the the Crusader color and about half the price.

So, the question is have anyone used this stuff, Ospho? My concern is Ospho may damage the hoses, wiring, senders, plastic parts, etc.
 
didn't know that stuff was still available. Can't speak to engine blocks - we used to use it on one of my old jobs for aluminum. The senior technician used to swear by it. It is a weak acid so should be ok on hoses and wiring in good shape. Same for most senders and plastics. I would still try to avoid contact with anything but the metal. A low pressure sprayer - a small "power painter" - would be ideal if it will reach everything. Thes stuff is about as thick as water so some dripping will occur.
 
Not long ago, I was in a bilge dealing with corrosion on some stuffing boxes. Anyway, used quite a bit of Ospho applied with a paint brush due to clearance issues. A lot of it ran down my arm, falling off the elbow. It didn't seem to burn skin right away, took an hour or so. Didn't faze the rubber hose, plywood, fiberglass, did remove most of the crusty corrosion products on the bronze. I like it, overall.
 
I like Ospho, it's old school "good stuff".

As a personal favor for the advise, please don't paint the hoses, belts, clamps, wires, (personal pet peeve #17) :cool:! Also, five dollars worth of plastic drop cloths and masking tape goes along way keeping the over-spray off everything else. I don't how many boats I have seen for sale with freshly painted motor mounts with big foggy matching color circles on the stringers :confused:(pet peeve #22a).

End of rant.
 
Thanks for the info. I am thinking of using it only on the rusted spots, lower engine blocks, below the spark plugs. The other side seems OK.
I would also like to do touches on the intake manifold, I hate those pockets of rust. I may need 2 pints at most. Then I will tape all the decals,
mounts, hoses, etc. The painting may be the easiest part.
 
It usually is....its the prep where all the effort lies. As I'm sure you know, that's the biggest determining factor in the end result.
 
I have never heard of that stuff. I probably could have used it numerous times, but I am hanging up ( so to speak) and searching it now.

Maybe we can compile a list of helpful agents that someonelelse has no experience with and pass it along

WELL: Just did some reading on this stuff. Sounds similiar to a wheel cleaner we used at the car wash called "acidex". It was a phosphoric acid based cleaner we diluted 50/50 and it would easily clean brake dust off of wheels with just a light spray of water after it soaked for about 30 seconds.

As Dave demonstrated saying it took an hour to burn...this stuff took about 5 minutes and you really needed to rinse your skin quickly. I am going to try it and compare the price difference is high. The wheel acid ran about 10. per gallon and this stuff is about 35.
 
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Knuckle,

When you compile the list, here are five of my favorite items kept aboard:

Oxalic acid

Penetrol

TSB

White vinegar

Murphy's oil soap
 
I remember reading that once you apply Ospho, let it sit for 24 hours before painting. This gives the product time to burn/etch the metal. Once I finish my tune up, I intend on the Ospho and painting project. 2 weeks of waiting and I finally got everything I needed from West Marine, price match is not always easy, and in this case not worth the $20 saving :))
 
Nice to be in Florida this time of year. The heater core in my F-150 blew and has NO HEAT since I by passed the loop. My hands are still numb from driving 65 miles to work and back today. When I went to check the boat a few months back the plug was still in with about 10 " of water standing in the corner of the bilge. It took me more than 10 tries to get it spun out with my bare hands...Numb again.

What are the special uses of these products Rev ?
 
I well remember the winters. Boat came out late Nov after strippers went south. March mild days was time to begin getting the boat ready.
Grew up in coastal Monmouth County. Having no heat during the drive to and from work is tough, hopefully the winter was milder this year.
 
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