[Terry M. Hunt]

As part of 4 previous engine builds, I used different machine shops for each. Each shop vatted the block and they all cleaned up fine. All of the blocks wound up with some traces/patches of rust staining on the outside. I’m not talking about flash rust that appeared on the block days after picking it up from the shop. This stuff was already there the day I picked these blocks up, so it appeared to be surface rust that was on the block but did not get removed by whatever method the shop used. Now, I compare my experience to what I see in every engine rebuild article in every car magazine I’ve ever seen. All the blocks in these articles are spotlessly clean and look like virgin cast iron. How is this look achieved? Shot peening? Some other product/process?

[Formulajones]

In the past I've had them put in a tumbler for lack of a better word, I think it used steel BB's and came out brand new. There is a name for the process that escapes me at the moment, someone will know.

[Sirrotica]

Shot blasting

[JSuchma]

steel abrading............the use of small steel balls to clean the cast iron with friction.

[PAUL K]

Thermal cleaner.... Heats the parts up and pelts it with steel shot.

[Formulajones]

Well there ya go, all kinds of names for it

[JSuchma]

If you wanted to do it yourself at home, get your 12 GA shotgun and a couple of cases of #4 steel shot! OH.......and a 6 pack of your favorite beer.

[hurryinhoosier62]

Originally Posted by JSuchma

If you wanted to do it yourself at home, get your 12 GA shotgun and a couple of cases of #4 steel shot! OH.......and a 6 pack of your favorite beer.

Uh, I don’t think so…

[Formulajones]

I can tell you how a guy I know tried to shoot a cast iron frying pan with a 12 gauge.

That didn't work out so well. I think beer was involved with that one too

[PAUL K]

Originally Posted by Formulajones

Well there ya go, all kinds of names for it

Lol... Not really. Tumbling is usually done with an abrasive material rotating in a drum, usually used for cleaning valves. Shot blasting is similar to shot peening but not controlled and won't remove grease, works great for cleaning rusty cranks and cast rods. Steel abrating is one of my favorite but won't work well on an oily block, the best process I've found for cleaning rusty parts like exhaust manifolds. Thermal cleaning heats up the block and is the only process mentioned that will remove rust, corrosion and sludge.... In short

Just trying to be informative.

[Formulajones]

Originally Posted by PAUL K

Lol... Not really. Tumbling is usually done with an abrasive material rotating in a drum, usually used for cleaning valves. Shot blasting is similar to shot peening but not controlled and won't remove grease, works great for cleaning rusty cranks and cast rods. Steel abrating is one of my favorite but won't work well on an oily block, the best process I've found for cleaning rusty parts like exhaust manifolds. Thermal cleaning heats up the block and is the only process mentioned that will remove rust, corrosion and sludge.... In short

Just trying to be informative.

It was an added process I've had done in the past that I do remember involved steel shot. It was also tanked with chemicals and all the other usual stuff. I just can't remember what he called it and I haven't had it done in a while. I really like how the block looks when it's finished.

[zippy]

Seen the new Laser rust cleaning??? Prob not used on blocks, most are bathed, then put into a shot blasting cabinet with steel BB's. But man, the new Lase tech is wicked!

[Half-Inch Stud]

The process per Post #17 is fantastic, making the old Pontiac castings look real good.

[Formulabruce]

Originally Posted by Half-Inch Stud

The process per Post #17 is fantastic, making the old Pontiac castings look real good.

Nah, chopped wire has sharp edges, which requires more machining, especially an Aling hone, which should be avoided. Steel shot is round, and blocks don't require the extra machine work. So method similar, Media is Not.

[Jack Gifford]

A long time ago (50 years?) a friend hand-ground and polished the outside of a Pontiac V8 block and heads ('58?) to a mirror finish, for a GMC-blown T-bucket on the show circuit. If I remember right (?) he didn't coat it with anything other than paste wax, since it almost never was run.

[ZeGermanHam]

It is pretty incredible to see the transformation. Here is the '68 400ci block that I will be building and installing in my '66 after I have shaken out the bugs for a year or two with the current running engine.

[ponchonlefty]

butler uses a tumbler of sorts. what about electrolysis?

[Sirrotica]

Originally Posted by ponchonlefty

butler uses a tumbler of sorts. what about electrolysis?

It works, but it may take a few days to get it really clean. Then you have hydrogen gas to contend with.

I used to have a 55 gallon drum 3/4 full of used carb cleaner that the local carb rebuilder wanted to get rid of, that works well, but again it takes a few days to work. You need to pull the parts out and agitate it periodically. It would cost too much if you had to buy carb cleaner, mine was free.

[Formulajones]

Yeah that's not going to be a viable option for a machine shop. They generally don't have several days to wait for a clean block. Time is money for them, and then we all know how people complain if their stuff isn't done when they think it should be LOL

[hurryinhoosier62]

Originally Posted by Sirrotica

It works, but it may take a few days to get it really clean. Then you have hydrogen gas to contend with.

I used to have a 55 gallon drum 3/4 full of used carb cleaner that the local carb rebuilder wanted to get rid of, that works well, but again it takes a few days to work. You need to pull the parts out and agitate it periodically. It would cost too much if you had to buy carb cleaner, mine was free.

Brad, we used to use a decarbonizing cleaner to soak aircraft engine components in to clean them before glass beading and NDT. It was EVIL smelling stuff that contained a boatload of prussic acid. It cleaned aluminum wonderfully but it also removed your skin and muscle down to the bone. IF I were involved in aircraft engine overhaul today, I would use a high pressure hot wash cabinet followed by wet soda blasting. As you pointed out, electrolysis releases hydrogen gas. It works great to clean out the water jackets and remove rust from the block.