Removing rust in water jacket

[Guest slyhog022056]

Hello folks, i need a little bit of help with my 52 olds 98 engine block. I need to clean the rust out of the cooling jackets of the block and heads. Everything is tore down. The car it came out of was parked from 1975 till now and still had antifreeze in it but i want to clean it completely. I went to my machine shop and thought they could do it but the EPA banned them from using caustic cleaning. Cant find a local (Dallas) shop with a ultrasonic cleaner to do the block and heads. I have a 55 gallon plastic drum i can submerge the entire block into for cleaning, i have already degreased it with industrial alkalai, looks brand new on the outside. Now i need to clean the cooling jackets. I have already taken a piece of 1/4" steel cable in a drill and knocked out a lot of it through the freeze plug openings and holes in the deck.

I have read a lot of outside forums saying i can possibly use vinegar. Has anyone tried this with an entire block?? I have been warned by several people to not use muratic or sulphuric acid as it will etch and destroy machined surfaces.

I am open to any suggestions for doing this. Dont want to have to buy $100 to $200 worth of chemicals to clean the block.

[Guest 51c8Joe]

Can't a radiator shop boil it out? That was the solution in the 50's and 60's, always worked well for me on a bare block/head. If the EPA has regulated radiator repair out of business we're all in trouble.

[joe_padavano]

I doubt radiator shops are set up to hot tank a 200 lb block. In any case, the problem is two-fold. Yes, there are environmental issues with caustic hot tanks, but the reality is that most modern motors are aluminum and would be destroyed in a hot tank, thus the replacement with steam cleaners in most shops.

[Guest slyhog022056]

Can't a radiator shop boil it out? That was the solution in the 50's and 60's, always worked well for me on a bare block/head. If the EPA has regulated radiator repair out of business we're all in trouble.

I have tried that, i went to or called almost 25 radiator shops and they didnt say no, they all said hell no. They have had to alter their chemical solutions also. Although caustic soda used to be the way to go the EPA has made it nearly impossible to dispose of it. Where i work at (industrial laundry) we go through that stuff all the time with disposal of spilled or depleted chemicals. And like joe_ says a 200 lb block is a different matter altogether not just weight but actually trying to get it in and out.

Guess no one has really tried so i guess I will take one of my sons 426 hemi heads and soak it for a few days in 50 / 05 mix of vinegar and water and see what happens. He has 7 complete heads and i only have 2 so it makes sense to me to use his.

[Owen_Dyneto]

A fairly dilute mixture of hydroxyacetic acid and oxalic acid is pretty much a standard for removing rust, used hot (boiling). Oxalic alone (available at most paint stores) is also reasonably effective by itself, it was one of the components of the old classic DuPont No.7 radiator and cooling system cleaner. The other ingredient was a neutralizer to be used second, probably sodium bicarbonate.

[Bhigdog]

Did you check other engine shops in your area? My guy still has his cooker going and routinely boils out blocks................Bob

[Guest slyhog022056]

I have tried oxalic acid mixed from a powder at a ratio of 1lb per 5 gallons of water ( mixing instructions from msds at work, we use a lot of it) Soaked some parts in it overnight, it removed light surface rust but didnt touch anything heavier even after a week of soaking, Left some really stubborn yellow staining on every piece i soaked in it for some reason, even after neutralizing and scrubbing, nut a spray of rust converter made it disappear.

Havent ever heard of the hydroxyacetic acid, wikied it and didnt tell me a lot there. And no i havent checked any more shops around here, i have done business with this 1 machine shope for 15 years and just figured if he couldnt do it neither could anyone else, guess i need to check around and quit being hard headed.