Cleaning engine water jacket

[hardtimes]

Originally Posted by ursus

Muriatic Acid (AKA Hydrochloric Acid) will dissolve rust very well. It will also dissolve a radiator. I have reservations about using it on engine blocks for two reasons: 1) cast iron is porous and you may not be able to fully neutralize the acid, which may continue attacking the sound iron, and 2) there is this thing called hydrogen embrittlement due to strong acid exposure which may lead to more cracks in the future. Maybe somebody familiar with metallurgy can comment about the risk of hydrogen embrittlement from the use of Muriatic Acid on iron castings?

X -TWO !
I've experimented with muriatic ! I would never use this STRONG caustic acid in an A/B block for exactly the words/ideas that you've expressed. Additionally, this acid IS dangerous/injurious if used wrongly and /or accidently. As stated by others, the rear of the A/B block is inaccessible to a large degree and , IMO, where a guy will find the most compacted rust. Ergo, you need something that WILL consume that rust totally/safely (to you and to block)....and that needs no neutralizing ! As I wrote previously, I've spilled Evaporust on pavement, on my clothes/boots and on my bare hands....with NO negative impact. Subsequent to my first writing, someone asked does it desolve other metals, i.e.-good solid metal and radiator. Well, in answer, I say that I studied every written bit of information that I could get my eyes on, prior to trying this product. NO, it does not attack other than rust ! Given enough time, it desolves rust in whatever form...AND STOPS when no rust to consume ! Conversely, just try drops of muriatic on cloth, cement, skin...heck, just smell the fumes if dumb enough. To stop its destructive behavior, you will have to have proper neutralizer on hand and let it interact for sufficient time to even stop it at all. It will not 'discriminate' between, radiator, good block metal, rust or your hide ! I once witnessed the FUMES of this acid...take the hair completely off of an animal and burn its skin/eyes/mouth, etc... extensively !! It lived, only thru much effort.
Like said previously , do you own reading /research

[BILL WILLIAMSON]

Originally Posted by Rex_A_Lott

I've used it on the outside of the radiator to clean it prior to soldering. It does a very good job for that. I've never tried it on the inside.

Rex,
I've used it for that also. I "think" it would be O.K. for the inside of the radiator itself, I'd do it OFF the car, a fairly QUICK soak & neutralize it thoroughly with SODA & WATER.
I don't "think" I'd chance it in the head or block.
Chief said in the "old days", vinegar was widely used for rust & calcium deposits, BUT, sometimes pin holes would show up, that were being plugged up by the calcium deposits! And that's straight from the Horse's Mouth, as he worked part time at Orville's Radiator Shop.
Bill W.

[tudoor]

Try white vinegar, it will work. Block the water outlet, fill the block, let it soak for a week or longer. You will be amazed how well it works.

[oliverguy]

what concentration of vinegar do you use? Is it straight out of the bottle? My radiator is not clogged at all and doesn't overhead, but it has grease in it from the PO greasing the heck out of the waterpump. I'd like to try and clean some of that out.

[Rex_A_Lott]

Originally Posted by oliverguy

what concentration of vinegar do you use? Is it straight out of the bottle? My radiator is not clogged at all and doesn't overhead, but it has grease in it from the PO greasing the heck out of the waterpump. I'd like to try and clean some of that out.

I did this recently, and I put 2 gal of white vinegar in and then topped it off with water. Drove it several times like I normally would over the course of a month or so. I was really surprised at the amount of crud it flushed out, and how many times of flushing it took for the drained water to run clear. Good Luck!

[Tom Wesenberg]

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Originally Posted by Rex_A_Lott

I did this recently, and I put 2 gal of white vinegar in and then topped it off with water. Drove it several times like I normally would over the course of a month or so. I was really surprised at the amount of crud it flushed out, and how many times of flushing it took for the drained water to run clear. Good Luck!

I have done the same, but be sure to keep an eye on the coolant level, because the vinegar will remove the grease from the lead packing rings in the water pump and the vinegar will leak out. It made a white mess all over the side of my motor, but it does clean up easily.

[BILL WILLIAMSON]

Originally Posted by oliverguy

what concentration of vinegar do you use? Is it straight out of the bottle? My radiator is not clogged at all and doesn't overhead, but it has grease in it from the PO greasing the heck out of the waterpump. I'd like to try and clean some of that out.

TSP did a nice job removing the oily/greasy coating from Minerva's system. She had NO rust.
It's been mentioned before, that it's good to remove the oily/greasy scum, BEFORE using VINEGAR, so that the vinegar can get direct to the rust.
Bill W.

[oliverguy]

thanks for the input, I'm going to try it this fall. I'm running a leakless pump not sure how they are constructed. I thought they had some other kind of gland so hopefully I'll be ok.

[Quigley1930]

Well, I just put two blocks in molasses; will let you know the results in 2-3 weeks.

SewallBlocks in molasses-2 (Small).JPG

Blocksin molasses-4 (Small).JPG

[Tom Wesenberg]

Originally Posted by Quigley1930

Well, I just put two blocks in molasses; will let you know the results in 2-3 weeks.

SewallAttachment 190314

Attachment 190315

Molasses works best when it stays above 90*, so black plastic over the tub should help.

[Quigley1930]

I'll do that since the real hot days are over.

Sewall