White vinegar as radiator flush

Lawson Cox

Lawson Cox

Well-known member
What are the do's and don'ts of flushing radiator with white vinegar. Also, what's the best rust preventer after flush. Thanks guys.
 
I've just done this with my model A. Vinegar sold in the USA is weak at only 5 or 6 % strength. I poured it into a non-running car and left it in there for almost three days. Then flushed the system with baking soda mixed with water to neutralize any acidity. Then flushed a few more times with simple green.
 
put in vinegar, run thru a least three cold hot cycles and then flush out with water and then add baking soda water mixture and run to temp and flush while it is running, you will not believe how much crud comes out
 
Just curious.....has anyone tried Evaporust as a radiator flush ?
It does a great job cold but it really works well/quickly hot.
 
32phil said:
Just curious.....has anyone tried Evaporust as a radiator flush ?
It does a great job cold but it really works well/quickly hot.
Click to expand...

I have used "Rust 911", which which works like Evaporust, but is a little cheaper. I thought the results were very good. I filled the system with it, ran three heat and cool cycles, and then drained and flushed it. I did this twice. Check out post #8 in this thread for pictures : https://www.fordbarn.com/forum/showthread.php?t=253207&highlight=rust+911

A poster named "Old Henry" (or maybe that was what he called his car) did a pretty detailed thread in which he did a cleanup on his water pumps. The results were pretty impressive. Look at post #30 on this thread : https://www.fordbarn.com/forum/showthread.php?t=123032&highlight=Evaporust&page=2
 
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M2M said:
I've just done this with my model A. Vinegar sold in the USA is weak at only 5 or 6 % strength. I poured it into a non-running car and left it in there for almost three days. Then flushed the system with baking soda mixed with water to neutralize any acidity. Then flushed a few more times with simple green.
Click to expand...

Exactly what I did on my 35 Fordor (avatar) several years ago. I could not believe what came out. Neutralizing acidic mix with baking soda is an important step after flush.
 
Put two cups of straight phosphoric acid in it, then flush with backing soda after a couple of hundred miles. Repeat as necessary. You might have to do this several times in a really bad system. If you have a clogged radiator, reverse flush or rod out.
 
Just be mindful of the other crud that may come loose.

I flushed the radiator on my '39 Buick with vinegar, then the soap from a dishwasher gel pack (they are all super-low sudsing).

Anyway - busted loose all kinds of crud in the block - that subsequently clogged my radiator!

The old stocking filter on the inlet pipe might have prevented the removal and professional cleaning that followed.

Good luck!
 
Just a point of reference, couple years back Old Henry posted a thread here about his testing of cooling system flushing components, including vinegar. I believe he found vinegar (don't know what strength) to have a short-active-life, at least effect compared to Evaporust and/or others.

Might be worthwhile to find what he had to say.
 
I would recommend using a product available from Harbor Freight called Rust 911. It is a colorless odorless concentrate that you dilute with water for use. It may be similar to Evaporust . Use as directed. I think you will find it more effective than vinegar. I used it to lean up a radiator that was completely blocked with rust and scale. Jim in San Jose.
 
I use "Rust-911" when I have large pieces. It works the same as "Evaporust", but from my experience, not quite as well. I think it is because it is a concentrate.

I would recommend those of you that are recommending vinegar review the "Old Henry" Thread mentioned in my earlier post (and one other). It is an acid and can damage cast iron and steel if used too long. Be very careful with it.
 
My 39 always had an issue running hot at at (on most summer days) 210. This is with 170 stats. Didn’t matter whether I was doing city driving or highway.

I pulled it over the winter and brought it to a radiator shop. He cleaned it chemically and then pressure tested it. Cost was best $80 bucks I spent in a long time. Car runs at a constant 170.

I should also mention, I think this is original radiator with the split down middle.
 
I used strait vinegar into a new radiator to clean out the block in my Model A. The new radiator had a flaw and leaked where the upper neck is soldered to the top tank. What a mess in the engine compartment and onto my slick paint job.
I also found vinegar must be followed by baking soda to get a clean radiator and block.
 
32phil said:
Just curious.....has anyone tried Evaporust as a radiator flush ?
It does a great job cold but it really works well/quickly hot.
Click to expand...

Yes I personally have, sorta. Using the similar product Rust-911, I was satisfied. Except for the volume of waste fluids it did what I wanted. 5 Gal of de-rust mix, and twice 5 gal of flush, so a lot of liquids to recycle.

My eventual solution was a recored radiator, but that was not the reason Rust-911 didn't solve the issue. I did an engine swap and lucked into a super fresh rad to exchange in at the same time as the powerplant.

And if any of you readers somehow have not had it register yet. Check out what Craig/Old Henry documented. He laid out a very good case! His deal is doing that against the Gummint' for us wronged citizens. So realize he's arguing a viewpoint. You can/should judge if it's the correct argument for your situation. A good guy and I miss his contributions. Hope he hasn't trashed too many aero-vehicles. Lord knows I've broken a few in my younger days.
 
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an old radiator man told me once, never put acid in a radiator as it will attack the solder first. just sayin
 
cas3 said:
an old radiator man told me once, never put acid in a radiator as it will attack the solder first. just sayin
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I wonder if that is why the solder joint failed on my A. It was a pressurized (4 pound) radiator and nearly new. it was straight vinegar.
 
Model A radiators were never pressurized. I wouldn't leave vinegar in for a long time, but it's really a very very mild acid. It'd take a long time to eat away on any type of metal. In my opinion.


Something like rust911 would probably be best. chelate. It's somewhat a citric acid based. You can buy citric acid in bulk and mix it to whatever percent you like.

https://www.amazon.com/Milliard-Citric-Acid-Pound-VERIFIED/dp/B00EYFKM32/?tag=atomicindus08-20


https://www.garagejournal.com/forum/showthread.php?t=69793





.
 
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To be perfectly clear, "Rust-911" and "Evaporust", while "Chelates" are NOT citric acid based. I mixed up a batch of citric acid and tested it with pH test strips. it tested out as quite acidic. When I checked "Evaporust" the same way, it tested absolutely neutral. It's time to put this one to rest.
 
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