Preferred method for flushing rust from engine water jacket?

[JamesR]

For an engine still installed in a car. I've used some of the flush related products, but have been concerned about leaving them in the cooling system too long ( concerned they might be too corrosive and damage gaskets.)

 

Now I'm starting to wonder if white vinegar could be an option? Anyone ever used it? I've never heard of anyone using it, but I know that it's an effective way to remove rust that's less aggressive than some of the caustic materials which are designed to complete the job in a few hours instead of a few days or weeks. I should mention that I'm not thinking about cleaning the radiator or heater core with the vinegar...just the jacket.

 

If vinegar won't work, I'd appreciate other ideas. Thanks. - Jim

Edited March 2, 2019 by JamesR (see edit history)

[edinmass]

Run evapo rust.......works great, can be left in for a season, won’t touch gaskets, brass, or copper. Heat will actually help the process along. I run it straight without diluting it, not cheap, but works fantastic. You can get it at harbor freight.

Edited March 2, 2019 by edinmass (see edit history)

[Walt G]

Evaporust is a great product. I used it to clean the inside of the gas tank on my 1930 Packard when I took the tank out after I used some grit to shake around in the tank to knock off any crusty stuff that may have been there I couldn't see. I then put a sealer in the tank after washing out the evaporust thoroughly. As Ed mentions you can get it at Harbor Freight.

[billorn]

What ever you use be sure to use some kind of filter to catch the junk before it goes back in to the radiator. Pantyhose works well and is cheap and you can just throw it away.

[mercer09]

vinegar works fine, but cant be in a hurry.

 

I totally fill my rads with it, let it sit for 6 weeks and then flush and flush. havent ever had a problem. but patience is a virtue and you mention not wanting to do that.........

 

vinegar only has 4-5% acid. the rest is pretty much water. it is a gentle solution. I also use it to clean gas tanks. again 6 weeks minimum.

[R Walling]

 One part of Molasses to nine parts of water make a good rust remover.

 I never tried it in a running motor but I did soak a block and crank that was out in the weather for years and it worked !

 

 I think that it would not block up the heater and radiator passage ways as the mixture only strips the oxygen out of the iron oxide, leaving free iron on the surface that looks like black dust.

 With the action of the heat and the water pump, the "dust" would probably stay in suspension.  (?)

 I would try it for the summer and see .

 The best part is that you can drain it on your lawn and not worry.

Edited March 2, 2019 by Roger Walling (see edit history)

[c49er]

Knock some core plugs out to do a proper flush... get it all out.

Flush the heater core and rad separately.

[edinmass]

Evapo rust has no smell, and you can drive the car. No reason to pull freeze plugs for a basic clean out. Placing a magnet in the top of the system to catch big pieces of scale works great. Also, it won't touch paint....vinegar will attack paint. 

[Marty Roth]

I've used DISTILLED WHITE VINEGAR as a flush with no apparent ill effect. It is relatively inexpensive. I bought mine as a case of gallons at a Sam's Club.

Installing a filter (or pantyhose) in the hose returning to the radiator is a good idea

[FLYER15015]

X2 on edinmass.

I used 2 gallons of Evap-O-Rust in my '40 Buick LTD .

Ran her for about a week thru several heat/ cool cycles.

Worked so well I had to replace 3 expansion plugs, as they started dripping.

Even at the back, a notorious place for rust to accumulate in a straight 8, she was as clean as a "boiled" block.

Flushed her out with distilled water, and added 50/50 Zerex, and no more overheating.

But I also did the "bypass valve " fix, by inserting a frost plug and drilling a 5/16" hole in the center.

This is a standard fix for Buick 8's.

 

Mike in Colorado

Edited March 5, 2019 by FLYER15015 (see edit history)

[JamesR]

3 hours ago, mercer09 said:

vinegar works fine, but cant be in a hurry.

 

I totally fill my rads with it, let it sit for 6 weeks and then flush and flush. haven't ever had a problem. but patience is a virtue and you mention not wanting to do that.........

 

vinegar only has 4-5% acid. the rest is pretty much water. it is a gentle solution. I also use it to clean gas tanks. again 6 weeks minimum.

 

Quote

Marty Roth said:

I've used DISTILLED WHITE VINEGAR as a flush with no apparent ill effect. It is relatively inexpensive. I bought mine as a case of gallons at a Sam's Club.

Installing a filter (or pantyhose) in the hose returning to the radiator is a good id

 

 

 

Mercer09, I actually have no problem with letting the car sit for weeks. I was just saying that most flush products seem to be designed for everyday drivers that don't have the option of being out of commission that long, so they end up being a little too corrosive. Thanks for your input, I thought vinegar might be a good option.

 

Marty, I'll probably just disconnect the radiator hoses and plug them. Is there a way I should neutralize the vinegar residue after it's drained from the jacket? Or will additional flushes with water do the trick? Also, for the purposes of flushing, there's no real need to use distilled water, is there?

 

Thanks for the heads up on evapo-rust, folks. I'd never heard of it ! If additional research on it is positive, that's probably the route I'll go eventually, but I'd first like to address and treat the rust in the jacket separately from the radiator and heater core.

 

 

[Spinneyhill]

Acetic acid (vinegar) is an acid and as such is corrosive.

 

Citric acid acts as a chelating agent for Fe³⁺ and will not attack Fe²⁺ as other acids will.

 

Evaporust also contains chelating agents for Fe³⁺ and again, will not attack Fe²⁺ non-rusting iron.

 

Another chelating agent for Fe³⁺ is oxalic acid, wood bleach. It is better than citric acid according to my reading.

 

I have used oxalic acid in my engine. I left it in for about three weeks but didn't get much time running the engine. Heat speeds up chemical reactions so the more the engine is running, the better. My engine was clean-ish but still over heated. I eventually removed the core plugs and had a good scratch around in the cooling jacket. It was pretty much blocked behind the rear cylinder and took a bit of chiseling to clean out. I scraped about half a cup of sandy stuff out, including some bits of wire used in the casting core.

 

I used a "half strength" solution of 500 g to 10 L of water. If I did it again, it would be full strength. Oxalic acid is inexpensive and now I would expect to leave it in for three months and have the engine hot as much as possible. Evaporust is more effective but vastly more costly too.

 

As you will have seen above, none of these things are instant fixes. It takes time for the reactions to occur. It won't happen in an afternoon. The rust iron atoms are "chelated", meaning they are taken into solution inside another molecule and thus come out when you drain the system. If you want to do it in the garage without the engine running, you will need pipework, a water heater and a pump and expect to leave it running for at least a fortnight. The water needs to be at about engine running temperature, about 80 to 90 ^oC.

[Guest]

3 hours ago, c49er said:

Knock some core plugs out to do a proper flush... get it all out.

Flush the heater core and rad separately.

This is the ONLY sure way.  Messy but effective.

Then always use antifreeze.

[John_Mereness]

5 hours ago, billorn said:

What ever you use be sure to use some kind of filter to catch the junk before it goes back in to the radiator. Pantyhose works well and is cheap and you can just throw it away.

Especially if an original honeycomb radiator (they usually need cleaned out and not easy to do and when really clogged you have a problem).

[auburnseeker]

You just need to be careful with evaporust. I found once I starting using it on one thing I started using it on everything.  Works awesome to clean up chrome and nickel door handles as well.  Works great on cleaning anything that's iron.  Works really well for cleaning oxidation off cadmium plated parts and even plain old pot metal parts.  (everything looked new when I ran it through it)   When I was selling NOS parts I constantly had stuff in it every day to clean it up for resale.  I couldn't believe all the years I had wasted blasting parts to clean them up for sale.  Plus it leaves the original raw steel finish untextured unlike blasting.  

It's almost addictive and works in a day or two for soaking parts. 

[John_Mereness]

1 hour ago, auburnseeker said:

You just need to be careful with evaporust. I found once I starting using it on one thing I started using it on everything.  Works awesome to clean up chrome and nickel door handles as well.  Works great on cleaning anything that's iron.  Works really well for cleaning oxidation off cadmium plated parts and even plain old pot metal parts.  (everything looked new when I ran it through it)   When I was selling NOS parts I constantly had stuff in it every day to clean it up for resale.  I couldn't believe all the years I had wasted blasting parts to clean them up for sale.  Plus it leaves the original raw steel finish untextured unlike blasting.  

It's almost addictive and works in a day or two for soaking parts. 

Cool, I will give it a try - there is always something unrestored I am working on that has original chrome that is "green" and I find chrome cleaner often is just too abrasive and wire wheel cleaner tends to be harsh, plus you have to take part off car so as to not get near paint and ...

Edited March 2, 2019 by John_Mereness (see edit history)

[60FlatTop]

5 hours ago, c49er said:

Knock some core plugs out to do a proper flush... get it all out.

Flush the heater core and rad separately.

 

There are low flow areas, especially at the rear of the block that need to be mechanically cleaned with stiff wires and picks. Then flushed generously. Get all the access you can. Some cars have distribution tubes or side covers that should be thoroughly inspected, just to double check previous work.

I serviced a Hudson Eight where Bobo, the mechanic, had cut a gasket fully blocking the side cover distribution passages. The old material was hanging inside and looked like my left ventricle before "I" was disassembled.

Depending on the car make sure your lower hose spring has not rusted away and your water pump seal dosen't suck air.

As above, always unit an antifreeze coolant and a small bottle of water pump lube.

 

Cooling system pressure testers are about $80. I use mine a lot. They come with adapters for older cars.

Bernie

[auburnseeker]

58 minutes ago, John_Mereness said:

Cool, I will give it a try - there is always something unrestored I am working on that has original chrome that is "green" and I find chrome cleaner often is just too abrasive and wire wheel cleaner tends to be harsh, plus you have to take part off car so as to not get near paint and ...

I had been using it on almost everything.  I then bought a parts store display of door handles.  I can't' tell you the labor to polish each handle as they were all green and the nickel especially plus many had some pits.  I didn't want to invest a few weeks into cleaning them all so I threw them all in the sauce as I call it around the shop.  A day later I took and rinsed them all off,  it only took a very light once over with a tooth brush and they looked like they were plated yesterday less the pits of course.  The nickel ones came out clean but not shiney so I just gave them a quick rub with mothers polish and they came up very well.  Took me longer to take them all off the display and put them back on than to clean them.   Nice thing is everything is clean the front, back plastic knobs etc.  I'll try to post a picture of them after I go out to the garage.  

[edinmass]

Evapo rust won’t touch organic contamination in the cooling system. I had a Pierce that the coolent was so rusty it looked like a rusty shade of coffee. Very fine particles in suspension along with the normal scale in the block. Ran it stright out of the bottle, figuring all or nothing, as the system was pushing all the coolent out the overflow due to all the junk plugging the top of the honeycomb radiator core. Started the car in the driveway several times a day for a week before driving it down the road. Presto, the car no longer pushed any water out......none at all. Figuring I had nothing to lose, I left it in till late fall, then drained it. The block and head looked like the entire coolent passage areas were sandblasted......it was that clean. I flushed with water several times, and added antifreeze. My original intention was to pull the radiator, head, and water jacket as usual on all my new purchases. The results were nothing short of fantastic. I ended up driving the car for six years with no issues, and finally had a cracked head, so then I pulled it all apart. Radiator was free flowing and had no issues even after backflushing it. I stitched the head to repair the crack, and pulled the water jacket. The block was spotless, although I did find some heavy wire in the bottom left over from the sand cores that had been in there for eighty years. Recently I bought a 1922 Snap On socket set, all very rusty with surface rust from years in a shed. Just let it soak for a few days using a stiff nylon brush on everything. Set looks like it’s only a few years old. I get lots of comments on it as it’s on display in the shop. If the parts are not too rusty, you can use it several times. Since you can drink the stuff, you can just pour it down the drain. Heat helps the process along, that why in a cooling system it works fantastic, below fifty degrees it works very slow. No mess, no smell, no cleanup issues. Worth every penny even though it probably only costs them fifty cents a gallon to make. I won’t use anything else. I still think one should plan to do the job right, but with the results I have had, I consider this just as good as tearing everything apart to clean it the old fashion way. And with Pierce Arrow head gaskets running two hundred dollars, the treatment is less expensive than all the time, expense, and mess of doing it the old fashion way. They it......all you have to lose is your rust.

Edited March 2, 2019 by edinmass (see edit history)

[JamesR]

Sounds like evapo-rust is an awesome product/. I might just have to give it a try first. Since my car is mostly a fair weather car...and I just put a brand new heater core in, I'll leave the heater unconnected  while I run the stuff through my system.

 

Edinmass, I certainly appreciate your enthusiasm for the product and for making the effort to educate me about it. I really benefit from the experience of others. 😉

[edinmass]

JamesR - no worries.......I tried it only for one reason, the summer in question I was so busy I didn’t have time to do it the “right way”. There are no short cuts in the hobby, after forty years I usually just take the long hard road and fix things once. That summer it was leave the car stationary or try a gamble with nothing to lose. Since then, I have treated several cars with a less sever condition, all with positive results. There is no doubt the heat of the engine makes the process much faster and efficient. Basics I now do this to all my new cars before I do most any other service, as I always rebuild water pumps with modern seals, and the treatment makes rebuilding the pump much easier as you don’t have to deal with internal rust, and often the finish is left alone to make the entire engine compartment look consistent. I hate the look of a used and serviced car with newly restored components hanging on the engine.

[Spinneyhill]

Another similar chemical to Evaporust is EDTA. This is used in your blood sample tubes to grab the iron. I haven't found a source yet, but it must be available somewhere. It is not only used in the medical field.

[auburnseeker]

5 hours ago, Spinneyhill said:

Another similar chemical to Evaporust is EDTA. This is used in your blood sample tubes to grab the iron. I haven't found a source yet, but it must be available somewhere. It is not only used in the medical field.

Seems if it has medical applications it will extremely unaffordable,  atleast here in the US.  Anything related to the medical industry seems to be crazy expensive. 

[edinmass]

Evaporators Rust isn't cheap......but for the amount of times most people will ever need it, along with the convenience and safety to the car, paint, and environment, why not just pay the dollars and get it done? Sometimes trying to save a few bucks just isn't worth it. I swallowed hard on the first time I used it, then realized how much time, money, and aggravation it saved me. My cars are big, so they take a lot of it.........usually six gallons or better. I watch to see when its on sale and buy it that way, not I have six gallons in stock at 20 dollars a gallon. Have not needed it for over a year........

[fraso]

I like citric acid for removing rust and scale and it works very well.  Citric acid is inexpensive and can easily be purchased from a local wine supply store.  See Cooling System.

[viv w]

Evaporust is not available in this part of the world, can anyone tell me what chemicals are in the stuff?

 Also reading all your comments above about vinegar and various acids or alkali that you are putting into your engines, you need to be aware that either acid or alkali will cause severe corrosion to aluminum heads that are fitted to cast iron blocks using copper/asbestos gaskets. This is one of the reasons for the badly corroded Aluminum heads on early flathead V8's and cars like the Auburns. 

 My 35 Ford V8 has aluminum heads with copper gaskets, the motor runs sweetly, but the block was full of scaly rust. I don't want to strip the motor, but I'm reluctant to put even mild vinegar into it, in case it destroys the heads. I ended up filling it with water, let it sit a few weeks and then flushed it until the water ran clear. I would welcome advice from others who have had this problem, and how they sorted out this type of motor.

 Lastly the idea of putting pot metal stuff into either an acid or alkali to clean it , is a bad idea. I put a right angle distributor drive from a 27 Chrysler 4 into a mild solution of phosphoric acid, to clean it up. Fortunately, I happened to notice 10 mins later, that the solution was fizzing madly, and I took it out. The housing was rapidly dissolving in the acid and extremely hot. I think another half hour in there and I would have had an unusable part.

[60FlatTop]

4 hours ago, auburnseeker said:

Seems if it has medical applications it will extremely unaffordable

 

Not a chemical, but I can give a great deal on the hip and shoulder joints, as long as you are qualified to install them. PM for a discount to creaky old Forum members.

https://www.ebay.com/itm/153392224680

 

Bernie

[edinmass]

Evapo Rust uses chelation to bond to the lose iron atoms and take them out in solution. They it won’t attack iron that is not rusty. It only reacts with iron oxide. Since aluminum doesn’t have any iron it it, it will not harm it. It is NOT an acid, and is PH neutral. That’s why it won’t touch copper, brass, rubber, ect.........google it and read about it.

[edinmass]

[Matt Harwood]

I'll vouch for the Evapo-Rust myself. Used it to clean the chrome wire wheels on my wife's '56 Chrysler and the difference was nothing short of amazing. Didn't hurt the chrome, but removed all traces of rust, inside and out. When my '35 Lincoln engine comes back from getting its block repaired, I'm simply going to fill the water jackets with Evapo-Rust and let it sit while I work on other things, then blast it out with water and compressed air. You can get the stuff all over your hands and it doesn't burn, doesn't bleach your clothing, and they say that you can simply wash it down the drain, although with large quantities I don't want to do that, and dispose of it with our used motor oil and other chemicals. Given how well it works, I wouldn't bother with the home-brew vinegar/molasses/cola tricks. It's a little expensive, but given how well it works, I think it's a no-brainer.

 

These before and after shots aren't the best, but it removed all traces of rust, even from the spokes and inside the hub, without damaging the chrome or the leather band that encircles the wheel to protect the innertube from the spokes. The wheels were decent, but this clean-up made them excellent. 

 

  

 

 

[JamesR]

So do I run 4 gallons of straight EvapoRust in my cooling system, or mix it half and half with anti-freeze?

[edinmass]

18 minutes ago, JamesR said:

So do I run 4 gallons of straight EvapoRust in my cooling system, or mix it half and half with anti-freeze?

 

Run it straight. Be sure the system has no oil or grease in it. What is your car? 

[auburnseeker]

Actually evaporust will degrease as well.  I have used it many times to clean up NOS door latch mechanisms that have a factory greasy film on them, usually encrusted with shop dust and some flash rust on things like the raw steel springs.  Makes them look like new when you take them out and anything cadmium plated on them looks like it was just plated,  nice and clean but not shiny like you tried to clean it up.   I usually followed it up with a fresh spray down of Wd40 to prevent flash rusting on those raw steel parts,  so when the customer got them,  they looked like they would have when they were new. 

[auburnseeker]

4 hours ago, Matt Harwood said:

These before and after shots aren't the best, but it removed all traces of rust, even from the spokes and inside the hub, without damaging the chrome or the leather band that encircles the wheel to protect the innertube from the spokes. The wheels were decent, but this clean-up made them excellent. 

Matt;  what did you use to seal them with so they wouldn't flash rust again?  Or is it just because they were neglected before.  I know sometimes just better dry / heated storage will prevent it from coming back if it wasn't too bad before.  I assume you must have gotten caught in the rain since which is usually why they flash rust again. 

[JamesR]

1 hour ago, edinmass said:

 

Run it straight. Be sure the system has no oil or grease in it. What is your car? 

 

 

 '54 Ford Y block 239.

[Matt Harwood]

3 minutes ago, auburnseeker said:

Matt;  what did you use to seal them with so they wouldn't flash rust again?  Or is it just because they were neglected before.  I know sometimes just better dry / heated storage will prevent it from coming back if it wasn't too bad before.  I assume you must have gotten caught in the rain since which is usually why they flash rust again. 

 

I let them dry in the sun and used an air gun to dry them thoroughly, then cleared the spokes and hubs. I left the outer rims uncoated so I could polish them if they needed to be cleaned up in the future. 

[edinmass]

32 minutes ago, JamesR said:

 

 

 '54 Ford Y block 239.

 

Just run the pure stuff, wait till the freeze danger is over, leave it in for two or three months, and be sure to drive it and heat cycle it at least twice a week. You won’t be disappointed. Ed

[auburnseeker]

Here is the door handle display and i was even able to find the original pictures that i bought it from right here on this forum. 

I'm still missing a few handles.  Ironically about a week before i bought this, I wholesaled out a big box of door handles and window cranks and I'm sure a few were the right ones to fill it out.  I have some extras but was trying to put the right handles in the right places.

Edited March 5, 2019 by auburnseeker (see edit history)

[sftamx1]

I have the radiator off of my '32 Terraplane. (I have already cleaned the coolant passages of the block thoroughly.) The radiator doesn't look bad from what I can see. Would evapo-rust work in the radiator if I seal the inlet and outlet openings,  and let it sit for a few weeks?

 

 

 

[auburnseeker]

Doesn't seem like it would hurt anything.  I haven't had any problems with brass being submersed in it.  The junk in the radiator should be rust deposits so it should break them down fine. If you develop any leaks afterwards I would suspect it would have been from leaks that sealed themselves with rust particles so they probably would have started leaking anyways.  

I have yet to do a radiator with it,  but just haven't had one that needed done since I started using evaporust. 

I will the first time i find one I think needs it.