White Vinegar

[mwizz]

I was recently told about using white vinegar to remove rust from old rusty parts. I know that there would be many on here that would know about this already but I thought I would share with those that have not heard of it or tried it yet.

I bought some parts from a 1924 Indian motorcycle and tried the white vinegar bath on a leaf spring as that was a smallish very rusty piece to start with. I bought 2 litres of white vinegar from Woolworths for $1.20 and soaked the leaf spring for a couple of days.

Before the treatment it looked like this:





After the soaking I took to it with a wire brush on an angle grinder. I took the leaf spring apart so I could get to each piece.







I was happy with the result. Supercheap are selling a rust remover for $37 for one litre so I think that the $1.20 for 2 litres of white vinegar is a better option.

[Dwayne]

Yep, that's all I use now.

First time I saw it was here:
https://www.youtube.com/watch?v=GkjL97DF-RQ

[BAC]

Oxalic acid solution works even better than vinegar IMHO.

Sold at Bunnings as Diggers Rust and Stain Remover - one container will last you forever.

[shaunp]

Molasses is the best. It removes every last bit of rust down to good metal just like new.

[stormin]

I tried molasses and couldn't get any result  with it.
Stormin

[Dwayne]

I use molasses if I can fit the part in the tub. Leave it for a couple of weeks then give it a good clean off.

[mwizz]

Molasses is the best. It removes every last bit of rust down to good metal just like new.

Do you need to mix the Molasses? I haven't used it but will try it. Best place to get it?

[BAC]

I tried molasses and couldn't get any result  with it.

You have to submerge the part in a tub of the stuff and leave it there for a couple of weeks.  Not convenient or economic for larger parts...

[Dwayne]

I used 1L molasses with 10L water in a big storage tub from bunnings. It stinks, so make sure you leave it outside with the lid on.

One of my staff has horses, so she got me 3L for $4 from the feed store. It leaked through the bottom of the milk container though after a month and made a big mess though.

[Husky350]

Oxalic acid solution works even better than vinegar IMHO.

Sold at Bunnings as Diggers Rust and Stain Remover - one container will last you forever.

i've seen guys run that through the radiator for a few minutes to remove rust in the block also

[BAC]

i've seen guys run that through the radiator for a few minutes to remove rust in the block also

Yep, certainly works quicker than vinegar and most other home brew rust treatments.

[barnett468]

SOS pads and 00 steel can in fact scratch the chrome . 0000 steel wool is what should be used if you want too insure the chrome will not get scratched.


I wrote the following at the request of some people a while back.

DIFFERENT RUST REMOVING METHODS AND THEIR GENERAL EFFECTIVENESS

There are several different ways to remove rust and rusty hardware, however, I will only go into one in detail which is Oxalic acid and it is fairly inexpensive . One of the more common rust removal products on the market is "Evapo Rust", and it costs around $22.00 a gallon and at best is only around 50% as effective as Oxalic acid when the Oxalic acid is mixed at what I refer to as a "Full Strength" ratio of 1 lb of crystals to one gallon of water and it also costs around 4 times as much.

The Oxalic acid mix will remove rust from tools parts, gas tanks and steel rims etc . . It can also be used to de-rust rusty automotive radiators and used as a periodic cooling system flush in cars and trucks . Another fairly effective method for removing rust is by Electrolysis, however, this is a bit more complicated and more of a PITA.

Oxalic acid is in some concrete driveway cleaners and wood bleaches that can sometimes be found at some hardware stores, however, it seems that fewer stores carry it these days, so if you don't find it there, pure Oxalic acid crystals can easily be purchased online, and amazon.com has some of the cheapest prices on it.

The cost to make the solution in maximum strength depends on how much you buy of the product and where you buy it . . If mixed at 1 lb per gallon, the cost per gallon can range from $7.00 to as low as $2.00 .  One of the cheapest places to buy it is from amazon.com where you can get for around $7.00 for 1 lb or $15.00 for 5 lbs or $35.00 for 20 lbs.

http://www.amazon.com/s/?ie=UTF8&keywords=oxalic+acid+crystals&tag=googhydr-20&index=aps&hvadid=34210609667&hvpos=1t1&hvexid=&hvnetw=g&hvrand=15446766872994692505&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_6i3ge8f3gs_b


MIX RATIO VS DE-RUSTING SPEED

The more acid you use, the faster it will work . . If you are on a budget and have up to a week before you need the item and it is moderately rusty, you can try mixing 1/4 lb of acid per gallon of water . If the item has light surface rust, it could be clean in as little as 2 days . I had 3ww member 3 Wheel Drive use the full strength ratio on his heavily rusted engine block . He let his block soak for around 5 days, at which point absolutely every single grain of rust was gone, however, it is possible that all the rust was gone slightly sooner.


SEE THE RESULTS

The before and after photos further below are of member 3 Wheel Drive's engine block . Unfortunately, the person he bought the block from had left it outside in on the ground in bad weather for many years . This caused it to rust heavily on the inside as well as the outside . This means the the outside wall of the cylinders was rusting in the water jacket area, and the inside of some, if not all of the oil passages were also rusting, and the rust inside the oil passages would have instantly destroyed the engine upon initial start up had it not been removed.

The oil passages could have been cleared of the loose rust with metal brushes, however, brushes will not remove rust that is still adhered well to the block, especially when it has created small low spots [pits] which the brushes can't easily get into . Even if those passages could be thoroughly cleaned with brushes, it is still impossible to clean everywhere inside the water jackets and he didn't want to build an engine for his car that was rusty inside so he asked me if I could suggest something which is the process I am posting about.


STORAGE AND REUSE OF SOLUTION

Once the solution has been made and used, it can be stored in a container and reused . Airtight containers will prevent evaporation and fumes . If you don't have an airtight container, you can put some type of lid over it even if it is just a piece of wood then try to store it in a ventilated area.


LIFE SPAN OF SOLUTION AND TESTING ITS ACID LEVEL TO EVALUATE ITS EFFECTIVENESS

The solution will not loose effectiveness if it is unused and stored in an airtight container.

The acid level goes down as it removes rust . The more rust it removes, the more the acid level goes down . The lower the acid level, the less effective it becomes so the longer it will take to clean the items, however, as long as the solution is acidic, it will still clean parts, but if the acid level gets low enough, the time frame can go from a few days for heavily rusted parts to a few months etc.

The acid level can be monitored with just litmus paper or an iodine test kit, both of which are available at any pool supply store and some hardware stores if they have a pool department which is usually by the gardening department.

You can test the acid level immediately after you make it so you have a baseline to compare future tests to . As long as the level stays near the starting level, the effectiveness of the solution will remain around the same.


SAFETY

When the acid is mixed at 1 lb per gallon of water, it is strong enough to discolor clothes and possibly put holes in them which would usually appear after washing them . It can also lightly irritate the skin if it gets on it, therefore, you should wear long gloves and maybe the ol' lady's apron when using this stuff.

The most dangerous part of it are the fumes from the mix or the powder that may go airborne when you are pouring it out of the bag, so use it in a well ventilated area and a paper face mask is also suggested . Try to avoid breathing any airborne powder at all costs . The mixed solution does not give off many fumes so it is not very dangerous . It's just not highly advisable to stick your face directly above the surface and start huffin it . The airborne powder can irritate your lungs a little if you breathe in enough of it.


DISPOSING OF SOLUTION

Once the solution is brought to a neutral ph of 7.5 to 8.0, it becomes so harmless that one could drink it, however, a little flavoring would be advised . In its neutral form, it can be poured onto grass or the planter etc, however, if you do this, I would dilute it some with plain water then water the area you pour it in with plain water afterwards to dilute it a little more . Now just in case some "Save The Planet" type people read this and want to start whining about how barnett468 is trying to kill the whales or the blunt nosed lizard etc by telling people they can dump this stuff in their yard, I can assure them that it is not only safe to pour into a yard, it is perfectly legal to do so . Oxalic acid is actually in many plants, some of which some people eat, and the baking soda used to neutralize the acid is used in many food products and the water used to mix with the acid is often consumed by people with only minimal side effects if it came from their faucet.


PRE-CLEANING LOOSE RUST FROM PART

If the part has heavily flaking rust, this process will remove it irregardless of how thick it is, however, it will clean the part much faster if the heavy, loose rust is scraped off first . Since this was an engine block, I had 3 Wheel Drive run a long bottle type brush through all the passages he could first . This included the lifter oil galleys.   


WASHING PRIOR TO SOAKING IN RUST REMOVAL SOLUTION

The product I use will not easily remove grease or oil, therefore, it will not easily remove rust from an area that has grease or oil on it if it even removes it at all.

Remove any grease and heavy oil deposits prior to "washing" it . This will reduce the the soaking time.

Some cleaning options are Spic N' Span or pure white Tide clothes washing powder . The Spic N' Span can sometimes be found at Sears or Hardware stores or home paint stores because it is sometimes used to clean walls before they are painted . Do NOT use Tide with green crystals . If you read his thread you will know why.

Mix around 1/4 cup per gallon of warm water and let the part soak for at least 4 hours . If the part is really grimy, let it soak for 24 hours.

Remove part and rinse the bejesus out of it with warm water . The rust remover won't work as well on soapy parts and these products can be difficult to rinse off completely.


PERIODIC INSPECTION OF PROGRESS

The solution may get too murky to see the part, so if it is a small item, you can tie a long piece of any wire to it then place it in the solution then drape the end of the wire over the edge of the container then simply pull the part out whenever you want to check its progress.

If the item is too heavy to do that with, you can try and find another rusty item which could even be an old nail etc then tie the wire to that and inspect it periodically . If both items had a similar amount of rust on then, the item you are de-rusting will be rust free at the same time the test item is.


NEUTRALIZING THE ACID ON THE PARTS

Once the parts are done soaking, they should be dipped in a solution of 1/4 cup of baking soda or soda ash per 1 gallon of water for 5 minutes, then they should be rinsed off and dried quickly . The ol' lady's hair dryer works nicely for this part after they are partially dried with a towel or paper towels first.


NEUTRALIZING THE ACID SOLUTION

This can be done with baking soda or soda ash . The higher the acid content is, the more baking soda it will require to neutralize it . . One method to do this is to mix around 1/4 cup of baking soda with 8 ounces of warm water and pour it into the acid solution, then stir it well, then test the ph level with a litmus strip or iodine swimming pool test kit . Keep adding baking soda mix until the ph is anywhere from 7.5 to 8.0.


DISPOSING OF SOLUTION

Once the solution is brought to a neutral ph of 7.5 to 8.0, it becomes so harmless that one could drink it, however, a little flavoring would be advised . In its neutral form, it can be poured onto grass or the planter etc, however, if you do this, I would dilute it some with plain water then water the area you pour it in with plain water afterwards to dilute it a little more . Now just in case some "Save The Planet" type people read this and want to start whining about how barnett468 is trying to kill the whales or the blunt nosed lizard etc by telling people they can dump this stuff in their yard, I can assure them that it is not only safe to pour in their yard, it is perfectly legal to do so . Oxalic acid is actually in many plants, some of which some people eat, and the baking soda used to neutralize the acid is used in many food products and the water used in if is often consumed by people with only minimal side effects if it came from their faucet.












There was a lot of rust inside the water jackets and around the outside of the cylinders inside the water jackets . . these are areas that no amount of spray washing or bead blasting can get to to clean.





Nice and rusty.





You can see very heavy rust scaling on the cylinder wall thru the rusted out freeze plug . . There was ZERO rust left anywhere when it was done.





Rub a bub bub, the blocks in the tub . . This is the acid solution it was placed in after being soaked in detergent in the same tub.





After soaking for a few days, I had him pour the baking soda mix in to neutralize the acid then he poured some solution out so he could see the block and marvel at its 100% rust free beauty.


















PREVIOUS KAWASAKI INTERNATIONAL R & D PROJECT ENGINEER AND ATV DEPARTMENT SUPERVISOR

[Dwayne]

Can the Oxalic Acid be wiped/brushed on etc?

I've got some surface rust inside my shock towers I need to get rid of before etch priming and I can't really soak my whole car in it.

[barnett468]

Can the Oxalic Acid be wiped/brushed on etc?

I've got some surface rust inside my shock towers I need to get rid of before etch priming and I can't really soak my whole car in it.

you can use naval jelly for that . it is gelled phosphoric acid.

[mwizz]

Thanks Barnett

[Dwayne]

you can use naval jelly for that . it is gelled phosphoric acid.

[BAC]

Can the Oxalic Acid be wiped/brushed on etc?

+1 for what Barnett says 

If you are in a pinch, you can brush on the Oxalic acid.  Just make it up as a paste rather than a solution so it will stick better to the rusty parts.

[shaunp]

I tried molasses and couldn't get any result  with it.
Stormin

You have to leave it in for a while, and water it down, then you just water blast it clean, it will eat the rust all the way down the bottom of each pit in the metal.

[mwizz]

What would be the best method of doing an old motorcycle frame as it would be too big for a plastic tub unless it was rotated submerging bits of it at a time

[BAC]

What about using one of those kids' clamshell plastic swimming pools or something like that?

[Dwayne]

What would be the best method of doing an old motorcycle frame as it would be too big for a plastic tub unless it was rotated submerging bits of it at a time

44 gallon drum or similar?

[barnett468]

I tried molasses and couldn't get any result  with it.

It seems to get the best results when used on a stack of pancakes. 

[barnett468]

I use molasses if I can fit the part in the tub. Leave it for a couple of weeks then give it a good clean off.

So you don't take a bath until your part is done?

[Dwayne]

So you don't take a bath until your part is done?

Nah, it's multi-tasking.  I can get a CBS wax while cleaning car parts 

[barnett468]

I can get a CBS wax while cleaning car parts 

I'm not even going to ask what that is but it sounds painful.