Using Oxalic Acid

[Call Me Ahab]

Hey guys,

I just read on another thread about a user who applied oxalic acid to his rusty parts -

Now, I have a few questions... If I have an old engine that has rusted parts inside, can I fill the entire engine with this and flush it?

Second, do I mix it with water? All my searches bring me a powder or crystal...

I read that it won't hurt rubber or plastic, what about aluminum?

Could I apply this stuff to oxidized aluminum bits?

 

[JEEPRUSTY]

Stay away from Oxalic acid dude the crystal form is pure and toxic as hell
dissolves cornea and nail tissue hows that for cool.

A picture of you engine innerds would provide a sound basis for us to make suggestions about. If its light surface rusting I would not worry much about it.

 

[JEEPRUSTY]

http://www.evaporust.com/

This stuff is pricey but it really works as advertized.

 

[Call Me Ahab]

Stay away from Oxalic acid dude the crystal form is pure and toxic as hell
dissolves cornea and nail tissue hows that for cool.

A picture of you engine innerds would provide a sound basis for us to make suggestions about. If its light surface rusting I would not worry much about it.

Holy sh.... O_O

Okaaaay.... I'll stay the hell away! I'm bad with chemicals, my hands shake and that sounds like a recipe for catastrophe D:

I'll check out the evaporust - I'll post pics of the engine as soon as I can get back to the shop, at the moment the owner's doing some work out there... Which apparently involves knocking over an engine hoist onto my freshly painted frame - not once, twice, no not even three times but FOUR ****ING TIMES!!! Ruined the clearcoat. I was furious, but there's no sense in staying angry.

Again, I'll post pics of what I'm dealing with as soon as I can get back out.

And thank you! I went out looking for it today, couldn't locate it. Was going to order it. I am very glad you stopped me!

***
Wow you weren't kiding about expensive... Ill see if you guys have any advice for taking care of the engine before I commit to ordering this stuff.

 

[Nessism]

Oxalic acid works great to derust chrome. It doesn't hurt paint while it'd working either. I've used it extensively in the past. Many deck wash products are oxalic acid; it doesn't hurt the grass if you dump the left overs in the yard. You need to cut it with water by about 10 to 1 if using the liquid product - add more if the action is too slow. Not sure about the powder stuff.

 

[Toasty]

I would be really wary of filling the engine with anything but oil...

What is rusty inside? People pour marvel mystery oil into the cylinders to free seized engines and run them like that for a while.

 

[JEEPRUSTY]

There is a reason this chemical is no longer used in wheel cleaners.
It is bad toxic stuff. In spite of its still being in use in deck cleaners and Barkeeper's Friend scouring powder.

Evapo rust all the way.

 

[Call Me Ahab]

Oxalic acid works great to derust chrome. It doesn't hurt paint while it'd working either. I've used it extensively in the past. Many deck wash products are oxalic acid; it doesn't hurt the grass if you dump the left overs in the yard. You need to cut it with water by about 10 to 1 if using the liquid product - add more if the action is too slow. Not sure about the powder stuff.

Hmmm... I'll look more into it then.. All I saw online were the crystals. If I can find a liquid that would be good, anything with a high enough concentration to eat my nails off is less than desirable =]


What's this mystery oil? I'll look that up too and see what it's all about =o

Okay I looked over the mystery oil site and I don't know that this is what I'm after. I wanted something to eat rust that's been building in an exposed engine with no oil.

 

[Call Me Ahab]

Evaporust does look like it would be the safest way to go here, but it is pricey. I'll have to set aside some money or work something out before I buy any of that.

Thanks Jeep, looks like that's the ticket =]

There's mostly just surface rust building on all the steel parts. However -

There also seems to be rust forming on my cam lobes... that worries me. I spray it with some prep n etch, rinse, and spray wd-40 over em every few days but it keeps coming back. I wanted something I could bath the engine in completely so it could break up any concealed rust before I put all the oil back in and fire it up when repairs are complete.

 

[Toasty]

Is the engine complete, but someone did something like leave the plugs out and store outside? What parts are rusty?

 

[Badooka]

Apple cider vinegar soak does a fine job of rust removal and its cheap and safe-
Keep it outside though- does have the bouquet.

 

[Nessism]

Now, I have a few questions... If I have an old engine that has rusted parts inside, can I fill the entire engine with this and flush it?

I hope you are joking about this idea.ray: The GS equivalent of a Darwin Award.

 

[JEEPRUSTY]

Surface rust is normal and you should not worry about it.
Even with a closed cranjcase you can get rusting on iron and steel bits
as long as the corrosion does not estend to babbit metal in bearing or mating surfaces then all is well.



I would jsut close it up and add fresh oil and change it after a short run in.

 

[Call Me Ahab]

Is the engine complete, but someone did something like leave the plugs out and store outside? What parts are rusty?

Engine is exposed from the pistons down - oil had to be flushed and the engine itself rinsed with kersosene, oil, more kerosene etc etc to flush sand and debris.

It's a long story, and a huge mess.

Apple cider vinegar soak does a fine job of rust removal and its cheap and safe-
Keep it outside though- does have the bouquet.

Can I let this sit inside the engine? Or... see Nessism's post below?

I hope you are joking about this idea.ray: The GS equivalent of a Darwin Award.

Ahh... Well, I wasn't, but I'll abandon the idea. I just wanted to make sure any rust that I can't see doesn't cause problems. But I think I'll follow Jeep's advice.

Surface rust is normal and you should not worry about it.
Even with a closed cranjcase you can get rusting on iron and steel bits
as long as the corrosion does not estend to babbit metal in bearing or mating surfaces then all is well.



I would jsut close it up and add fresh oil and change it after a short run in.

All right, as soon as the replacement parts arrive (piston rings, valve spring retainer, studs etc) I'll be able to seal it all up. Valves have been lapped and cleaned, seals replaced. Cylinders have been honed, not overbored - have STD piston rings incoming. New intake boots incoming.

The engine was in desperate need of a fixup.

But, as the side covers are off, oil drained, and the shop is NOT environmental controlled, humidity has been a factor.

 

[Guest]

From an oxalic acid MSDS (Material Safety Data Shee)

Routes of Exposure: Inhalation, Ingestion, Skin, Eyes
Summary of Acute Health Hazards: Oxalic Acid is corrosive to tissue. When ingested, oxalic acid removes calcium from the blood. Kidney damage can be expected as the calcium is removed from the blood in the form of calcium oxalate. The calcium oxalate then obstructs the kidney tubules.

Ingestion: The fatal adult human oral dose is estimated at 5 grams (0.18 oz.). Death occurs rapidly. May irritate and cause burns of the mouth and throat. Symptoms may include burning pain of the mouth, throat and stomach followed by profuse vomiting. Small doses may cause headache, pain and twitching in muscles and cramps, while larger doses can cause weak and irregular heartbeat, drop in blood pressure and signs of heart failure.

A delayed effect of ingestion is kidney damage, possibly leading to renal damage, possibly leading to renal failure. Chronic ingestion exposure to solutions of Oxalic Acid is linked to stone formation in the kidneys and urinary tract, resulting in difficult and painful urination and painful
abdominal spasms during passing of stones. Inhalation: May irritate the nose, throat and respiratory tract with symptoms such as sore throat, coughing and difficulty breathing. May cause inflammation of the respiratory tract. Chronic inhalation of Oxalic Acid can result in formation of kidney and urinary tract stones.

Skin: Product can act as corrosive agent to the skin, especially if contact is prolonged. Repeated or prolonged skin exposure can cause dermatitis and slow healing ulcers. Excessive contact may produce a delayed localized pain and discoloration of the skin with the fingernails becoming brittle and blue with possible gangrenous ulcerations of the skin. Oxalic Acid may be absorbed via intact skin. Chronic skin absorption of Oxalic Acid can lead to formation of kidney and urinary tract stones.

​

That fatal dose would be less than a teaspoon.

In general, people without specific training in use of particular chemicals should stay away from them, and use only products designed for general usage.

Many acids are effective at removing rust. Vinegar contains acetic acid, which is pretty mild. Even vinegar can cause pitting if left on a part long enough. Phosphoric acid is used industrially for removing light rust. A big problem with acid treatment is that it also sort of primes the surface for immediate rusting as soon as the acid is removed.

WD40 supposedly lubricates/protects with fish oil. It leaves a very thin film, which probably can't block oxygen. Oxygen + iron = rust. Motor oil should work better. Grease should work even better. White grease is available in aerosol cans, dispensing like WD40. The difference is that it leaves a much thicker film, and should protect parts better.

 

[Call Me Ahab]

Okay, so NO oxalic acid...

Even though others may have had good results that's something I'm going to avoid. I'm the person who can trip while walking across a level, empty lot. It happens. Add chemicals like that into my day to day life and something's bound to go horribly wrong.

Thanks for the info and the MSDS - I can't use grease, but it looks like I'm okay anyways - another member has told me that I'm getting myself too strung out over some minor rust. Not a big deal. I'll Metal Resue bathe my camshafts, valve buckets etc, but the rest will be okay.

I found a cheap alternative to the Evaporust at Home Depot, got a damaged bottle for fifteen bucks. Will use this on all my old, rusted parts - then I'll look into powder coating them or just coating em with a rust inhibitor.