In the past I’ve used 90% grade phosphoric mixed with 6 to 7parts water. This works really well except a 20 litre drum has gone from $90 to $400. $1000 to fill a 1000 litre pod…. Too expensive for me now. I’ve also done the electrolysis method using a large steel plate and baking soda in solution and a battery charger. Keen to hear any other cost efficient immersion methods. I just spoke to the local produce store and can get molasses for $120 for a 100 litre which will make 1000 litres…. But I’ve heard it gets on the nose… I think this will be the direction I go for the moment.
powdered citric acid seems popular, and you can tip it out on the garden after, no personal experience with it but another avenue to look at
Molasses works great! Derusted my entire roadster body with it. I put a cover on the box so there was basically no smell. I'd do it again! Rust removal.......the miracle of molasses! | The H.A.M.B. (jalopyjournal.com)
I use the citric acid,,,,,this is from 24 hours soaking,if you want a better result, leave it in for longer time.
cirtric, does a great job . Molasses leaves a messy part to clean, citric just give it a wash with something to stop flash rusting and your done.
Molasses works, but stinks. Not straight away but it ferments. It is not a pure product. I use home brand vinegar, but not in 1000 l volumes. (pics of results in my sloper thread) No smell and you can play with it with bare hands.
With the quantity of molasses that you have to have to clean large piece getting rid of it could be a real hassle if you don't live way out in the country were you can dump it down on the back 40. I've got pack of Citric acid but haven't tried it but have something that I want to clean so I might see if I can mix up a batch tomorrow and use an old tote I have.
I too vote for citric acid. I haven’t soaked entire panels, but lots of little things. I had a early Corvette shifter that was frozen stiff with rust. Soaked it for a few days and after rinsing with water and a brush, it worked like new. Did not damage chrome at all. I just pour out in yard when finished.
I have used the citric acid method on a number of parts and it worked really well. It was suggested to me by a fellow member 'two couped up'. One pound of citric acid powder per three gallons of water. Let the parts set for a day or two. I brushed the parts with a stiff bristle brush after a day and let them set for a second day. Then rinse with clean water and dry.
I like citric acid as well. no need for gloves, and you can dump it down the drain. can also use it to strip zinc coatings from hardware.
I love reverse electrolysis! Last summer I tried citric acid and wasn’t impressed. Now I think the concentration was too low so will try again this summer. The electrolysis is great when doing wheels. A day or two, rinse, prime, and paint: done!
When you full a large container. Use other containers full of water to offset the dead space and reduce the amount of chemical needed. I had a 60 gallon tank and a lot of gallon jugs of water with the lids glued on. Put part in, arrange the jugs to raise the level of the tank. I use phosphoric, citric, oxalic for different things, prefer oxalic for chrome, phosphoric for heavy rust. Soaking a towel in phosphoric, laying it in surface and keeping it wet works pretty well on large flat parts
I was a solid skeptic before I read about citric acid here on the Hamb...used it last year to de-rust several sbc cranks in a 5 gal bucket. I wouldn't have believed it until I saw it with my own eyes. The cranks came out looking like brand new. Sold them for 5x what I was asking before the soaking. Bought smaller quantities of citric acid at Walmart in the canning section for around $4 jar. Still have plenty left over. Unbelievable stuff.
Do it!! If you still don't like it, use it to clean your coffee maker...... no smell like you get from vinegar. Also takes those weird blue-ish stains out of your stainless steel cook wear. It's great for removing hard water stains too. (no I am NOT Helouise from 'Hints from Heloiuse')
I used a 1:1 ratio with water, or maybe a little stronger. The more the merrier, and it is pretty cheap. Bob
Is that 1:1 a pound per gallon? I actually wound up with a about a pound to a gallon as was told I over mixed it.
The threads that I was following were using a cup to a gallon of water, which worked for me to start. I actually mixed it with about 1 1/2 cups of citric to a gallon of water. Seems like it depends on how much rust you're removing. But then again, if not strong enough, just let it soak longer. I only had to do my cranks overnight on one end, standing up in a 5 gal. bucket, then flipped them over the following day. Bob
yeah, I probably end up around 1-2 cups of citric acid per gallon of water. I don't really measure, it's not critical.
One cup of citric acid per gallon of water? That's a LOT. That's 1/16 or 6.25%. I probably mix closer to 1%. Maybe less. A fresh warm solution helps performance. If it's bubbling, it's working.
I have used powdered molasses diluted in water, and it works ok. Recently, I bought a bag of powdered citric acid from Amazon, and am now a believer.. The molasses starts to smell as it ferments, and I am afraid of attracting rodents if I can’t cover the container. Citric acid is much more accommodating, and seems to work faster.
I’ve never measured the amount of citric acid to water. I add rusty part and water to plastic tub and sprinkle in citric acid. I probably don’t add enough to work super fast, but I’m cheap and don’t want to waste it. I usually leave the parts soaking for a few days before checking on them.
I use 25 pounds in this tank. Then a couple years later, I add the other 25 pounds. I clean it out every 4 years or so. I have left parts in for as long as 10 minutes (cleans up dirty chrome) to 4 months. It freezes in the winter, so I wait for it to thaw. Some on the end of the cycle it takes a bit longer.
I've been using citric over 10 years, does a great job. Item needs clean of grease and oil and underseal. Will soften primer but not paint. Will clean rust under scratches. I use 3 x 25 kg bags for 1000 litres, lasts 3-4 years easily. Wash off with high pressure after to clean and neutralize it, then wipe a coat of phosphoric acid to stop flash rust and prevent surface rust later. The phosphoric wash will stay good for quite a long time and wipe again if any further light rust appears. If the tank isn't used often, it can go a little stagnant so I throw in a cup of bleach to help stop that.
The Jalopy Journal
