Have never used Citric Acid on rusted parts before. Have used vinegar, Evaporust, Ospho, phosphoric acid, etc. Have a few latter parts to do so thought I would give citric a try. Is there any particular brand name you guys use or type. Some say food grade others cleaning grade. What say all of you? Thanks.
No need to use food grade. Just be sure to take precautions to keep the powder dust out of your eyes, nose, mouth and wear gloves.
Just bought this 10lb bag for my neighbor. Showed up same day, food grade or not doesnt matter. I just look for a cheap price. Ive used this stuff w great success many times.
Naval Jelly. Works great on light to moderate rust. Safe to work with. To get the best results, do not let it dry out. Every few minutes scrub lightly with a scouring pad, fine steel wool or a wire brush and replenish the stuff as needed. This greatly speeds up the process. For parts that have more serious rust and appearance is not a big issue there's nothing that beats Muriatic acid. Available in the paint department of major hardware stores. A little bit in water works wonders quickly. The stronger the solution, the faster it works, but don't over do it. You need to closely follow safety instructions and wear goggles and rubber gloves. Never add the water to this acid unless you enjoy getting a bath. Always add the acid to the water. Neutralize with a strong solution of baking soda dissolved in water when you're finished. Rinse well. Citric acid is the stuff in citrus fruits that gives it it's tang. Very weak stuff. I use it as a stop bath in my darkroom.
I buy citric acid at Walmart, in the canning department, or near the canning supplies. About $4 for a jar of it. I use about 1/2 to 1 cup per gal. of water, preferably warm. Don't overthink it as it will get cold eventually anyway. Cover the parts all the way with the solution and wait. For these bumper ends it took about 36 hrs. Rinse well when done. Has always worked well for me.
I use the same stuff, bought on Amazon, as shown above, @Lone Star Mopar . If you can lightly agitate it, it speeds it up. ( I sit my container on running dehumidifier in shop). Day or two later, rinse and dry.
Thanks for the reminder, I have a part I have been wanting to clean and have a pack of the citric acid stashed away if the mice didn't get into it. This is a pretty sad piece but I want to save it if I can for reasons that folks will understand.
I have bought it from Amazon and eBay in 5-lb size. Save the label... or else it looks like a prop out of Scarface. I store it in an old Tupperware container. I mix a large drink cup to 5 gallons or so of water. I usually soak stuff in covered storage bins, have used old cat litter totes for small parts. That one I have suspended a kitchen strainer basket from some copper wire. It doesn't seem to react like aluminum would.
Great stuff. Just don't get it on your clothes, the stain won't come out. For really heavy rust, after a day soaking, I take the part out and use a wire brush and water. Put it back in and repeat.
And for the guys wondering a 10lb bag will derust ALOT of stuff, It'll be damn near a lifetime supply.
My brother and I tried citric acid dipping this summer. We tried molasses dipping last summer and had great results. We have a 400 gallon plastic farm tank, about 6 feet round. We used 50 pounds of citric acid, purchased from Amazon. We dunked a bunch of rusty sheetmetal in it, leaving for three weeks. Snagged the parts out, washed off with a pressure washer, and amazingly they were perfectly clean. About what we experienced last year with molasses, but without the stink and staining. So, we dunked another batch of parts in the same tank and left them for another three weeks. Pulled and cleaned them with the same method, and they were just as clean. Tried batch of parts number three, leaving for the same three weeks in the hot summer sun, and upon pulling them out, there was hardly any rust removed. We've determined the citric acid has lost it's appetite after the first two batches. We will buy another 50 pounds and continue with a fresh batch for the rest of the summer. Next year might be different though. The molasses purchase was around $300 and it lasted all summer. We only dumped it in the fall cause we didn't want it to freeze in the winter and crack our tank (we live in Iowa). The citric acid cost about half, but only lasts half as long. Will still need to drain in the fall.
I used muriatic acid once in my shop, never again. Everything piece of steel within 10 feet rusted up. I like phosphoric acid. Lots of products have it as the main ingredient. I like Krud Busters product.
Another tip, for citric, muriatic or molasses, is use weed trimmer line to suspend the parts. Doesn't react with the solution, easy to handle, and most everyone has it around.
Make sure you fully submerge whatever you're soaking. If you do not, and depending on how strong the citric acid solution is...you are at risk of getting an etch line you can't get rid of easily (or at all). I found this out the hard way on a Lyon wheel cover.
I soaked some frozen up castings for my tractor wheels in it. Mixed it too strong (I was told here) but after a day or so, I reached into the solution, pulled them out for a look. Let them sit another day the grabbed another bucket and mixed water and baking soda to neutralize it. But never had so much as a tingle in my hand. The stuff worked so well I went around and grabbed all the froze up adjustable wrenches I could find and most of them freed up.
Try to get as much dirt and grease off the parts before the dunk, it hinders the process. The longest soak I used was about 2 weeks... a set of horseshoes I forgot I had in the tub. Most suspension parts, coil springs, nuts and bolts were clean of rust in 3 days. It does "wear out" with use. This is why I use a small of a batch as possible.
I have used molasses, and liked the results other than the mess. Used vinegar liked the results other than the cost. Used citric acid cheap and not a lot of mess. Now I used vinegar for small parts and citric acid for larger parts.
If you've used oxalic acid (wood bleach) citric acid is about equivalent. I prefer oxalic for chrome. Citric is good stuff, fairly mild, inexpensive to do a "submerge bath" If its heavy scale - or you're impatient - go with phosphoric. I don't use phosphoric on chrome.
I have used it on Panels to pull out rust from pockets that a grinder will not get at. I used thin dish towels to avoid the etching and stacked heavier towels on top to hold citric moisture. Keep the towels wet for a few days.
I have a connection at a company that makes environmentally safe cleaning supplies that utilize citric acid. Invariably they receive pallets with some broken bags. Since they cannot use those for processing, they have to be hauled away by a paid service. I am that paid service. Yesterday I hauled off another 300lbs.
FWIW, I've had a 5 gal bucket (with a lid) half full of vinegar in my garage all summer and it still dissolving rust quickly, so it doesn't seem to weaken with time like citric acid
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