Citric Acid Method (By: Candog)

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Citric Acid Method (By: Candog)

#1

Post by idigrust »

CITRIC ACID: Suggested Utilization techniques

By Tom Chegash. This article is dated 21 April 2006



INTRODUCTION .

Hi, I'm Tom Chegash; Alias “Candog” or whatever anyone calls me at the time. (Usually just “DOG”), you will find me on the newsroom message board periodically. Well, I have been asked many times to do this article, and I have written up pieces of it in Rustlings a couple times, but I think this might be a good thing to add to the website for all interested can dumpers to read.



If you can't decide between using Oxalic acid or Citric acid to soak your rusty gems you'll have to make up your mind on your own, I'm not going to try and sway you, (well Ok I will.) However, I do get my drawers in a wad when Oxalic users say that Citric doesn't work. That is just plain wrong! Anyway, supposedly there is an article coming on the use of Oxalic acid, and hopefully we will be able to offer advice on both methods; you'll just have to determine what's right for you.

When I started using citric years ago, there was a raging debate going on in the BCCA about the health risks of using Oxalic. (The RB did not exist then.) I don't know the real truth about one or the other, but I had very young children at home, and I was not going to chance using what I knew to be a toxic agent around the house. You can do your own research on Google now, so I don't need to go there. The Material Safety Data Sheet for Oxalic can also be obtained at http://www.jtbaker.com/msds/englishhtml/o6044.htm it is hazardous. On the other hand , Citric acid is recognized as safe for use in food by all major national and international food regulatory agencies. It is naturally present in almost all forms of life, and excess citric acid is readily metabolized and eliminated from the body. Contact with dry citric acid or with concentrated solutions can result in skin and eye irritations, so don't get it in your eyes, and wear gloves if you have a cut. I usually wear a protective apron, and use padded tongs to handle the cans. Oh, by the way there is no MSDS for Citric Acid!

HISTORY.

Now, I've been using citric acid in one form or another since 1981 when I started collecting and dumping. So I have about 25 years of experience using this stuff. At first I used concentrated lemon juice as it was just .75 a quart back in the early 80's, but as the cost went up to $2.75-$3.00 a bottle I started looking for the powdered form. When I moved to Chicago in 1993 I discovered "Sour Salt" (this is a kosher seasoning) which could be bought for $2 a bottle. One bottle (like a seasoning bottle) would clean one load of about 40 cans. There were 4 oz in that bottle, and that's where my initial use measurements came from; 4 Oz of Sour Salt in 2 Gallons of water. Later, as I did more dumping I was buying out the food stores of all their sour salt and the sour salt became harder to find. So in 1995 I finally made the transition to buying citric acid in bulk, after I found a source for supply. I prefer the powdered form as it dissolves easier and more completely. You can purchase it from http://www.chemistrystore.com and you will usually get the powdered form.



Now, there are really two types of Chemical Citric, powdered and crystal form. The powdered form is very fine, finer than iodized salt; the crystal form will have granules larger than salt. Be sure to determine which type you are using. Either type works just fine, but if you get the crystal form you need to make sure the crystals are completely dissolved BEFORE putting your cans in the solution. You also should not add additional Crystal Citric as it will not readily dissolve in cool water. This is a major difference in the use of the two chemical solids, so please remember this tip if you get the crystal form shipped to you. To dissolve the crystal citric try using a cooking pot, boil the water on the stove; dissolve the citric in the pot, then pour the water into your soaking solution. This seems to work best for crystal citric. Powdered citric does not have this issue.



GETTING STARTED.

Now if you only have a couple of items to clean or are just getting started and you don't want to spend bucks on a bucket of citric acid (from $3 to $1.40/lb), then I suggest trying concentrated Lemon Juice first. Use the cheap lemon juice (store brand) as REAL LEMON can get expensive. The mixture is 1 quart of lemon juice to 1-1.5 gallons of water. If you need less water to cover the item, then reduce the amount of lemon juice by the appropriate amount. What I used to do is place the cans in hot water until they are just covered, then dump in a bottle of room temperature lemon juice.


A lightly rusted item would only need to soak for an hour or two; a heavily rusted item could need to soak for up to 24 hours. You can check the can while it's soaking for the level of rust removal if you want. After an hour or so take it out and use a soft toothbrush under warm running water and brush off the rust, rinse the can off, and place it back in the lemon juice if it needs to soak more. I would suggest keeping notes for yourself, so you can determine soaking times and cleaning levels for various stages of rusty cans.

CITRIC ACID.



( The remainder of this article will deal with the powdered form of citric.)



If you have used Oxalic Acid in the past and are trying Citric for the first time please be aware that the two methods of use are different. I think that Citric cleans cans better. That is my opinion, and I also contend that if you get bad results with citric, you are using too much acid, too hot of water, or leaving them in to long or not long enough. Remember, you need a lot more Oxalic Acid than you do Citric Acid, but Citric cleans slower. There is also a modification of the technique needed for silver crowntainers.



So why use citric instead of oxalic acid? Well, there are no fumes to inhale, you do not need to worry about ventilation issues, citric acid is used in many different foods and drinks so there is no immediate danger to children, (I would not put the stuff on my tongue though!) We know that citric will not kill the bacteria in your Septic tank, so there's no need to neutralize the acid before you dump it down the drain.



What is the danger in citric? Well as a powder it will sting like heck if you get it in a cut on your hands. The same goes for the dissolved liquid. The powder, although not likely to become airborne, can sting if it gets in the eyes, and it will make you cough if you breath it in powdered form. Once it is dissolved, the fumes will not hurt you, but it will stain things yellow over time, and it does smell after a day or two. (after a week it will get moldy!)



USE:

First; always pre-clean your cans before soaking them. Get the excess dirt, leaves, mice, and ants out of your cans, and brush the excess rust off of the outside. For this I use nothing more than plain warm water. No soap, no cleaner, and I do not try and scrub the rust off of the can; just clean off the dirt. Place the pre-cleaned cans off to the side when you are done. (Don't sink them yet!)



The mix of acid to water ratio should be less than 1/4 cup of Citric (about 2-3 Oz) to a gallon of water. Using more acid will not clean any better. You will just be dumping unused acid down the drain. With this ratio I can clean 60 mystery cans with about 8 gallons of water in a 12 gallon cooler using no more than a level cup of citric. Other ratios I have used: 1 teaspoon of citric for a single can soaking in a small candy jar; 2 teaspoons for 4-5 cans in a small cooler; ½ cup of citric for 30 cans in a medium cooler….you get the idea.



I use hot tap water at about 120-125 degrees. I run the water into a cooler with a lid pour in the acid, mix it up so it is dissolved, and then sink the cans. After sinking close the lid, and let it go. I soak heavily rusted mystery cans for 20-24 hours; readable cans for 4-6 hours, lightly rusted dumpers for 1-2 hours. Now if you are just cleaning a little rust off of a good can, use a smaller container, "warm" or “cool” water, and watch it while it soaks! Just like Oxalic! You can use citric in COOL water too! Silver crowntainers will clean in citric using cool water from the tap. The crowntainers may need to soak a full 24 hours. I would use warm-cool water for Metallic cans too, if you are worried about it.


One thing citric does exceptionally well is clean seams and rims. If you like rusty looking rims and seams use oxalic, if you like your seams and rims cleaner use citric. I think part of the issue is if you use citric you MUST scrub off the seams, lids, and rims and that's a little more work. Whenever I trade for, or buy a can that is cleaned in Oxalic, I always re-soak them in citric (for a couple hours) and the rims and seams always come out cleaner. One thing I have discovered with powdered citric is that you can only get 1 soaking out of a batch of acid if you are soaking mystery (heavily rusted) cans. Also, because citric is a bio-chemical, sometimes if conditions are right, you can get fungus like growths on the lids. Why this happens I don't know, but they scrub off fairly easily. I have never seen these small growths on the labels.



That's pretty much it. The rule is “Less acid, more time”.

Once again its personal preference and I would take home those bad dumpers to experiment with citric. The citric will not clean as quickly, that is true. However, you will use less acid, which will save you money in the long run.



From Dave Wheaton: All I can say from personal experience is that hot acid in heavier concentration works great on many standard-issue dumpers...but never, NEVER go hot and heavy on indoor cans - particularly those done up in metallic. Weak and cool is the name of the indoor game, if you even want to risk it. Metallic's often bleach and fog with acid treatments, so watch the concentration and duration CAREFULLY.



My note on this is that indoor cans will sometimes have been waxed by a previous owner or dealer. If you sink waxed cans into HOT acid, the can will fog up and appear to loose its color. This is not the fault of the acid; it is because of the hot water! Sometimes fogged up cans will come back on their own, sometimes they won't. They only way I have found to un-fog the cans is spray them with an acrylic spray paint. Usually the color comes right back. WD-40, Vinyl sprays, more wax, does not seem to work.



CANDOG


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Re: Citric Acid Method (By: Candog)

#2

Post by henry porter »

http://www.jtbaker.com/msds/englishhtml/C4730.htm

MSDS for citric acid if anyone's interested
Wanted: Malt Lager breweriana and Malt Lager cans:
8oz flats: Gluek Stite 241-05, Bulldog 239-10, Schlitz (Class Book) 56-13, 56-14.
12oz flats: Country Club 51-37, 51-37-5.
12oz tabs: Colt 56-22; Colt 45 56-05, 56-10, 56-11–05, 56-12; Country Club 57-18; Red Bird 239-32; Schlitz 121-15.
16oz tabs: Calgary 146-23; Carling 147-01, 147-01-05; Colt 147-22; Schlitz 166-10

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Re: Citric Acid Method (By: Candog)

#3

Post by Candog »

Yep there is an MSDS for Citric Acid. I don't know how I missed that one. Here's a summary of the health effects of the two acids:

Citric Acid:
Potential Health Effects
----------------------------------

Inhalation:
Causes irritation to the respiratory tract. Symptoms may include coughing, shortness of breath.
Ingestion:
Causes irritation to the gastrointestinal tract. Symptoms may include nausea, vomiting and diarrhea. Extremely large oral dosages may produce gastrointestinal disturbances. Calcium deficiency in blood may result in severe cases of ingestion.
Skin Contact:
Causes irritation to skin. Symptoms include redness, itching, and pain.
Eye Contact:
Highly irritating; may also be abrasive.
Chronic Exposure:
Chronic or heavy acute ingestion may cause tooth enamel erosion.
Aggravation of Pre-existing Conditions:
No adverse health effects expected.

Oxalic Acid:
Potential Health Effects
----------------------------------

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.

Inhalation:
Harmful if inhaled. Can cause severe irritation and burns of nose, throat, and respiratory tract.
Ingestion:
Toxic! May cause burns, nausea, severe gastroenteritis and vomiting, shock and convulsions. May cause renal damage, as evidenced by bloody urine. Estimate fatal dose is 5 to 15 grams.
Skin Contact:
Can cause severe irritation, possible skin burns. May be absorbed through the skin.
Eye Contact:
Oxalic acid is an eye irritant. It may produce corrosive effects.
Chronic Exposure:
May cause inflammation of the upper respiratory tract. Prolonged skin contact can cause dermatitis, cyanosis of the fingers and possible ulceration. May affect kidneys.
Aggravation of Pre-existing Conditions:
Persons with pre-existing skin disorders or eye problems, or impaired kidney or respiratory function may be more susceptible to the effects of the substance.

Just thought you ought to know.
:smt024 :smt018 :smt021
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Re: Citric Acid Method (By: Candog)

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Post by Cap-Sealed »

So what are the disadvantges of Citric acid? Isn't it hard to monitor the progress because it is slow? Do you have to watch it every 4-6 hrs if you have something rare soaking? Do you scrub the cans every now and then while they are soaking? Doesn't it make holes that are all ready in the can bigger? Does it eat metal? Does it attack metallic paint? Are there any other surfaces/paints to be careful of when using citric (ie aluminium?) How clean does the can have to be before going into the acid? If the can is covered in mud & rust, can the acid still get thru? Is one cleaning enough - if you re-soak, does it buy you anything? Can you damage the can if you do a re-soak?
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Re: Citric Acid Method (By: Candog)

#5

Post by Candog »

I don't know of any. No. No. You can. No. No. No. I've never soaked aluminum. Just like Oxalic. Sure. Sometimes. Sure, if you use too much, too hot, too long. :smt024 :smt021 :smt018
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Re: Citric Acid Method (By: Candog)

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Post by Cap-Sealed »

Guess that says it all!
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Re: Citric Acid Method (By: Candog)

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Post by mtracy64 »

Cap-Sealed wrote:Doesn't it make holes that are all ready in the can bigger? Does it eat metal? Does it attack metallic paint? Are there any other surfaces/paints to be careful of when using citric (ie aluminium?)
Yes, yes, yes and Crowntainers.

I tried citric for a while and even converted briefly until I had some major issues. Citric tore the paint right off of an Old Ox Head Ale Crowntainer I found in upstate NY; the can was beautiful with a nice grade 2 face right out of the ground. I also observed that not only did tiny holes get larger, but that citric made holes where there were none on some late 1950's cans. I think it was a Matt's flat that I pulled out of the citric after six hours or so and the damn thing had turned into a sprinkler...it must have had 50 little pin holes in it that weren't there when I started soaking it, water and acid squirting out of every one of them.
I haven't used citric since.

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Re: Citric Acid Method (By: Candog)

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Post by TRAPPER4440 »

how do i keep paint on cans every time i clean them paint fades or comes off could the arizona heat do it i soak in citric take can out use soft brush and paint justs falls of any help thanks terry
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Re: Citric Acid Method (By: Candog)

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TRAPPER4440 wrote:how do i keep paint on cans every time i clean them paint fades or comes off could the arizona heat do it i soak in citric take can out use soft brush and paint justs falls of any help thanks terry
The Arizona heat could be a factor and the soil conditions where you're finding cans could also be an issue. There is one thing I learned about citric in the short time I used it that I didn't mention above. I found that I was much less likely to brush the paint off of cans if I ran the cans under cold water when using the toothbrush. If you've been running the cans under hot water (or no water), give cold water a try.

Better yet in my opinion would be to switch to oxalic acid. But bear in mind that oxalic works much faster and needs to be used much more carefully than citric - make sure you have good ventilation, don't breathe the fumes, use rubber gloves so you're not touching the oxalic, etc.

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