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Neutralizing formic acid

Discussion in 'Tanning' started by rasorbackq, May 17, 2012.

  1. Today was the day that all the pickling is done for the season.
    I have been using a FORMIC ACID PICKLE for several weeks pickling 6 deer capes, one at a time, adding salt as required to maintain a 40-50% rate as well adding acid as required to maintain 2 PH.

    Today I tried to neutralize the pickle with baking soda.

    The bucket only had 5-6 gallon of solution.

    I added 5 table spoons of BS and checked the ph .

    It was still 3.

    Left it sit for 30 minutes and still was 3 ph.

    Dropped in a lb of BS and after an hour was still 3 ph.

    Doubled up on the water still at 3ph dropped in a second 1 lb box of bs and still reading 3 ph.

    The foam that rises on the solution has a ph 5-7 . But the solution after foam dies off is still 3 hp.

    Does this sound right?
    Am I using Baking soda to neutralize a Doric acid pickle??
  2. cyclone

    cyclone Posts: 400001

    I assume that you are neutralizing to dispose of the pickle?

    Keep adding BS until it stops foaming...

  3. Yes I am disposing but should it be 10 lbs of bading soda.
    I read something on here by you Cyclone about wiping the hide and then squeezing out the liquid from the hide and testing that. I noticed last couple of hides I could feel the acid on my hands as I was mounting the capes. How well do you think it was tanned with a paint on tan. Bear essentials stuff?
    How long to neutralize the cape in the bath?
  4. cyclone

    cyclone Posts: 400001

    If the pickle is still foaming vigorously when you add the baking soda then it is not yet neutralized.

    How much acid did you originally? What concentration of acid?

    As for the other question, you'll have to ask the Bear Essential folks..
  5. Acid wise it was at PH above 2 but below 3 . I use strips and they can be hard to read . It had been a couple days since I added any acid but if the pickle was to be used with the same hide I would have needed more formic acid to get it back down to 2.
  6. Rhino

    Rhino Too many irons in the fire will put the fire out!

    Dont you mean, the tan you are using is sold from Orion Taxidermy Supply? Anyway, the tan isnt in question here.

    Sounds to me, like you are adding acid to the same pickle, over and over again, while ATTEMPTING TO MEASURE SALT CONTENT. That is virtutally impossible without some type of professional water testing. :eek:

    Salinometers are rendered USELESS after a pickle is used ONE time. The density of the water changes from, we'll just say, "skin trash". About the only thing you can do, is "guestimate", and add 1/4 lb per deer cape, that you remove from the pickle, before adding new ones. Skin sizes would dictate that "guestimation".

    One very good reason no to re-use a pickle more than once. Shouldnt re-use at ALL!

    To make a long story short, NO, you did NOT tan those capes, if they were still acidic. That type of tan, will only fix to collegen with a pH of 4.5 and HIGHER.

    For formic acid: Every gallon of 80degF water, 1/4lb salt, 2oz baking soda, for SEPERATE NEUTRALISATION BATH, for 45-60 minutes.
  7. George

    George The older I get, the better I was.

    Cyclone also asked a very pertinent question though I know you don't know. What was the CONCENTRATION? Formic acid simply won't go below 2.0 and if you just kept pouring acid in trying to achieve that, it didn't happen. You did however, multiply the concentration if. I you've added that much baking soda and it hasn't completely neutralized, you must have used one helluva lot of acid.
  8. cyclone

    cyclone Posts: 400001

    That's what I was getting to George..

    Additionally, one has to be careful testing with strips. Put a drop of pickle solution onto the strip as opposed to dipping the strip in the pickle. Dipping can and will cause the indicator to leech out of the strips giving false readings.
  9. This was the first time for me to reuse a pickle . Read about it on here all the time how pickles can be reused. Guess its a bad idea.
    Old shaver , I bought the tan from Sirius Taxidermy in Canada.
    In my neutralizing bath I did not add any salt.
    As for concentration . Started with a pink strip 2 hp and after 2 days 3 more ozs to 5 gallons size.
    It was just starting to raise 2.5 on the fourth day. I shaved the hide. and back in solution for 24 hrs
    Learning alot this [past week.
  10. cyclone

    cyclone Posts: 400001

    How much formic acid did you physically add to the solution? ...Forget pH right now. A pint? a quart? gallon?

    By using pH strips in this manner you are trying to judge the size of an iceberg by melting the tip...guess what? More ice will show up?
  11. Not sure on the amount but before I placed hide in the used pickle I tested I added a glug from a 4 liter container to get the ph strip nice and pink where before it was not.
    A few days later i measured and added 3 oz. That was 2 glugs.
    For a new mix I would add 7.5 oz to 5 gallons.
    So right now I can assume that the 3 last hides are still acidic and not tanned properly.
    Can I just wash them to remove the paint on tan and neutralize them again and start over.?
    What is the plan?
  12. cyclone

    cyclone Posts: 400001

    How many "glugs" is 7.5 oz?

    The plan is to teach you that a "glug" is not an acceptable unit of measurement..
  13. George

    George The older I get, the better I was.

    Methinks your friggin pickle would glow in the dark if you turn the lights out. Seeing as how most pickles say use ONE HALF FLUID OUNCE PER GALLON OF WATER, I'd presume that a "glug" would be sufficient for about 120 gallons of water. This is what Cyclone has harped on for years: CONCENTRATION STRENGTH. Folic acid is going to read 2.0 pH regardless if it is completely pure or diluted with a ratio of 1:256 or .5: 128 as they suggest.
  14. So the recipe I have used is
    1.5 oz formic acid (85%)
    1 gallon water
    1 lb salt
    Is this wrong?
    So how do I save the last 3 hides . wash and rince the paint on tan out . neutralize and tan again.
  15. cyclone

    cyclone Posts: 400001

    So I guess that you were being facetious when you state:

    If that should be the case then I'd have to suspect either one or more of the following:

    1. The pH strips that you are using are bad or you have no idea how to use them.
    2. The baking soda that you are using is somehow very impure or not baking soda at all.
    3. You actually have no idea how much acid you added.
    4. You are joking and have wasted our time. ::)

    Really, you shouldn't be messing with any pickle solutions until you figured what the fiddlesticks you did with the first one. :-\
  16. Why does it always have to turn this way.
    Listen I know I screwed up. I am trying to learn how to use a new acid pickle .

    Guess there is a lot of misinformation on here.....IE reusing pickles.

    To answer the last questions . I have 2 types of strips 1-12 and 1-4 I used both when I get odd readings.
    Baking soda not pure ......... Not sure on that. All I can do is read the box and purchase.
    I didn't add more then 7 oz to the last batch or I would have just made a new batch.
    What is a good recipe for formic acid pickle ??
  17. George

    George The older I get, the better I was.

    Look, it's difficult to maintain patience when we're asking specific questions and you don't know the answers. I'm sure there's enough "misinformation" here to go around, but some of us TRY to squelch it as soon as it appears. Oftentimes, we're ridiculed for "slamming" a method when we do it, so sometimes, we just say to hell with it, let them learn like we did.

    I have no idea where you found anyone endorsing "reusing" a pickle. Old Shaver has consistently told people it's not a wise mose. A lot of these Krowtann wizards have endorsed reusing that solution, but when mixed PROPERLY, so very little acid is needed to make a viable pickle, it really doesn't make a lot of sense to keep dunking new hides into the pea soup that develops in a pickle.

    Next, can that friggin formic acid. And before you say it, I know millions of people use it. Formic is a "safe" acid as the pH never goes below 2.0, HOWEVER, sometimes with questionable hides, a pH of 1.0 is nice to have in your pocket. Safetee Acid is simple to use and very cost effective because it takes less to achieve the same quality.

    FINALLY, stop playing with your chemistry set. When you're dealing with caustic or hazardous chemicals, a "glug" is likely to sell your ass down the river. Just like the nitwit who decided to pour some potassium permanganate into a container of glycerine. Both are sold by "supply companies" and many figure that's a free pass. IT'S NOT! Follow directions and follow them explicitly. Once you become comfortable with the method and learn how you can SAFELY and effectively tweek it to serve you better, then give it a try on a small scale before attempting it on an elephant.

    If you think it's frustrating on your end, try ours where we can't possible get there from where we are.
  18. Too true George , the elephant may not like swimming in formic acid !
  20. George

    George The older I get, the better I was.

    In my opinion, there isn't one, but if you're so damned insistant on using it, try this:

    1.25 FLUID OUNCES (Not a "glug") Formic Acid
    1 Gallon of water
    1 pound of salt

    That should get you a pickle about 2.0