Tanning with Murphy's Oil Soap experiment

[JessiL]

That sounds about right from what I remember from high school chemistry!

So, let me get the proposed work flow straight...

Pickle raw pelts 1-3 days in undiluted white vinegar.
Flesh out pelts.
**Here's where I am uncertain - is the initial pickle likely to be enough, or should the fleshed pelts be put back for another round, like you do with salt/alum?
Neutralize acid by bathing in baking soda and water solution.
Rub hide side with plenty of Murphy's Oil Soap.
Let dry/tan at room temp or lower.
Break hide when almost dry.
Profit?!?

 

[Zass]

They are usually returned to the pickle after fleshing to allow the acid to fully penetrate areas of skin that previously had flesh and fat on them.

Keep the pickle somewhere cool.

After neutralizing I usually use towels to remove as much water as I can from the hide, and put it in a cool place with good airflow to dry the fur side as fast as I can, usually in front of a fan. You can actually start drying the fur while the pelt is folded and absorbing the oil.

Profit? I suppose they are sellable.

They won't be washable, and I have no idea how long they will last.

 

[JessiL]

Thanks, Zass - I was just trying to make a reference to an internet meme with the "Profit??" part!

I have done a lot of reading, and am excited to try a variety of techniques. My first three pelts are in vinegar, ready for first fleshing tonight. I picked up a lot more vinegar and salt from CostCo today, and have citric acid, neatsfoot oil, pH test strips, and the Rittel's EZ-Tan 100 kit on the way. My plan is to try comparing vinegar, citric acid, and alum pickles followed by either neatsfoot oil, Murphy's oil soap, or the Rittel's product. We decided to empty the freezer of our stash of pelts, so we have a ton of stock to go through. I'll start a new thread for that.

One last thought on the vinegar pickle though - it's probably best to add salt to the vinegar if the pelts were not salted ahead of time, correct? That is what my scattered readings have indicated, is that acid and salt always go together.

 

[Zass]

The ez-tan is a syn-tan and will have an acid and a tanning oil with it. Usually the oil is based on neatsfoot oil. Syn-tans have some serious advantages of being washable, and producing a pelt that will last forever. They are generally compatible with any acid.

When you use the citric acid make sure to check your PH frequently. The same goes for the saftee acid in your kit. The acidity can change pretty dramatically during the first 24 hours with the saftee acid, and I think throughout the whole process with the citric acid.

Alum is something I haven't played with yet. It's considered a pickle and a preservative, but not a true tan.
It takes so long to accomplish...I just haven't found the time for it, but it is on my list.

Well, oil-soaping a raw or pickled skin isn't a true tan either! It's just an oiled raw-hide. The pickle doesn't tan it after all, it just preserves a pelt temporarily it and gets it ready for tanning. (except alum, which preserves it much much longer than an acid pickle typically would. Alum has it's own niche when it comes to tanning, somewhere between a tanning agent and a pickling acid)

Of the materials you mentioned, only the syn-tan will chemically alter your leather in a permanent fashion. Alum can sweat out or be rinsed out of a pelt over time, and the oiled rawhides would probably be totally spoiled by wetting. Syn-tanned pelts rehydrate well and just need re-oiling if they are washed too much. I actually went back and re-broke to my first pelts a few years after I tanned them, since I had accumulated the experience to do a much better job at breaking. The pelts were better-than-new.

This is where syn tans shine over chrome tans. Chrome tanned leather doesn't rehydrate as readily when it's a few years old. It's more of a concern for taxidermists than clothing makers.

The syn-tanned pelts do however need to be re-broken when wet. I haven't found a tan (other than commercial chrome tans) that doesn't stiffen up upon washing.

I would always use salt if I was doing a syn-tan or using alum.

The oil soap method is basically an imitation brain tan, and everywhere I've read says that salt is not used for brain tanning, so I left it out and suggested refrigerating it instead as an additional line of defense against the bacteria that causes slip.

I have also read that salted pelts CAN be used if care is taken to rinse all the salt out before braining.

It's up to you.

 

[JessiL]

I am excited about the syn-tan chemicals, at least somewhat washable pelts seem like a good idea.

And I don't mind (too much) a little experimentation, so why not give a couple of things a try? I'll try to keep good records and share the results, so all can learn from my mistakes.

BTW, I was looking for a little more advice with using vinegar as a pickle, and found a forum where someone posted these scanned pages. Apparently this was advice from Rittel at one point or another...

 

[Zass]

And I don't mind (too much) a little experimentation, so why not give a couple of things a try? I'll try to keep good records and share the results, so all can learn from my mistakes.

BTW, I was looking for a little more advice with using vinegar as a pickle, and found a forum where someone posted these scanned pages. Apparently this was advice from Rittel at one point or another...

By all means experiment! I think you have a really good lineup of things to try out. It sounds really fun.

Just don't ever use the "good skins" to learn on. Save those for when you have a method you really like worked out.

That acid reference is excellent!!!
Thank you for posting it! Those are exactly where you would want the acids for temp and salinity if you were using a syn-tan like EZ-100 which I believe is compatible with any of those.

Alum is occasionally used as a pickle before tanning with another tanning agent, a lot of people don't know that.

I see the ph on the vinegar is 2.5. I am a bit surprised by that. I don't have the years he put into this though. I just use 1 as my "safe number".

Saftee acid is very good stuff. A little goes a long way.

BTW, You can read a ton of Bruce Rittel's writing over on taxidermy.net. I'm not sure if he's still around to answer questions directly, but I know he did for the longest time and all those archives are still accessible.

 

[JessiL]

Ok, so my first experiment with the Murphy's Oil Soap did not end well... Hair slip and a general lack of softness to the flesh side.

It is possible that the problem was in the acid pickle step. This was my first attempt using vinegar, and it was before I looked up the "official" vinegar formula. So I had used straight vinegar with a handful of salt thrown in. pH unknown. So perhaps the pickle just didn't happen.

But I also found myself wondering when to apply the Murphy's - should I have dried the pelts somewhat after neutralizing the acid, or just spread it on immediately after rinsing the baking soda solution away? And how generous should I be with the Murphy's - just a light brushing-on, or pretty much douse the hide in it?

Currently I have four pelts from a proper vinegar pickle just starting out in Rittel's EZ-100 tanning agent. I'm excited about those! And more pelts in vinegar, alum, or Saftee acid on deck. It just takes so long to flesh them all...

 

[Zass]

Ok, so my first experiment with the Murphy's Oil Soap did not end well... Hair slip and a general lack of softness to the flesh side.

This is typical for first time pelts. Slip can be started anytime after an animal is killed. During skinning, during freezing or thawing, in the pickle if there isn't enough salt or acid, after pickling if it takes a really long time to dry, etc.

It is possible that the problem was in the acid pickle step. This was my first attempt using vinegar, and it was before I looked up the "official" vinegar formula. So I had used straight vinegar with a handful of salt thrown in. pH unknown. So perhaps the pickle just didn't happen.

Usually a more acidic pickle will usually harm nothing, but without a way to test PH, who knows? Your acidity may have dropped out. I use my litmus strips to test my PH at least twice a day unless I'm using a really stable acid.

But I also found myself wondering when to apply the Murphy's - should I have dried the pelts somewhat after neutralizing the acid, or just spread it on immediately after rinsing the baking soda solution away? And how generous should I be with the Murphy's - just a light brushing-on, or pretty much douse the hide in it?

I don't wring pelts, but I will gently squeeze as much water as I can out and then use towels to dry it even more. You definitely want those babies to dry as fast as possible. I had mine in front of a fan the whole time.

As to the amount of oil soap, I used a light brushing-on. I didn't really feel it was enough after breaking it, so I soaped it a second time and used more. Obviously, that isn't something you can do with a slipping pelt.
As it actual instructions...Your on your own! :razz: I don't have a method, since it was just an experiment to see if it was even possible.

Currently I have four pelts from a proper vinegar pickle just starting out in Rittel's EZ-100 tanning agent. I'm excited about those! And more pelts in vinegar, alum, or Saftee acid on deck. It just takes so long to flesh them all...

Oh, I can't wait to hear how they all come out! I hope no more of them slip on you, but don't be discouraged if they do! I know how it can feel after spending so much time skinning, fleshing and money on supplies just to see the hair fall out in your hands when it's almost finished. We all have had to go through that at some point.

You should have seen me crying when all the hair fell out of that caribou.

 

[alforddm]

Sorry to bring an old thread back up to the top but as a soaper I thought I might could add some additional perspective.

Murphy's soap oil is a soap with a high % unsaponified oil (tallow and citronella oil) and some other ingredients. Thus, if you test the ph, I bet it will probably be about 9 or 10. I wonder if this is a factor in the tan? If it is you will have to be especially careful to neutralize any vinegar or acid before you try to tan. Acids and bases produce heat when they react not to mention possibly neutralizing each other to the point of being ineffective.

 

[Zass]

Yep, I just checked The PH is 9.

One should always thoroughly neutralize any pelt that has been in acid.

Even without a soap as the "tanning agent" the acid would corrode the leather over time.

(baking soda and water are the standbys, because it's cheap, effective and readily available)

 

[JessiL]

Thanks for chiming in, Alforddm. Back when I tried the Murphy's, I wasn't well informed as to what the acid step was for. So, to clarify, if one was to hold a pelt at the proper pH in whatever acid one chose, could you then "tan" it acceptably with Murphy's (after neutralizing the acid)? I'm willing to try it again with a couple of not awesome pelts.