Mineral oil bad for leather? Or good? Or neutral?

[SUP]

@fredk Yes of course. A proper experiment.  I don't mind your mentioning all the steps to take. It has been a while since I even stepped into a lab. Good to be reminded. I will measure  and maintain proper documentation. Just a tad busy right now so will probably get everything set by Sunday.

I have been investigating what is used to oil-tan leather - it is not really tanning as much as a treatment of chrome-tanned leather, where the leather is immersed in oils/fats. What I have discovered  is that in earlier times they used to use fish oils but now use synthetic oils and complexes. I plan to call a leather store here to see if they can direct me to someone who can give me more information. Since oil-tanned leather is already well exposed to and impregnated with oils and waxes, our results will be skewed unless we know what is used, at least in the leather I use. So I will start with veg-tanned leather and do the oil-tanned leather if I get all the relevant information.

@chuck123wapati welcome to the experiment. Tallow is something to which I do not have access, so that is a welcome addition,

The surface on which the leather is kept will be a part of the documentation.

I think, @fredk, once we have everything set, we could share  procedures, so we all follow the same methods. 

 

  

 

[fredk]

Tallow is something I cannot get or make. Due to the UK having BSE* in cattle a long time ago its illegal for butchers to sell beef fats and other parts and even porcine fats and parts are restricted but for another reason

But I may be able to get pork fats, but not for a while

Anyway, I have enuf oils to test

I don't think we need copy each other's tests, but I think they'll be similar anyway. 

I'm off to the shops soon to get supplies

 

*BSE = Bovine Spongiform Encephalitis

 

[Sheilajeanne]

10 hours ago, fredk said:

But I may be able to get pork fats, but not for a while

Fred, all I need to do for that is to fry up a pan of bacon!  (and strain out the bacon bits afterwards.)

Not so very long ago, farmers never thought of buying fat at the store. It all came from their animals - tallow from cows, lard from pigs, goose grease, etc. And the indigenous leather supply company I sometimes buy hides from has an ample supply of bear grease, which, unfortunately can't be shipped outside of Canada. 

Excellent research on the bees, Fred! Well done!

[SUP]

@fredk, no we don't need to mirror the experiments but they need to be similar and, like you said, probably will be. 

Animal fats like tallow, bear grease etc. I leave to others. At the most, I can do lanolin, which I do use in my leather conditioner anyway.

@Sheilajeanne, won't bacon fat smell of bacon? So the leather will too. And an invitation to mice and rats?

[Sheilajeanne]

Sup, yes my thought exactly. But how is it any different from pork fat (lard)? Or beef tallow? Even neatsfoot oil is just processed fat from the lower legs of cattle: 

Quote

The lower legs of slaughtered cattle (less the hooves) are boiled, skin and all. The fat that is released (as an oil) is skimmed off, filtered, and pressed. The first pressing is the highest grade; the second produces both a lower grade and a solid press cake or stearin product used, among other things, to make soap.^[1] 

 The fact it was processed didn't stop the mice from nibbling on my tack! 

I looked up how to make pork lard for cooking. You can do it yourself. You basically put the pork fat in a strainer, and heat it in the oven for 4 or 5 hours, with a Dutch oven or other large pot underneath the strainer to catch the fat. That's all there is to it - just make sure all  cracklings are removed.  

We've come to expect that everything we buy in the store goes through some sort of complicated process before being sold. And that isn't always the case. https://www.daringgourmet.com/how-to-render-lard-and-why-you-should-use-it/

Edited September 23, 2023 by Sheilajeanne

[SUP]

@Sheilajeanne I have no idea how bacon fat is different from pork fat -  it is the same thing! Probably the smoking of bacon gives the fat that smoky fragrance as well.

Neatsfoot oil smells unpleasant to me, but I like the use of it, so I use gloves when using it. If not, I feel  the smell remains for hours, no matter how much I wash my hands.

That is so true about processing fats. Everything is made, for the most, part, as it has been made for centuries, except for the  packing and the exorbitant prices!

I also plan to add mink oil to my list.

 

[fredk]

I hadn't even thought of lard. Any amount of fat I get from my cooked bacon is not enuf to fill a teaspoon.

Bacon and pork are just the same, one word is derived from the original Anglo-Saxon for pig and the other is derived from the original Norman-French for pig. The same for almost anything about cows

Anyway, I can buy lard in the supermarket. I think its beef lard though as the shops here are catering more and more for the Jewish and Muslim shoppers. Its actually getting harder to buy anything pork-ish in some of our supermarkets.

I think the lard has salt and food preservatives added. But as we are testing commonly available oils that might be ok

4 hours ago, SUP said:

I also plan to add mink oil to my list.

ah, good on yer. I never considered  mink oil. I even relocated several tins of it just on Friday too!

Just another thought; all leather test pieces should be about the same thickness. Yet another variable! I mostly use thin leather. I do have some up to 11oz /4.5mm but my stock of leathers is mostly in the 4oz  to 6oz / 1mm to 2.6mm thickness range. I think I'll use about 2.4/2.6mm thick. And I'm down sizing the test pieces. 6x4 inches is not necessary. Half that size should be big enuf, maybe even just 3 x 3 inches would do

edited to add a PS

This is gonna take up some leather. Make shure you can spare it

Also, the same oil may react differently to a  piece of the leather of a slightly different area. eg when I was making some coin purses all the parts were cut from the same hide. I marked some pieces which were from right next to each other on the hide. When it came to the dyeing they came out different shades, one part might end up a bright green and the other part dark green. On some that I dyed 'light' blue some parts were bright blue but their matching part almost a midnight blue. All dyed at the same time and in the same way with the same dye

The oils might do the same. But we shall see

I have to do some rivet sorting today

Edited September 24, 2023 by fredk

[SUP]

About the leather, I am using 5oz leather, so about 2mm. I am using relatively good leather. but not the best. I have made the pieces of 3 inch by 3 inch size. That should be sufficient, I think.

I have experienced the same thing that you have, with dye.  I plan to apply the oil and wipe away any excess after a set amount of time, maybe 5 minutes. I will label each piece and note the extent of absorption as well; I will not be able to quantify the extent of absorption though, except in the most general of terms. Let's see. We will surely have to modify some of the steps as we go on.

I know bacon and pork are the same but a world of difference in the taste!  I love bacon but not pork in any other form. And don't start on shops catering to one community over others.  Why some think they are more important than others is beyond me and why others listen is an even bigger mystery. Hindus don't eat beef but we do not object to others eating it or it being sold in stores. We just don't buy it. Why can't other communities do the same?  

Leaving that topic aside, and back to leathers and oils.

I will do the sets for mineral oil and neatsfoot oil today and then need to be away for a week or so, so incommunicado. Will continue, both in this thread and the experiment, when I return.

 

[chuck123wapati]

so i cut 5 pieces inch square. then used 1/4 teaspoon of each which turned out to be to much so i soaked some off with a paper towel. Then I applied neets foot oil to the one marked peanut oil, lol switched those around, then ran a thread through all and hung them in my green house. 

1 Neets foot oil

2 peanut oil

3 feibings golden mink oil

4 elk tallow

5 control piece.

NFO and peanut oil are both very light oils so soaked in nicely. The tallow and Mink oil had to be heated with a hair dryer. I can tell already the elk tallow is way to heavy on its own as a liquor for leather however it may work well as a mixture with lighter oils as a water proofing. The golden mink oil I believe has a good portion of petroleum jelly in its mixture.

[chuck123wapati]

12 hours ago, SUP said:

@Sheilajeanne I have no idea how bacon fat is different from pork fat -  it is the same thing! Probably the smoking of bacon gives the fat that smoky fragrance as well.

Neatsfoot oil smells unpleasant to me, but I like the use of it, so I use gloves when using it. If not, I feel  the smell remains for hours, no matter how much I wash my hands.

That is so true about processing fats. Everything is made, for the most, part, as it has been made for centuries, except for the  packing and the exorbitant prices!

I also plan to add mink oil to my list.

 

bacon oil has nitrates and or salt in it which will have a negative effect on leather  imo. plus it usually burns to some degree in the frying process Lard and tallow are rendered by boiling in water so burning doesn't happen.

[fredk]

You're both well ahead of me!  

I'm still getting organised. I got to a shop this morning and picked up a block of lard 

I'll be back, later, dudes   

[SUP]

@fredk that's okay. This will be such a long term experiment, a few days delay will not make much of a difference. So take your time. it should not be a burden.

[TomE]

8 hours ago, chuck123wapati said:

 Lard and tallow are rendered by boiling in water so burning doesn't happen.

I thought the main reason to use tallow instead of lard is that tallow resists oxidation/going rancid. 

[dikman]

Yep, tallow lasts almost forever. I made mine from suet (from sheep), the butcher gave me some, I used an electric slow cooker and cooked it on low for a few hours then poured off the liquid which cooled to a nice milky-coloured slab. The remaining bits didn't taste too bad either. I still have some that is nearly 10 years old, the shed it's stored in has gone through hot summers (up to 40C) and cold winters (near 0C) and it hasn't affected it. 

[SUP]

Back. Got everything ready with mineral oil, neatsfoot oil and mink oil; not sesame seed oil yet. Will do that soon.

Also trying to determine what oils are used these days to process oil-tanned leather.  I know it used to be fish oils and some probably use it still, while others use synthetic compounds, my research suggests.   Spoke to people where I get my oil-tans from - Springfield leather -  Angela  has to contact the supplier for that specific  information. Very helpful people at Springfield leather and it is Kevin from Springfield leather who confirmed that fish oils are used in oil-tanning treatment.

Once I know more, I will decide if it is worth while adding oil tanned to my list of leathers to treat with the oils.

[fredk]

I'll update later

[fredk]

The oils I'm using; NFO Compound, Baby Oil, Vegetable Cooking Oil (Rape Seed Oil), Extra Virgin Olive Oil, Lard (pig fat) and 3-in-1 oil

My test squares are 8 cm x 8 cm, about 3 inch x 3 inch. Each piece has one hole punched in one corner, this is for set #1. Set 2 will have 2 holes punched there. Each piece has a number of holes punched in another corner; 1 to 6 holes, which correspond to the oil used on it - see further down. Leather is approx 2.2 to 2.4 mm thick, about 5 - 6 ounce (?)

The index of my note book; I use coloured paper clips as page markers in books. One extra section in case I decide to add in another oil. Details of each leather & oil combination will be written down in each corresponding section marked by the coloured paper clip

The leather squares, shortly after being oiled. Oil was applied using a clean piece of sponge for each oil

These were put into my special car just as you see them laid out here. They went in at 23.00 on 10/1. In the car they'll stay dry but get the full sun on them thru the day and chilled at night. I'll need to check the temperatures.

Looked at, but not inspected, in the morning of 10/2 & 10/3

I'll need to make a frame so I can hang set #2 up outside. I think I can get that done this coming weekend

Comments?      Ideas?     Suggestions?

[SUP]

@fredk I like the idea of the different numbers of holes. I will do the same. 

I think you have covered everything.

I am using 5 oz leather,  cut into 3 inch squares. Also using coconut oil instead of Sesame seed oil. I want to check if the rancid smell disappears or can be masked.

So I am testing 4 oils - neatsfoot  oil, mink oil, coconut oil and mineral oil. Planning to also check the effects of orange oil - I have the food grade variety and use it for all my cleaning. Very effective. Want to know its effects on leather as well. I will use it undiluted on one piece and if it does show damage in a week, since it is a solvent, I will use it undiluted, else will dilute it with mineral oil.

I applied the oils with a kitchen paper towel. 1/4 tsp was just about right for the 3X3 inch pieces. 

The control pieces are all with my rolls of leather, in the house - temp controlled, humidity controlled, at least relatively.

The ones in the car that I use regularly, I am keeping in an open box, exposed to light and darkness, heat and cold, car movement. And whatever else there is in the car!

Outside, they are also kept in a box, on paper towels, exposed to the elements.

In the garage, they are kept in a flat layer in an open box.

I keep all my information on my computer in an Excel spreadsheet.

[SUP]

Oops! if orange oil does NOT show damage, I will use it undiluted, else diluted with mineral oil.

[fredk]

First report from me; 13.15, 10/05

Initially all the test pieces curled up a wee bit, then they flattened out, as they did their colour came back to almost the non-oiled look. Just a faint trace on a couple.

I'll check the pieces again later

Edited October 5, 2023 by fredk

[SUP]

Yes, mine have curled up a little too, all of them. Will see what happens over the days.

[fredk]

10/8 18.30. Almost 1 week on

None of my pieces have any smell nor any growth of anything on them, which I will loosely call 'fungus'

Piece #3, Lard, is slightly stiffer than Control

Piece #4, NFO Compound is slightly stiffer than Control and is very slightly stiffer than #3

Piece # 6, 3-in-1 oil, is noticeably stiffer than Control and #3 & #4 

All other pieces seem to be equally flexible as Control. But these, including Control are slightly stiffer than the leather they were cut from so I'll have to have a #2 'Control' in my leather-working room 

I've not yet sorted the #2 set for hanging up outside

[chuck123wapati]

ditto nothing really new, this will take some time.

[fredk]

Anyone testing Vaseline?

That might be my mystery #7  

[SUP]

I missed last Sunday and decided to move to this week-end directly. This is what I observed:

Mineral oil – darkens a little, remains smooth, does not curve in any of the sites.

Mink oil - Slight darkening, slightly dry, slight curvature with drying, not always smooth.

Neatsfoot oil – significant darkening everywhere, maintains flat, smooth, soft texture except when exposed to continuous changing environment in the car.

Coconut oil – smell disappeared within 2 days of application; darkened the leather the most everywhere; slight dryness everywhere.

 

At this point, mineral oil has the best effect. It darkens very slightly, remains smooth,  does not significantly soften or harden the leather or deform it in any way.

Mink oil also does not darken very much but dries the leather slightly.

Neatsfoot oil darkens as expected but the leather remains smooth and flat for the most part.

Coconut oil darkens the most but also dries the leather.

 

There is no fungus or any type of damage to the leathers at this point.

That is my report for this week.

 

I had planned on adding Vaseline but could not find it. I will look for it this week. 

 

 

 

 

 

Edited October 16, 2023 by SUP