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

[Wepster]

As this thread progresses, I think we should keep in mind, thread. As we condition leather products, what ever we use is also affecting the thread. I doubt olive oil would affect the stitching, but other products might, as most threads seem to be synthetic. So, perhaps these experiments should be on stitched leather (and stitched with various thread types).

Good luck. I will keep following this thread. I certainly do not have any answers.

Hmm, I wonder about the Scandinavian soap finish (used on floors and furniture) would fare on leather? Cheap, natural (depending on your definition), used on human skin. Don't know what it would add or protect from though (but it does have the word "finish" in it).

[ScottWolf]

18 hours ago, SUP said:

@ScottWolf I have discovered that mineral oil  makes leather shine. I was not sure of the sealing properties but that becomes icing on the cake as we use it last when getting a shine anyway

I am going ahead with making a conditioner with mineral oil - what I have is food grade. If the leather deteriorates over time, I will leave instructions in my will for that information to be put up here.

 

 

 

So, I would direct you to my post in the forum here that I made about an actual leather conditioner recipe and the subsequent posts in that thread that have been made since I first posted it.

CONTEXT. That is something that seems to be glossed over in threads like these in leather forums. Some people only deal in absolutes and refuse to acknowledge any differing information or they simply parrot things they have heard /read about.  For example.... " I don't use "X" ingredient because my sisters brother cousin said it goes rancid and Larry the Legendary Leather maker guy said the same thing" 

OK, lets look at this critically and put it into context, because that where an ingredient like mineral oil falls into. First off the term "rancid" is actually referring to an ingredient oxidizing and not necessarily going bad like meat or milk or any other food item turning rancid. While some ingredients can actually do just that, and this is where the context comes in, those ingredients are usually not used solely by themselves on leather, they are used in combination with other ingredients that actually retard and or prevent said ingredient from oxidizing. Natural preservatives like beeswax, Vitamin E, etc are all ingredients used in A LOT of commercially available products along with ingredients like Mineral oil, if one takes the time to read product MSDS's.

Neatsfoot oil (NFO) is actually a good example to use. Used in excess and by itself, can and will oxidize and form into hard crystals that sit and abraid in between the leather fibers and cause it to degrade over time. Not opinion, scientific fact. However, used in moderation and or combined with other ingredients, those negatives are negated and the item will likely wear out before those negative effects occur or are ever seen. Neatsfoot compound is something I've not seen recommended in leather forums for some time, as it's typically made for use on machinery as it does have a higher concentration of petroleum ingredients and other undeclared ingredients in it that can be harmful to threads, etc. To further put things into perspective, LEXOL is a popular product used by some but it is simply Neatsfoot oil if you look at the MSDS. The interesting part is that it is 80% water, 5-10% NFO and the remaining ingredients are preservatives/stabilizers that keep an oil and water from separating from one another. So in reality, very little NFO is actually being applied to a piece of leather when products like Lexol or other NFO based products are being used. The same holds true for products that have mineral oil or a petroleum based ingredient in its mixture. 

As I stated in my initial post, mineral oil  forms a barrier and isn't actually absorbed into the leather like an actual conditioner ingredient would be. So it's a really poor leather conditioner compared to other ingredients commonly used in commercial products like Tallow, coconut oil,avocado oil, almond oil, etc. However, it is useful in sealing in moisture and oils that those other ingredients are known for and adding a shine. This, combined with those natural or man made preservatives and used in moderation in the ratio of ingredients is why you find a good deal of commercial products have a mineral oil/petroleum based ingredient in them (not all obviously).

 

Like many things, if used in moderation and not strictly by itself, but with other ingredients/preservatives, mineral oil as one of several ingredients in a product is not going to prove detrimental to the life of the leather itself.

 

Edited September 20, 2023 by ScottWolf

[kgg]

On 9/19/2023 at 4:11 AM, SUP said:

Why do so many people say mineral oil is bad for leather? 

What I do for my work boots and I'm no expert is I use 100 percent JOJOBA cold pressed oil and white food grade mineral oil. I rub about two ounces of JOJOBA oil per work boot oil into the leather and let it get absorbed then I apply about six ounces of mineral oil in and let the boots sit overnight. Seems to work at making the boots water resistant, softens the leather and seems to add back some moisture into the leather. The downside is that the tan colored leather will be darken but for a work boot I don't mind. The JOJOBA oil is probably the closest thing to sperm whale oil.

kgg

[SUP]

@ScottWolf that is exactly the point @fredk made earlier, that people blindly repeat  what they have heard, not necessarily from  their own experience. If you wants to hear the actual voice of experience, you need to have worked with leather for years and remember what was used, several decades later, to know what was or was not detrimental to it, and there are so many other factors that can damage the leather as well. I, for one, am too new to leatherwork and will be long dead and gone before many decades have gone by. Ergo my comment about instructions in my will.

It is not a matter of refusing to acknowledge information as much as the widely present views of today - " I saw it online, so many people online said it, so it must be true. Even if you say different, so many online say so, so I believe them'.

About oils turning rancid, it is the smell or texture that is unpleasant most often.  Besides I do not know what the products of those oxidative processes are and they may affect the leather, or not. 

Additives will retard or prevent the oxidation of oils but then, you have to have the correct proportions of the additives for preservation, else it is pointless. That becomes another chemistry experiment. 

I should think anything used in excess would cause some issue or the other, excessive softness or even remaining on the surface causing greasiness. 

Like you said, most commercial products, if you read the MSDS, contain many of these oils and waxes . I have been reading them up when researching leather conditioner recipes.  It is a little amusing when people refuse to use neatsfoot oil or mineral oil or petroleum products and then swear by products with these very ingredients. 

 One thing I have noticed is, when people say that leather deteriorated, it is often the threads which rotted away.  Natural fibres deteriorate faster than leather, naturally. That happens even in ordinary cotton clothes with cotton or linen thread. Cotton and linen themselves deteriorate over time. I wear a lot of cotton and some of my favorites are not usable 20 years later. That is all the time it it takes.  No one uses any oils on ordinary clothes!

Leather itself falls apart sometimes but I suspect that is because of excessive oils or the way it is used.

Not knowing what causes the damage, the easiest to blame is the oils used. Commercial companies with ulterior motives push this further and a myth is born.

To debunk this, our experiments with leather might help just a little. Putting in a few stitches with  cotton and synthetic threads is a good idea. 

@kgg  that is good information about jojoba oil. It is said to have a composition similar to skin oils. You are talking from personal experience.

@Burkhardt which vegetable oil do you use?

I hope others join @fredk and me in this experiment, using oils  and scraps they have at hand. 

 

 

About mice. Please don't remind me. My cat caught one and placed it behind me on the sofa. It fell behind the cushions and I found it a while later while cleaning. It has nearly petrified within a few months. Evidently in that place it was deprived of air. Not a pleasant experience.

Mice will eat anything and are smart too, and cute. I always hear people squealing about their cuteness - does not deter from their unpleasant pee and stealing and chewing habits!

I believe the smell of cloves deters them.. No idea if that is true and I do not  I want my leathers to smell of it.

Edited September 20, 2023 by SUP
Correction of errors.

[SUP]

The deterioration of leather and the thread happens over time. I I will apply the oils on the leathers and keep them somewhere safe, and check through the months, with periodic updates if there is damage. @fredk what do you think?

 

Incidentally, does anyone have natural fibre threads that have deteriorated without use? I know my regular stitching thread does so, and I have no reason to expect otherwise from thread used for leatherwork. 

[kgg]

2 hours ago, SUP said:

About mice.

What a lot of RVers use to deter mice is use bounty dryer sheets. Before using them spring always brought a surprise after the winter and not a pleasant one. No matter what I done the little buggers would get in and destroy something in either the engine bay or inside the RV. The solution was the bounty dryer sheets and laying them everywhere, in cupboards, under seats, glove box, engine bay, under carriage storage, etc. The end result was no more mice just normal spring cleanup before the next trip.

kgg

[SUP]

@kgg and better smelling too.

[billybopp]

41 minutes ago, kgg said:

What a lot of RVers use to deter mice is use bounty dryer sheets. Before using them spring always brought a surprise after the winter and not a pleasant one. No matter what I done the little buggers would get in and destroy something in either the engine bay or inside the RV. The solution was the bounty dryer sheets and laying them everywhere, in cupboards, under seats, glove box, engine bay, under carriage storage, etc. The end result was no more mice just normal spring cleanup before the next trip.

kgg

Rodents HATE the smell of peppermint as well - they make a peppermint oil-based rodent repellent that you can buy, even ....   Sometimes it's the simple things!

- Bill

[chuck123wapati]

To think the effects of various oils on leather has never been considered is silly, its been studied for centuries,  you just have to look for the research its a multi billion dollar industry. Here is one i found in about ten minutes. I will add you will have to find old studies for reliable information, any new info will be tainted by the climate change agenda so I'm sure fossil fuel derived oils will not be on the top ten list in any new publication.

https://www.researchgate.net/publication/339328369_Leather_and_Textile_Uses_of_Fats_and_Oils

I have more but my links were dropped when i re-set my box. 

[fredk]

3 hours ago, SUP said:

The deterioration of leather and the thread happens over time. I I will apply the oils on the leathers and keep them somewhere safe, and check through the months, with periodic updates if there is damage. @fredk what do you think?

Good plan. I'll sew some of my usual threads into the leather. But most of my thread is bonded nylon which resists most chemicals and lasts a long time. About 10 years ago I cleared out my father's fishing tackle box. One reel was still full of bonded nylon line. It was from about 1956 (supporting evidence) and was soaking in some sort of oily mixture. After cleaning the nylon line was still usable. Test strength was about 50lb. I used it as leader for beach casting for several years

3 hours ago, SUP said:

Incidentally, does anyone have natural fibre threads that have deteriorated without use? I know my regular stitching thread does so, and I have no reason to expect otherwise from thread used for leatherwork. 

yes. recently I found in the back and bottom of my spare threads drawer several, 8 iirc, wenzels of linen thread from when I started leather working 23 years ago. Each card had about 10m of thread, black, brown and white. I'd bought them from Le Prevo. Some of each had deteriorated. As I unwound the thread off the cards the thread came apart in short sections, and the ends of those sections were separating into individual tiny fibres