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

[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