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

[MikeRock]

Fred,

Do you use Castrol in your Austin?  Sure loved the smell when I was racing bikes...  I wonder if the castor oil addition makes a difference on your leather auto straps?

[fredk]

I do use Castrol in my Austin engine. But it doesn't get any where the straps on the outside. Its getting hard to get now though

@SUP 60 -70 mph winds and weak hempen twine

[SUP]

@fredk, like during the monsoons in Bombay, now Mumbai. 'Curl up with a good book and a cup of hot tea and biscuits' weather, we called it, while the wind rattled the windows and palm fronds lashed violently.

[fredk]

They would be very strong but as ex-postie I enjoy being out in the wind and rain

[SUP]

I understand that! In my teens, my friends and I used to walk along the shore in that rain and wind. Rocky shore, so not much sand to contend with. Else that would not have been possible. But great marine specimens to be found post- storm!

[ThisIsMyFirstRodeo]

MOD any chance we can make this a sticky?

There seems to be some solid data and observations gathered through scientific method, both supporting and debunking various anecdotal hypotheses/practices, and  I already see them being invaluable resources that I will continue to refer to. 
I know there were others contributing as well, but props to FredK. Have you by chance assembled a compendium of your research/experimentation?
 

I also want to add in that the historical practices also have much to learn from. Again, I know others contributing to the conversation, but thank you Aventurine. Any particular go-to sources that you pull from? I love learning about the history and foundations of my various hobbies. 

Edited September 8 by ThisIsMyFirstRodeo
Give credit where credit is due

[fredk]

Here we are; 1 year completed (more or less)

September 30 2024

Set #1, the car set - Pieces treated and kept on the top of the dash in the south facing  windscreen (windshield) of a car

1. Baby Oil; Both sides are very dark, More flexible than Control 1 (C1), No smell,  No sign of rot or fungus

2. Cooking Oil (rape seed);   Both sides very dark, Slightly more flexible than C1, No smell, No sign of rot or fungus

3. Lard (pork fats);  Light but darker than C2, Slightly more flexible than C1,  No smell, No sign of rot or fungus

4.  NFO Compound; Both sides very dark,  Flex is better than C1, No smell,  No sign of rot or fungus

5. Olive Oil ( Pure Extra Virgin); Both sides very dark, Flex is only slightly better than C1, Slight odd indistinct smell,  No sign of rot or fungus

6. 3 in 1 oil (benzine); Both sides very dark, but back less so, Flex is stiffer than C1, No smell,  No sign of rot or fungus

7. Vaseline; Very slightly darkened both sides, Flex is slightly stiffer than C1, No smell,  No sign of rot or fungus

 

Set #2 were hung outside on a wood frame. They got light and heavy rain with periods of sunshine,  warm overcast and wind, both light breezes and strong winds

The same oils were used in the same sequence . Control C1A was hung with the other pieces

1. Baby oil; Both sides are very dark, Flex is better than C1A, Slight smell of leather  No sign of rot or fungus

2. Cooking oil;  Both sides very dark, Flex is very slightly better than C1A, No smell, No sign of rot or fungus

3. Lard; Both sides slightly darker, Flex is about the same as C1A, No smell,  No smell, No sign of rot or fungus

4.  NFO Compound;  Missing, blown away

5. Olive oil;  Both sides and fairly dark, Flex is better than C1A,  No smell,  Grain surface feels oiled, No sign of rot or fungus

6. 3 in 1 oil;  Both sides are now a very dark brown, Flex is better than C1A, No smell, No sign of rot or fungus

7.  Vaseline;  Both sides very slightly darkened,  Flex is only very slightly better than C1A, No smell, No sign of rot or fungus

None of the pieces seem to require re-oiling

All but 1 test piece have a neutral smell, or none.  That 1 piece, #5 of Set 1, the slight odd smell is so very faint and its not a bad smell therefore I'm not worried about it.

#4 of Set 2 went AWOL just the day before  I brought the pieces in to record them

In conclusion; No rot or fungus. Just the loss of smell - either of leather or of the oil used. The darkening of the leather by some oils and greater flexibility by most

I think thats it for now

 

[SUP]

Thank you @fredk.

My one year update is long overdue. Strapped for time.

I am keeping watch and all leather appears unchanged from last time. The detailed descriptions, I will be able to get to it by late Oct or early Nov.,2024.

[fredk]

I was thinking no-one was interested in this anymore      

I look forward to your report, whenever you can make it  

[SUP]

Oh, I am interested. I am watching the leather pieces as well. 

A lot going on right now so I don't have the time to make the tables and give the careful descriptions that I like to do. Ergo the delay.

I will be interested as long as I live, I think. it is that sort of experiment.