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

[fredk]

I can tell you more tomorrow. One piece has been out in the rain since the start of March

[SUP]

I'll wait for your input.

[fredk]

Not a proper report

8 pieces have been hanging outside. It been raining a lot here, including today

All the pieces except vaseline show darkening caused by them soaking up water. The vaseline one is still as light coloured as a non-treated piece. It also show a little  of repelling water. Its lost its slickness which it had before. Other pieces also show water repelling but they are showing as having absorbed water, not a little but a lot, as much as you'd want for wet moulding

Therefore, it looks like vaseline can be water repellent or a mild waterproofer. I'd not dare venture to say it is a waterproofer

[SUP]

That's good information. I will use Vaseline on several pieces and check the extent of water absorption over hours and days.

Right now, I have applied a mixture of mineral oil and coconut oil (10%) to new leather pieces and kept them with the others.

I will prepare a new set for the Vaseline. I need to also record the thickness of the leather very specifically for each piece too, not just a generalized 5oz description.

Today, it is bright and sunny outside. Hope it rains soon.

[fredk]

7 monthly report. 26th April 2024

Pieces treated and kept on the top of the dash in the south facing  windscreen (windshield?) of a car

#1; Baby Oil;  Colour = Dark, Flex = Stiff 7/10,  Smell =  No Smell,  Other (fungus, deterioration ) = 0

#2;  Cooking Oil (rape seed); Colour = Dark,  Flex = Stiff 7/10 ,   Smell = very slightly 'leather',   Other = 0

#3;  Lard (pork fats);Colour = Light, lighter than Control #1,  Flex = Moderately stiff 5/10,  Smell =  A hint of oil,  Other = surface feels a bit 'greasy'

#4; NFO Compound; Colour = Dark, Flex is good, 4/10,  Smell = neutral, Other = 0

#5; Olive Oil;  Colour = Dark, Flex is good 3/10  Smell = very slightly of oil,  Other = 0

#6; 3-in-1 Oil;  Colour = Dark, Flex is stiff 9/10.  Smell = Slight smell of leather and a hint of oil,  Other = 0

#7; Vaseline;  Colour = Light, lighter than Control #1, Flex is stiff 6/10,,  Smell = faintly of 'leather'   Other; Surface feels very greasy

#8;  Control #1; kept with #1 to #7; Flex has stiffened, Colour = mottled light and slightly darish,  Flex = Stiff 7/10, Smell = Neutral, Other = 0  - 

Thats all for now

I'll be back soon with a report on the pieces kept outside, in rain,  sunshine and wind

[SUP]

@fredk That's a good report for a single location. For you too, mineral oil (baby oil) has stiffened quite  bit.

I have used Vaseline on several items that I made for home use - they get wet off and on but do not seem to absorb any. So for leather that will get wet for short periods, Vaseline is evidently a good water repellent.

It has not rained here recently, unfortunately. so cannot do the next test just yet. Keeping watch on the weather. As soon as rain I predicted I will start the Vaseline test. I plan to check after 1 hour in the rain, 2 hours and so on for a few hours, to see what happens. I will be very specific about the thickness of leather used, maybe use different thicknesses. Shopping trip tomorrow for that, methinks.

 

[fredk]

We are getting enuf rain for both of us!  Its raining in between the showers, and when its not raining it teeming down 

I think I will copy you and do several pieces of leather with vaseline on them. I, too, want to check the waterproofing

Having written that now the rain will stop for a few weeks!  

 

[SUP]

That is what happened here too.  

[fredk]

01:30

I just cut a piece of 1.5mm - 4oz into 5 unequal sized pieces and coated them liberally with vaseline, front, back and edges

Tomorrow, later today, I'll figure out how to present them to the rain (if)

[fredk]

I checked the leather. The vaseline has been absorbed into the leather leaving just a slight slickness on the surface

and, the weather forecast, and indeed, is for no rain. A weekend of cold & sunshine. 5% chance of rain  

[SUP]

 Yep. That is how we humans control the weather.

Another way is to get the car cleaned and waxed - it is sure to rain that day - did so even in bone dry Nevada!

 

Edited April 27 by SUP

[fredk]

There was a small amount of rain during last week but I was otherwise busy and never got the Vaselined pieces out. I got them out today but there is no rain forecast

[SUP]

They forecast rain this week but dry as ever although the air is very humid.

I have the leather ready. I live in hope!

[fredk]

There was misty rain this morning and I checked the vaselined pieces

Most strange; the control piece showed 100% water absorption, as expected, but the test pieces are in a range from 5% to 100% = 5. 10, 25 75, 100% 

I'll dry them and try them again

[SUP]

Oh. I wonder why. Do you think multiple layers of protection might work? I mean some oils or waxes and then Vaseline?

[fredk]

Might. But I'll stick with the vaseline on these. They had about a week for the vase to 'soak' in. Next time I'll put them straight out

[SUP]

Okay. 

[fredk]

Its been raining today. Not very heavy. I put vaseline on the pieces again and put them out

One piece after about 1 hour. Seems the rain is soaking in at the edges. The water is being repelled on the surface

Another piece after 1 1/2 hours. The rain has soaked in but its also being repelled on the surface

On its own and in one coat its not good at waterproofing but I think multiple coats, each allowed to soak in and be absorbed before the next coat is put on may be a decent waterproofer

I don't think I have anything to try out my thoughts. It would need a leather hat or a shoulder bag and I don't have anything like that made

[SUP]

I'll maybe make a small coin purse with veg tan ad try Vaseline on that. Let's see.

[fredk]

Excellento

[SUP]

I kept several pieces of veg-tanned leather with petroleum jelly , which I shall now call PJ, in the rain. These results are after a night long, heavy exposure. It rained heavily overnight and I could check the leathers only in the morning..: 

I used 6 pieces of leather as follows:

	Petroleum Jelly	Mineral oil
Control.	N/A	N/A
CM	N/A	Yes
PJ1	Yes	No
PJ2	Yes	No
PJM1	Yes	Yes
PJM2	Yes	Yes

 

Observations and conclusions follow.

Edited Monday at 02:54 PM by SUP

[fredk]

PJM1 is looking promising

What oil?

[SUP]

OBSERVATIONS:

	FRONT	BACK	EDGE
CONTROL	S, WD0, TN; FD	S,TN, FD	S
CM	S, WD0, TS, FD	S, TS, FD	S
PJ1	S-, WD, TN, FDRY	S0, TN. FDRY	S50, TN, FDRY
PJ2	S-, WD, TN, FDRY	S0, TN, FDRY	S50, TN, FDRY
PJM1	S, WD+, TS, FD+	S, TS, FD+	S
PJM2	S, WD+, TS,FD+	S, TS,FD+	S

The key: 

Soaking:		S = heavily soaked.
		SL= lightly soaked
		S- = surface water absorption
		S0 = no water absorption.
		S50= half absorption
Water droplets		WD=water drops present
		WD0= no droplets
		WD+ = Many water droplets
Feel of leather:		FD = damp
		FDRY = dry
Texture:		TN  Normal
		TS = soft

 

Control: Soaked through no water drops on surface, not softened. Sides clearly soaked through as is the back.

Control plus mineral oil: Darkened due to the oil, no water drops on surface, soaked through, sides and back are soaked as well. Noticeably softer.

PJ1: Darkened due to PJ, Water drops on surface, surface water absorption, sides show water absorption on surface, back dry, texture unchanged.

PJ2: Darkened due to PJ, Water drops on surface, surface water absorption, sides show water absorption on surface, back dry, texture unchanged.

PJM1: Darkened due to PJ and MO, plenty of water drops on surface, complete water absorption, sides show complete water absorption, back show water absorption, texture soft, leather feels damp.

PJM2: As for PJM1.

CONCLUSIONS:

It is clear that PJ does inhibit water absorption by leather, this inhibition being affected by other factors. Here, the mineral oil clearly decreased this water repellent effect.  Petroleum Jelly is not absorbed by the leather. It remained on the surface. When applied on plain clean leather, it stays in place and is an effective repellent. When applied on top of mineral oil however, the 2 greasy materials slide against each other and the petroleum jelly being on the surface, probably did not spread well and possibly got drained away by heavy water drops and left the leather vulnerable.

With a night of being exposed to heavy rain, the leather pieces with only PJ are still not soaked through. For short exposures, petroleum jelly appears to be a good water repellent.  

When and with what to use it and how to ensure it remains in place are the next questions.

I will next try to see if warming the leather after petroleum jelly application helps.

Unfortunately, although PJM1 and PJM2 both had plenty of water drops on the surface, they absorbed a lot of water as well.  Need to see how to avoid that, other than not leave the leather out in torrential rain all night!

[fredk]

Your PJ is different to my vaseline. The leather absorbed the vaseline

I'll do some more tests later

[SUP]

I'll go get the Vaseline brand of PJ and see what happens.