Leather smell loss + skin safety - dyes, oils, finishes.

[BadDog]

Hi,

I fell in love with the smell of leather. Started creating on my own with scrap leather and enjoyed it as well. My intentions for the further projects are:
- using veg tan leather
- items worn on naked skin (bracelets, harness, armor, sandals, eventually even garment; 3/5/8 oz) - that means stronger requirements for dye/oil stability, skin-safety.
- staying as close to low ecological footprint in general

I tried with couple of samples, several types of colors, even oils. Here are some problems and questions I'd like to ask for help with:

Dye:
- EcoFlo water based dye, Fiebing's Institutional dye - primarily experimented with water based because I expected the resulting product would be more skin-safe. Though the leather (any thickness) hardens quite a lot and the dye smell is dominant even several days after drying
- EcoFlo Oil Dye - leather gets nicely softer, some color smell perceptible. I guess this one is less-ecological and less-safe if it is worn on the skin? (+sweat, weather)
- ROC dye (Danish brand) - good color results, color smell quite perceptible. Not eco at all I guess, possibly more harmful on naked skin?
1. Does the dye smell eventually subside?
2. What's you experience with garment-grade final products - any staining, skin allergies etc? Should I avoid certain type of dyes, oils, finishes?
3. Did you ever have good experience with this combo: water based dye > 1 day's drying > oiling?

Leather softening:
- Neatsfoot oil does not do miracles with dye smell (it stays), but it has its own smell that is way too heavy. Marrow bone. Beef soup. Totally suppressed any trace of natural smell of leather. Does not subside that much even after days.
- Brilliant Oil (mixture of 6 vegetable oils + neatsfoot oil) - somewhat nicer, but 3x more intense "perfume-like" "brilliant" odor that reeks from leather. Leathery smell I sought for: gone.
- Coconut oil - slightly heated up, penetrates easily, surpisingly neutral (I really do not want my leather to smell like coconut cake), though I have no clue what will happen to the leather in long run.
- Olive oil (EVOO) - slightly heated-up, yet to see (sniff) if any of that "olive"/"acid" smell of EVOO remains.
4. Does the neatsfoot oil odor eventually give way for the leather to smell like leather again? How long does it take?

Heating:
5. Do you have any experience/recommendations on heating the oil before application? Does it make it more prone to gone rancid in the feature? As I have tried, it penetrates the leather much faster and allows better control not to drown the leather in oil. Some craftsmen recommend even 120C/248F.

Oil dye:
An interesting thing happened after using EF oil dye (perhaps too much), drying, and then NF oil (perhaps too much) - in next day the leather was leaking oil+color heavily.
6. Does the oil dye actually ever set in the leather? Will it always (even with more cautious dosage) leak? Will it affect naked skin?

Dye+oil:
Another recommendation I found was to immediately mix NF oil (this time cold) with oil color (others just do-not-work, even non-water based ones) - and thus dye & soften/oil it simultaneously, in careful doses, with rag. 
7. Any experience here? Any chance of ruining the color, chemically? Any chance of dye not stabilizing in leather and future color-leaking from the leather garment?

Finish:
I will experiment with Fiebing's Institutional Leather Finish and Carnauba Cream - I do hope these are more-or-less natural & skin-friendly.
8. Any other recommendation for garment-grade finishes ok for bare skin?

Flesh side:
9. Do you apply a) dye, b) oils, c) finishes - only from the top grain side, or also from the flesh side - that will be more probably in contact with the skin when worn?

So far my experience with purchased leather items was ok, except one pair of trousers, that used to leak black dye and stain my legs that I could not wash afterwards for days. I would like to avoid creating this situation again.

[LatigoAmigo]

4 hours ago, BadDog said:

Here are some problems and questions I'd like to ask for help with:

Because there are so many types of leather and tanning processes, there could be more than one correct answer to your multiple choice questions. If you seriously want a response to these (too) many questions, you might try to target them to the various categories on this forum.

[BadDog]

This is not that diverse set of questions as it seem. It relates to correct application of the dye/oil/finish and the question of smell (particularly of the dye/oil). The type of leather should be pretty narrowed down by my statement that it is veg tan (cowhide) leather.

[tsunkasapa]

Sadly, the "leather smell" fades with time, just like "new car" smell. As for the smell of what you put on the leather, they too will fade, some just takes longer.

There is nothing I know of to preserve the "smell" you are trying to capture. Even SKUNK fades away with time. 

[Sheilajeanne]

I know from long experience with NFO and horse tack that the oil will penetrate better if slightly warm. Pure NFO actually solidifies slightly at low temperatures! 

When oiling an abused bridle or halter, I used to warm the leather with my hand after applying the oil to help it penetrate. Since it's a pure animal product, getting it on your hands is actually GOOD for the skin!  But make SURE it say 'pure NFO'. The other type has petroleum chemicals added to it which I would NOT want on my skin, and which also help rot stitching over time!