Leather sweat band care?

Never noticed till now looking at this photo, being my most worn hat it's conformed to my noggin shape best. Off-topic slightly but I must be long oval as you can see looking at the sides and front/back on the inner hat band.
You can see some of the crown at brim level at the sides while stitching stays true front 'n back but you can see how it has come in at the side to meet my head and block.

 

On the Leather Doctor, I ordered the Hydrator and Fatliquor and applied them faithfully, but I did not get the Degreaser. I figured I wanted to maybe apply the solution to sweatbands in the hat.

My idea turned out not to be a good one. Roger Koh answers:

Hydrator-3.3 > Fatliquor-5.0 > Hydrator-3.3 system commences once the leather sweatband is free from grease and its pH balance to charge the leather protein fiber ionic positive (+ve) to hydrogen bond with the ionic negative (-ve) fatliquor (fat and oil).​

When the leather contamination from body grease that clogs up the fibrillary spaces, there is little room for the fat and oil content to make contact with the leather fibers.​

The sweat contamination shift the leather fibers ionic negative (-ve) as leather is an amphoteric material, thus it will need Acidifier-2.0 (with a pH value of less than 2.0) to pH balance the leather protein fiber back to the ionic positive (+ve) state.​

Fatliquoring works by hydrogen bonding, and pH value of the leather has to be conditioned to an acidic pH value of between 3 and 5 with the help of Acidifier-2.0.​

What I am sharing with you is the theory and practice of leather chemists in every modern tannery.​

The practice follows the proven theory and may go wrong when the preparation is not up to standard, as in this case.​

Bam. Bad Daniel.

The lotions went in as indicated, I thought all went well. Not so much.

Here is the test case failure. As you can tell, the sweatband was already in tough shape. I had already written it off before testing. At the end of treatment it seemed like it worked out well, the leather was softer and flexible. Then slowly it dried, thinned out, and came apart.

 

Thanks for the update even if poor results Daniel.
Yeah, i can see how the pH requirement not being met could negate any further reactions.
Nice try though.
That last picture with the thin crispy blackened bland looks like a Stetson 100 band i tried everything on to save. Heartbreaking.
B

 

Yes, I was not so sure about the pH requirement because the Hydrator and Fatliquor are already acidic. And this sweat was already toast, a good crash test dummy.

The liquids definitely entered the leather. The sweatband soaked up the Hydrator and got fat and wet. I applied the Fatliquor over as it dried, then the Hydrator again as a last step.

The crispy result only started to appear a few days later. I noted the worst parts were those that had been colored black before I started; these would apparently be where sweat had already affected the pH of the leather. This brought the missing Degreaser to mind, something Roger Koh has confirmed with scientific enthusiasm.

 

Of course what I am really looking for is a solution to treat the sweat on the hat. Just something to simple for not-too-damaged leather that will keep it from suddenly disintegrating on me.

This may not be possible, given that this treatment involve fairly soaking the leather. Worse, those sweatbands that suddenly disintegrate already had serious problems under the skin. Working this Fatliquor process without the degreaser would likely end the same.

 

I await your trials with extreme interest Daniel, as i currently have a very old Stetson No.1 that i dedicated as my new favorite fly fishing hat which to me is a honored hat amongst all my hats. It had a wonderful thick, beautiful, pliable sweatband noteworthy of some of those old Stetsons.
I wore it on two hot summer occasions this year and sweated through the band and out into the brim. The last outing included much rain. I thought nothing of it as it had been bullet proof all these decades.
Wrong...it dried hard as a board in it’s entirety.
It has been treated with Pecard Antique Dressing with zero response which mystifies me as Pecard’s has miraculously saved much lessor leather jackets and sweatbands in the past. It has been slathered for a couple months and seems not able to absorb the dressing. Very odd.
I have no doubt the alkalinity of the sweat, @7.0 for humans, is the reason the leather “can’t” respond. The sweat is the only variable in the equation.
Therefore, i’m a bit hesitant to select another Vintage hat as my “best hat on the stream” to show honor to my trout adventures.
Please update us all as you delve deeper into this conundrum.
Sincerely.
Bowen

 

Here again is the leather care forum. It is run by Roger Koh, who markets the leather care brand Leather Doctor. As you can see, he answers questions and is quite responsive.

https://www.leathercleaningrestorat...owthread.php?16313-Sweatbands-on-Vintage-Hats

Here is the link to the Leather Doctor product line. I am not affiliated with them, I am just trying them out rather slowly.

http://www.leatherdoctor.com/

All the best,
Daniel

 

Great info, Daniel.

 

I went ahead on the three step process on a Vitafelt sweatband that had deteriorated in one spot so much that it burned a whole through the leather, separating into two parts.

I applied the degreaser, the hydrator, and the fat liquor.

The degreaser went right into the leather, then seemed to push out a film from the leather as if it was degreasing. I am stating the obvious, but it was a bit of a surprise. The hydrator went right in as well as the fat liquor.

The end product is darker than original and the edges have pulled in a little unevenly. When I applied the hydrator the leather swelled up and soaked, and quite a few little pieces from the sewing holes came off. They were brittle and probably dead leather. The rest of the sweatband seemed to do well.

Parts that were dark with deterioration to start with seemed to remain stiff. I thought this was problematic because these darker parts are what we are trying to restore. I applied more fat liquor and they seemed to soften up well after a little more attention.

The final product looked ok, but there were still two points where the leather had been weak with a full ‘pre-crack‘ very noticeable to the touch. After treatment I could still feel these cracks when I ran my fingers over the leather. When I casually rolled the leather over one spot it cracked.

I believe these parts are either too far gone to fully restore, or they require more attention. The uneven edges and torn threading along the edges is fairly serious from a restoration perspective. It is enough to discourage the effort unless it is totally necessary.

Also, this three step process cannot be done unless the sweatband is completely removed from the felt.

My probable long term solution to tough cases will be to work on this process then glue the old sweatband to a new one. Roger Koh notes that all glued are not the same, that what is required is a glue that does not destroy the leather’s natural fat liquors. That will require a bit more reading.

Pics follow.

 

Here are my initial pics of the sweat. You can see where it burned through and darker spots of potential deterioration. Roger Koh pointed out that the leather goes bad when our perspiration enters the sweat and that perspiration deteriorates. This makes the leather sweat basic (in terms of pH) rather than its natural slight acidity; the later burning is a reaction between this base and our acidic perspiration.


The biggest hurdle to overcome may simply be that sweatbands are thin. One significant dry rot crack or reaction can wipe the whole thing out. Other thicker leather products have more depth to work with.

 

Here are some in process pics. The next to last one is the half moon shaped dark spot. It seemed to contract with the treatment, then filled in with the fat liquor and relaxed a bit. The last pic is of the film that seemed to come out with the degreaser.

 

Here are pics with the fat liquor and after. The last pic is not that great, but you can see the edges are a little uneven and the leather is definitely darker.

 

Here is a closeup of the later crack in the leather. I could feel the full line with my fingers and when I rolled it a little it cracked along the fault. I think this is really a result of the unforgiving thinness of the sweatband, and it will probably motivate me more to try gluing the old sweat on to a new one for stability.

As evidence that this treatment works, the leather portions behind the sticker absorbed less product and ended much less flexible. I added fat liquor there and it softened.

On this pic you can also see the edges and how they are no longer smooth. I don’t know if this is from my technique or a product of the process.

*I added two pics with a white background to help show the final results.

 

My final question to Roger Koh was if adding the just fat liquor to an antique sweat would make it more resistant to disintegrating or burning. I don’t mean a full restoration, just a preemptive treatment.

He has not answered that question yet, but if anyone is interested in following up or asking more here is the thread again:

https://www.leathercleaningrestorat...owthread.php?16313-Sweatbands-on-Vintage-Hats

 

Here is an old #1 Quality sweatband that turn black, thinned considerably, and pulled back from the hat and tearing off the thread. I have been (very carefully) adding the fat liquor and Picard’s antique leather dressing in combination.

The result of this combination appears to be a softening of the leather, although two deep cracks remain and threaten to split completely. I think the process works ok, but we’ll see.

*Roger Koh’s instructions are to add the degreaser in order to lower the leather pH and prepare it for the fat liquor. Unfortunately I can’t make this work for a sweat inside the hat.