Hardening leather: the finer points (not remaking the wheel)

[Gregoire de Lyon]

gregoire,
Thank you for sharing that thread, it is of great interest to me personally. This will solve many arguments.

A thought. I have seen many people argue that a likely for of hardening for leather was to "half tan" the leather. If we could figure out the properties of half-tanned leather then maybe we could focus on a hardening method that produces results similar to the half-tanning. While it would be nice to use actual half tanned leather i hear it is rare and expensive.
Odd

Hi Odd-

My pleasure.

It was exactly because of the discussion of "half-tanned" leather that I asked the docent whether it was fully tanned or rawhide. Her answer was that they are looking into to it and that all she knows for now is that it is "poorly tanned".

[Oddbjorn_Mjolksiglandi]

Gregoire
AS a historical interpreter myself (paid docent) I take exception to the value judgement of calling it poorly tanned, especially when they are not certain of how much tanning happened. Jut looking at that armor it is obvious that it was well made (unlike mine) so what ever level of tanning it received was likely deliberate (end professional rant)

As for finding hardening process that create an end result similar to half tanning, do you think thats a viable line of research?
Odd

[Gregoire de Lyon]

Gregoire
AS a historical interpreter myself (paid docent) I take exception to the value judgement of calling it poorly tanned, especially when they are not certain of how much tanning happened. Jut looking at that armor it is obvious that it was well made (unlike mine) so what ever level of tanning it received was likely deliberate (end professional rant)

As for finding hardening process that create an end result similar to half tanning, do you think thats a viable line of research?
Odd

Hi Odd-

I don't think it was a value judgement from the docent. I think it was an observation that it was not what we accept today as a well tanned piece of leather - it wasn't a uniform tanning. Thus poorly tanned, or at leas that is how I took it.

I'm not sure that hardening a tanned piece of leather will ever give you a result that is similar to starting with a half tanned piece. I'm not an expert though, and there are others here who can give you a lot more info than I have on the subject!

Cheers,

[Russ Mitchell]

Are you looking to:
1) replicate the hardness of Dobson's pieces, using half-tanned leather baked on a last?
2) treat finished leather until it has behavioral properties similar to half-tanned leather?
3) have leather that is tanned, but dries stiff and rigid like rawhide does?

All three have different answers.
(I can occasionally be tone-deaf in my typing, and come across in unintended ways -- my comments have been meant to help rather than discourage, and while I'm not a leather chemist or an industry pro like Kel, I'm glad to help to the degree that I can.)

[Kel Rekuta]

Hi Odd-

I don't think it was a value judgement from the docent. I think it was an observation that it was not what we accept today as a well tanned piece of leather - it wasn't a uniform tanning. Thus poorly tanned, or at leas that is how I took it.

Exactly. Harness makers tend to say many bad words when they find an untanned inclusion in a piece of leather, usually because they located it by chipping a knife edge.

Since this topic has been active on and off since last spring, I've been trying to import some scabbard butts from England. The N.Am. dealer for that particular UK tannery is a doofus. I'm still waiting on the order since April 2011. A brief discussion with an American tannery rep got some comments from their tanner. Purposefully tanning hides almost to completion leaves a thin core of incompletely tanned but stabilized core. Not exactly rawhide but not yet leather. The tanner knew what scabbard butts were for, understood the process and wanted to know if we would like a run of a couple hundred hides.

I have yet to see anything detailed about scabbard butts in older industry texts but I don't have quite a few that only seem to survive in England. I'm sure there might be something in German or Swedish as both countries had substantial tanning industries in the past. The search for answers continues. BTW, you haven't handled fine sole leather until you get your hands on German soling. If we were talking about fabric, American sole leather would be denim and German sole would be heavy silk drapery. Awesome stuff to handle.

[Kel Rekuta]

Are you looking to:
1) replicate the hardness of Dobson's pieces, using half-tanned leather baked on a last?
2) treat finished leather until it has behavioral properties similar to half-tanned leather?
3) have leather that is tanned, but dries stiff and rigid like rawhide does?

All three have different answers.
(I can occasionally be tone-deaf in my typing, and come across in unintended ways -- my comments have been meant to help rather than discourage, and while I'm not a leather chemist or an industry pro like Kel, I'm glad to help to the degree that I can.)

Interesting you mention leather that is stiff and rigid like rawhide. When leather is "burned" by the tanner rushing it through too strong tanning liquor to reduce pit time, the result is hard and crunchy like rawhide but not quite as brittle. Wet shaping that poor quality stuff might actually work, especially with glue sizing to coat the fibre and resist cracking when flexed.

One of the very serious but poorly discussed problems with working partially tanned leather is the cutting process. What sort of tools were necessary to cut this stuff accurately? Or was it simply worked wet? The poorly tanned sole leather I have on hand (as does Gavin) is a bitch to cut, even with the cobbler shop tools I have. I managed to cut some wet, with a lot of effort. I cannot imagine a medieval leather worker liking the material any more than I do. Maybe its just because it is so thick... The extant pieces at the British Museum and these vambraces everyone is so excited about do not appear to be even half as thick. Scabbard butts are available in 3-4mm thickness IRRC. Big difference from 12mm.

[Russ Mitchell]

Yeah, Kel, and what STILL strikes me about Dobson's piece is that it's the only piece of leather I've seen that was anywhere near that range (say, 4-6mm, I'd have to measure) that was rock-hard. So he seriously might be onto something.

I got some alum-tawed latigo in, and will try glue-hardening it tomorrow just for kicks. This appears to have been slightly finished, unfortunately, but it still has a LITTLE bit of pop-and-crunchy to it once you're away from the belly.

[daggrim2]

Hm, so maybe this incompletely tanned, or "burned" leather is what I'm experiencing with the saddle skirting I use for helmets. There are often thinner sections on the ends that are hard and shiny. These I have leaned to use for specific small pieces of the helmet.
Also, there are sometimes clumps, or areas of leather that are more fibrous than the rest of it, and it can take 20 passes with an exacto knife to get thru them. Is that just a natural part of the hide, or is it a result of imperfect tanning?
I've finally purchased some "tooling hides" instead of the "economy hides", because of the uniformity of thickness thru the whole hide, but I have yet to cut into them. Gradually, the product is getting better and better in quality. The decision to spend more for better leather was partially motivated by how much easier and faster my production has become.
Hopefully the quality problems I've had to work around will be gone with the better stuff.
Still planning to try the hot water immersion method, with Titebond in the mix. I'd like to waterproof the entire piece of leather, rather than just a surface coating on the outside. Currently, a good rain would soak the leather helmet in a short time, as it trickled thru all the seams. A soggy helmet would retain a helmet shape, but get soft enough to distort.
Perhaps just including wax in the pot would do as well or better than glue. Maybe something like 25% wax,75% water. That would avoid having to melt the wax separately. Anybody ever tried mixing hot water and melted wax? Sounds crazy, maybe.

[Oddbjorn_Mjolksiglandi]

daggrim, I would think that the wax would remain separate from the water making it hard to get a coating of the wax let alone penetration. I do know that water hardened leather will accept the wax after hardening. Simply heat the leather at low temp in the oven and place wax on the leather, it will melt through. or baste molten wax onto the leather. It will absorb especially into stitching holes.

[Oddbjorn_Mjolksiglandi]

Kel,
you mentioned vambraces, would you link us so we can follow the discussion?

[daggrim2]

Oddbjorn, that's a good suggestion, but I do 15 or 20 parts like an assembly line when I do cuir bouilli, so I'm looking for fewer steps. I think I'll make up a flow chart of all the techniques I've seen on this forum, or some kind of matrix, and see if I can come up with something innovative, then do some experiments. Maybe there is no short cut, but I'm looking. I'll post the results, but it'll be sometime in
April prob'ly.

[Kel Rekuta]

Kel,
you mentioned vambraces, would you link us so we can follow the discussion?

viewtopic.php?f=1&t=143600

[Russ Mitchell]

Huh. Got the alum-tawed stuff in the oven now, Kel -- turns out I got a cheap, crap-tawed hide where they used a paste rather than a soak... the center appears to be mostly untanned. It's only partially "crackly" unfortunately, because it looks like they used a brutal bate on the hides -- there are lots of spots around the belly with an unusually open grain, which I'd normally need to hot-stuff to achieve.

[Kel Rekuta]

Hm, so maybe this incompletely tanned, or "burned" leather is what I'm experiencing with the saddle skirting I use for helmets.

Separate issues. Incompletely tanned has hard inclusions. Rock hard. Burned leather is over tanned or more specifically tanned too hard, too fast. One might compare the problems to an undercooked BBQ chicken versus one charred to a crisp outside and dried out inside.

Also, there are sometimes clumps, or areas of leather that are more fibrous than the rest of it, and it can take 20 passes with an exacto knife to get thru them. Is that just a natural part of the hide, or is it a result of imperfect tanning?

Poor tanning, sometimes one finds this in South American tanned veg but more frequently leather tanned in South Asia. (i.e. India, Pakistan, Bangladesh) Frequently the hide is from water buffalo, which still clears customs as "bovine leather."

I've finally purchased some "tooling hides" instead of the "economy hides", because of the uniformity of thickness thru the whole hide, but I have yet to cut into them. Gradually, the product is getting better and better in quality. The decision to spend more for better leather was partially motivated by how much easier and faster my production has become.

Yup.

Perhaps just including wax in the pot would do as well or better than glue. Maybe something like 25% wax,75% water. That would avoid having to melt the wax separately. Anybody ever tried mixing hot water and melted wax? Sounds crazy, maybe.

Yes, it does. Wax is insoluble in water. That's why wax is useful as a water repellent. A thin coat on all surfaces prior to assembling your product should be sufficient. Personally, I prefer commercial preparations like SnoSeal, SnoProof, Montana Pitch Wax, any brand of Dubbin et cetera to parafin. YMMV.

[daggrim2]

Thanks Kel. Maybe brushing some heated SnoSeal on all sides of the finished, dyed pieces before assembly would be the best way to make the helms waterproof. That's be something I could do on my benchtop as one of the standard ops. I do like SnoSeal. I tested a few products for rain proofing at one time, and that was the best I found.

I'd like to be able to wipe an acrylic (sorry) over some helms for a nice shine, so I'm not sure it'd work over SnoSeal.

Maybe wiping a 50/50 solution of Titebond/water over the leather would provide a seal that could be acrylic coated.

Or maybe the acrylic floor wax or polish that somebody referred to in an earlier post as a substitute for Resolene?

Part of me hates the idea of using acrylic, but part of me like the final look. After all, I sell these helms at Renfaires...they're not meant for an A&S competition, or for living history.

[Azus]

OOP, but Minwax makes a wood hardener that is available in most Lowes and Home Depots. It is waterproof once dry. I have successfully used it on leather. Wear rubber gloves, soak the leather and form it. Allow it to dry and Bob’s your uncle.

How long do you let the leather soak?

[Konstantin the Red]

Welcome and well come -- back -- Azus. Long-time lurker, eh?

It'd be like overdoing the casing of the leather to prep for tooling it. Moderately squelchy.

[Ismaels-Legacy]

Just out of curiosity, but has anyone tried submerging leather in water/hide glue mixtures?

Yes, in conjunction with baking. Maelgwyn showed it to me when I went down to visit him for the day once. Works well.

Do you happen to remember what ratios were used? How hard did the leather get when prepared in this method?

[Russ Mitchell]

When I've done it, I used a fairly loose mixture, on the watery side, but I have a memory (which may not be accurate) of Maelgwyn's being pretty thick.

[Kel Rekuta]

Thanks Kel. Maybe brushing some heated SnoSeal on all sides of the finished, dyed pieces before assembly would be the best way to make the helms waterproof. That's be something I could do on my benchtop as one of the standard ops. I do like SnoSeal. I tested a few products for rain proofing at one time, and that was the best I found.

Warm up the pieces not the paste. The paste will penetrate better in warm fibre. I tell retail customers to put their boots or whatever in a sunny window or over a radiator prior to applying waterproofing pastes. Works a treat. A little electric heater would do the same thing for you on the bench. Just backstop the heating area to retain the temp.

I'd like to be able to wipe an acrylic (sorry) over some helms for a nice shine, so I'm not sure it'd work over SnoSeal.

Nope. It would work the other way around but seems redundant.

Maybe wiping a 50/50 solution of Titebond/water over the leather would provide a seal that could be acrylic coated.

Again, a process designed by the Department of Redundancy Department.

Or maybe the acrylic floor wax or polish that somebody referred to in an earlier post as a substitute for Resolene?

Look up posts by Kilkenny. Whatever he uses has proven satisfactory to him - & he's on the ball with this stuff. I use Resolene for modern "fashion" pieces but Leather Balm with Atom Wax for just about everything else. Not as fine a shine but more durable. Liquid floor polish is bound to be waaay cheaper.

Part of me hates the idea of using acrylic, but part of me like the final look. After all, I sell these helms at Renfaires...they're not meant for an A&S competition, or for living history.

Exactly. RennFolk likes bling, they does... and dragons and elves and batwings.

[daggrim2]

'preciate your guidance, Kel.

[Kilkenny]

One of the very serious but poorly discussed problems with working partially tanned leather is the cutting process. What sort of tools were necessary to cut this stuff accurately? Or was it simply worked wet? The poorly tanned sole leather I have on hand (as does Gavin) is a bitch to cut, even with the cobbler shop tools I have. I managed to cut some wet, with a lot of effort. I cannot imagine a medieval leather worker liking the material any more than I do.

I do have what may be a useful insight on the cutting. My beverly shear makes quick work of cutting this stuff, while knives simply do not get through the core. Therefor, I cut mine with my B-2

I expect they may have had some equivalent shears about.

[Kilkenny]

H
Perhaps just including wax in the pot would do as well or better than glue. Maybe something like 25% wax,75% water. That would avoid having to melt the wax separately. Anybody ever tried mixing hot water and melted wax? Sounds crazy, maybe.

That process simply will not work. Waxes that you really want to use for this purpose are likely to have melting points higher than the boiling temperature for water, so they won't melt in the first place. Even if the wax does melt, it won't mix with the water but will very much remain separate.

Thus, the choices there are: (1) big pot of molten wax (which will be near flashpoint temperatures, handle with great care and work out of doors if at all possible); (2) hot water for dipping the leather and a separate process for melting wax into it (numerous options, all of which will involve waiting for the water to clear out of your leather so the wax can get in); (3) Baking wet molded leather in the oven and, as the leather is drying and the color returning to normal, start basting with molten wax. Let the leather stay in the oven, where the molten wax can find its way into the leather as the water is being forced out by the heat and the wax displacing it.

If I wax my leather (and I do this with bottels and jacks, but not with armour) I will generally brush on, or do a quick dip in, molten wax and then some time in a Very Low Heat oven and maybe some more time with a blow dryer, depending on how it looks when it cools. The blow dryer lets you focus on evening out the wax and gives you the chance to produce a nicely buffed and uniform appearing finish.

[Kilkenny]

Just out of curiosity, but has anyone tried submerging leather in water/hide glue mixtures?

Yes, in conjunction with baking. Maelgwyn showed it to me when I went down to visit him for the day once. Works well.

Do you happen to remember what ratios were used? How hard did the leather get when prepared in this method?

chuckle. Yeah. 10:1 water to glue, roughly. If you don't bake it, this won't change the leather in any material way. The hardening comes not from the glue in the solution, but from the chemical change that occurs in the leather at 167 degrees F.

I started using the Titebond III as a modern alternative to hide glue. Hide glues are always water soluble, so to get away from that problem, I went with a glue that cures to be waterproof. We are pretty sure they put hide glue on their leather armour, but we aren't really at all sure why. I suspect it has less to do with hardening the leather than it does with prepping the surface for painting. I think the hide glue is there because it was part of the gesso applied to prep the leather for painting. That's just my thinking on the matter, so take it for what it is worth

[daggrim2]

Kilkenny, good on you regarding the glue not used for hardening, but for surface prep. I think you must be right. Looks like the best one step hardening/rainproofing for a production line would consist of cuir bouilli by immersion in a glue/water mix maybe 25/75. Alternate would be brushng sno seal onto warmed, dry, hardened leather. I'll experiment in March, and let you all know.

[Kel Rekuta]

I suspect it has less to do with hardening the leather than it does with prepping the surface for painting. I think the hide glue is there because it was part of the gesso applied to prep the leather for painting. That's just my thinking on the matter, so take it for what it is worth

Agreed. Hide or fish glue sized into leather or some variant of processed hide is my current thought on "cuir boillie". It has been packed or finished with glue to prepare a base for decoration, much like wood panels for painting. Why bother showing up to a behourd in functional but bland harness when you could do the bling thing. Seems terribly appropriate for 14thC Western European nobility. Once the leather is outside the mail, its functional decoration.

[daggrim2]

As promised, here are the results of my looking for an alternate method of waterproofing leather for an assembly line .

A) Method: Dye over Glue (Titebond 3)

Cuir Bouilli by immersion
Dry
Leather Balm
Deglaze with alcohol after Balm is absorbed
Titebond 3 brushed on. Glue/90%, Water/10%
Dye

Results:
Glue beads up when brushed over Balm.
Glue goes on ok after Balm is deglazed with alcohol.
Dye goes on well over the glue...a little dark.
Water Test- One big drop of water, left on for 5 minutes. Dye rubs off when wet.
FAIL

B) Method: Glue over Balm

Cuir Bouilli
Dry
Dye
L. Balm, restores leather, makes dye richer
Deglaze
TB3 glue

Results:
Glue spreads well over deglazed Balm.
Dries semi gloss.
Water Test- Glue gets milky looking right away when wet.
Leaves spot when dry.
But, spot buffs away, leaving no spot.
Looks fine when dry.
Due to unsightly milkiness when wet...
FAIL

C) Method: Glue over Dye

Cuir Bouilli
Dry
L. Balm
Deglaze
Dye
TB3

Results:
Dye over deglazed Balm...very bad, spotty.
So, every subsequent step looks ugly.
FAIL

D) Method: Resolene Acrylic

Cuir Bouilli
Dye
Balm
Resolene

Results:
Balm makes dye look great
Resolene goes over Balm very nicely.
No need to deglaze Balm.
Water Test- Minor absorption with 2 coats. Spread on with rag.
Negligible absorption with 3 coats.
PASS

E) Method: Sno Seal

Cuir Bouilli
Dry
Dye
Heat Leather
Sno Seal

Results:
No melting of wax needed.
Slightly difficult to apply evenly with brush.
Feels tacky when absorbed. Picks up dust.
Time consuming to heat the leather.
Expensive!
No need for Balm.
Water Test- Excellent. The best of all methods.
PASS

Backside of leather waterproofing results:
Titebond 3- Good
Resolene- Marginal
Sno Seal- Excellent

So, there it is. Take it for anything you can use. I know most or all of you are using tried and true methods, but I just wanted to explore further afield.

I decided not to use the one-step, one-pot method of combining cuir bouilli with waterproofing by mixing TB3 with the water, as some preliminary tests showed that the dilution of the glue would make it ineffective as a sealant.

If there is a less expensive product like Sno Seal, I'd like to know. The big advantage is that it's usable right outta the tube without melting.

[Oswyn_de_Wulferton]

On B, are you baking, immersing, brushing the TB 3? I have never had any issues with spots when wet. Not sure why the leather balm is needed (you are restoring leather, to then dry it out?) or deglazing. If you were usnig a 1part tb3 to 3 pts water, that may also cause the issues (too much glue). STick with a 10/1 water/glue ratio and it works much better.

[daggrim2]

I'm using the immersion method of CB, then drying thoroughly. The Balm helps restore oils to the leather which may have been leached out. Just a step to insure the leather won't crack or degrade after the customer has spent a lotta money on something. The deglazing part comes because the glue doesn't want to lay evenly over the waxy Balm. It just cleans the excess wax off the surface. Yeah, I'mtryng some wacky ideas, but I'm just trying to be exhaustive in my experiments, so i have recorded reults for many different combos. Perhaps a diluted glue would be better than full strength. I'll try that.

[Maelgwyn]

Is there some reason you want to dye after hardening? Dying first works well for me.

[daggrim2]

Well, I just started out doing it that way. I was afraid that the immersion would leach the color. It does to a small degree, but dyeing before hardening might actually be a smart change to make. Much easier to dye flat leather than curved leather. Always trying to improve the process.

[Vaeringr]

Hi Odd-

I don't think it was a value judgement from the docent. I think it was an observation that it was not what we accept today as a well tanned piece of leather - it wasn't a uniform tanning. Thus poorly tanned, or at leas that is how I took it.

Exactly. Harness makers tend to say many bad words when they find an untanned inclusion in a piece of leather, usually because they located it by chipping a knife edge.

Since this topic has been active on and off since last spring, I've been trying to import some scabbard butts from England. The N.Am. dealer for that particular UK tannery is a doofus. I'm still waiting on the order since April 2011. A brief discussion with an American tannery rep got some comments from their tanner. Purposefully tanning hides almost to completion leaves a thin core of incompletely tanned but stabilized core. Not exactly rawhide but not yet leather. The tanner knew what scabbard butts were for, understood the process and wanted to know if we would like a run of a couple hundred hides.

I have yet to see anything detailed about scabbard butts in older industry texts but I don't have quite a few that only seem to survive in England. I'm sure there might be something in German or Swedish as both countries had substantial tanning industries in the past. The search for answers continues. BTW, you haven't handled fine sole leather until you get your hands on German soling. If we were talking about fabric, American sole leather would be denim and German sole would be heavy silk drapery. Awesome stuff to handle.

"Scabbard butts": (Purposefully tanning hides almost to completion leaves a thin core of incompletely tanned but stabilized core)
sounds like what we call "rårands"-leather in swedish?
It is the type of leather mostly used when making Scandinavian scabbards.

I have some Swedish pre 1940 scientific literature covering European leather industry from 1700 to 1940.
It is mostly focused on the chemical aspects of leather (graphs, molecular structures etc) manufacturing but I can translate parts of it for you.

[Kel Rekuta]

I would be grateful to have a look and ask questions. Please contact me by PM.

[Kilkenny]

As promised, here are the results of my looking for an alternate method of waterproofing leather for an assembly line .

A) Method: Dye over Glue (Titebond 3)

Cuir Bouilli by immersion
Dry
Leather Balm
Deglaze with alcohol after Balm is absorbed
Titebond 3 brushed on. Glue/90%, Water/10%
Dye

Results:
Glue beads up when brushed over Balm.
Glue goes on ok after Balm is deglazed with alcohol.
Dye goes on well over the glue...a little dark.
Water Test- One big drop of water, left on for 5 minutes. Dye rubs off when wet.
FAIL

B) Method: Glue over Balm

Cuir Bouilli
Dry
Dye
L. Balm, restores leather, makes dye richer
Deglaze
TB3 glue

Results:
Glue spreads well over deglazed Balm.
Dries semi gloss.
Water Test- Glue gets milky looking right away when wet.
Leaves spot when dry.
But, spot buffs away, leaving no spot.
Looks fine when dry.
Due to unsightly milkiness when wet...
FAIL

C) Method: Glue over Dye

Cuir Bouilli
Dry
L. Balm
Deglaze
Dye
TB3

Results:
Dye over deglazed Balm...very bad, spotty.
So, every subsequent step looks ugly.
FAIL

D) Method: Resolene Acrylic

Cuir Bouilli
Dye
Balm
Resolene

Results:
Balm makes dye look great
Resolene goes over Balm very nicely.
No need to deglaze Balm.
Water Test- Minor absorption with 2 coats. Spread on with rag.
Negligible absorption with 3 coats.
PASS

E) Method: Sno Seal

Cuir Bouilli
Dry
Dye
Heat Leather
Sno Seal

Results:
No melting of wax needed.
Slightly difficult to apply evenly with brush.
Feels tacky when absorbed. Picks up dust.
Time consuming to heat the leather.
Expensive!
No need for Balm.
Water Test- Excellent. The best of all methods.
PASS

Backside of leather waterproofing results:
Titebond 3- Good
Resolene- Marginal
Sno Seal- Excellent

So, there it is. Take it for anything you can use. I know most or all of you are using tried and true methods, but I just wanted to explore further afield.

I decided not to use the one-step, one-pot method of combining cuir bouilli with waterproofing by mixing TB3 with the water, as some preliminary tests showed that the dilution of the glue would make it ineffective as a sealant.

If there is a less expensive product like Sno Seal, I'd like to know. The big advantage is that it's usable right outta the tube without melting.

Interesting process and commentary. A couple of things of note.

With the milky appearance, I can pretty much guarantee you that is not the Titebond 3 going milky, but the Leather balm. You might want to do a test where you leave out the Titebond and just do the water drop test against Leather Balm.

Resolene gives water resistance, but not reliable waterproofing. Combine Resolene (or acrylic floor polish - really.) with Titebond 3 treatment for good water resistance for appearance sake and excellent water resistance for functionality.

The idea that Titebond 3 could serve as a sealant is one that sort of comes out of left field. I pioneered the use of this product for hardening leather and the idea, from the very beginning, was to get the glue to penetrate into the leather as much as possible. That's not achieved by painting a thick glue on the surface, but by immersion in a thinned glue solution. Water carries the glue into the leather, and then evaporates. This gives an additional binding of the fibres of the leather and it is not water soluble once it cures. The leather still needs a proper sealant to minimize water absorption, even though the Titebond is unaffected by water.

[daggrim2]

Aah, thank you, man. The immersion advice is very helpful...makes great sense, and clarifies why it's better than coating the surface. I'll surely try it out. Sounds like you have the concept dialed in. Combining the TB3 immersion and Acrylic in separate treatments is something that was way back in my mind, but I wasn't going to bother with it. I will go back to my original idea of doing cuir bouilli in a solution of water and glue. Hope the glue keeps it's gluelike properties in 175 degree water.
I expect that you're right about the Balm giving the milkiness. Early on I used to finish my helms with Balm and Atom wax. It gave a great appearance, but it was NOT waterproof, and spotted badly in a sprinkle.
Someday, when there's a TV commercial during Superbowl halftime, showing a truck driving harmlessly over one of my helmets in a rainshower, you can know that you had something to do with it.