how to identify chrome or veg tan

[chuckgaudette]

I've got several bags of scrap leather people have given me. My question is, how do I know what is chrome tan and what is veg tan? Is there some technique you use to identify the one from the other?

thanks

chuck

[machinehead]

 

[chuckgaudette]

this interesting. I will give it a try. So should I assume then that there's no way by just looking at a piece of leather or working with it I can determine with some accuracy if its chrome or veg?

[Thor]

Some experience and close observation will make a boiling test unnecessary for about 95% off all leathers. Try learning something about the tanning process and the various uses for the individual type of leather. Also there's not only chrome and veg tan. It has become a rare find, but there's also alum tanned leather out there. 

Most chrome tanned leather is drum dyed and a lot softer than veg tan. If they are tanned only and not dyed yet, they are called wet blues and this will be found in most chrome tanned leathers. It's a grayish or blue core. However, if they are drum dyed the will be dyed thru in many cases (it really depends on the tannery and what time they take with it). Some nutcase believes that this makes the leather more durable. Can't see how color will make a leather more durable or more tensile. The person is a great salesman, but not very knowledgeable about leather.

 

[RockyAussie]

Just to confuse it further what about retan? Part chrome tan and part veg or even a mix of others. Both veg and chrome have their own excellent uses and so does a retan but wet molding and carving is best on some types of veg but that's just my opinion.

[Thor]

4 minutes ago, RockyAussie said:

Just to confuse it further what about retan? Part chrome tan and part veg or even a mix of others. Both veg and chrome have their own excellent uses and so does a retan but wet molding and carving is best on some types of veg but that's just my opinion.

LOL, I did write about that, but deleted it again to not confuse him about this and didn't include the fact, that even chrome tanned leather can be tooled if that property is included in the tanning process, but is very expensive. Same goes for dyeing chrome tanned leather. There are some that can be dyed and others will not accept the dye and bleed forever.

Latigo leather would be the classical example for re-tanned leather. I believe there's an overview on leather types on this board as well, but I couldn't find it right now, so here is another one http://oldmillleathercrafts.thewesternsource.com/about-leather/

[chuckgaudette]

Thanks guys. I've only been doing leather work for about 6 months and have learned a lot. But there's so much more I need to know.

[Art]

It will come with time.  Leatherworker.net helps a lot in the knowledge arena.  Another test is to cut a strip and put a match to it.  Veg tan doesn't burn all that well and will go out when the match is removed.  Chrome tanned will smolder and ember burn a lot after the match is removed,  After the fire, if you rub the burned end of the veg tan on a white piece of paper (copier scrap works fine) it will trace black, whereas chrome tan will trace a greenish color.  Most of us can tell by feel what it is, and on some things, most of us can be fooled.

Art

[chuckgaudette]

Art, that is a neat trick too. I just tried it and it worked as you said.Thanks. One more piece of knowledge!

 

[Weaver Leather Supply]

That is an interesting video, I hadn't heard of that test before.  I have done the burn test.  If you burn a corner of the leather the ash on the chrome will turn visibly green.  However, I don't know about retans and if they perform like a straight chrome or veg in these tests, or a combination.  

[chuckgaudette]

So I just got around to doing the Siegel test on a lot of leather I was either given or bought. Turns out 90% of it is chrome tan. I know that there is more chrome tan around than veg tan, but the shocking thing is most of what I bought from local merchants was marked veg tan. 

One more question. I've noticed that some leather is referred to as chrome free but not actually veg tan. What would that be?

Edited August 7, 2016 by chuckgaudette
added chrome free question

[Northmount]

I just cut up a side of cowhide I was given.  The cowhide was sent to a tannery by the ranch owners.  Then after it was tanned, it sat for many years and travelled across Canada and back.  Then sat in my storage for another year or so.  Seemed to absorb water somewhat, but not like vegtan.  Could stamp it, but didn't leave good crisp impressions.  Had been drum dyed, but centre was blue grey.  Also could not wet form the leather.  The blue grey colour in the middle clinched it for me.  Chrome tanned.  If struck through, the other behaviours here may help sort out the type of tannage.

Finally used it to make a set of saddle bags and gave them to the fellow that donated the hide to me.  He has MS, can still do some riding.  When he can't ride anymore, he can through them over the back of his wheelchair, or I can remove the yolk and split them into two separate bags with whatever type of handles he wants.

Tom

[Weaver Leather Supply]

On 8/7/2016 at 4:19 PM, chuckgaudette said:

So I just got around to doing the Siegel test on a lot of leather I was either given or bought. Turns out 90% of it is chrome tan. I know that there is more chrome tan around than veg tan, but the shocking thing is most of what I bought from local merchants was marked veg tan. 

One more question. I've noticed that some leather is referred to as chrome free but not actually veg tan. What would that be?

We are seeing some leather being sold as "synthetic tannage" but i am not sure what it is.  

[zwallz]

Here's a short comparison between vegetable and chrome tanned leather:

http://rainierleather.com/quick-guide-vegetable-tanned-leather-care/

[Baldpacker]

Sorry for bumping this old post but it's what came up in the search results.

I  just did the "Siegel Test" to confirm whether the 'veg-tan' leather I bought in Morocco was really veg-tan or not. 

I have 3 different hides. With 2 of them, the samples immediately curled up and stayed curled which seems to confirm they're veg-tan.

With the 3rd hide, the samples (I tried a couple) immediately curled up but then straightened back out after being in the water for 5+ seconds?

I tried the burn test and the hides acted the same (no green ember I could see and they didn't burn very well, though the hide that 're-straightened' seemed to bubble out more liquid). The burned ends appear to scratch black (rather than green) on paper once burned.

The hides were all dyed through already and seem to absorb water well.

I think it's all veg-tan but I still feel uncertain - any other tests I can do? I won't be selling anything from these hides but I'd still like to know for sure what I'm working with!
 

[LatigoAmigo]

3 hours ago, Baldpacker said:

I still feel uncertain

It isn't always an either or situation. Latigo is both veg-tanned and chrome tanned. Typically veg-tanned can be tooled after being "cased", if that might help your determination.