stiffening chrome tanned leather to make a firmer temper

[Aari]

I have some very nice 3-4 oz red chrome tanned leather. Problem is that it is too soft a temper to make a stand up bag I'm planning. Is it possible to use the 180 degree water method or 180 degree bake method to improve the temper, prior to cutting and sewing, so that it will be a bit firmer?

Edited June 4, 2019 by Aari

[mikesc]

No..to both your questions..

But, you can make a "lining bag" sewn to it out of veg tan, or you can add stiffener poly( ethylene or urethane ) panels to do the same..

You could even sew stiffener to each piece of your chrome tan, and then assemble your bag..and add another liner from other leather or textile..

Search the forum for various "how tos" by Brian "RockyAussie"..he's done some posts explaining ( with pictures ) how to stiffen bags..

Not chrome tan leather bags, , but the principle and methods are the same.

if you only wanted your leather to get a little stiffer, you could paint onto the inside with PVA glue or similar, when it dries you'll gain some stiffness, but it will eventually soften again.

[Aari]

Thanks

 

[mikesc]

Another thought, you can iron chrome tan..so..If you got some "iron on stiffener material"..Pellon* type ( like that used for stiffening textiles ) you could iron it onto the "flesh" side of your chrome tan ( you have to use a "crepe" textile between the iron and the Pellon, to stop the iron from sticking ) ..then assemble the pieces..and add a textile liner if you wish..

You could also glue plastic liners to each chrome tan panel "flesh side" before assembly..that would help it "stand" in a similar way that some of the Vuitton sacs made with coated leather are slightly more rigid because of the coating, but yours would be on the inside..Stitching would have to be done more carefully..

Some bag shapes are naturally more inclined to stay up right than others..cylinders will "flop" less than boxes.

Depending on the design you could make a stiffer internal "frame"..Lot of potential solutions, unfortunately heating the leather ( as can be done with veg tan ) won't work, the structure of chrome tan is not the same after tanning as the structure of veg tan.

*there are other "brand names"..

Edited June 4, 2019 by mikesc

[Aari]

So sewing in 3 oz "firm" goat veg tan would work?

[LatigoAmigo]

I have used iron on fabric interfacing, but due to the oils in chrome tan, the interfacing does not always adhere. I have glued fabric interfacing with Barge cement, and that has helped, but since it is not sewn in, it might pull away from the leather over time.

On my latest project I'm lining a bag with Salamander Bonded Leather because it needs a lot of support. The description reads in part "... By finely milling vegetable leather scraps as well as chrome shavings which we obtain from all around the world, and adding natural fat and latex as a binder, ... SALAMANDER bonded leather fibre material is made of over 90 % natural and re-growing raw materials ... we obtain bonded leather fibre material - a continuous product, which is available in a number of qualities and thicknesses." 

https://www.etsy.com/listing/677134510/salamander-bonded-leather-04-50cm-x?ref=related-5&frs=1

There are other similar products available, but I like that this one is available in various weights. I have found that because this is real leather, it bonds well to other leather, so I'm hoping that is does not have the same tendency to pull away as the fabric interfacing does. Time will tell.

Edited June 4, 2019 by LatigoAmigo

[fredk]

I made my dottir a shoulder bag out of chrome tan upholstery leather by using two layers sandwiching a bit of compressed card

Back to my old favourite; cellulose thinners. My chrome tan is pre-dyed and lacquered, by washing it down with cellulose thinners and re-dyeing it becomes very much stiffer.

[johnv474]

I am currently making a stand-up bag with a soft temper leather.  I cut each panel twice the size, with an additional 1/4" to allow me to fold it over itself.  I put a piece of firm canvas (eg denim) in between.  A generous coat of contact vement and some careful folding later, and I have a thicker, firmer panel of that leather.  I stitched along the top and it looks good so far.

This is the approach any time I use thin, soft leathers but need a firmer panel.