What plastic glues well to leather?

[htraps]

I'm thinking of making the welt of a knife sheath out of plastic sandwiched on both sides with leather rather then building up the welt with multiple layers of leather. I have ordered some bakelite which I assume will glue and cut/machine well but am now hesitant because its damn hard stuff and have some concern about it damaging the edge. Has anyone had success gluing plastic to leather? What plastic should I be looking at for this purpose? 

[Dwight]

Bakelite is far too hard for your purpose . . . it will destroy the edge of the knife . . . just by pulling it out and putting it in.  Bakelite is also brittle . . . and will break . . . leaving broken pieces to fall down into the sheath and do even more damage.

There is really no plastic I can think of that will glue well to leather . . . and honestly . . . I really do not understand your reluctance to use leather. 

I make cheek pieces for rifle shooters . . . stackingup leather to as much as 1 1/2 inches.  

A knife sheath should not need more than one welt of 8 oz leather which is 1/8 of an inch thick . . . and glues or contact cements well to the outer pieces of the sheath.  

The welt is more than anything else . . . there to protect the threads . . . by being made of leather . . . it also protects the knife edge.

May God bless,

Dwight

Edited September 1, 2021 by Dwight

[zuludog]

5 hours ago, Dwight said:

Bakelite is far too hard for your purpose . . . it will destroy the edge of the knife . . . just by pulling it out and putting it in.  Bakelite is also brittle . . . and will break . . . leaving broken pieces to fall down into the sheath and do even more damage.

There is really no plastic I can think of that will glue well to leather . . . and honestly . . . I really do not understand your reluctance to use leather. 

I make cheek pieces for rifle shooters . . . stackingup leather to as much as 1 1/2 inches.  

A knife sheath should not need more than one welt of 8 oz leather which is 1/8 of an inch thick . . . and glues or contact cements well to the outer pieces of the sheath.  

The welt is more than anything else . . . there to protect the threads . . . by being made of leather . . . it also protects the knife edge.

May God bless,

Dwight

This answer sums up my response - I make knife sheaths from 3mm thick leather.......alright it varies a bit around there, but  is usually 3 to 3,5mm 

I don't know if they have proper names, but I do two styles, the one piece fold over, and two piece front & back. Though strictly speaking these are two piece and three piece respectively, as they have a welt, which is made from the same leather, and I don't have any problems with that

But just at the moment I'm making a knife from a small, narrow blade so I'll use slightly thinner leather, about 2,5mm, and the same for the welt; I'm not expecting any problems, it is, if you like, self compensating, as the leather used will vary with the item, going up to 3,5 or 4mm for a machete or an axe cover

I've watched many sheath making videos, and I think they all use a leather welt, though some do use a plastic or wooden insert, which is slightly different to a welt

Mostly the welt is one thickness of 3mm leather, but sometimes I add an extra layer at the top or hilt area of the sheath to give a larger opening, and skive it to blend in - usually because I've misjudged  cutting out the pieces! 

Edited September 1, 2021 by zuludog

[battlemunky]

I've made many sheathes and have also only used leather for welting. Initially I recoiled at the idea of using plastic but I don't see why you couldn't. It would need to be the right plastic too though. You would want something similarly pliable to leather so the edge can rest up against it and it gives a bit but still can protect the stitching. I don't think the bakelite is going to work because it will break and become a potential hazard because the sheath won't work correctly. 

Although it is unconventional it isn't wrong. If you pull it off, share pics and let us know how it carries.

Also, I'd go with contact cement, either Barge or Weldwood. You don't want the eco-friendly water based versions for this. The smellier and more volatile the better. If you can find one that extincted everything on Mars due to its volatility and then fell to Earth, it'd probably be the one I chose.

[fredk]

The only plastics I can think of which might suit are nylon and HDPE

[chuck123wapati]

11 hours ago, htraps said:

I'm thinking of making the welt of a knife sheath out of plastic sandwiched on both sides with leather rather then building up the welt with multiple layers of leather. I have ordered some bakelite which I assume will glue and cut/machine well but am now hesitant because its damn hard stuff and have some concern about it damaging the edge. Has anyone had success gluing plastic to leather? What plastic should I be looking at for this purpose? 

no! just use leather there is no benefit to overthinking this. if you glue and hammer your welts then there ill be no seam for the blade to find. useing plastic wont guarantee this. 

Edited September 1, 2021 by chuck123wapati

[tsunkasapa]

Plastic??? Really?? 

[ljk]

You could try cording/welt.   Sailrite or Rockford Supply.

[RockyAussie]

On another forum the other day I saw an odd knife where the owner was wanting a sheath made. This knife was heavily sharpened on both sides at the tip end and had no stopper or shape to the handle end which made me recommend a plastic end stop inside the sheath. I suggested I could print one out in pla+ and I know this will hold glue pretty well but I would do it so that the plastic would be fully inside the stitch lines of the leather. I would also think to bring the shape around enough to make the blade make the contact further up than the tip. The shape of this knife would easily allow little pressure to push right through the leather welt bottom I think.

[RockyAussie]

This is the one I was mentioning above. What do you think?

[Dwight]

2 hours ago, RockyAussie said:

This is the one I was mentioning above. What do you think?

I think I could make a sheath that would stop at the wood . . . angled so it always stops in the same position . . . and I would make the welt in leather exactly the thickness of the blade . . . and the welt would be exactly the shape of the blade from the tip on top all the way down..

I would also make the welt at the bottom far enough up into the sheath that I could double sew that whole sheath.

But that's just how I'd do it . . . probably at least 99 other ways.

May God bless,

Dwight

[chuck123wapati]

On 9/1/2021 at 6:20 PM, RockyAussie said:

This is the one I was mentioning above. What do you think?

#98 i would use a tightly formed sheath  with maybe a chape on the end of the sheath or just a copper rivet or two to prevent any push through at the welt. 

[chrisash]

On 9/2/2021 at 12:43 AM, RockyAussie said:

On another forum the other day I saw an odd knife where the owner was wanting a sheath made. This knife was heavily sharpened on both sides at the tip end and had no stopper or shape to the handle end which made me recommend a plastic end stop inside the sheath. I suggested I could print one out in pla+ and I know this will hold glue pretty well but I would do it so that the plastic would be fully inside the stitch lines of the leather. I would also think to bring the shape around enough to make the blade make the contact further up than the tip. The shape of this knife would easily allow little pressure to push right through the leather welt bottom I think.

I would use Brian's suggestion, but with Nylon rather than PVC as a gentler material than PLA on the blade

Another way would be to make a tip cap with that ballistic material Kydex

Edited September 6, 2021 by chrisash

[RockyAussie]

On 9/6/2021 at 5:52 PM, chrisash said:

I would use Brian's suggestion, but with Nylon rather than PVC as a gentler material than PLA on the blade

That's a good point....for a point