Hydro/ vacuum formed knife sheath

[ComputerDoctor]

This is my first attempt at Hydro/ vacuum forming so I thought I'd try a hunting knife.

I used a 4 oz Veg tanned, alligator patterned medium, which was thin enough when soaking wet to form well under vacuum. Drying took a few days and then the 2 halves were glued together as shown in the last picture. It is not anywhere near complete yet. I will post the results.

Sam

[JD62]

looks good so far! look forward to see where you go from here.

[BDAZ]

I have one unit for leather and one for sous vide.

I generally put the sealed bag in the sun to set the leather for a few hours and then open it up. It will never dry in the bag!!

Bob

[chrisash]

It looks like there are constrictions on it being unable to pull the knife out, you could put infills in place where the narrow parts are with say plastic or wood at the start , so the final sheath is a tight but straight pull out

[garypl]

3 hours ago, chrisash said:

It looks like there are constrictions on it being unable to pull the knife out, you could put infills in place where the narrow parts are with say plastic or wood at the start , so the final sheath is a tight but straight pull out

I agree with Chrisash - first thing I noticed was the leather formed around the handle bump as a potential barrier to drawing the knife.

I use a small vacuum bag from my kitchen for small items and I place a smooth piece of wood behind the leather to prevent the cross hatch pattern from the vacuum bag from imprinting on the leather.  The bags have the cross hatch only on one side to pull the vacuum.

Gary

[Sanch]

Okay first of all I don't know if he posted this here for constructive criticism, or maybe to get some advice? First off 4 oz is too thin for a knife sheath in my humble opinion, it will get floppy on you . secondly I see no mention of any type of welt being used, if that blade has any type of Edge at all your stitches will last all of maybe two or three pulls, or the sheath itself  being so thin will catch no slack....Thirdly if your Stitch line follows the Contours of that knife at the distance it should 2X the thickness of the leather you will never pull that knife out of that sheath! Good luck and let us know how it goes 

[bikermutt07]

2 hours ago, Sanch said:

Okay first of all I don't know if he posted this here for constructive criticism, or maybe to get some advice? First off 4 oz is too thin for a knife sheath in my humble opinion, it will get floppy on you . secondly I see no mention of any type of welt being used, if that blade has any type of Edge at all your stitches will last all of maybe two or three pulls, or the sheath itself  being so thin will catch no slack....Thirdly if your Stitch line follows the Contours of that knife at the distance it should 2X the thickness of the leather you will never pull that knife out of that sheath! Good luck and let us know how it goes 

I agree. Can I actually see the blade color showing thru the leather. My first sheath was made out of 5-6 ounce for a knife this size. I think that was too thin.

[supercub]

Lots of very good suggestions on this thread. 

I first used vacuum bags for knife sheaths almost 20 years ago and see a lot of the same issues I encountered.  First, you really need to use heavier leather and a welt.  Second, put the smooth side of vacuum the bag against the finished side of the leather and use a smooth piece of cardstock against the bag's hatch pattern to prevent unwanted marks on your sheath. Third, be careful with high detailed molding since it is easy to make a sheath that  is too tight.  A final suggestion that worked for me when vacuum molding with food saver bags - put the sealed bag/knife/sheath in the freezer until the leather is hard.  Remove the bag from the frozen sheath and leave it in the freezer for a few hours so it can "freeze dry" (works best with a frost free freezer).  It won't dry completely, but it will evaporate a lot of the moisture and retain its shape so that it can air dry without loosing detail.

Looks like you've got a good start.  A little tweaking and it ought to work out well.

[BDAZ]

4 minutes ago, supercub said:

A final suggestion that worked for me when vacuum molding with food saver bags - put the sealed bag/knife/sheath in the freezer until the leather is hard.  Remove the bag from the frozen sheath and leave it in the freezer for a few hours so it can "freeze dry" (works best with a frost free freezer).  It won't dry completely, but it will evaporate a lot of the moisture and retain its shape so that it can air dry without loosing detail.

 

GREAT! suggestion!!

[noobleather]

9 hours ago, supercub said:

Lots of very good suggestions on this thread. 

I first used vacuum bags for knife sheaths almost 20 years ago and see a lot of the same issues I encountered.  First, you really need to use heavier leather and a welt.  Second, put the smooth side of vacuum the bag against the finished side of the leather and use a smooth piece of cardstock against the bag's hatch pattern to prevent unwanted marks on your sheath. Third, be careful with high detailed molding since it is easy to make a sheath that  is too tight.  A final suggestion that worked for me when vacuum molding with food saver bags - put the sealed bag/knife/sheath in the freezer until the leather is hard.  Remove the bag from the frozen sheath and leave it in the freezer for a few hours so it can "freeze dry" (works best with a frost free freezer).  It won't dry completely, but it will evaporate a lot of the moisture and retain its shape so that it can air dry without loosing detail.

Looks like you've got a good start.  A little tweaking and it ought to work out well.

Yeah great advise,thankyou