Here’s a fast and simple custom knife sheath project using ABS. ABS is very similar to Kydex but about one-half the cost so it makes a great material to develop your plastic fabricating skills with.
I purchased a bulk lot of Imperial Apex small fixed blade knives to use around the shop. The knives are decent quality and rugged enough for the price but the sheath supplied from the factory leaves alot to be desired. I needed a sheath that kept the knife handy and safely stored without the awkward two-handed snap retention strap. Multiple carry positions would also be a plus. This custom sheath can be clipped to your belt or pack with a carabiner or hung with cord anywhere.
The materials that are required:
1- piece of .060″ ABS, big enough to wrap around the knife blade and half the grip.
1- 3/8″ grommet, I used a canvas grommet because that’s what I had on hand.
1- carabiner. large enough to fit on your belt
Tools that are required:
Scroll saw
Belt or disc sander
Dremel with a cutting burr
sandpaper
Drill with a 3/8″ bit
hammer
grommet setting tool
CAUTION: Use gloves when handling the hot plastic and safety glasses when cutting the plastic and observe ALL safe knife handling practices.
A Sheet Press makes these types of projects much easier. This sheath was pressed in an improvised press made from a foam lined rifle case. I had to place newspapers under the foam to provide enough pressure to the plastic when the case was closed.
Pre-heat the oven to 250 degrees and place the plastic on an upside-down baking pan. Setting the plastic on a flat object will keep it from forming itself to the oven rack. Heat the plastic approx. 3 minutes until it is soft and workable and when soft, remove from the oven and wrap the knife as shown. Place it into your press, close the press and let the plastic cool around the knife.
Open the case and remove the sheath. There should be enough detail to show the outline of the knife and hilt. This detail will allow the sheath to have something to grip to and retain the the knife. If there isn’t enough detail to work with, put the piece back in the oven and try it again.
Remove the knife and install the grommet. Remove the excess plastic and roughly shape the sheath with a disc or belt sander. Next,work on the knife retention. This will require fitting the knife into the sheath several times and removing the excess ABS material around the knife’s scales or handle. You may need to use a candle to shape the sheath’s “mouth” to allow the knife to be placed in the sheath easily but be held firmly in place when seated fully into the sheath. Once you are happy with the retention, give the sheath it’s final shape and sand the rough edges. Here’s a photo of the completed sheath. It hangs horizontally from the carabiner.
And here’s a photo of this sheath and a variation that hangs slightly more vertical and can also be worn vertically upside down like a neck knife. The factory sheath is also shown for comparison.
Some notes and comments:
1) You can fasten these sheaths together with many types of fasteners: rivets, grommets and
chicago screws are some types of common fasteners.
2) Kydex and ABS can be found at your local plastics dealer or on ebay.
3) The above method is crude at best, but it gets the job done. A press designed just for this type of molding is available and recommended if you have many items to fabricate. UPDATE: Click Here for instructions to Build a Kydex Press
4) If you can work with wood, you can work with plastic. All tools used in this project are ordinary woodworking tools.
Justus
