Letter Re: Do It Yourself Kydex Sheaths and Holsters

Mr. Rawles,  
As a concealed carry permit holder I have a thing for gun holsters, being a big guy, I spend a lot of time making sure that my holsters are comfortable and work well with the clothing I wear.  Something I have noticed with holsters and “gun guys” is that we all end up with a box of old holsters we never use.  Looking through my collection I see that the majority of holsters I use on a daily basis are either Kydex or combinations of both leather and Kydex.  That is no surprise when you look at the benefits of Kydex.  Its cheap, rugged, non-marring of your gun’s finish, moldable for good retention, smooth for a consistent draw, and does not react to normal temperatures or gun solvents or oils.  

Being a do it yourself (DIY) enthusiast, it did not take me long to want to try my hand at molding Kydex.  For those of you that do not know, Kydex is the trade name for a propriety thermoplastic sheet.  It’s rigid and strong, but when heated to about 330-380° it becomes pliable. (The sheet will burn at a temperature greater than 400°F).  Kydex does not have a memory, so that once it has cooled; it retains the shape it was molded to fit.  Kydex is not the only plastic compound that has this property, but what makes Kydex so valuable to do-it-yourselfers is that unlike other heat formable plastics like PVC, Kydex will not off gas toxic fumes at normal forming temperatures.  

Most people use either an oven (full size or toaster depending on the size of Kydex your working with), or a heat gun.  It really depends on the thickness of the Kydex your working with, and how big of a piece your molding as to which is a better heat source.  Normally I find the oven works best to begin the project, and I use a heat gun to spot heat for adjustments.   Besides a heat source, gloves, and trimming tools, one of the most basic tools to mold Kydex is a press.  A Kydex press normally costs from $80 to $180 depending on size, but it is a simple tool that I decided to make one myself.  

At its simplest a Kydex press is a rigid board with a thick piece of foam glued to it as a base, with top made the same way.  The heated Kydex is wrapped around whatever it will sheathe, and then sandwiched between the two pieces and then clamped or weighted heavily until the plastic cools.  

I went a little more complicated, as I put a set of hinges to connect the top and bottom pieces.  I connected them this way because I plan on making knife sheaths for the time being until I get enough skill to try more complicated gun holster designs and by being connected, it gives me more leverage for clamping.  If I was making a press for larger items like gun holsters, I would not add a hinge, or I would make the hinge adjustable.  

Being cheap, I did not want to waste Kydex practicing, so I searched for alternatives to Kydex that I could up cycle.  I needed to find thermoplastic that could be heated without off gassing cyanide or other toxic compounds.  It also needed to become pliable upon heating without turning liquid (this left out soda bottles).  I also wanted something that I could get from trash.  I doubt I would be able to get Kydex sheet in a grid down situation, and its not very high on my stockpile list.  

ABS sheet plastic is usable, but I found that the plastic from milk jugs and detergent bottles also work.  Milk jugs are thin, so heating them in the oven isn’t always practical, and they are not UV stabilized so they become brittle in the sun so they are not practical for holsters.  I did find that milk jugs do make great practice pieces, and I made sheaths for all my kitchen knives using milk jugs to practice. 

Thicker laundry soap bottles work great for knives.  They form easier than milk jugs, and you can “weld” the edges together with heat so you do not have to use rivets as you do with actual Kydex sheet.  

Whatever plastic you use, once it has cooled, its simple to open the press and trim the extra plastic away.  I use aviator snips for most of my work, but a dremel tool, band saw, bench grinder all would work as well.  

Some very good concealment holsters are made using both leather and kydex to utilize the advantages of both.  If take a piece of plywood and cut out the center in the shape of your handgun so that only half or a little more is molded into the kydex sheet, you can rivet the kydex to a large piece of leather and attach whatever mounting brackets you desire to the leather making a very comfortable and secure inside the belt concealment holster that molds to your body, while still giving you a slick kydex draw.   I must practice more to enhance my skill, but considering all the pros and cons of the process it is relative easy to do, and may provide for cottage industry after a grid collapse since many more people have guns and knives than have proper sheaths for them. – David N.

JWR Adds: Every family should own a basic leather-working kit, a riveting mandrel, a large assortment of rivets, and a large spool of sturdy waxed saddle stitching thread. That way, even after Kydex becomes unavailable, you can continue to make holsters and sheaths, the old-fashioned way.