Bolster wrote: ↑Tue Mar 16, 2021 1:34 pm
I just wanted to bring a pic of this nice looking modified Mule down further. I didn't mean to hijack the topic with my kydex suggestion.
TomAiello wrote:
That's a really nice looking Mule modification. :)
Xplorer, I'd love to hear your detailed instructions on kydex. Fitment issues are a continuing problem for me.
For someone that is already doing Kydex it would be easier if you tell me what you're having trouble with specifically and I'll offer my best suggestion for addressing that issue.
But, to offer a starting point here's some tips..
Basically if you have a problem fitting kydex it's either too loose or too tight. Let's examine the causes of each.
Too loose -
1. The knife wiggles and rattles in the sheath....
A. Most likely either the kydex was not hot enough or pressure was not applied quickly enough and therefor too much cooling is allowed to occur prior to molding. This results in a shape that is not as detailed and does not conform to the edges and contours of the knife crisply. Solution is to increase oven temp or soak time depending on the temp and soak time you were using...or (very important) get the pressure applied to the hot kydex faster. As fast as possible. I set up my oven directly above my press so that I can make that transition as fast as I can. Even though I have my temp, soak time and process all dialed in now, sometimes I struggle with placing the knife in exactly the right place quickly enough and end up having to re-heat and re-do. When this happens to me it's almost always with folded sheaths, as it can be a PITA to get the spine exactly where you want it and line up the drain hole quickly enough.
B. Too much tape was used on the blade or handle during the molding step. The solution is obvious.
2. The knife pulls out of the sheath too easily...lacks enough retention.
A. The placement of the top eyelet or grommet is critical for retention. If it is placed too low it will allow the kydex to flex too easily at the retention / flex point. This is not so much a fitment issue as it is a design/engineering issue.
B. The amount of kydex that wraps around the grip point on the knife/handle will change how hard it is to insert and remove the knife. Too little material won't hold the knife securely enough, too much makes the knife hard to insert into the sheath. Each knife is different in this regard and some provide a better natural gripping point than others. Again this is not so much a fitment issue as it is a design issue.
Too tight -
1. It's hard to insert the knife and there's a lot of friction removing the knife.
A. No tape on the blade while molding can result in such a "perfect fit" that it leaves no room for movement at all. This generally results in "great" retention but makes it hard to use the sheath. It also results in debris getting jammed between the blade and the kydex, eventually in-bedding itself in the kydex, and then sheath scratches the blade every time you use it. Solution is to use 1 or 2 layers of clear packing tape or similar on the blade to add slightly to it's thickness, but be careful not to use too much. **IMPORTANT** take your time and cut and place the tape carefully. Bring it right up to the back edge of the ricasso but not onto the handle at all. No tape is needed on the handle as that will just result in a rattling knife and reduce retention needlessly. You may need to experiment with the thickness of tape you have in order to decide if you prefer 1 layer each side, 2 layers on one side and 1 on the other, or 2 layers on both sides. I vary my choice a little depending on the knife but I generally use either 2 pieces on both sides or 1 on one side and 2 on the other. I have also use blue masking tape successfully but again you have to experiment with whatever thickness you use at first in order to know how much is just right.
B. The top eyelet is too high and not allowing the kydex to flex to the appropriate degree upon entry and exit. This is a design issue.
2. Can't get the knife out of the sheath without pulling dangerously hard.
A. Like above, the top eyelet may be too high. With some knife designs it's possible that it could also be too close to the handle and interfering with the blade.
B. There is too much kydex surrounding the handle near the flex point and some more trimming or sanding/shaping is needed.
These are the most common issues that come to mind, but if you have any specific concerns that I did not address let me know and I'll do my best to help you.
Best regards,
CK
:spyder: Spyderco fan and collector since 1991. :spyder:
Father of 2, nature explorer, custom knife maker.
@ckc_knifemaker on Instagram.