Kydex assistance please.

dwardo

Bushcrafter through and through
Aug 30, 2006
6,463
492
47
Nr Chester
Hi All and Happy new year :)

I have decided to give Kydex a go with the aim of making a few leather/Kydex hybrid setups. I have done the usual and watched a few Youtube Video`s so obviously I am now an expert on all things Kydex :happy:

Whilst I get the basic principals what I am after is a assistance with sourcing the bits and bobs to get me going. So links preferably Amazon for ease to both the kydex sheet (no idea what thickness I need), the thick foam to use in the mould (way to many to chose from) and also the eyelets/associated crimping device.

Leatherwork side I am all good.

Thanks in advance,
 

C_Claycomb

Moderator staff
Mod
Oct 6, 2003
7,624
2,686
Bedfordshire
Sorry. I bought nearly all my bits from Knifekits.com in the US. The foam needs to be heat resistant (I don't care what anyone else claims, blue kip mat foam is almost worthless). I see it as time vs money, and I value my time more. By buying from a source that is dedicated to knife supply (and Knifekits are arguably the best), time is saved on figuring out what will work.

I don't know if they have any annoying objections to UK shipping now, but I would not expect so since it will be easy to rack up more than £135 on parts and materials.

While you can make small things and kydex sheaths with a single piece of foam, cut into two halves, I would recommend getting two squares.

If you build a press, the 600lb Irwin Quick Grip clamps are what you want. Do not waste your time or money on anything else....even if you have a load of other clamps already. A high compression, fast acting press makes a huge difference. Vertical presses are better than DIY hinged presses. More versatile, less likely to cause slippage, easier to get high compression.

1.6mm to 2mm kydex will do for bushcraft knife size sheaths. Thicker is better for belt loops, although UPVC down pipe is probably even stronger for belt loops.

Two pairs of cotton gloves from Boots allow you to hold and manipulate the hot plastic.

1/4" eyelets are the standard. These are eyelets that fit in 1/4" diameter holes. NOT eyelets with 1/4" inner diameter. I think they have a 3/16 inner. Press tool flaring dies are better than dies that you hit with a hammer. I use my big bench vice to drive the dies. You can assemble sheaths with Chicago screws, especially the kind where the male part can pass completely through the female. I have some 1mm rubber sheet and use a 10mm and 6mm punch to make washers that go under the Chicago screws so that there is a little give when tightening them down.

Register at kydexpro.com forum. Some good info, but you have to register to read.

The standard fasteners often sold for Kydex use 8-32UNC screws. If you need extra screws, I can recommend Accu Screws here in the UK.
 

dwardo

Bushcrafter through and through
Aug 30, 2006
6,463
492
47
Nr Chester
Thanks Chris. I was hoping to gently ease into it cost wise but I get that the right tools make the job easier.

In regards to foam there is a huge choice on Amazon but will keep reading. Shipping wise I am not getting stuff that's been shipped from within the UK never mind the states, its a complete mess at the min but hopefully that will change.

I will sign up for kydexpro and have a look see.

Thanks.
 

C_Claycomb

Moderator staff
Mod
Oct 6, 2003
7,624
2,686
Bedfordshire
carry Kydex, and they are a lot cheaper than
but the latter carry the proper eyelets without going to the US

Good video on this page.

Regarding the choices on Amazon, there are an awful lot of listings for the same foam from different sellers as if it is different foam. All described the same "EVA foam, medium density of 38 density." Personally I try hard not to buy anything from Amazon, on principle, but I am particularly wary of Chinese sellers on Amazon, and that does seem to be where a lot of the "Kydex moulding foam" sellers are from, with names like xiemao, xiangsing, duilianshangwuzixun and fuzhoujiasimeigoumao.
 

zackerty

Nomad
Dec 16, 2004
329
70
Christchurch...New Zealand
The correct foam is EVA

Ethyl vinyl acetate, 40 density, the type they use for running shoes etc for the spacer between the sole and shoe...
I use 20 to 30mm thick between two 6mm plywood backed "plates."
I stand on the mold and balance like a ballerina for at least a minute, and the check for fit around the knife... :)
 
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ESpy

Settler
Aug 28, 2003
925
57
54
Hampshire
www.britishblades.com
Remember the days when some silly bugger would buy up a load of 8'x4' sheets by the pallet from the importers and chop them down to 1' squares and flog them at little more than cost?
:D

Chris' advice is spot on. I'd maybe suggest the Screwfix speed clamps, as a possible alternative, but the throat depth isn't great and it can be problematic if you're doing anything large.

Rivets really should be flared, but even with graphite in the dies sometimes the little sods tear.

I'm sure I used (foamed) neoprene in the early days? Not greatly temperature tolerant IIRC.
 

C_Claycomb

Moderator staff
Mod
Oct 6, 2003
7,624
2,686
Bedfordshire
Remember the days when some silly bugger would buy up a load of 8'x4' sheets by the pallet from the importers and chop them down to 1' squares and flog them at little more than cost?
:D

Chris' advice is spot on. I'd maybe suggest the Screwfix speed clamps, as a possible alternative, but the throat depth isn't great and it can be problematic if you're doing anything large.

Rivets really should be flared, but even with graphite in the dies sometimes the little sods tear.

I'm sure I used (foamed) neoprene in the early days? Not greatly temperature tolerant IIRC.
I think I may still have a little of one of those sheets. I was sold it as a 4'x4' piece! Right PITA to carry across the showground back to the car :lmao:

Regarding clamps and presses. I started with a DIY hinged press with long handle. I didn't do a good job designing the hinge and as result I didn't get the best of results. When I changed to a book press (as in like what was used to press books, not open like a book) I tried some lighter quick grips than some sturdy Record F-Clamps before finally getting the 600lb Irwin Quick Grips like the pros recommend. Wished I had used the latter clamps from the start, saved myself much time and poor pressings.
 

demographic

Bushcrafter (boy, I've got a lot to say!)
Apr 15, 2005
4,758
781
-------------
I have absolutely no experience with kydex but as a carpenter who has some Record/Irwin quick grip clamps,everyone who uses them rates them.
One of those tools that just helps out in so many situations although for me the 150mm version is a bit small for most uses, the 450 one is good and the 600mm more versatile.

I expect that the 150 would be fine for kydex pressing but limited otherwise.
 

C_Claycomb

Moderator staff
Mod
Oct 6, 2003
7,624
2,686
Bedfordshire
for clamp capacity, you want at least 100mm working access, 150mm better, then you need at least 50mm to accommodate two layers on 25mm foam, and I would recommend 36mm more to work with 18mm backing plywood. I think the 150mm version does not have enough capacity. I think mine are the 30 or 45cm version.
 

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