More Micarta Questions

David Wesner

David Wesner

Joined
Jan 5, 2005
Messages
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I'm currently working a full tang O1 blade that I'm putting linen micarta scales on.I'm using a couple Loveless fasteners with some mosaic pins,([1] 1/4" pin & [2] 1/8) + a 1/4" thong tube.I have noticed considerable shrinkage when drilling the micarta.As far as the 1/4 pin and tube I had to go back and ream the scales with a .252 reamer and they are still tight.The loveless brass pieces mic. @ .312,I had initially ground my own 5/16 step drill but had to go back and ream to .314 and let the reamer dwell for a moment(they push in pretty nice now.Now for the assinine move on my part,the 1/8" mosaic pins are currently stuck in the blade and scales I'm sure I will end up scrapping,(I have more to finish the job so no big deal,just a learning curve).I was getting close to finish grinding the scales before final glue up and thought that I would just "tap" the 1/8" pins in to locate everything correctly and when I went to disassemble I found that I could not get the scales off because the pins are basically press fit into the scales.I plan on using a slightly ground down .125 punch to drive the pins out and redrill the scales with a #30 drill(.1285) for the 1/8 holes.I dont know what I was thinking when I tapped those pins in after finding the other holes tight.I have found consistantly about .003-.004 shrinkage on all the holes I have drilled in the micarta.What do you guys do when using micarta?I have put a nice size countersink on the blade holes and the backside of the scales for glue room.Which brings up another question.The micarta is very smooth and shiny on the purposed glue side,do I need to rough it up a bit for good addhesion?I have drilled 8 glue "ports" in the tang,should I do the same on the scales too?Also I have JB Weld and several epoxy's on hand.What is my best choice for the materials I am using?Sorry for the long post.All constructive critisism is welcome.Every day is a new learning experience.I LOVE IT !!
 
My only criticism is to stop using so much damn precision. See where it's gotten you! ;) Since you obviously have a background in machine work (or at least measuring stuff), I suggest forgoing the fixed blades and go straight to folders! :D
Seriously, from what I've noticed, when I use what is sold to me as 1/8" pin material, I use a 1/8" drill bit. Same for 1/4". I may even work the bit in and out a bit to very slightly enlarge the hole, and this is for the exact reason you mentioned. I tried to get all fancy schmancy on my last knife and I drilled/reamed a true 1/8" hole. Everything fit so tight I couldn't do a mockup or get things back apart. I had to drill my pins out to start over. So, I say when you're using epoxy on a regular user fixed blade to just go caveman. Having a bit of play in the works will give your epoxy some room to move in, too. Unless I screw up while drilling, I've never seen a gap in a 1/8" hole I put a 1/8" pin in that could be seen with the naked eye, personally.
 
I think I will write that advice on my shop wall.I am still learning and I need to here stuff like that!Thank You.Sincerely!!
 
Oh, and just because I said it doesn't make it so. Just my opinion! I'm the opposite. When it comes to anything precision I fall apart. Must be a happy medium somehere! :D
 
You need precision/accuracy in folder making. While I do agree that you can be a little "off" or "oversized" in a small hole in a micarta scale, at the same time, most everything else needs to be precise.
Some materials just have a little shrinkage. Titanium does that, and many guys use the next size up, when tapping.

Trapper,
May I ask how you ground your own size drill bit, to a custom size?
I have heard this done many times, and would like to know the procedure, and the tools needed.
THanks.
 
For a full tang knife I use a letter F drill to drill a 1/4 diameter hole and a #30 drill to drill a 1/8 diameter hole. I have found that if you use a 1/4 inch and 1/8 inch drill for micarta the hole will be too small. Also if the holes are too tight then there is no room for epoxy.
 
Thanks for all the responses and sorry for the long response time between my posts,I was offline for awhile.I will try your technique Mr. Lewis,that was definately a concern I had,the lack of glue space around the pins and tubing.Razor-I didnt actually grind a "custom size drill".What I did was just make my own step drill for the Loveless style fastener.I checked the major dia.on the screw that comes with the fastener @ .160 so I used a #18 drill (.1695) for my clearance drill thru the tang and the scales for the screw.The little brass pieces that come with the fastener I checked @ .312 dia. x .286 long. I just took a 5/16 drill and chucked it up in my cordless drill and dressed a nice sharp corner on my standard 6" bench grinder and using my opti-visor so I could see a little better I started the drill spinning and ground a .156 pilot on the end of the 5/16 drill.after grinding the pilot I took the drill out and ground some relief on the btm.cutting edge and it was that easy.Nothing fancy but functional.I dont know what size the step drills are that you can buy in Catalogs like Texas Knifemakers supply but I imagine they are similar to my sizes.Standard rule of thumb clearances for socket head cap screws are generally 1/32 over nominal size and standard counterbore pilots are generally ground for that.That seemed like to much slop for me,so I just made my own.Like I said though,I had to go back with a .314 reamer into the 5/16 counterbore to get a good fit for the brass pieces.I think I will remake the step drill with an "o" drill which is .316 and that should work without having to go back and ream.And Razor thanks for the heads up on the Ti being similar to micarta as far as shrinkage,I will remember that.Thanks again guys.Talk to you later
 
when I drill my micarta I use a drill clamp shown in the link. This keeps the micarta where it should be. On the drill table and not riding up the drill bit.
http://bgoodeknives.com/images/tangholes.jpg
After I drill the micarta the hole is ragged. Dont worry about it....I do make sure that the pieces are knocked back and away from the hole so they wont fall into the hole and block it up when I glue everything up. I also use one screw to hold the brass nut and press that sucker in the hole to make sure the hole is big enough. I use a steped drill bit from texas knifemakers supply. (DONT USE THIS BIT UNLESS YOU CLAMP THE MICARTA DOWN. IT WILL RUIN THE PIECE BY BEING JERKED UPWARD)

Anyway. when your glueing up just have your drill ready and that will pull the bolts in the hole for you. You dont need them to fit loose before hand but some may not agree.

Hope I didnt ramble too much and someone else may help correct me if I am doing something wrong too ;)
 
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