Finished Scales to Rat 2! Link to gallery

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Tll6

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May 14, 2016
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Hey guys. I posted a thread about scalloping the stock scales on an Ontario rat 2. I have since decided not to attempt any modifications and instead make new scales out of micarta.

I will be using a rotary tool for the rough shaping and then files and sandpaper to finish it off.

I have a few concerns before I begin construction:

1) how straight do the screw holes need to be? I don't have a drill press so I will be attempting to hand drill the holes as level as possible (any tips are welcome). I know the pivot holes are going to be most important to avoid blade centering issues

2) after disassembling the knife to polish the bushings I found the stock scales have almost a rim around the side that contacts the liners. Will I need to machine this into the new scales or is it okay if they just sit on top of the liners?

3) the most important issue: can I expect the results to come out decent? I have made fixed blade scales before which came out to my liking, and I am pretty handy. The thing I am most worried about is drilling the holes precisely enough so they don't screw up centering or end up not tight enough.

Thank you for any help you provide!
 
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You should make all the holes as straight as possible, they all will have a effect on blade centering and lock up. I don't think that there is a need to mill the small lip that nest the scales to the liner for any other reason that looks.....welll I guess it would add a certain amount of strength ...but not necessary. I say go for it, the worst that can happen is that you mess up some Micarta and learn something in the process.
A few tips.
Use the stock scales and not the liners as a template to mark / drill your holes.
Clamp everything solid before drilling.
Drill pilot holes
Drill holes before grinding a pattern into the scale.
WEAR A RESPIRATOR!!!!! and eye protection too.
Good luck and have fun with it.
 
Thanks for the response.

My girlfriend's dad might actually have a drill press I can use so we will see about that. I'll pick up a respirator before I start. Hopefull if it isn't hot as hell outside I can do most of the grinding outdoors.
 
The holes need to be placed accurately, but straightness of the holes isn't likely to be a problem. I often drill them with a rotary tool. Drilling a pilot hole first is a wise method.
 
Stacy E. Apelt - Bladesmith said:
The holes need to be placed accurately, but straightness of the holes isn't likely to be a problem. I often drill them with a rotary tool. Drilling a pilot hole first is a wise method.
Click to expand...

Oh okay that is a relief. I can usually drill accurately just not very straight.

Does anyone have any advice on tapering/countersinking the holes? Do I just use a larger drill bit to allow the head of the screws to fall into place? I'm planning on measuring how much of the threaded part of the screw leaves the original scales and try to match hat by slowly taking material out of the hole on the new scales and measuring from there. Hopefully that made sense
 
You can use a larger drill bit to countersink for the screws. Not ideal, but it will work. I'd suggest you start out with a shallow depth on the countersink and see how that fits, then go deeper. Remember, you'll need to countersink them deep enough so you can still shape the handles as you want. You can always go deeper later if you need to, but you should try to get the depth right before contouring the scales, if possible, or the holes won't come out round if you have to make them deeper after contouring (if you are countersinking with a drill bit).

Also, if you're open to it and it isn't too late, I'd suggest using G10 for the scales. G10 is "softer" or less dense than micarta and much easier to shape using crude tools.
 
I think the method you described is what I was trying to explain in my previous post. I'll probably drill all the holes in the roughed out scale before I do any finer details to it.

I've already ordered the scales but I think a harder material will be better for me. It will prevent me from taking too much off too fast, which seems to be a problem I have lol. I also really like the ringed patterns that show when micarta is contoured.

I'm planning on doing an Anso contour on the handles and leaving the area where the pocket clip touches the habdle flat and smoot to prevent snagging. Good idea or bad idea? I was thinking of just doing a slightly rounded shape, but if I do that it isn't going to look much different than the stock scales. Maybe frillier but still look flat black
 
Transfer punches will be very helpful. If not a full set, just get the sizes you need.
 
I like to use masonry bits for countersinking holes on soft material like micarta and plastics. They don't cut as fast as a metal drilling bits and is easier to control the depth, and will center itself in the hole drilled for the screw.
 
I do live near a harbor freight so maybe I'll go check out what they have. I'll look into masonry bits too. Thanks!
 
If by "countersinking" you mean the stepped hole that button head scale screws are placed in, that is done with a counterbore. It drills the shaft hole for the screw and the seat for the screw head all at one time. You can drill a hole with a smaller bit for the shaft and then carefully drill the head seat with a larger drill, but there is a lot of variability in doing that. If you don't want to buy a counterbore ( most knife suppliers sell them, as well as places like Mcmaster-Carr), a better choice is to use a small cylinder burr in your rotary tool.

If you mean an angled seat for a flat head screw ( usually 82 degrees), then a small 90 degree bearing bur ( AKA setting burr) is the best way to make the seat foor scales. A jeweler will probably give you an old one for free. You will need one that is about .2mm larger than the screw head.
 
By countersinking I meant the stepped hole. Sorry about that. I have a few cylinder burrs so maybe I will do that instead. If I have any scraps of micarta left I'll see what works best. Would I just widen the hole with the cylinder burr, grinding around the edge?
 
Yes, drill the smaller pilot hole and then re-drill it to the screw shaft size. Use the cylinder burr to carefully bore the seat by slowly lowering it down on the starter hole. Go slow and don't cut too deep. You can always make it deeper later on. Try hard to hit the shaft hole centered.

If you have doubts about your skills, use a drill bit that is just a tad smaller than the screw head and just barely start the seat. Then switch to the cylinder burr to square up that starter seat and deepen it.
 
Great I'll give it a shot

Any advice on how to remove material for the liner lock scale side?
 
Like I said drill with a masonry bit after your pilot hole as you advised you have a hard time drilling straight. A masonry bit won't bite like a standard metal drill bit in soft material givimg you more control since you sound like you're drilling by hand without a drill press and a bur has the chance to walk all over the place If you want a flat bottom then switch to the Cylinder bur to flatten the bottom. Likely the holes are too small to matter that the masonry bit has a slight angle on the tip vs the size of the pilot hole the screw goes through. The bottom of the hole will virtually be flat for the size fastener you're using.



This is a piece of PTFE I used to make replacement vise jaws for a 2" vise. Drilled the pilot hole with the screw size and counterbored/countersank the hole with a masonry bit. Zero effort as its bit self centered and cuts slow unlike a metal bit and easier to control than a cylinder bur that will have a tendency to bite and want to walk and the very very small angle left by the masonry bit is unnoticeable and will fasten just fine with micarta.
 
I'll see if my local store has any in the sizes I need. I'll practice with regular bits first and if they don't workout I'll pickup some masonry bits

For the liner side question I meant the almost ramp that is cut into the scale. I think it is meant to allow the liner lock to disengage. Is there any tool that is used to make that? Maybe a chisel?
 
I'm not an expert but I have reasonable tools and I try to be careful. Here is a caution-
I was cutting some micarta scales for a fixed blade project and countersinking holes in the scales with my drill press. I have a new set of sharp bits and the sharp bit grabbed the scale and drilled all the way through it before I could see what was happening. I've drilled and countersunk more than a dozen sets of scales before this without problems. I'll be more cautious next time to be sure that the scales are held down on the drill press table well enough.
 
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