backspine/grinder question

[darrin]

i am currently making a GX6. i would like to do some filework on the backspine and i also want the backspine to fit flush with the liners. should i grind down the backspine to meet the liners before or after the filework? file work aside, can i do this reduction of of the backspine while i also shape the scales? i assume i should use the 1 x 42 belt sander that i just purchased. any guidance on what grit(s) to use to do this? any input is most appreciated and will save me 'experimentation time'. thanks in advance.

[Ray Rogers]

You should grind the spine before doing the filework, otherwise you risk grinding away the filwork later.

I grind the spine, scales, and liners all in one chunk but it doesn't have to be done that way. With a 1x42 you may have to grind some parts separately to keep from bogging the machine down.

Same grits are used as for most any other grinding job. 60 grit if you need to move a lot of material, then 120, then 220, then 400 and then as far as you want to go. Depending on the belts you use, your grits may not follow exactly these numbers - they're just a guide line...

[darrin]

thank you for the help. i plan to gring everything in one chunk as well.

[Osprey Guy]

Here's a couple of thoughts/ideas for you...

Back when I was making kit knives I did more than my share of backspines, both from the stock spines that are sold by knifekits.com and spines I made myself...and I might add, the GX6 was one of my favorite kits. If you bought the spine from knifekits.com it's gonna sit a bit "proud" above the liners. They do that on purpose to give you the option of leaving it slightly raised (which when done well can be a really handsome, desireable look...especially depending on the filework pattern).

Since your liners come to you pre-made to size, I would not suggest grinding the backspine to shape while attached in-between the liners. That is the method you will probably want to use later, when you start making your own liners...But for now you probably should approach it a little differently. If you try grinding the spine while it's screwed in place you greatly risk grinding into the liners, especially without practice...and on a small grinder that might not be steady enough to allow for such fine finesse. It can be done, but it takes a careful, gentle, and practiced touch. And there's really no need to risk it.

There's always more than one way to skin a cat...here's what I recommend...
Start off by putting the knife together, with the oversize backspine screwed into place. if you want the spine to be flush with the liners, then carefully score the oversize spine where it rises up above the liner edge. This will be your grind line for the backspine (if you want it "proud" than use a marker instead and let that marker line be your guide, and grind to slightly above the line). Then take the knife apart and use the score as a guide as you grind it down to the desired size. You're not going to be removing a whole lot of steel, and what little you are removing should be done with finesse, not brute force. So I would start off with a finer belt in your grinder...maybe a 120. Leave it slightly oversize because you're still gonna loose a little more material as you sand it to a finer finish.

Before I begin filework I like to start with a good, clean "canvas"... So you'll want to get the backspine to a nice finish...but no need to go nuts at this stage. No need to go beyond 400 at this time....because you're just going to wind up going back over it again after you complete your filework. Then you'll want to hand finish it to 800 or better. BTW-Until you have more practice with the grinder you might want to consider hand-sanding the backspine the rest of the way after you get it to the initial rough size with the 120 grit belt.

FYI- For my first 1/2 dozen kits I used my Dremel to grind down the spine....worked fine.

Have fun!


Dennis Greenbaum

[darrin]

thanks for your advise. it is well taken and appreciated.