Stuborn Micarta

C

CTone03

Member
Good afternoon, folks.

I've been a long time reader, and decided not long ago to become a member here. First off, I thank all of the people here that post pro-tips and answer questions for those who are trying to get into knife making. It's a big help. I appreciate what you do.

If y'all don't mind, I have a question (problem) that I can't seem to solve, and I'm looking for suggestions.

I'm working on my first commissioned knife, and it's a problem child. It's an O-1 EDC (5/32" thick) with a 3 1/2" blade and micarta handles. My customer wanted O-1 so that he can do his own patina, and as such he wanted to be able to remove the handles. To fasten it mechanically strong (without epoxy and pins), I used 1/4" x 5/16" SS standoffs in between the scales and the tang, with 8-32 high torque button-head screws counter bored into the scales. The scales are micarta with copper liners.

The problem I'm having is the scales will not sit flat on the tang. I have surface ground the knife on the grinder platen (KMG), and surface ground the copper liners as well, followed up with careful hand sanding. I get everything to sit flat and beautiful when I hold it together with my fingers and hold it up to the light, but when I put the screws in the scales lift off the tang at the top and bottom. It seems the flatter I get things, the worse it looks. My understanding as of right now is that the pressure that the screws exert makes the area around the standoffs bulge slightly, which lifts the scales, but I am open to other ideas.

At this point I want to throw this knife in the river, as I have put a ton of labor into making things right, but it's been an uphill battle. I'm a perfectionist, and that comes with a burden. I do not have a surface grinder, but it's on my list as the next piece of equipment to get. Am I going to have to accept some gap with using screws to hold the scales on? I've even made a jig that fits onto the outside of the scales in the screw-holes to put pressure on them like the screws would when tightened; the grind pattern is definitely different, but when I put the knife together the gaps still appear, and really look worse. I would appreciate your thoughts and ideas.

Thank you all very much!

Respectfully,

Carlton
 
As with solving most problems, the more pictures the better.
have you tried tightening both screws at the same time, slowly, to equalize the pressure? I'm almost sure you have.
perhaps the hole bored to fit the screws in slightly askew or something is snagging the assembly? that would cause some misalignment when tightened.
 
Thank you for your reply. I did try different pressure with the screws, but the gap is still there. Attached are pics:

DSC_0538_zpsfbf9d31c.jpg.html
DSC_0539_zps69929f83.jpg.html
DSC_0540_zps407670a5.jpg.html
DSC_0541_zps7bfb11bf.jpg.html
 
lay everything on something flat, a piece of granite or glass and check for flatness, it sounds like your holes are raised either in the micarta or the blade.sometimes the micarta will raise a little from the heat from drilling.
 
bladegrinder said:
lay everything on something flat, a piece of granite or glass and check for flatness, it sounds like your holes are raised either in the micarta or the blade.sometimes the micarta will raise a little from the heat from drilling.
Click to expand...


I will check on that. Thank you.

Are my pictures visible?
 
As you can see in the first pic, the plunge lines look terrible. The blade had a slight kick to the right after heat treat, and I had to regrind it flat, which took material off the right side. I'm not happy about that, but it's been a learning experience. I'll order precision ground stock until I get a surface grinder.
 
Carlton, it seems to me that some of your difficulties may be due to the positioning of your screws. I suspect the middle screw when tightened is forcing the front of your scale assembly to bend upward. I would not spend any money on either a surface grinder or precision ground stock at this time.
 
Jon Kelly said:
Carlton, it seems to me that some of your difficulties may be due to the positioning of your screws. I suspect the middle screw when tightened is forcing the front of your scale assembly to bend upward. I would not spend any money on either a surface grinder or precision ground stock at this time.
Click to expand...

Sounds right. I cannot add another screw forward because the drill bit won't even scratch it. But yeah, the knife looked good on paper. Next time I'll add a screw further forward or space them out. Why no surface grinder?

Thanks much!
 
Jon Kelly is right, you have to spread out the load.

As for flattening on your platen, chances are nothing is really flat. The platen has a tendency to slightly radius anything from the top down (direction of belt spin). If your heart is really set on that screw configuration, Scribe the inside of either your tang or scales 3/16" from the edge all around and relieve the surface inside the lines with a small sanding drum on a dremel. This will allow the ends of the scales to lay down tighter. That's the quick fix (maybe) but it won't be pretty when taken apart. Personally, I'd go after both scales and tang by hand sanding and using the glass as suggested to flatten the scales. You might as well learn something while doing it right.



Rudy
 
CTone03 said:
Why no surface grinder?
Click to expand...

I suppose if you can source one at a good price it would be a great asset to have, however as illustrated in this case, getting things flat is not necessarily the only determining factor in final fit and finish. I would simply hate to see someone lay out such a considerable sum of money for a piece of equipment to solve an issue that could be resolved through other means most of the time. For example, a 9" disk grinder with machined flat faced disks would be a cheaper alternative to the surface grinder, yet still provide satisfactory results. It is also important to remember that no amount of equipment (or glue,lol) will overcome improper procedure, poor planning or bad design. My two cents.......
 
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Rudy Joly said:
Jon Kelly is right, you have to spread out the load.

As for flattening on your platen, chances are nothing is really flat. The platen has a tendency to slightly radius anything from the top down (direction of belt spin). If your heart is really set on that screw configuration, Scribe the inside of either your tang or scales 3/16" from the edge all around and relieve the surface inside the lines with a small sanding drum on a dremel. This will allow the ends of the scales to lay down tighter. That's the quick fix (maybe) but it won't be pretty when taken apart. Personally, I'd go after both scales and tang by hand sanding and using the glass as suggested to flatten the scales. You might as well learn something while doing it right.



Rudy
Click to expand...

Awesome. I will give that a try with the dremel, as you said by scribing a line. If I can get it flat, I'll still sell to my customer at materials cost. The labor I put into it is now vested in lots of experience. I love this stuff. I know I'll get better with time.

Thank you!

ETA: I'm not sold on the screw configuration; I had just finished drawing it about an hour before the guy said he wanted it. I see now that I can add either a third screw or space the two out better. I have very little experience with screwed handles (pardon my pun); I like pins or SS tubing epoxied to the handle.
 
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Jon Kelly said:
I suppose if you can source one at a good price it would be a great asset to have, however as illustrated in this case, getting things flat is not necessarily the only determining factor in final fit and finish. I would simply hate to see someone lay out such a considerable sum of money for a piece of equipment to solve an issue that could be resolved through other means most of the time. For example, a 9" disk grinder with machined flat faced disks would be a cheaper alternative to the surface grinder, yet still provide satisfactory results. It is also important to remember that no amount of equipment (or glue,lol) will overcome improper procedure, poor planning or bad design. My two cents.......
Click to expand...

I have a 6" disk grinder, and it works within reason for small knives. My brother and I are both making knives, and we would both benefit from having one. I have found that I can make both sides pretty flat - though not "precision" flat - but I know that both sides are probably not parallel. I'm not sure if this makes a difference with occasional warpage; because material is taken away unevenly, would that make the blade favor one direction over the other?

Fit and finish is definitely something I have to work at. I have the drive to do it right. Improvement will come with time.

Thanks again!
 
Before you go scabbing it up.....
Consider flatening your scales first. That copper should come down more easily than any other thing you'll try.


Rudy
 
This may be a dumb idea, but it's just an idea. I do a little woodworking too, and when you need to clamp up a panel that's pretty wide, you can't always get a clamp to the middle of the work piece. Common trick is to used a curved clamping caul. That's just a board with a gentle curve belt sanded onto one edge. When you put the curved side down and clamp the ends, it puts even pressure across the whole caul.

Couldn't you do the same thing, except in reverse? If you could find or make a very gentle radius sanding block and sand a slight recess across the bottom of the scales, they should pull down evenly. It would have to be an even radius from end to end, but I think it might work. Basically, exaggerate the problem you have now, but in reverse. Does that make sense?
 
I may be looking at this from the wrong side of my brain but, if the center has too much pressure and pulls the ends up, wouldnt recessing that area exaggerate the problem?
 
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chevytrucking said:
This may be a dumb idea, but it's just an idea. I do a little woodworking too, and when you need to clamp up a panel that's pretty wide, you can't always get a clamp to the middle of the work piece. Common trick is to used a curved clamping caul. That's just a board with a gentle curve belt sanded onto one edge. When you put the curved side down and clamp the ends, it puts even pressure across the whole caul.

Couldn't you do the same thing, except in reverse? If you could find or make a very gentle radius sanding block and sand a slight recess across the bottom of the scales, they should pull down evenly. It would have to be an even radius from end to end, but I think it might work. Basically, exaggerate the problem you have now, but in reverse. Does that make sense?
Click to expand...

Chevy,

I tried exactly that at first, when the scales wouldn't sit down. That was before I added the copper liner. I put a slight curve in the center of both scales, so that I could see light in between, and when I squeezed slightly with my fingers everything went nice and flat; but when I added the screws the gaps appeared again. Ultimately, I didn't do so hot with the placement of the screws. But as I see it, if I can bend micarta with just finger pressure, then screws would only make things worse. I haven't seen this problem before when using pins, as I don't think they put that much downward force on the scales.
 
Sounds to me like your holes are misaligned with each other. The holes in the liner, tang, and micarta must be drilled at the same time.
 
Wall e,
No, your brain isn't lopsided. You're right in principle but when I saw that he "surface ground" everything on the platen.....my brain tells me that all the edges could be lower than the middles. Without the knife in hand, it's tough to know. I'd like to think I learned something about my belt grinders in the last 30+ years. That's also why I wrote "maybe". I still maintain going at it properly instead of the quick fix. In the time this has been kicked around, I could have fixed the problem by hand flatening and had another knife going.


Rudy
 
Rudy Joly said:
Wall e,
No, your brain isn't lopsided. You're right in principle but when I saw that he "surface ground" everything on the platen.....my brain tells me that all the edges could be lower than the middles. Without the knife in hand, it's tough to know. I'd like to think I learned something about my belt grinders in the last 30+ years. That's also why I wrote "maybe". I still maintain going at it properly instead of the quick fix. In the time this has been kicked around, I could have fixed the problem by hand flatening and had another knife going.


Rudy
Click to expand...

Perhaps surface ground was not an ideal word; the platen is the best I have for now. I did hand sand the tang twice - the first time I did feather the bottom edge of the tang down; I couldn't see it but I checked with a caliper. I then reground the flats and very carefully hand sanded again. I did the same to the copper liners.

It's very obvious that I have jacked this one up pretty bad. As y'all have pointed out, it's probably a number of things that I'm working against. For the time being I am taking Jon's advice and looking into a good 9" disk sander. As for a surface grinder, I'm keeping an eye out on Craigslist for a used one at a decent price. I'd like to be able to make things precision ground, as that's one less factor that I will have to worry about.

Thank you all for taking the time to reply to a newb!
 
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