Can it be too tight.

Mark Barone

Mark Barone

Well-Known Member
Sorry for the click bait, but it is really the question. This is in regards to to pins and handles. So the holes I drill in the blades, the pins slide In nicely. But I like it when my pins are just a bit larger that the holes in the wood scales. Then just turn the pin in my drill and sand it down until it just fits with a bit of pressure. I don’t like seeing the epoxy around the pin. But is that micro amount epoxy enough to hold it together ?
 
Pins that are snug will eventually crack wood or bone scales. Maybe not right away but eventually as material expands and contracts with humidity. Look at all the old knives with cracked handles. Gather some wood dust of your handle material in a small cup and mix with epoxy and use that. The seam will be nearly invisible.
 
I like them easy to push in and push out. My train of thought is that gives the Epoxy a place to go. If you make them to tight it will wipe most if not all the epoxy off the pins. Its like over tightening the clamps on your scales all the epoxy squeezes out! But I'm no expert!! LOL!!
 
Gliden07 said:
Its like over tightening the clamps on your scales all the epoxy squeezes out! But I'm no expert!! LOL!!
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Wait - are you geekin' here or is that really a thing? This is important... asking for a friend who is a real noob at this...
 
Greg Rice said:
Wait - are you geekin' here or is that really a thing? This is important... asking for a friend who is a real noob at this...
Click to expand...

Yep. That's a thing. The epoxy needs a tiny bit of thickness to do its thing. If you squeeze the scales so tight that you squeeze out all of the epoxy you won't get a great hold. Same with pins. My pins will literally fall out of the pin holes in the scales. That clearance fit allows room for epoxy but not enough room to get a ring around the pin.

That's another Ed Caffrey tip. 1/4" pins and size F drills for the holes.
 
A while back I asked a similar question in this posting.

Pin & Hole Sizing - What method do you use?

I'm still on a vertical learning curve with knife making, having done a couple dozen at this point. A reoccurring issue is how to get a tight (but not too tight) a fit when installing pins in a knife scale. For instance: when drilling for a 1/8" G10 pin that measures .125 I'll try a 1/8"...
knifedogs.com
Since that posting I've used Ed's pin chart with success on G-10 scales. Previously, I was doing a hammer tight fit. But, using a drill size around .002-.003" or so bigger than the pin seems to work well without any noticeable gap. I also learned from this to make my pins longer and take time to rotate the pin in the hole to even out the epoxy coating. Holes drilled in certain woods seem to have a level of elasticity and shrink after drilling. In those cases I've sanded the pins to fit with hand pressure, not too tight.
 
The pins should slide in and out easily. If they are tight the handles will crack and you will have insufficient glue. Been there, done that
 
Ok thanks for the tips. I am Always struggling finding that drill bit just a bit larger than the pin. I think I need to find the pin and drill it’s that work together and stick with that. I have So many different brass pins and mosaic pins I am always going to Home Cheapo to buy bits.
 
Mark Barone said:
Ok thanks for the tips. I am Always struggling finding that drill bit just a bit larger than the pin. I think I need to find the pin and drill it’s that work together and stick with that. I have So many different brass pins and mosaic pins I am always going to Home Cheapo to buy bits.
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Another tip.....buy good bits, probably have to do it online. Shop at Mcmaster Carr or MSC or someplace like that. Cheap bits might not be accurately sized.

Good cobalt bits in sizes we use for pins are only a couple bucks each and will last a long time and will be accurate.

I always steer clear of most any bits you could find in a local big box or hardware store.
 
J. Doyle said:
Another tip.....buy good bits, probably have to do it online. Shop at Mcmaster Carr or MSC or someplace like that. Cheap bits might not be accurately sized.

Good cobalt bits in sizes we use for pins are only a couple bucks each and will last a long time and will be accurate.

I always steer clear of most any bits you could find in a local big box or hardware store.
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Good to know , thanks John. i will definitely check those sites out.
 
J. Doyle said:
Another tip.....buy good bits, probably have to do it online. Shop at Mcmaster Carr or MSC or someplace like that. Cheap bits might not be accurately sized.

Good cobalt bits in sizes we use for pins are only a couple bucks each and will last a long time and will be accurate.

I always steer clear of most any bits you could find in a local big box or hardware store.
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i agree with John, Cobalt bits are the way to go. Also you may have to use number or letter size bits. One more thing : the tubing and rod stock may vary in size , so check it with a good caliper.
 
John Wilson said:
Yep. That's a thing. The epoxy needs a tiny bit of thickness to do its thing. If you squeeze the scales so tight that you squeeze out all of the epoxy you won't get a great hold. Same with pins. My pins will literally fall out of the pin holes in the scales. That clearance fit allows room for epoxy but not enough room to get a ring around the pin.

That's another Ed Caffrey tip. 1/4" pins and size F drills for the holes.
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I knew on the pins - but was just about to blow it on clamping some scales. I figured with the extra holes drilled for balance and epoxy - that you just grip-n-rip with the clamps just like golf (yep-I suck at golf too) - so you know that begs a very similar - but much harder to quantify question... Just how tight should the clamp 'grip' be? just touching? just snug? just tight? 60/40?

Agree on the drills - cobalt only and stay outta the big box for drills and knife steel
 
I think I recall something like .007-.008" thickness to have a good bond. I think you'll have a hard time squeezing out past that thickness if you sufficiently rough and prep your surfaces. By rough, I mean at least 60 grit and uniformly random scratches. I use a 50 grit abrasive roll for my final texturing. Others have even suggested 36 grit. Sandblasting is probably best. Holes and other mechanical texturing also provide a surface that doesn't allow squeeze out.

So to answer your question, clamp snugly don't get silly.
 
I dont really buy into the whole "clamping too tight will squeeze all the glue out" theory.

I've seen a few knives where guys loosely clamped scales to keep the epoxy from squeezing out......and you can see a big ugly glue line between tang and scales. Poor craftsmanship.

Put clamps on and snug them up good. You don't have to bear down on them as hard as possible but epoxy should squeeze out. If you can see a glue line between scales and tang, you did it wrong.
 
tkroenlein said:
I think I recall something like .007-.008" thickness to have a good bond. I think you'll have a hard time squeezing out past that thickness if you sufficiently rough and prep your surfaces. By rough, I mean at least 60 grit and uniformly random scratches. I use a 50 grit abrasive roll for my final texturing. Others have even suggested 36 grit. Sandblasting is probably best. Holes and other mechanical texturing also provide a surface that doesn't allow squeeze out.

So to answer your question, clamp snugly don't get silly.
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I think that's the key. If you rough up the tang and scales you should have no problem. The squeeze out probably has more to do with clamping the everloving snot of it. That's not necessary. If everything is relatively flat (and the pins aren't in a bind to begin with) then contact is contact. Squeezing it harder doesn't do any good, and probably causes deformation which might be the culprit more than the squeeze out aspect.

I can say this: I use Gflex 650. If I lay a paper thin layer and let it dry (thin like a film) I can tear it. If the layer is just more than double that it's tough as nails. So I do think there is *something to the the squeeze out theory. Two part poxy isn't CA glue. Whether the thickness matters more for having enough of the two components for a good reaction to bond, or whether the structure of the epoxy just needs more meat there to hold, I don't know. I've always wondered if it's like concrete. If you lay it on super thin you can come back when it's dry and kick it loose like a sheet.
 
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