epoxy

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DevinT said:
There’s a lot of dumb comments in this thread.

Hoss
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Don’t just call us dumb and walk away…. I‘d really appreciate your thoughts on the subject. Do you have any particular techniques when using epoxy? I’m still thinking through the epoxy reservoir and epoxy bridge concepts. Any insights you don’t mind sharing would be great. I need all the help I can get.
 
Glue wars has been around since makers started using cutlers resin, I think some people need to stop asking. They need to start doing research then testing on their own . They're some good points to be taken from the topic, like the changes in acetone. Same experience, Had a similar problem with rubbing alcohol. Same brand but suddenly during covid it started leaving a film. Look for those changes.
There are a few tried and true expoxies, a few tried and true techniques for every process we use. When something new comes along its up to each of us to make it work for you and ultimately Your Customers
 
Lorien said:
so you must be using sacrificial pins, which are drilled out after?
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Yes … I use a process stolen …. Errr … “borrowed” from horsewright. temporarily attach one scale blank to the tang, drill the holes in the scale. Flip over, temp attach the other scale, drill the holes in that one using the first scale as a guide. Remove scales, place temp pins ( to keep them aligned) the shape and finish the front of the scales, and rough cut the remaining outline. Glue both scales to the tang using temp pins (coated with wax). Remove the temp pins (just takes a tap), shape and finish handle, then ream the outer portion of the holes. Run a drill through the holes to remove any epoxy. Cut final pins to length (allowing extra for peening), then peen until the pins just fill the reamed out opening. Then carefully sand of any protruding pin material being careful not to do any reshaping of the handle material. This produces a nice clean interface between the pin and the handle. It’s fast, works for any size pins, and gives a really solid holding force for the scales. I have not use corbys or any other mechanism for several years now…
 
In order to avoid excess squeeze-out when clamping, I generally use small paper "washers" between the handle scales and the tang to prevent all the epoxy from being squeezed out. The photo shows the idea (this is just a mock-up for the photo - tang has not been ground or cleaned yet post-heat treat) The pins are temporary, I pull them out after the epoxy has started setting-up. After the handle is shaped and finished, I install new, peened pins.

On Folding knives, I super glue a couple of thin strips of paper (1/8" x 1/2") to the liners, before gluing and pinning the scales.
Saludos
J

dgICoxs.png
 
Cushing H. said:
Yes … I use a process stolen …. Errr … “borrowed” from horsewright. temporarily attach one scale blank to the tang, drill the holes in the scale. Flip over, temp attach the other scale, drill the holes in that one using the first scale as a guide. Remove scales, place temp pins ( to keep them aligned) the shape and finish the front of the scales, and rough cut the remaining outline. Glue both scales to the tang using temp pins (coated with wax). Remove the temp pins (just takes a tap), shape and finish handle, then ream the outer portion of the holes. Run a drill through the holes to remove any epoxy. Cut final pins to length (allowing extra for peening), then peen until the pins just fill the reamed out opening. Then carefully sand of any protruding pin material being careful not to do any reshaping of the handle material. This produces a nice clean interface between the pin and the handle. It’s fast, works for any size pins, and gives a really solid holding force for the scales. I have not use corbys or any other mechanism for several years now…
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thanks for that!
 
You guys know... Epoxy strength is semi easy to test... We all have screw drivers, hammers, ovens (to simulate hot days on a dash in a car), etc.

Personally I'm moving away from the 24hr epoxy's like blade pro and g/flex. I use pins and want something that will release with heat (those won't). But then again I sandblast the tang and inside of the scales with 100 grit alox and use skeletonized tangs.
 
Cushing H. said:
Yes … I use a process stolen …. Errr … “borrowed” from horsewright. temporarily attach one scale blank to the tang, drill the holes in the scale. Flip over, temp attach the other scale, drill the holes in that one using the first scale as a guide. Remove scales, place temp pins ( to keep them aligned) the shape and finish the front of the scales, and rough cut the remaining outline. Glue both scales to the tang using temp pins (coated with wax). Remove the temp pins (just takes a tap), shape and finish handle, then ream the outer portion of the holes. Run a drill through the holes to remove any epoxy. Cut final pins to length (allowing extra for peening), then peen until the pins just fill the reamed out opening. Then carefully sand of any protruding pin material being careful not to do any reshaping of the handle material. This produces a nice clean interface between the pin and the handle. It’s fast, works for any size pins, and gives a really solid holding force for the scales. I have not use corbys or any other mechanism for several years now…
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I‘ve thought about a similar process but I’ve had concerns based on things I’ve seen using my method. I taper the holes then fit my final pins so they’re snug to the point I have to pull them out by clamping them in a vise. I put all the final pins in the scales and get the scales perfectly flush with the tang all the way around using the 2x72 and/or disc sander. After that I do any surface prep and apply the epoxy then install and peen the pins. Often, after all of that, the tang will be proud somewhere on the handle meaning something has clearly moved in the peening process. Not a big deal as it generally just takes a few minutes to touch up after the epoxy sets. I’m worried that peening them after the epoxy sets could put a lot of sheer stress on the epoxy which generally isn’t good.
 
ScarFoot said:
I‘ve thought about a similar process but I’ve had concerns based on things I’ve seen using my method. I taper the holes then fit my final pins so they’re snug to the point I have to pull them out by clamping them in a vise. I put all the final pins in the scales and get the scales perfectly flush with the tang all the way around using the 2x72 and/or disc sander. After that I do any surface prep and apply the epoxy then install and peen the pins. Often, after all of that, the tang will be proud somewhere on the handle meaning something has clearly moved in the peening process. Not a big deal as it generally just takes a few minutes to touch up after the epoxy sets. I’m worried that peening them after the epoxy sets could put a lot of sheer stress on the epoxy which generally isn’t good.
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Not sure what to say about that. Just peening *should* not put any shear stress on the scale/tang joint … but clearly something is happening in your case. Do you sand the scales flush with the tang *before* you glue the scales to the tang? Or are you sanding the scales flush to the tang after they are glued on, and the epoxy has comp,etelt cured?
 
Cushing H. said:
Not sure what to say about that. Just peening *should* not put any shear stress on the scale/tang joint … but clearly something is happening in your case. Do you sand the scales flush with the tang *before* you glue the scales to the tang? Or are you sanding the scales flush to the tang after they are glued on, and the epoxy has comp,etelt cured?
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I make everything flush before I add epoxy but the pins are so tight nothing “should” move when I peen them. You can’t push/pull the pins out by hand while I’m fitting. They either have to be tapped out with a punch or clamped in a vice and pulled. It doesn’t happen every time but it has happened enough that I’ve kept the same process so everything can get where it wants to be before the epoxy is cured. I just found it quicker and easier to do it this way and touch up any high spots once everything is set. I do flatten the tang and scales on a disc sander so warping really shouldn’t be a factor either.
 
I was sure hoping you'd find this thread, teehee
 
ScarFoot said:
I make everything flush before I add epoxy but the pins are so tight nothing “should” move when I peen them. You can’t push/pull the pins out by hand while I’m fitting. They either have to be tapped out with a punch or clamped in a vice and pulled. It doesn’t happen every time but it has happened enough that I’ve kept the same process so everything can get where it wants to be before the epoxy is cured. I just found it quicker and easier to do it this way and touch up any high spots once everything is set. I do flatten the tang and scales on a disc sander so warping really shouldn’t be a factor either.
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It is my opinion/experience that it is very, very difficult to do a fit-up of any kind prior to final securing (in this case before gluing) and reliably get the same fit up after gluing. Again, just my opinion, but you might want to experiment with gluing first, then afterward doing the refinement of the outline of the scales and making them flush to the edge of the tang.
 
Cushing H. said:
It is my opinion/experience that it is very, very difficult to do a fit-up of any kind prior to final securing (in this case before gluing) and reliably get the same fit up after gluing. Again, just my opinion, but you might want to experiment with gluing first, then afterward doing the refinement of the outline of the scales and making them flush to the edge of the tang.
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I agree and this is essentially what I’m doing now. On my latest batch I just finish the front of the scales and rough everything else in then epoxy and peen everything. After that I make everything flush and re-etch the tang to match everything else where applicable.
 
Lorien said:
I was sure hoping you'd find this thread, teehee
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Only checked in because an old friend mentioned this thread to me, and out of morbid curiosity I was fool enough to look.

There’s no real point in posting in here, and I have no intention of explaining any processes, because no one will listen, or they’ll nitpick without bothering to examine, or they’ll reply over me in bold, colored text while continuing to be proven wrong. Knifemakers certainly aren’t the only ones to display this behavior, but they’re likely some of the worst offenders. Rather than seeking out input from sources with actual, credible, calculated and scientifically sound answers, they’ll form a sewing circle where voices that ought not have any weight or merit are somehow regurgitated as gospel. The absolute LAST place I would look for solid information is in a forum like this.

Here‘s the only input I’ll offer, and I can say with complete assurance that it will unequivocally fall upon deaf ears: if you’re looking to build a bridge, contact an engineer with experience building bridges. Don’t ask Chet at the town hardware store. All the internet research in the world isn’t going to turn up information worth a shit, because you don’t understand enough to parse through it and discern the dreck from the gold.

Adhesive manufacturers - real ones, used by companies that RELY on adhesives, like aerospace - all have customer service people. Their jobs are to help you not only understand HOW to use their products, but to also help you choose the CORRECT product for your application. This thread is specifically about epoxy, but even a brief skim through it shows me that many of you probably shouldn’t even be using epoxy the way you are, and would be better suited to other adhesives. The only reason I recognize this is because I’ve talked with engineers that work for some of these companies that have helped me. They’re not guessing - they can’t afford to guess. Lives can be at stake with their other customers. I just get the advantage of all of the testing and research they’ve done for real customers.


But don’t take my word for it. I’m merely a schlub sticking parts together in my basement while I play knifemaker.
 
ScarFoot said:
I agree and this is essentially what I’m doing now. On my latest batch I just finish the front of the scales and rough everything else in then epoxy and peen everything. After that I make everything flush and re-etch the tang to match everything else where applicable.
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sounds good. Pls let us know how things go as you experiment with this approach?
 
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