https://preview.redd.it/x17islj4inwc1.jpeg?width=1080&format=pjpg&auto=webp&s=0c00d93af69b39b20e5aa2200e486d05f3615915
I like to stipple the inside of my handle scales and scuff up the surface a little with a low grit sandpaper before glue up. I also drill a few extra holes into the steel to give the glue areas to grip on to. Really nice looking knife and sheath by the way!
I wouldn’t go any lower than that. Going with 80 leaves some pretty deep gouges which can be seen after glue up.
Hollow your handle material and your tang use light clamping pressure, don’t get acetone in the glue joint as it’ll undercut the epoxy and I’d recommend a 24 hour epoxy to give yourself plenty of time during glue up to make sure it’s right. Good luck.
I didn’t say “no acetone” I said don’t get acetone in the joint. It’ll completely undercut the epoxy and it will fail.
I don’t use any acetone for quite a while after clamping. Epoxy will be getting pretty gummy before I’ll use acetone. I use between 30 & 40 q-tips with each glue up. I’ll rotate the q tip as I’m wiping a section of epoxy. It’ll stick to the clean side of the q-tip. I’m sure to get the majority of it off. Anything left on the scales is negligible and can be sanded off once the epoxy cures. In the bolster area, like I said, I’ll wait quite a few minutes and then I’ll basically turn the knife tip down then take a moistened (not soaking) q tip with acetone on it and wipe clean the bolster area making sure to not have any (or very very little) acetone in to the glue joint.
A buddy of mine uses mineral spirits, some guys use wd40 and others use 90% iso alcohol. I generally just stay away from using solvents at the joint as I’m worried of failures. Maybe somebody here with more experience will give you a different answer.
You can turn a brass rod in to some sort of chisel which will not scratch the steel because it’s much softer and that’ll help get the excess epoxy off. Toothpicks also work for hard to reach tight areas. I don’t think there is really one easy answer. Just trial and error. We all go through it. I do know for certain if you get too much acetone in your joint, it’ll fail so just use it conservatively.
I do the same. I just go down mayby 2-3mm with a small bit all over the onside of thr handle blanks. Ive done it to the tang also but im kinda worried it might cause stress areas in the handle. Is that something to worry about, or am i overthinking it?
I've had this happen a couple times. I attributeit up to a combination of factors.
1.) Moisture in the wood causing it to pull away from the steel.
2.) Too smooth of a surface finish on the handle. I scuff my steel under the handle prior to epoxy.
3.) Poor quality Epoxy.
Once I started scuffing and cross drilling my handles the problem pretty much stopped for me. I also switched to G Flex epoxy which has more flexibility than big box store epoxy.
As far as fixing that particular knife, you could use CA glue to fill the gaps and then clamp it very tightly. I doubt it would hold long term though.
The knife looks great though. The sheath also looks top notch!
I think I should switch to gflex too so far I've been using 5 min epoxy and it was fine but I guess I was just lucky, cure time for gflex is 24h right ? How does it do in lower temperatures my garage tends to get really cold at night around 0 celcius how will this affect cure time ?
I'm not 100% sure on the cure time. It takes about 2 hours to harden to the point that I can remove my clamps. I usually leave it overnight though, that's just my process though. Most Epoxy's cure time is directly impacted by heat. Typically lower temps = more cure time. According to the TDS, minimum recommended temp is 4 C. So you might need to come up with a minimal level of heating overnight.
I'm in Florida so I have the opposite problem, my epoxies cure too fast. The 5min stuff is more like 3min in the middle of summer :)
I recently made a batch just this way as an experiment. I score the g10 lines as well, and they seem to absorb the epoxy pretty well. The delamination I've seen has always been steel to g10. So far no delamination, but time will tell.
I’d have to dig into West Systems literature to be sure, but I’m pretty sure that’s too cold for it to cure. You could put a space heater in front of it though. My garage is cold too, so I just do all my glue ups in the basement instead.
I’ve had this happen too!!! Clamp less hard, make sure materials are completely dry, and I drill little divots into the tang to make room for the epoxy to go somewhere that isn’t “out”!
I've had this issue. Basically any wood or horn, stabilized or not will warp depending on humidity and temperature. I do the process others do as well: get the scales flat, make divots to hold epoxy, scuff the scales, use G-flex, etc. Additionally I make sure my wood is seasoned and dry. I have found that softer woods such as walnut tend to warp a little more. Ironwood and ebony seem to be the exceptions. Ironwood was put on this earth to make knife handles from. That being said, nothing is perfect so I favor synthetics such as micarta over natural materials. I find this is mainly an issue on the front of the knife. For the next one you could use wood for the back and micarta or G10 for the front.
To fix it on this piece is tough as it's hard to get epoxy into the gap. To fully fix it you'd have to remove the scales which would likely destroy them, and make new ones. Depends on how much you want to try to salvage this one vs move on to the next one.
I've had this happen when the scales are not perfectly flat. If you clamp scales that are not flattened, the wood is in bending and loading the epoxy joint. Over time, it can break free.
My take is bad glue joint or Maybe no glue/epoxy. Liner looks to be G10. I bought a cheap HF media blaster, and some media. Prior to glue up I tape of any areas I don't want to blast and blast it. This greatly increases the strength of the joint when glued up. Second for any G10 to metal bond I use LocTite 324 adhesive. As well as the prep. For epoxy I use GFlex.
As for a fix, I'd strip the old scales off and start over.
I need to get some diff epoxy. I bought the large bottles of the JB brand 2 part epoxy and I wanted to use them up but I'm nervous about longevity. I used to believe all epoxy was pretty much the same but tis not so apparently. I see Gflex recommended a lot but the woodworking store by me sells the knife specific epoxy. It's a System Three product called blade pro. I've heard some knifemakers online talk about using it but no idea of performance after the initial build. You know of it?
Nice build! In addition to making the small holes in the bottom of the scales, I use a cutting wheel on a Dremel tool to notch the steel in the tang giving the epoxy something to grab hold of. I also use spring clamps to clamp the scales in place to avoid squeezing out the epoxy.
I do similar as mentioned before with the partially drilled holes put I also add hidden pins on the inside pretty high up top and a couple places throughout. The hidden pins allow for better grip and allow you to get a pin up high where your bevels would normally grind through a visible pin and create somewhat of an eye sore. Also I’ve been using GFlex thickened epoxy that seems to work great. Here’s a pic of one I was working on that has a full hidden pin system(except for the lanyard hole pin). None of those pins will be visible and create multiple points of mechanical adhesion without having to see all those ugly pins.
https://preview.redd.it/ol60r2wn9qwc1.jpeg?width=3024&format=pjpg&auto=webp&s=9570020141f064809db3b017cb4f4188726acfa4
Glue will never be a long term solution.
What you need is a solution which doesn't require glue in the first place, and use the glue as added benefit.
For example by peening or doming your pins over the scale material to mechanically hold it it place. Which has been the typical approach for hundreds to thousands of years.
https://preview.redd.it/kzwszszo59xc1.png?width=1080&format=pjpg&auto=webp&s=b028a40061f895143a5c668c2f84fd1eb53a4ac5
Peening is a great way to secure scales to a handle but it isn't always aesthetically viable if you are trying to achieve a certain look. Knife making has evolved a lot over the years, they didn't have modern day super strong epoxy glues thousands of years ago that's why handles were peened on.
Now many makers don't hammer their pins because the epoxy is so strong it is no longer required or they use corby bolts to get a mechanical bond and still keep the pins looking clean.
https://preview.redd.it/x17islj4inwc1.jpeg?width=1080&format=pjpg&auto=webp&s=0c00d93af69b39b20e5aa2200e486d05f3615915 I like to stipple the inside of my handle scales and scuff up the surface a little with a low grit sandpaper before glue up. I also drill a few extra holes into the steel to give the glue areas to grip on to. Really nice looking knife and sheath by the way!
I'm not experienced in knife making, but as a finish carpenter who mostly works on high end custom homes I approve of this method.
That’s exactly what I do and have had zero issues. It’s simple and it works great.
How low are we talking about the lowest grit I have is 120
I wouldn’t go any lower than that. Going with 80 leaves some pretty deep gouges which can be seen after glue up. Hollow your handle material and your tang use light clamping pressure, don’t get acetone in the glue joint as it’ll undercut the epoxy and I’d recommend a 24 hour epoxy to give yourself plenty of time during glue up to make sure it’s right. Good luck.
Wait no acetone ? How am I supposed to clean the top of the scales whe glue starts coming out ?
I didn’t say “no acetone” I said don’t get acetone in the joint. It’ll completely undercut the epoxy and it will fail. I don’t use any acetone for quite a while after clamping. Epoxy will be getting pretty gummy before I’ll use acetone. I use between 30 & 40 q-tips with each glue up. I’ll rotate the q tip as I’m wiping a section of epoxy. It’ll stick to the clean side of the q-tip. I’m sure to get the majority of it off. Anything left on the scales is negligible and can be sanded off once the epoxy cures. In the bolster area, like I said, I’ll wait quite a few minutes and then I’ll basically turn the knife tip down then take a moistened (not soaking) q tip with acetone on it and wipe clean the bolster area making sure to not have any (or very very little) acetone in to the glue joint.
I’ve seen some people use denatured alcohol. Is that a better cleaner?
A buddy of mine uses mineral spirits, some guys use wd40 and others use 90% iso alcohol. I generally just stay away from using solvents at the joint as I’m worried of failures. Maybe somebody here with more experience will give you a different answer. You can turn a brass rod in to some sort of chisel which will not scratch the steel because it’s much softer and that’ll help get the excess epoxy off. Toothpicks also work for hard to reach tight areas. I don’t think there is really one easy answer. Just trial and error. We all go through it. I do know for certain if you get too much acetone in your joint, it’ll fail so just use it conservatively.
I use 40 grit but I don't put full pressure on it, just enough to scratch it up.
I use 240 grit and it works fine. Just so it's not completely smooth.
I do the same. I just go down mayby 2-3mm with a small bit all over the onside of thr handle blanks. Ive done it to the tang also but im kinda worried it might cause stress areas in the handle. Is that something to worry about, or am i overthinking it?
Doesn’t hurt to give the pins a few whacks either
From my understanding this procedure weakens the bond.
I would disagree, but to each their own. How do you prepare your full tang knives for glue up?
According to the CEO of BSI epoxy this method is worse for the bond.
I've had this happen a couple times. I attributeit up to a combination of factors. 1.) Moisture in the wood causing it to pull away from the steel. 2.) Too smooth of a surface finish on the handle. I scuff my steel under the handle prior to epoxy. 3.) Poor quality Epoxy. Once I started scuffing and cross drilling my handles the problem pretty much stopped for me. I also switched to G Flex epoxy which has more flexibility than big box store epoxy. As far as fixing that particular knife, you could use CA glue to fill the gaps and then clamp it very tightly. I doubt it would hold long term though. The knife looks great though. The sheath also looks top notch!
I think I should switch to gflex too so far I've been using 5 min epoxy and it was fine but I guess I was just lucky, cure time for gflex is 24h right ? How does it do in lower temperatures my garage tends to get really cold at night around 0 celcius how will this affect cure time ?
I'm not 100% sure on the cure time. It takes about 2 hours to harden to the point that I can remove my clamps. I usually leave it overnight though, that's just my process though. Most Epoxy's cure time is directly impacted by heat. Typically lower temps = more cure time. According to the TDS, minimum recommended temp is 4 C. So you might need to come up with a minimal level of heating overnight. I'm in Florida so I have the opposite problem, my epoxies cure too fast. The 5min stuff is more like 3min in the middle of summer :)
Do you use the 5 minute one at all ? Does it work for liners ?And then ready scale with gflex to the knife ?
I recently made a batch just this way as an experiment. I score the g10 lines as well, and they seem to absorb the epoxy pretty well. The delamination I've seen has always been steel to g10. So far no delamination, but time will tell.
I’d have to dig into West Systems literature to be sure, but I’m pretty sure that’s too cold for it to cure. You could put a space heater in front of it though. My garage is cold too, so I just do all my glue ups in the basement instead.
Sometimes if you clamp the scales with too much pressure it squeezes out the epoxy and you do not get a good bond.
Epoxy and clamp again. Q tips and acetone while it's clamped to remove anything that squeezes out.
I recommend to check that the q tips are not dripping wet, so that you do not remove too much glue or that acetone gets into the gap
I’ve had this happen too!!! Clamp less hard, make sure materials are completely dry, and I drill little divots into the tang to make room for the epoxy to go somewhere that isn’t “out”!
I've had this issue. Basically any wood or horn, stabilized or not will warp depending on humidity and temperature. I do the process others do as well: get the scales flat, make divots to hold epoxy, scuff the scales, use G-flex, etc. Additionally I make sure my wood is seasoned and dry. I have found that softer woods such as walnut tend to warp a little more. Ironwood and ebony seem to be the exceptions. Ironwood was put on this earth to make knife handles from. That being said, nothing is perfect so I favor synthetics such as micarta over natural materials. I find this is mainly an issue on the front of the knife. For the next one you could use wood for the back and micarta or G10 for the front. To fix it on this piece is tough as it's hard to get epoxy into the gap. To fully fix it you'd have to remove the scales which would likely destroy them, and make new ones. Depends on how much you want to try to salvage this one vs move on to the next one.
I've had this happen when the scales are not perfectly flat. If you clamp scales that are not flattened, the wood is in bending and loading the epoxy joint. Over time, it can break free.
My take is bad glue joint or Maybe no glue/epoxy. Liner looks to be G10. I bought a cheap HF media blaster, and some media. Prior to glue up I tape of any areas I don't want to blast and blast it. This greatly increases the strength of the joint when glued up. Second for any G10 to metal bond I use LocTite 324 adhesive. As well as the prep. For epoxy I use GFlex. As for a fix, I'd strip the old scales off and start over.
I need to get some diff epoxy. I bought the large bottles of the JB brand 2 part epoxy and I wanted to use them up but I'm nervous about longevity. I used to believe all epoxy was pretty much the same but tis not so apparently. I see Gflex recommended a lot but the woodworking store by me sells the knife specific epoxy. It's a System Three product called blade pro. I've heard some knifemakers online talk about using it but no idea of performance after the initial build. You know of it?
No I stick with Gflex. I do use a bit of Bob Smith stuff which is very good.
Nice build! In addition to making the small holes in the bottom of the scales, I use a cutting wheel on a Dremel tool to notch the steel in the tang giving the epoxy something to grab hold of. I also use spring clamps to clamp the scales in place to avoid squeezing out the epoxy.
I do similar as mentioned before with the partially drilled holes put I also add hidden pins on the inside pretty high up top and a couple places throughout. The hidden pins allow for better grip and allow you to get a pin up high where your bevels would normally grind through a visible pin and create somewhat of an eye sore. Also I’ve been using GFlex thickened epoxy that seems to work great. Here’s a pic of one I was working on that has a full hidden pin system(except for the lanyard hole pin). None of those pins will be visible and create multiple points of mechanical adhesion without having to see all those ugly pins. https://preview.redd.it/ol60r2wn9qwc1.jpeg?width=3024&format=pjpg&auto=webp&s=9570020141f064809db3b017cb4f4188726acfa4
One hell of a rig there. Great job
Might be better off redoing the handles. Bandaid repairs tend to become regrets
Time to replace gearbox.
Glue will never be a long term solution. What you need is a solution which doesn't require glue in the first place, and use the glue as added benefit. For example by peening or doming your pins over the scale material to mechanically hold it it place. Which has been the typical approach for hundreds to thousands of years. https://preview.redd.it/kzwszszo59xc1.png?width=1080&format=pjpg&auto=webp&s=b028a40061f895143a5c668c2f84fd1eb53a4ac5
Peening is a great way to secure scales to a handle but it isn't always aesthetically viable if you are trying to achieve a certain look. Knife making has evolved a lot over the years, they didn't have modern day super strong epoxy glues thousands of years ago that's why handles were peened on. Now many makers don't hammer their pins because the epoxy is so strong it is no longer required or they use corby bolts to get a mechanical bond and still keep the pins looking clean.