I bought a blank etc. from texas knife supply and am trying to build it but my handles won't stay on. I rough up the blank, clean it, apply the epoxy, and clamp it in the vise. I let it sit for about two hours and when I take it out to drill pin holes etc. the scale just pops off. Should I let it sit longer or what? I'm using Devcon 2-ton epoxy and walnut scales. Thanks
-
The BladeForums.com 2024 Traditional Knife is available! Price is $250 ea (shipped within CONUS).
Order here: https://www.bladeforums.com/help/2024-traditional/
What am I doing wrong?
- Thread starter 345peeler
- Start date
- Joined
- Nov 13, 2013
- Messages
- 201
I've handled a few blanks...I may be able to help you with this one.
First off:
Here is the link to the info on Devcon 2 ton epoxy. 2 hours @ 72deg and it should be cured enough to work with. At least close enough. But you may want to wait a little longer.
http://www.devcon.com/prodfiles/pdfs/fam_tds_179.pdf
What is the epoxy like when the scales come off? Is it hard, gummy, still sticky? Is gummy or sticky it could be either bad mix ratio, not mixing enough, or not enough cure time.
Secondly: And more importantly...you are gluing the scales to the tang...then drilling for pins? That seems to be opposite of how I have added scales to finished blanks. Generally I drill my pin holes, rough cut to shape, put on the scales with just pins and finish profiling, shape scales to 90ish% of final shape, then take apart finish the front part of the scale (to avoid damaging the blade area), and lastly epoxy it together and clamp lightly. (Then final sanding and finishing)
One other tip I often see, and was guilty of doing before I read it, don't over tighten when you clamp or you can drive out most of the epoxy.
First off:
Here is the link to the info on Devcon 2 ton epoxy. 2 hours @ 72deg and it should be cured enough to work with. At least close enough. But you may want to wait a little longer.
http://www.devcon.com/prodfiles/pdfs/fam_tds_179.pdf
What is the epoxy like when the scales come off? Is it hard, gummy, still sticky? Is gummy or sticky it could be either bad mix ratio, not mixing enough, or not enough cure time.
Secondly: And more importantly...you are gluing the scales to the tang...then drilling for pins? That seems to be opposite of how I have added scales to finished blanks. Generally I drill my pin holes, rough cut to shape, put on the scales with just pins and finish profiling, shape scales to 90ish% of final shape, then take apart finish the front part of the scale (to avoid damaging the blade area), and lastly epoxy it together and clamp lightly. (Then final sanding and finishing)
One other tip I often see, and was guilty of doing before I read it, don't over tighten when you clamp or you can drive out most of the epoxy.
- Joined
- Jan 1, 2011
- Messages
- 1,798
You should be drilling holes before gluing. Yes, you should likely wait longer for the epoxy to dry. I've never used Devcon, but I usually let the Acra Glass dry for 24 hours before touching it. Also, you may be clamping it do hard, and squeezing all the epoxy out. You said you are roughing up the blank, but are you doing anything to the scales so the epoxy has something to grab on to? Try taking some pictures of what you are doing. You will likely get a lot of good feedback.
- Joined
- Oct 5, 2011
- Messages
- 263
Clean your blank and scales well with acetone then alcohol. Flood and wipe without allowing solvents to dry. Toss the Devcon 2hr epoxy. Most likely past its expiration date on the store shelf and virtually guaranteed to fail. Try slow set epoxies like West Systems G/flex or Brownells Acraglass. I have and use both and they have yet to disappoint if I do my job right.
Also sandblast steel prep is demonstrated to be best but applying epoxy and scouring into clean steel with a fresh piece of 80 - 120 grit paper will make a meaningful difference in joint strength. (I have tested this myself.) This info is supplied as an insert with the G/flex.
Probably too obvious but dont overclamp and be sure to allow enough time for epoxy to cure properly before stressing joints by drilling etc. This means overnight + with either product above.
Keep at it and good luck.
Also sandblast steel prep is demonstrated to be best but applying epoxy and scouring into clean steel with a fresh piece of 80 - 120 grit paper will make a meaningful difference in joint strength. (I have tested this myself.) This info is supplied as an insert with the G/flex.
Probably too obvious but dont overclamp and be sure to allow enough time for epoxy to cure properly before stressing joints by drilling etc. This means overnight + with either product above.
Keep at it and good luck.
http://www.amazon.com/West-System-6...8&qid=1392751935&sr=8-2&keywords=g+flex+epoxy
This will last a long time. Dozens of knives. It works really well, is not too smelly, easy to mix and you do not need to race to get the handle/pins/bolts in place. You can take your time with the glue up process. Of course, the epoxy will take it's time too, 24 hours before ready...
Drill holes first. Dry fit everything. Glue up with hardware. Are the scales nice and flat or are they bowing in the center a bit and fighting the glue? If not flat, sand them flat.
Good Luck!!!
This will last a long time. Dozens of knives. It works really well, is not too smelly, easy to mix and you do not need to race to get the handle/pins/bolts in place. You can take your time with the glue up process. Of course, the epoxy will take it's time too, 24 hours before ready...
Drill holes first. Dry fit everything. Glue up with hardware. Are the scales nice and flat or are they bowing in the center a bit and fighting the glue? If not flat, sand them flat.
Good Luck!!!
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
Moderator
Knifemaker / Craftsman / Service Provider
- Joined
- Aug 20, 2004
- Messages
- 38,521
You have created a glue starved joint by clamping hard. The epoxy was all squeezed out. When installing handles, use the lowest pressure clamps available. I like the tiny $0.49 cheap spring clamps from HF.
I make a slight hollow grind in the center of the tang when I grind the knife so there is a reservoir of epoxy. That plus a few extra holes makes for a strongly bonded handle.
Many folks drill the handle like Swiss cheese to assure the epoxy has a grip from scale to scale. This is often called "Epoxy Rivets". Done along with pins/rivets it makes a strong handle.
Drilling a bunch of shallow divots in the scales can do the same thing.
I make a slight hollow grind in the center of the tang when I grind the knife so there is a reservoir of epoxy. That plus a few extra holes makes for a strongly bonded handle.
Many folks drill the handle like Swiss cheese to assure the epoxy has a grip from scale to scale. This is often called "Epoxy Rivets". Done along with pins/rivets it makes a strong handle.
Drilling a bunch of shallow divots in the scales can do the same thing.
Pretty much the same thing everyone else has said. I can afford to take my time so I finish and match the ricasso side of my scales. I use the slowest set epoxy I can find. I think 1 hour working time is advertised. After roughing and cleaning the surfaces to be glued, I wet each surface individually with a thin coat of epoxy, to fill in all those scratches. I then glue one scale in place (@ 24 hr.) and drill the holes using the tang as a template. I then place and glue the second scale in place and let the glue cure (another 24 hr.). I then use the first scale as a guide for drilling the holes in the second scale. I then finish the scales in place.
- Joined
- May 2, 2011
- Messages
- 181
Coming from the Corian counter top industry, I can tell you that the appropriate pressure for expoxy without "starving the bond" is always guaranteed with Pony (or cheaper brand) 2" spring clamps. If you cant sandblast your blade (scale area), I have, from time to time used a cutting wheel on a dremel/foredom to "scuff" the blade. Cleaning prep is also underrated. You have to make sure that all lubricants (cutting fluid, machine oil, etc) is removed. I only use denatured alcohol, as some of the other solvents leave a residue, which means degradation of the epoxy bond. Then, do not touch the cleaned area with bare hands (natural oils in hands). When doing the prep and gluing procedures, I wear a pair of powder free latex exam gloves. Keeps the hands clean of epoxy and keeps you from depositing oil from the hands. 30 minute plus epoxy is the only thing to use then forget about the knife for the next 24 hours. Since epoxy is a chemical reaction, I "accelerate" or enhance the cure by placeing the glued up knife in a second hand dehydrator over night.