Why Won't My Handles Stay On?

Use Corby or Loveless bots,and you can't pop the scale with anything less than a hammer.
 
Michael,

You can attach them reliable without bolts. For those occasions were I do not use bolts or pins I drill pass through holes in the tang and equally important I use a 1/4 inch roughing mill (a dove tail mill can also be used) to mill into the scales about 50 or so thousandths deep. The deeper permitted the better. This cuts ridges into the sides of the milled areas for the epoxy (I use Brownells Original Glass Bedding Compound) to embed. Where you originally sink the roughing mill there will be no ridges so I always mill a strip(s) most of the length of the scales. This takes more time than using bolts but it will provide a death grip on the assembly.

rlinger
------
 
This is a great thread. I used to pein all my pins, but have since used the drilling through the tang of extra holes and no longer pein my pins. I also slightly (ever so slightly) undersize my holes through the handle material and freeze my pins to zero degrees F. The pins will slide easily into the pin holes and will grow when they warm back up to room temperature, providing a slight press fit pin. Things never move after that! The drawback is that if you undersize them too much, you can crack handle material. The added benefit of the extra holes in the tang, is that you can take weight out this way and get a more balanced feel to your knives.
 
The extra holes in the tang is a great tip, but can be improved upon. Instead of just drilling more holes in the tang, drill through those extra holes, partially into the handle material on both scales. Butter each slab with epoxy and you have now created an "epoxy nail" through each of the extra holes. Can't remember where I heard this one but certainly cannot take credit for it.
Matt Doyle
 
Bro, your handles won't stay on because of the residues still left on your hands from sleeping in Mace's truck at Ashokan... OVER A YEAR AGO!

Goes to show you, man -- nothing comes clean after contact with that big lummox! He shook my hand after admitting defeat at the Ashokan International Invitational Thumbwrestling Championship of the World and the smell wouldn't come off for weeks!:barf: :D

One of the problems I had keeping slabs on wasn't a function of cleanup, I was just clamping it so hard the epoxy literally got squeezed out! The epoxy in the 'lightening' holes would hold, but the edges would let go a bit. All I did was relax the death grip of the vise I was using and all was well. In fact, all I use now are those cheap springy band clamps.
 
I think its because you may be finishing the ricasso area much finer than the tang. Maybe you go through so many more grits up front near that area that youre actually taking some thickness off the steel. That way, even if your scales are flat, the front area near the ricasso is a few thousandths "lower" than your scales. Might explain why it always seems to be up front....
 
I agree with all of the obove posts, especially what bruce said about putting a concave in the slabs (very importent). First you need to determine by inspection if the glue is releasing from the blade or the scales, I will bet it is from the tang. Next toss all the 2 ton epoxy, probally Devcon. Next go to Tap plastics and get yourself some marine or 4 to 1 epoxy, it is expensive but worth every penny. Be sure the tang is flat and cleaned well with acetone and do NOT TOUCH it with your fingers, bead blast or sand to roughen, be sure you you have a few thru holes for the epoxy to cross bind the scales and USE at least 2 pins. I use four. If you follow these steps you will not be able to remove the scales without milling them off.

Leon Pugh
 
I've got a few questions:
exactly what adhesive are you using?
exactly what are you using to clean the surfaces off before gluing up?
You said everything pops up a little, I'd agree with the others the scale isn't flat.
The most important thing about adhesive is surface prep.
If you are using Devcon twin tube stuff, stop no matter how much you spent on it. Find another kind. Seriously.
 
The method I use and described will work. It bonds the two scales together and does not rely on tang bonding, which does not happen anyway. Rough mill your scales to as close to front and back as permitted and as close to other scale perimeter as permitted. Keep clamped until reasonably cured. I like Brownell's Original. Does not fail in the above description.

rlinger
------
 
Joe, I hope you don't think those two letters went to my head, but c'mon...I'm still allowed to bust chops....especially Mikes.:rolleyes:

On the other hand...it does mean you can't bust mine. This is directed to Matt. You don't live far enough away from me to be safe.:eek:


All good advice Mike.

How old is your glue and has it been out in a cold shop?

A couple of years ago I bought a package of two tube epoxy only to find out the hard way it was two tubes of hardener. What a mess!:grumpy:

I can feel the love.
Mace
 
rlinger, I will bet you any thing that when I attache the scales the way I instructed above that you can not remove them or the adhesive from the tank without sanding, milling or grinding, I have tried. I have milled the scales down to less than .010 and attempted to scrape the epoxy off, it does not happen. I had to belt sand the tang to remove it.

Leon Pugh
 
Kerry Hampton said:
I know what it is...You didn't sacrifice a red chicken, douse it with kerosene, light it and point it's flaming body North while chanting "camma camma camma camma camma cameleon". :eek: :rolleyes: :D

Seriously, man cannot live by adhesive alone. Pinnith and sin no more.
Click to expand...

I prefer the magic chicken bone. I have an old magic chicken thigh bone I carry in my pocket, when I glue up my scales I take out the chicken bone and rub it between my thumb and forefinger and chant the following phrase: "Chicken bone, chicken bone, magic magic chicken bone" I repeat this 3x and I haven't had scales lift in 3 years!

P.S. It also works for traffic lights.
 
Ilovetoolsteel said:
I prefer the magic chicken bone. I have an old magic chicken thigh bone I carry in my pocket, when I glue up my scales I take out the chicken bone and rub it between my thumb and forefinger and chant the following phrase: "Chicken bone, chicken bone, magic magic chicken bone" I repeat this 3x and I haven't had scales lift in 3 years!

P.S. It also works for traffic lights.
Click to expand...
I think I will try it, seems like it would be a lot less work. Which bone, the wish bone?
Leon Pugh
 
Mace said:
On the other hand...it does mean you can't bust mine. This is directed to Matt. You don't live far enough away from me to be safe.:eek:
Click to expand...


Very true, brother... all the more reason we should plan a get-together! I run a mean barbeque, and I'm not afraid to share it! BTW, when are you sending me some of that 1/4"x1-1/2"?


I'm really surprised at the variety of methods that everyone uses! Overlooking the chicken bone system (which, of course, uses the power of the spirit world to ethereally bond handle slabs), there are a few I plan on trying soon. I'm also amazed at the number of posters that insist on the use of pins or bolts of some kind as a necessary form of reinforcement. Sounds like we ought to do some tests during a hammer-in or something and see what happens...
 
Way back when, I had problems with some kitchen knives I made doing the exact same thing. What ultimately fixed it for me, was to degrease (with acetone) both the tang and the handle material.


Jamie
 
I am not a knifemaker and have never tried to epoxy horn or micarta. Having said that, I work a lot with epoxy. I am an amateur boatbuilder and work with the stuff a lot. Despite not making knives, I have replaced the grips on existing knives many times, always with timber and epoxy. Some of my comments have already been covered in earlier posts to this thread:

1. Surfaces that are to be epoxied need to be clean - sand and de-grease them. Don't touch the surfaces with your fingers. Wear disposable gloves when you handle them before and during the application of epoxy.

2. Thicken the epoxy if you intend to use it as a glue. There are different types of glue powders - a specialist boat building supplies or fibreglass shop will sell you the correct thickening powder. It can be hazardous to breathe when in powder form so be careful.

3. Roughen the surfaces to be epoxied. Gouge or drill them. I often scratch them heavily with the corner of a screwdriver blade.

4. Wet any porous surfaces with unthinned epoxy and let it soak in a bit first - this minimises epoxy starvation caused by absorption of the epoxy after the 2 surfaces are brought together.

5. Don't clamp too tightly - this forces the glue out of the join.

Epoxy does not adhere to most plastics. I don't know whether this applies to Micarta or not.
 
B Finnigan said:
Are you using pins or rivets also? The only time I have not pinned is when I used cabon fiber since it glues real well and is not very sensitive to temp and humidity. Otherwise I always pin or rivet.
Click to expand...

i'm using just pins, but i have had the problem using corby style fasteners too.
it always seems it sticks to the handle material fine but doesn't stick to the tang of the knife
 
kerry i'm just waiting on a full moon to try that one out


Mace you suck!
no seriously though i always get the bulk of it flat with a 4X36 sander. nice and cool with an 80 grit. then move to 220 nice and easy on a surface plate. and damn are they flat as can be. then i fit em. trim excess from all sides and go from there. so i got that one covered

LRB:

i've had this happen on almost every knife i've worked on. i must have gotten atleast one flat right? man i hope so :(
i think the tang holes are the next plan. but even as far as not flat enough i've seen handles with mean gaps on em and not flat at all tangs but the epoxy just filled up the gaps and still helt together tight

Fitzo: I've used pops epoxy in the past,and acraglas but 99% of the time its slow cure decon and for the second try on this last knife i used JB weld
I'll have to post picstures if i have some time and also look into that glue wars again and buy some expensive glue and a blast cabinet :D new toys!

Chuck: i've tried all the motions and found i kept steadier with the pull in one direction motion. and have gotten the scales very very flat. i've also had this problem a number of times with (whats supposed to be flat) materials like micarta and stuff. again see what i posted to LRB i've seen some ugly fit an finish but the stuff still holds together.

Jim: i feel the pain

JT & Flatgrinder: been there done that with no luck

Caswell: Yeah exactly trouble with even stabilized materials is whats buggin me. I've even had knives i've done with moose and had them shrink a noticeable ammount around the tang without popping off. but this is just killing me i can't see why its not working

Larry: i'll give it a try but i'm just worried about this handle getting some contouring i might blow through to the "epoxy pin"

Bruce: i kind of like that idea, but still a little weary about just the super glue

JDM: yeah he's a jackass huh? all went to his head
ahhh hidden tang isn't my game though. i like the full tang deal. i have thought of the spacer material, but then again i'm having the trouble with the glue not sticking to the tang the handle material always stick nice

Bruce: be careful you've seen those geico insurance commercial with the cavemen right?

Stacy: tried the corby's but still had a little gap after a few days of sitting, i know its not gonna fall off but i sure as hell hat the thought of that look to the knife, and what kind of nasty critters can live in there

Roger: i might have to try that, but have no mill. i'll work something out with a flex shaft though maybe.

Doyle: i'll give it a try. i think ya might have heard it in larry's post a few behind you:foot:

Matt: bite me. yeah i know he's a stinky bastard. when me and larry picked him up last year we pulled in the yard and the local zoo was there hozing and brushing him. they explained it was a community service thing they do:D

i don't think i have a death grip problem. i've tried spring clamps and tried regulars, but when i pull the handles off i can still see a layer under there. and i barely tighten the clamps. jut enough where they start to catch.

dave: I run the whole blade when polishing it up. i don't hit the ricasso seperately anymore, just for that reason. i figure i might be creating a dip. but like i said earlier havent we all seen knives with terrible fit and finish but they still hold, just a nasty epoxy line there

Leon: its off the tang, i'll have to try some new bonding agents. i'm thinking of the loctite one that was listed in the glue wars

Mickley: i know you know you bonding agents. so i'll go with you ideas. I do use the devcon and i clean everything down with acetone before seembling

Mace: I always buy new stuff, keep the small tubes so its not sitting around. and i keep it away from cold weather

Tool steel: once again i'm waiting to try that on a full moon with the whole kerosene cama cameloeon gig

Matt: you got it there i've had handles stay together and i know a ton of people who use nothing but some type of epoxy and some pins and they have never had this problem.

2Manyknives : yeah i think i'm going to have to look into better bonding agents. because i do the steps above. and yet no luck


Thanks for all the replys guys. I think i need to re-think my epoxy, drill some blind tang holes and double check my pressure on the slabs during gluing, but i don't think the pressure is it.
i also shoe shine sand the handle to polish, using some shop rolls but i've seen that employed in tutorials and shops without problems.
let me try to get some pictures next
 
Michael, you can get a cheapo blast gun for about $30 from HF and use it outside. Wear a face shield at the least, along with a cap. it's messy, but it's cheap.

Something else occurs to me, Michael: do you grind much on the tang itself fitting the handle, after it's glued on? That can generate enough heat to let the epoxy release from the metal. I ran into that problem a couple times early on back when I did fulltangs. The wood acts like a heat sink and you never realize how hot the metal gets. Almost all epoxies will release with heat.

When Tracy and Steve did Glue Wars, there was a repeated claim that the acetone left a film. I thought it was coming from wiping cloths or paper towels, because laboratory-grade acetone is clean as can be. We rinsed all our glassware in acetone, and it had to be clean because the slightest soil showed up and could contaminate a reaction.

I did the following experiment: cleaned a piece of plate glass and allowed to dry in air after rinsing with distilled water. It was very, very clean. Next, I laid it flat and dripped a puddle of acteone onto the surface and let it dry. There was a film from the crap coming out of the can from the hardware store. I bought another jug and had the same problems. "Home" acetone isn't that clean. 90% isopropyl alcohol from the pharmacy was cleaner. Distilled water was the best. I'd recommend wash (see that thread for soap recommendations), rinse with tap water, rinse with acetone, then follow last with distilled water and allow them to hang to dry. Hit 'em with a heat gun after to drive off any remaining moisture. Overkill, perhaps, but better than failure.
 
You must log in or register to reply here.
Back
Top