My Knives Scales are Falling Off...

Dovetailed bolsters can also add some extra mechanical support.
 
Bruce Bump said:
I use corby bolts or pins with tapered holes peened in and super glue after the handle scales are installed. The only time I use epoxy at all in for hidden tang handles.
Click to expand...

I'm curious about this...What do you do with the super glue after the handles are done? Just seal off where the scales meet the tang? If so by the time you sand it all down is there any glue still left there? Thanks.
 
As Tracy said surface prep is more important that the epoxy used.

Loctite E-120 epoxy is the best I've found for full tang knives. It beats acra-glass in the bonding department. Acra-Glass is the best choice for hidden and through tang knives because it does not shrink and is super tough.
 
I have been using acraglass for the last ten years and never had any problem with bonding. I clean and then use 36 or sixty grit belt to roughen surfaces then appy glue and clamp tight and let dry over night. In my testing of this the scale material will break before the glue lets go.
 
What do you all use to clean the surface of the blade with before gluing? I have been using Isopropal Alcohol, is that a good choice?
 
On the first couple of knives i did i had the same problem. my handles would become loose of i could actually peel them off by hand. I was using devcon 2 ton. also tried devcon minute. same problem. I read somewhere about over clamping the epoxy and basically causing almost all of it to squeeze out. I backed off on the over clamping. and that seemed to work. since then i have also switched to gorilla glue instead.
 
I have been taught that a near perfect fit and a small amount of glue will make a stronger joint than a gap and lots of glue. I am not saying that anyone who has a system that works for them should change their ways just telling how I do full tangs. I do hidden tangs pretty much the same as Ed C. I found out recently that you can fit a stick tang too tightly to a handle with the result being a cracked handle.
 
Last edited:
CDHumiston said:
What do you all use to clean the surface of the blade with before gluing? I have been using Isopropal Alcohol, is that a good choice?
Click to expand...

I used brake cleaner on mine--it seems to have worked OK.
 
Denat Alcohol or soapy water.

No one has mentioned epoxy handling yet so.... warm epoxy, keep it warm during curing, proper mixing rate if your using the two bottle stuff, good stirring procedure- all are very important I have found.

I nixed the "value hardware store" epoxies a long time ago. I will vouch for the Loctite E-120HP, that stuff is woderful- solves the mixing issue outright. I also have had great success with Sumo glue and the new Gorrila white glue- you just gotta work quickly but once you get it, it will hold quite well. I also use some form of mechanical fasteners.

One thing to think about - if you use a liner and dont use a bolt fastener, then your scales are attached only as well as the liner is to the scale- dont short-cut that attachment- it wont matter if you use the best epoxy in the world between the liner and tang if the scales comes loose from the liner.
 
Could be, Fletch. I do use acetone to wipe off epoxy "ooze", it works great for that. It's a powerful solvent, but not a good cleaner. There's a difference! For goodness sakes, open a window, acetone fumes are pretty nasty.

Side-note: my shop isn't heated, so I keep all my chemicals (glues, dyes, Danish oil, etc.) in the house. I do my glue-ups and whatnot on the kitchen table, where the temp and humidity are fairly stable. A cold night, or hot humid day can do very weird things to many of those chemicals, both in storage and as they cure.
 
Well, after taking everything into account that was suggested here, reading glue wars, and trying a few tests of my own I made a choice for my latest knife.

I went with Gorilla Super Glue. I glued up various objects this weekend with 1 hour epoxy, Gorilla Glue 5 minute Epoxy and Gorilla Super Glue. Some of the items I cleaned and prepped and some I just glued together to see what would happen.

Cleaning definately seems to be the most important variable. Not leaving a rough grind on the knife tang was also one of my main problems.

I'm not going into great detail because the war has already been done. However, I beat some G10 with a hammer after only 10 minutes of hardening using the super glue and I can't get it apart.

I'm sure holding capability will vary with different types of material, but we'll see how this goes. I am going to start using pins or corby bolts as well, but this knife has only 2 Mosaic pins and I need the glue.

I would like to say thanks again to all who gave advice. Only time and use will tell how well this glue really works.
 
An amateur butting in W his .02 cents.

I'm no expert but, let me toss my .02 cents in here just for squints & giggles.:D

I think proper surface prep is a mandatory step in all areas of knife making, or painting for that matter but it's especially true when working W adhesives, I used to like to clean W lacquer thinner, I know that the proper type of alcohol will work well also.
I also only finely finished up to the area left uncovered by the scales. (tang stamp area)
I found it helpful to get the scales and tangs true flat which I feel requires at least going to about 220 or so then I would go back and use a very narrow strip of 36 through 80 grit wrapped around a very hard, smooth, narrow (steel or micarta) sanding block on the center areas of both scales and tangs being very careful to stay away from all the mating edges to make sure all the handle seams would mate flush against the seating surface, thus creating if you held your mouth just right a very fine join that seems almost seamless.

Having said all of that, I have still had a number of scales come off after 3 to 10 yrs of hard use, especially if I didn't use any pins (Important step: flare hole & expand the ends of the pins), but I NEVER had 1 accidentally come off that I used bolts or revolver grip screws on even W/O any Epoxy, I tend to like my scales to be easily removed for routine maintainability or just a change of pace on fixed blades any way, so . . .

To the New guys:
Good solid advice has been given by others in this thread (especially the old Dogs) but remember there's always more than 1 way to skin a cat.:cool:

When I do finally start makin again I will stay away from Adhesives as much as possible (like the plague), but I just might give that HD loc-tite a try, after I test it out 1st. of course.

Good luck to all, Woof!
 
Chris, I know I'm chiming in a little late here, but here are a couple of my thoughts. I think surface prep is paramount, the toothier the better, 60 grit is good. Also I keep an old hair drier on my bench to heat the adhesive and the materials to be bonded. You can see the epoxy melt at a certain temp. I think this helps with mixing and also helps provide a better bond, as it flows into the surface roughness at a microscopic level.
Also be vigilant about keeping the materials from overheating as you grind them to final shape after bonding.

Good Luck
Alden
 
You must log in or register to reply here.
Back
Top