Epoxy? Resin? shellack ( YES!!!)

[Dave Barker]

Here is something to get you thinking, but I guess it really applies to the scandi /hidden tang makers.

What is best of the above.... I know there are pros and cons for them all.. IMVHO I believe that shellack is the best method for fixing the blade to the shaft and not epoxy... WHY :confused: well......

Epoxy is very strong I agree, but it also has a melting point of 70 degrees ( araldite), and I know from experience that once it has melted it will not harden properly again.

The second thing is this, if you use the multi pack ( the big one with 2 seperate tubes) there is a chance that there has been a mix up,and or one can have problems mixing the harderner and the glue so that it actually sets.

Shellack has some great advantages.

1. it is a natural product,
2 it can be melted and reused time after time
3 it is water tight,
4 there is no mixture to get "wrong"
5 it is strong
6 there are 2 ways to use it, one which sets fast ( 3 minutes until it can be used handy in the field huh) and the other that take a little longer.

Be interested to hear your views on this one.

[keith_beef]

..snip..
IMVHO I believe that shellack is the best method for fixing the blade to the shaft and not epoxy... ..snip..

Epoxy ... has a melting point of 70 degrees ( araldite), and I know from experience that once it has melted it will not harden properly again.

The second thing is this, if you use the multi pack ( the big one with 2 seperate tubes) there is a chance that there has been a mix up,and or one can have problems mixing the harderner and the glue so that it actually sets.

Shellack has some great advantages.

1. it is a natural product,
2 it can be melted and reused time after time
3 it is water tight,
4 there is no mixture to get "wrong"
5 it is strong
6 there are 2 ways to use it, one which sets fast ( 3 minutes until it can be used handy in the field huh) and the other that take a little longer.

Be interested to hear your views on this one.

Dave, I'm very interested in this. Is shellac the same stuff as the "cutler's resin" that I've seen mentioned in rec.knives?

You use it to harden and waterproof your tollekniv sheaths, don't you?

You mention melting it... I bought 1 litre of shellac dissolved in methanol, and the same shop sells it as yellow flakes. How thick does it need to be for gluing, as opposed to leather hardening?

Keith.

[Dave Barker]

Leather hardening is usually only done ( by me anyway) on the top half of the sheath after itis dried etc.
This stuff has the same consistancy as meths for example.

As for shafts, remember the word lakk means varnish, so i do not use it here. i have used it before as waterproofing in the lower end of the sheath, but now use leather fat before sewing.

For gluing it needs to be of the same consistancy as say, warm epoxy so that it actually fills the hole made for the tang. It takes a bit of time to cure cos the spirit / solvent has to disperse in the woodetc before it harden. I suggest getting a piece of scrap wood, oil it as you would a shaft, drill out a smallish hole. Fit a screw into the hole with the mixture and adjust the strength til it cure as quickly as you want.

The melting bit is much easier. Mash the flakes up in a pestle and mortar or something similar so it is relatively fine, and fill the hole with it. Fix the blade in a vive with the tang free. Warn the tang with a burner til it is slightly red and then push it into the shallack filled hole. (you may have to do this several times.)

When the blade is in, take a scalpel and crease the excess so that it can be removed ( and resused)

Put the blade in cold water for 3-5 minutes, remove the hardened shellak by snapping it or with hardwood or bone, thats it!

If the hole is not completely filled then you can melt the shallack on a screwdriver and top up.

The beuaty of it is tht if the blade breaks or is worn sown by sharpening, you can warm the blade, take it out, and either get it repaiered or another remade in the same design..... Warm the tang and bobs you uncle.

they both work, but mixing is easier. You just have to play with the ratios a little.

Help??

[keith_beef]

..snip..
The melting bit is much easier. Mash the flakes up in a pestle and mortar or something similar so it is relatively fine, and fill the hole with it. Fix the blade in a vive with the tang free. Warn the tang with a burner til it is slightly red and then push it into the shallack filled hole. (you may have to do this several times.)

When the blade is in, take a scalpel and crease the excess so that it can be removed ( and resused)

Put the blade in cold water for 3-5 minutes, remove the hardened shellak by snapping it or with hardwood or bone, thats it!

..snip..

Thanks a lot, Dave.

I would think that it's easier if the blade is tang down, or the powder would fall out of the hole, wouldn't it?

Your method would also have the effect of tempering the tang a little, making it less brittle.

As for grinding in a pestle and mortar, maybe a pepper mill would be as easy.

I'm going to try this shellac method on one of my puukkoja. I'll let you know how I get on.


Keith.

[Martyn]

Warn the tang with a burner til it is slightly red and then push it into the shallack filled hole.


Wouldn't that ruin the temper of the blade?

[jbaron]

that's what i thought

[Dave Barker]

I forgot to mention that it is only the tip of the tang that need to be redish, this is enough to melt th shellack. I tend to wrap thr rest of the blade in a damp tissue to stop the heat transfer to the actual blade.

As for the blade. If you have the blade horizontal keith then the shaft sort of slots on. Providing you have a tight fit and that the blade is straight with no need for adjustment.

The thing to remember is that hting the blade will not neccessarily destroy the temper... people use a grinde to cut the tabg afterall and I don't think you need 200 degrees to warm the tang up. Besides if you have to take the blade out then it is probably wrecked anyway. This way repairs are quick... new blade to same dimensions ( great for the mass produced type) bit of heat, 3 minutes and back in business.

[keith_beef]

Wouldn't that ruin the temper of the blade?

Just heating the tang, keeping the blade cold. Maybe clamp a big piece of copper (for a heat sink) -to the blade, with some thermal greasepaste between the steel and copper...

Maybe only the last half of the tang needs to be heated, so that up towards the ricasso ;-) (OK, so to the shoulder, or whatever the bit where the tand joins the blade is called) you get pale straw colouring.

I suppose that only an inch or two of the tang needs to be hot, and this will melt the shellac as it's pushed into the hole.



.

[Dave Barker]

As I said, just the first 2 cm. This hits the flakes first.and melts it.

[keith_beef]

As I said, just the first 2 cm. This hits the flakes first.and melts it.

Look at the times of posting... you got your post in while I was finishing typing mine.

Great minds think alike, Dave ;-)


Keith.

[Dave Barker]

See we expats aint so bad guys!!!!! LMAO

[Colin KC]

Moved to tips & tricks ('cos Peter quite rightly pointed out, that's where it needs to be;))