Sizing the hole in a handle to fit the tang?

[Frederick Skelly]

Hi guys,
I didn't want to hijack the other "handle thread", so I'll ask my question here.......

How do you decide what size hole to drill in a handle, to fit the tang tightly without splitting the handle?

Background. I have several Iwasaki Carving Files. They have tangs the are about 2" long and are usually about twice as wide at the top (near the teeth) than at the other end. They are essentially long triangles, if that makes sense. In the past, I measured the width of the tang half way along its length and drilled the hole that size. Because I didn't know about ferrules at the time, I didn't use them. This time, I will.

What works for you?

Thanks!
Fred

[lowell holmes]

I don't know why I would try to answer this question.

If I were faced with this problem, I would take a dowels about the same diameter and length as chisel handles and drill various size holes in them. I would push the dowels with the various diameter holes onto the file and see which worked best. After making a choice, I would try one file to see if it was right.

Then I would put the real handles on.

[Frederick Skelly]

Thanks Lowell!

[John Vernier]

Bob Roziaeski made a suggestion on his blog about this problem, for chisel tangs, which I have tried and like: drill a small hole to accomodate the small end of the tang, the full depth you want the tang to seat, then use the square tang itself as a reamer to make the hole conical. Stop a little before you reach the depth you want (say 1/4 inch shy), then drive your handle home with a mallet. He was using this method as an alternative to "burning in" the tang, which always ends up coming loose. I am currently using this method to re-handle a set of tang chisels I'm rescuing, and I think it's the neatest, least fussy method I've tried.

[Frederick Skelly]

That's a good idea John! Thank you!

[Derek Cohen]

Drill to depth at the diameter to match the end of the tang.

Mark the diameter of the top of the tang on the face of the handle.

Using the same drill bit, pull the spinning drill bit at an angle, effectively removing the waste to the inside of the mark. I would use a saw drill bit for this.

http://www.inthewoodshop.com/ToolRestorations/Rehandling%20an%20Oval%20Bolstered%20Mortice%20Chi sel_html_m211b68be.jpg

You can clean up with a narrow chisel, or use the tang as a reamer now.

Regards from Perth

Derek

[Reinis Kanders]

I have successfully used those tapered drill bits they sell with countersink cutter on top.

[lowell holmes]

I would alter the procedure I described. I would drill a small diameter hole the full depth and chase 2/3 od the depth with a larger diameter, repeat this a time or two more and see what develops. After I worked the issue out, I would drill the real handles. If I found a tapered drill bit I would try it first. I would still do one as a prototype and then proceed .

[john zulu]

Another method is to heat up the tang to cherry hot and place it into the handle.......

HOWEVER: If these are very expensive chisels or hard to find. I would not suggest it as it can ruin the temper of the steel.

[Frederick Skelly]

Thanks guys! These are all good ideas. I think I'll do some experimenting to see what works best for me.

I appreciate your help!
Fred

[allen long]

I have been using the heating up of the tang to burn in the chisel into the handle. You first drill a hole slightly under the diameter of the largest portion of the tang. I use a small C-Clamp to hold onto the chisel the part just pat the tang. This works as a heat sink. You can heat up the tang with a propane torch (I don't go to cherry red at the thickest part of the tang). This will not take the temper out of the business end of the chisel since the heat is localized. My first go was without the C-Clamp and while the blade became hot, it was not hot enough to burn my hand. I use the c-clamp as an extra measure both for heat dissipation and for a handy handle.

I would note that you do not force the tang all the way in the first attempt because the smoke/fumes will need to vent! I then set the tang the last 1/4 or 1/8 inch with a mallet.

That said, I am going to try John V's method on a chisel or two this evening.

Many Kind Regards . . . Allen

[John Vernier]

I've tried the burn-in method and it works, but I think it makes for a weaker attachment. The wood next to the tang basically turns to charcoal, which crumbles over time and the handle eventually comes loose. Several of the old chisels I have rehabbed were mounted this way, and those handles were quite loose. If you are going to try burning in, you don't need to heat the tang to a bright glowing red - do the process in dim light, heat the tang so it's just barely dull red, then let it cool until you see no glow at all, then press the handle on. It will be hot enough! It's amazing how much moisture and black tar will ooze out of the apparently dry wood. And of course, plenty of smoke too. Overheating the tang will just scorch the wood excessively, making more charcoal inside the handle.

[allen long]

That is all good information know. I had not thought about the charcoal formation at the tang being a potentially weak area. I will be using your suggested method from now on.

Thank you, John!