drilling ebony - help plz

[tonysa]

I picked up a small amount of ebony with the aim of making some pens. that was until I tried to drill the 7mm hole.

Damn that stuff is hard !!!!

I reckon its easier to drill through steel than this stuff !

Took ages just to get through one blank.
I'll be here hours just for 2 pens.
Any suggestions best way to drill the hole, fast, slow etc.
I'm using a HSS Brad Point.

I managed to crack (hairline) 3/4 way down one side of a blank, had clamp too tight. If I flood with thin superglue and clamp, whats the chance of not seeing the crack when the pen's finished ? I don't really want to chuck it, took too long to drill the damn hole.

Thanks
Tony

[kiwigeo]

Ebony IS hard..its why its used on guitar fret boards. Drilling the stuff? It takes a bit longer but you just have to perservere. Make sure you have some wood underneath the stuff youre drilling to help prevent drill bit tearing out wood as it emerges.

[barryr]

thats right , Ebony is real hard and ya need a nice sharp drill bit . If you get stuck give me a bell I can drill em out on the metal lathe for ya pretty easily .

Bazza

[Schtoo]

That's right, sharp bits help. Also make sure the bit cuts but doesn't bite. That's when it goes all pear shaped is because it's not only hard, but brittle too.

Last time I used a standard HSS bit, nice and sharp, lowish speed in the drill (1000rpm for a 1/4" bit) and fed it in slowly. It tried to bite in, but not too much and I got a nice clean hole, no splitting and dead straight too.

Until I stuck the knife blade in the hole, it was 7mm or so, and the handle cracked.

Yer right, a drop of water thin superglue, move the crack to help the stuff wick in, wipe off the excess and it should hide pretty well. I wouldn't use anything to make the glue go off any faster, it might make the repair stand out, especially on really black stuff.

Small tip, when turning this stuff, actually hone your turning tools rather than off the grinder. Made a world of difference for me.

[KristianH]

I've made some pens out of african blackwood , which is somewhat harder then ebony. Just use a standard HSS dirll bit with titanium nitride coating at about 1000-1500rpm ( or what ever your drill press recomends for drilling steel).

[barryr]

I've made some pens out of african blackwood , which is somewhat harder then ebony. Just use a standard HSS dirll bit with titanium nitride coating at about 1000-1500rpm ( or what ever your drill press recomends for drilling steel).

not sure I agree Kristian , African Blackwood has a high resin content like cocobolo or lignum vitae and I've found it to drill out or cut much easier than Ebony .
Having said that , I drilled out a few Ebony pen blanks last weekend with no dramas . Like I said before though , I drill em in the metal lathe so you don't split too many pieces of wood .

[tonysa]

appreciate the help fellas, and your offer Barryr
I'll have another go, doesn't seem as though I'm doing anything wrong, just gotta take my time. If it still fails I might have to take you up on your offer.

i'll make sure the drill's sharp, although my drill sharpening skills leave a bit to be desired, especially with the brad points

I didn't have too much trouble turning a small piece but will try the honing idea, anything to cut down on the sanding.

Thanks once again

Tony

[mikmaz1]

Hi Tony,
Try drilling with a smaller dia drill bit first, may help.
Do you get a sloppy fit with using 7.0 drill bits ?
I use 6.9 on hard timbers and 6.8 on softer timbers to get a better fit.
seeyasoon mik.

[outback]

I don't reckon a brad point is the way to go. They are great for softer woods, but as you've discovered ebony can be a tad tougher than pine.

[barryr]

good thinkin Mik , where do you get the 6.8 and 6.9mm drill bits ? or are you using an imperial equivalent ?

Bazz

[mikmaz1]

Hi Bazz,
Any machinists shops will have them. cant remember which dealer i dealt with ,probably blackwoods. Any way check out the yellow pages or google it.
seeyasoon mik.

[gatiep]

Personally I won't use a brad point bit for drilling hard pen blanks. They are good for dowelling holes but give a sloppy fit to the pen tubes. I use a 6.9 mm twist drill bit that I buy from Carbatec in Perth. It does a fine job in both soft and hadwoods, acrylic etc. Just make sure the end of the blank is supported by some wood, otherwise there is a good chance of the blank splitting when you drill through into thin air. I drill my blanks on the lathe usually, the bit in a jacobs style chuck in the tailstock and the pen blank in a scroll chuck with ling nose jaws. Take it easy with the lathe at about 750 to 1000 rpm.
Good luck.
:)

[tonysa]

Thanks for the feedback, interesting about the twist drill bit over brad point, will give it a try. I have a drill press but only 50mm travel so either make jig so I can raise table and keep in same alignment, or get jacobs chuck.

Dontcha just love it when a plan comes together.

Cheers
Tony