Drilling problem - drill type ?

[OldWood]

I think it was the September issue of The Woodturner that had an article on making pomanders - I borrowed the issue photocopied the pages but they don't say which issue it is.

Anyway I suppose any pomander is a hollow vessel but there's one which hangs and has a series of holes on the upper curved surface. Not having done a hollow vessel before I hunted out a chunk of 4" white pine for at trial run. I've got a drill guide so getting the right position and angle was OK, but I found that with an ordinary drill, (and I know it's cheap pine) I got serious breakout from the 8mm holes. I'm concerned that I turn up a decent piece of wood and get the same problem.

Is there a technique I should be using or some specific drill type ?

Rob

 

[mike s]

i assume the tearout is on the inside?
drill the holes while the walls are fairly thick then turn them thin

 

[OldWood]

i assume the tearout is on the inside?
drill the holes while the walls are fairly thick then turn them thin

Thanks for replying.
No these are on the outside. I did a 6mm pilot (the smallest drill guide I have), and then 8mm. The article doesn't give any specific comment on the drilling and instructs to drill after turning and finishing the outside.

Rob

 

[Tazmaniandevil]

I had a similar problem with a cruet set. I got around it by putting several layers of tape over the piece before drilling.

 

[stevebuk]

what about trying to hold a piece of wood against the outer wall you will push through..

 

[gus3049]

The attached had the same problem to start with. I did wonder about making a curved block to press against but all the changing curves rather put me off.

In the end it was down to sharpness and technique. I started with a 2mm drill freshly sharpened, used in the air tool at 74000rpm. Then drilled out the bigger holes but with almost no pressure at all, just let the drill do the work. I used a cordless drill running at its highest speed. As you feel the bit breaking though, back off any pressure at all. Yew is pretty bad for splintering but this just needed a very light sand to remove the odd small splinter from round the holes.

I did attempt it in the pillar drill but firstly, its too slow and getting all the holes at the right angle would have been a nightmare.

I reckon with a 6mm or 8mm hole things might be trickier but I'm sure high speed and sharpness are the secrets. I use ordinary metal drills rather than wood drills. Tape sound like a good idea.

 

[Jonzjob]

Have you tried a lip & spur drill? 8mm should drill quite clean with one of those.

I do like the pot Gordon!!

 

[OldWood]

Thanks for all your comments guys. I don't know how many of you read to article in Woodturning that I referred to, but the author, Nick Arnull, had his webpage included, so I dropped him a line.

He had used what he called a "brad point" drill and drilled the holes free hand once marked and bradawled. It seems brad point is the US name for what we call tip and spur. Free hand drilling I can see point of as I found using a guide meant that the drill speed was low and the pressure erratic as I tried to keep everything lined up.

Rob