Ways to tackle this work?

[GLFaria]

Hi

I have been asked to enlarge the holes in a pair of candlesticks, from (on average) 21mm to 22mm diameter, and from 15mm to 25mm depth (see pictures below)

I don't have access to a wood lathe; if it wasn't for the deepening, I would just use a small abrasive drum to enlarge the hole; as it is, the only way to do it that comes to my mind is to plug the hole with a wooden plug, mark the center, then very carefully use a 22mm Forstner bit on my drill press, with a purpose-made jig to hold the pieces vertical.

The main glitches:
-the depth of the hole; this I think may perhaps be overcome by doing several relativelly shallow passes so as not to let chips and dust accumulate in the bit, and letting the bit cool in-between
- the wood looks suspiciously like African Blackwood (Dalbergia melanoxylon) - which means I may ruin, or at least severely blunt, a perfectly good (new, for that matter...) forstner bit.

Any suggestions on a better way to do it - or on not doing it at all? Remember - no lathe.

Many thanks for any help.

G.

 

[dzj]

Enlarge the hole with abrasive drum and drill out the rest with the F. bit. Use a jig as suggested.
Drilling a pilot hole might also take some stress off the 22mm bit.

 

[RogerP]

As a test I just drilled a 20mm hole (no 21mm available) 8cm deep in a scrap of mahogany then enlarged it to 22mm with ordinary twist drill http://www.amazon.co.uk/Speed-Steel-Straight-Shank-Twist/dp/B005GBEL12 - no problem and really couldn't be any quicker or easier.

 

[Mar_mite]

Drill a 22mm hole in some scrap, then find a way to center it over the hole you want to enlarge and clamp it somehow. You can then use the scrap with the hole to guide the Forstner bit. Once it has started itself you'll be away.

 

[Jacob]

I'd suggest reducing the diameter of the candles instead.

 

[SteveF]

could you camp a router guide somehow and route them out ?

Steve

 

[GLFaria]

Thank you all for your suggestions.

I think that dzj's is the one to follow, simpler than what I had thought of doing.

I don't think I am going to buy a 22mm twist drill for a one-off job.

And, of course, reducing the diameter of the candles would be the obvious choice, except it's not candles the owner wants to use them for...

G.

 

[dejaa]

Hi

I would concentrate on deepening the hole first. If you use your 20mm drill you can centre it by getting some 0.5mm thick veneer (or sheet metal) and cutting it to 15mm x 66mm (21mm x 3.142) then trim the end so that it just fits inside the hole, then drill out to the 25mm depth required. The "new" side walls will guide the drill so no need to be worrying about centres

You then only have to worry about the diameter; If you can create a starting taper then your 22mm drill should do the job, otherwise use your abrasive drum?

David