Hollowing out with flat wood drill bit?

[helphil]

I have turned a vase and used a forster bit to remove most of the neck waste.
But I need an extension bar to reached down the rest of the neck to do the rest.
A forstner extension bar is about £30.
But I have found a flat wood extension bar for £4.
Can you remove stock waste using a flat wood bit with extension bar? as the price difference is quite a bit and I am not going to be doing this that often, and happy to run up the sizes with the flat bars in the Jacobs chuck.
Any help appreciated.
Thanks
Phil

 

[nev]

You can use either bits but flat bar extension bits are generally a bit floppy may well wander a bit.
Flat bits have long points, especially the bigger ones, forstner bits have much shorter points and are a lot less prone to grabbing.
Going up in increments with flat bits or forstner bits is not a pleasant process as the point (guide) has nothing in which to locate so the bit will bounce around and make rather a mess of the entrance hole before finding its own route through the wood and not necessarily following the previous hole. Just use the one the size of the hole required and go slowly.

 

[helphil]

Nev
Thanks for your tips, they make a lot of sense. I'll go for the cheap option and use the larger flat bit on a slow speed. And see how it pans out.
Thanks again.

 

[Dalboy]

As Nev stated some drill bits can wonder if the hole is not one that needs to be exactly on centre and only used to aid depth and remove the material from the centre then they will do the job just fine. Also as stated remember the little point on the end and allow for that when drilling.

 

[Paul Hannaby]

I don't know how deep you are trying to drill but an alternative worth considering is to use a beam drill. They are a twist drill on the end of a long shaft. The only drawback is you need a lathe with a long bed to use them!

 

[Bm101]

I'm not sure this is the advice you're after. But just in case.
I'm a big fan of star-m bits. Japanese bits. They are not cheap but they are excellent. Bear with me here.
Their auger bits are incredible. Designed for hand tools or machines. These people know what they are doing.
I needed a 20mm bit. Fine Tools sell a good range but postage is a tenner. Workshop Heaven sell a limited range. And yaknow, nice people. So I ordered one of these from WH.

https://www.workshopheaven.com/star-m-j ... ngles.html

These are sold as no breakout bits. That's a pretty good description, Breakout is minimal to non existent. If anything they need a scrap on the entry hole as they can raise a chip going in. That's ironic.
Anyways.

Finally. Sorry!
Point being...
If you ever drilled a mortice etc with a drill bit it's not ideal.
These bits allow you to hand drill and share the mortice. That shape at the front of the bits means you make domes not cylinders at the base of your drill point.
That means you can basically you don't get stuck in one hole. You have some artistic effect. Do it all by hand except the clean up.

 

[CHJ]

A forstner extension bar is about £30.
Phil

The turners Retreat appears to have a cheaper version only 6" but together with the bit shank etc. should give adequate depth.