Forstner bits - any advanced tips and tricks?

[Homerjh]

Hi all, after a long time without any woodwork (house move and finally starting to get straight!) i have made a simple ping-pong ball holder for the better half, basically a strip of pine, 12 holes, all rounded off with the router and then as it was cheap pine, got some 'dark oak' wood dye just to colourise it and it has turned out quite nice for what i think is a straightforward thing to make, but the forstner holes are not as neat as i would like.

so when using a forstner, do you have any tips or tricks to use them as well as answers to below :

1 - the 'nib' in the center obviously has left a small indentation, can this be removed and if so will it affect the use? how best to remove it?

2 - How do you get a perfectly smooth base? i expect it is either a substantial amount of sanding or expensive forstner, this is slightly ragged, and the dye has been soaked in and expanded the small bits (or is this to do with the wood used?). Every time i have used a forstner i get the same base issues.

3 - would the speed of the drill affect the base finish? i cant remember the speed it is set to, so may be wrong?

some pics of the item, and TBH the holes in the bottom, will be covered by the balls anyway and wasnt meant to be a fine woodwork project!

http://imgur.com/a/5MFxZ

 

[Phil Pascoe]

Pine (spruce?) will always tear a bit. Afaik. all forsners have the centre point - it centres the bit. You could remove it, I suppose, if you were to have the drill in a stand and clamp the work piece down. They are designed to bore a hole with clean sides, more so than with a clean base, so if you wanted a really clean bottom you'd be better using a router with a templet. Your speed shouldn't so slow that it snatches, but not so fast that it burns. Make sure the bit is 100% sharp.

 

[CHJ]

OK, some queries about your bits and observations as I see them based on your images.

• What pattern of so called Forstener bits do you have?
  Original Brand with solid side walls and ultra sharp cutting edges or cheaper clones or maybe saw tooth variants?
  
  Are you using a Pillar drilling machine or hand held?
  
  You have soft easily bruised and friable timber, you need the sharpest cutting edges you can achieve and to prevent drill wander during starting cut, a rigid location of work and drill.
  
  The only way you are going to achieve a flat base straight off the drill is to have two bits, one with the starting location spike and one without this and suitably sharpened that can locate in the part formed hole.
  The obvious option for dealing with the central detail is to insert a blanking disc of thin wood or felt.

You can get away with cheaper bits in harder species of wood with denser grain.

 

[marcros]

if you were to make another, I would either do as suggested and line the base with something, or use a router and template.

 

[Homerjh]

thanks all, yes i didn't expect a £3 plank from B&Q to be the best to work with and as i know it is likely to tear, will remember that.

CHJ -

What pattern of so called Forstener bits do you have? -dunno - sawtooth i think (http://www.screwfix.com/p/forstner-bits ... -set/83345)

Original Brand with solid side walls and ultra sharp cutting edges or cheaper clones or maybe saw tooth variants? - Saw tooth.

Are you using a Pillar drilling machine or hand held? Pillar

 

[AndyT]

Another approach for a neater job - which you could still do - would be to make your project from two pieces of wood. Drill your holes all the way through one piece (remembering to put some scrap wood underneath while you do so) and then glue on a new base board, with a nice smooth finish on it.

 

[Homerjh]

Andy, i did think of that, but decided this route, but can always try a similar process with a bit of plank to see how it works

 

[CHJ]

Sawtooth:-- make sure cutting edges are as sharp as you can get them, including the saw teeth, sharpen them as you would a hand saw.

If starting in soft wood, try applying sanding sealer to surface to stiffen and hold soft fibres in place for a crisper edge.

Pillar Drill:- clamp work piece to table to prevent any vibration moving piece a fraction during hole start.

 

[GLFaria]

As for speed - search for "forstner bit recommended speed", you will find several tables (not always in full agreement) and recommendations.

I work mainly with soft pine, never managed to get a smooth bottom. And may I be excused if I say that at the price shown your bits are certainly not top quality...

I would go with the remedial suggestions from some of the posters above.