Faustner vs Augur for floating shelves

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Hi,
I'm looking to put up some floating shelves made from some offcuts of 40mm deep oak worktop. I intend to drill the 20mm diameter and nearly 200m deep holes across the grain with an electric hand drill. I gather that this is a tricky task to complete owing to the harness of the wood and the inaccuracy of a hand drill.
With that in mind, should I be looking at Faustner or Augur drill bits? Has anyone done this type of task before and are there any tips I should know?
 
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Forstner (note the spelling) bits are designed to drill shallow, flat bottomed holes but lack directional stability on deep holes. They do not clear waste well, either. That is why they are unsuitable for deep hole boring. For that task you need an auger bit. Auger bits are designed for drilling deeper holes, which is why you get them in 230, 450, 600m and longer lengths and the screw nose helps pull them into the work. Unlike many other bits once the screw nose has obtained purchase in the wood the bit will draw itself in - no need to push it at all if it is sharp. Use at low speed (1000rpm or less) for straightest holes.

I recommend spending a bit more on a single good quality bit (e.g. Bosch, Fisher, Wurth, Fisch, Trend Irwin, etc) rather than a full set of cheap and nasty Chinese ones from Screwstation (look on eBay). The better quality auger bits can be sharpened with a triangular file or slipstone when blunt - cheap ones are very hit and miss. Also, avoid auger bits with 1/4in hex drives - whilst designed for use in impact drivers they have a weak neck just below the hex where they are prone to snap if stressed (don't ask me how I know this...)
 
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when I needed to do something similar I spent ages fixing a drill to a table top - horizontally.
Lots of shims and packing to get it 100% level.

Then I used the timber like a sled and moved it towards the rotating drill, forward and back.
In theory it was impossible to drill squint as there were right angles to check slippage.
It worked
 
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Clamp the shelf to a vertical surface (ideally the front face of a joiners bench, but the side of a floor joist, etc would do), then clamp a piece of straight, planed 2 x 1 softwood to the shelf, next to where the hole is going and perpendicular to the edge of the shelf. Use that as a guide to see where you are (should be) drilling. Deep drilling vertically is generally easier to do accurately than deep drilling horizontally, where there is a tendency to be pulled down by gravity, I find.

Regardless of the method, I fully agree that carefully setting up hole drilling like this before starting (together with taking it slowly and continually checking) is an absolute must
 
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I saw a thread where the opposite was advocated as when drilling horizontally a ring spanner can be placed over the bit shank as a guide to vertical alignment. I've got some offcuts, so I might try all options I can find to see what I get on best with.
If you have any more tips then I'd love to hear them.
 
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I think I'd avoid running the web 9against anything metallic in case it caused damage or wear. Once you start drilling the hole it's the web which actually guides the auger bit allowing you to bore a straight hole. Damage it and you might find the bit binding or pulling to one side or the other, and putting side pressure on an auger can bend it, in which case it will never again drill true.

images.jpeg-84.jpg


There is also the danger that the spanner will catch in the flighting and pull back suddenly towards you, so not a good idea IMHO.
 
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