2 inch auger bit?

[Badgerland]

I have a job lined up where I need to fit some (approx) 5 inch x 4 inch sweet chestnut posts over some 2 inch galvanised iron posts. The best solution I could come up with (in theory at least!) would be to get a 2 inch hand auger (ring auger? or whatever they're called) and drill into the posts from the bottom end. The wood is green so cutting shouldn't be a problem.

 

I found some a while back on the old interweb – japanese and very expensive I seem to recall, but I'm damned if I can find them again. Anybody out there know where i can get one or even what the correct term for them is? Any help gratefully received.

[woody paul]

Forstner bit is what you need to Google.

[GreenGui]

I bought a 38 mm auger from Irwin last year really hard going into oak, cost about £25 on amazon UK. Going into the end grain I would imagine 'bit wander' will be an issue - for 50 mm try these guys

 

Auger Bits in Inch Measurements for Machine and Hand Drilling | FINE TOOLS

 

135 Euro's ouch!!

 

Good luck

[sean]

http://www.amazon.co.uk/s/?ie=UTF8&keywords=forstner+bit+60mm&tag=googhydr-21&index=aps&hvadid=40775800610&hvpos=1t1&hvexid=&hvnetw=g&hvrand=8872417290926456622&hvpone=&hvptwo=&hvqmt=b&hvdev=t&ref=pd_sl_9shunme36m_b

[GreenGui]

The problem with Forstner bits is that they wander big time at larger diameters.

 

I do post a rail fencing in chestnut using a 1.5 inch veritas tenon cutter. I started out using a forstner bit for the socket but they just wander, I now use a simple flat bit. If a forstner wanders going across the grain you can be damn sure it will going end grain.

 

If you go with an auger use an 1/8th drill as a pilot, 1. because at 2 inch diameter the auger lead screw is too fierce on an electric drill and 2. the auger bit will drill true following the accurate 1/8th hole.

 

Have you thought about cutting the posts down the centre, routing out and boxing round the metal posts? Might be easier and cheaper...

[Badgerland]

Thanks for the ideas guys.

 

Greengui – I agree. Forstner bits are a pain in the butt with green wood, and in the end grain would not even go in at all. They'd just spin on the surface.

I did think about cutting the posts down the middle, but they're for cleft post and rail, so it would compromise the strength and look pretty obvious. Also, one of the client's is an artist and aesthetics are a major concern. If I was doing it in partially seasoned oak I could possibly get away with that, but not in green chestnut.

 

Unfortunately it will have to be an auger bit as i need to make the hole at least 1 foot deep. That's why I was looking at a hand cranked one. My drill would disintegrate before it got an inch in, and if it didn't it would probably try to break my wrist.

[se7enthdevil]

i used to use my cheap china made forsteners to go in the endgrain of 5" newel posts. granted that was dry timber but they did not wander and we were going 4-5" in.

 

forsteners would be the best option in my opinion but you have to keep them sharp and you can buy extensions to go in deep also if you want to prevent the possibility of wander then i can turn you a split collar to go over the shank to keep it in line over the course ofthe depth.

[Badgerland]

Well I stand corrected.

 

I did have a little practice with a 51mm forstner into some end grain chestnut this afternoon and after putting in a pilot hole just to keep it steady when I started it seemed to go ok. (Don't have a great deal of confidence in them if I'm honest. Not had that much success with them in the past but that might have been a sharpeness issue combined with green timber.) Still not too sure how it will go when it's a foot in though. The gizmo on my makita that prevents you burning out the motor kept kicking in, whenever the drill bit caught or dug in too deep. Tad annoying!

 

Cheers for the offer of making a split collar Steve. I reckon I can probably get away with it free hand, as it doesn't have to be too exact (I hope!) but if not I can always dust off the lathes and knock one up myself.

 

Incidentally, what do you use to sharpen your forstner bits? I tend to use a diamond board, but is there a better way that you'd recommend?

[se7enthdevil]

some sort of diamond file would do fine to sharpen the bottom cutting edge in my book.

 

i used a pillar drill to go into the newel post so if possible stick the post in a vice at an angle and once you've started drilling use your bodyweight to help with the drilling.

 

that may have been why your previous forstener bit was spinning as they are not self feeders (some are) and if it was a bit blunt it would definitely spin rather than drill.

 

 

forstener drill bits are used all the time by us turners to go into all sorts of grain including endgrain when drilling out the centre of vase blanks to about 10" and wander is not a problem i've had before.

 

 

try to keep the cutting edge cool so it keeps its edge longer.

[se7enthdevil]

Well I stand corrected.

 

I did have a little practice with a 51mm forstner into some end grain chestnut this afternoon and after putting in a pilot hole just to keep it steady when I started it seemed to go ok. (Don't have a great deal of confidence in them if I'm honest. Not had that much success with them in the past but that might have been a sharpeness issue combined with green timber.) Still not too sure how it will go when it's a foot in though. The gizmo on my makita that prevents you burning out the motor kept kicking in, whenever the drill bit caught or dug in too deep. Tad annoying!

 

Cheers for the offer of making a split collar Steve. I reckon I can probably get away with it free hand, as it doesn't have to be too exact (I hope!) but if not I can always dust off the lathes and knock one up myself.

 

Incidentally, what do you use to sharpen your forstner bits? I tend to use a diamond board, but is there a better way that you'd recommend?

 

 

i used an electric drill geared to a slow speed that had lots of torque. i braced the drill and flexed my muscles to hold it straight. that may tire you out if there are lots to do.