Forstner lube
 

I'm boring into some hard end grain using a pretty big forstner bit. This is on a lathe at a pretty low speed. Lot of smoke and heat with the first 1/4 inch, so I thought I'd stop and ask if I should lube the bit. I seem to recall seeing a demo where the guy used a light brush on of WD-40. The last thing I want to do is start a fire on the lathe.

Yes, I should be using gouges for hollowing, but I absolutely suck at this (although I anticipate improvement with practice).

Any thoughts?

Larry

Forstner lube
 

Gramps' shop wrote:
I'm boring into some hard end grain using a pretty big forstner bit. This is on a lathe at a pretty low speed. Lot of smoke and heat with the first 1/4 inch, so I thought I'd stop and ask if I should lube the bit. I seem to recall seeing a demo where the guy used a light brush on of WD-40. The last thing I want to do is start a fire on the lathe.

Yes, I should be using gouges for hollowing, but I absolutely suck at this (although I anticipate improvement with practice).

Any thoughts?

Larry

Start with the largest bit you will use and go about 1/4 inch deep.
Change to one 1/2 inch smaller and go 1/4 inch, and so on til you get
to about an inch diameter bit and go as deep as you are going, pulling
it back often. Pull it out and cool with air gun and blow out chips.
Then do the reverse, using the next larger bit. It will cut only a
small part of the hole and create less heat. You have a shallow hole
to start each bit in since there will be no center dimple to hold it.

I measure the desired depth from the flat bottom of each bit and make
a mark on the shaft or even on the chuck with a magic marker so I will
know when to slow down and check the depth of the hole.

When the bit gets hot it expands and chatters when pulling back. I
try to let the bits cool between uses and sometimes touch the sides of
the warm bit with a piece of paraffin wax while it is warm. This
lubes it some.

Use a chuck with a drawbar hole in it and screw a piece of all thread
rod into it with a washer and thumb nut on the other side of the
tailstock. I did not do this when I first started and one day I was
backing out and not paying attention and the Forstner bit stuck. It
pulled the chuck out of the tailstock before I knew it. A spinning
piece of wood with a Jacobs chuck hanging out the end and slamming
into the ways every turn will wake you up in a hurry.

--
 GW Ross 

 Kinkler's First Law: Responsibility 
 always exceeds authority. 

Forstner lube
 

On 10/11/2013 9:03 PM, Gramps' shop wrote:
I'm boring into some hard end grain using a pretty big forstner bit. This is on a lathe at a pretty low speed. Lot of smoke and heat with the first 1/4 inch, so I thought I'd stop and ask if I should lube the bit. I seem to recall seeing a demo where the guy used a light brush on of WD-40. The last thing I want to do is start a fire on the lathe.

Yes, I should be using gouges for hollowing, but I absolutely suck at this (although I anticipate improvement with practice).

Any thoughts?

Larry

Larry, you are probably not feeding fast enough #1,
try candle wax, at least if you light it, it will be a candle.;-)
no seriously, I use wax sometimes, but I find burning a result of not
feeding fast enough. I used to think my friend abused his tools as he
always pushed the things to the point of bogging down, but he never
burned anything, so there was something to his madness...
__Now that you have smoked the bit, take it out, sharpen it__, then try
again with more feed speed.

--
Jeff

Forstner lube
 

Gramps' shop wrote:

I'm boring into some hard end grain using a pretty big forstner
bit. This is on a lathe at a pretty low speed. Lot of smoke and
heat with the first 1/4 inch, so I thought I'd stop and ask if I
should lube the bit. I seem to recall seeing a demo where the guy
used a light brush on of WD-40. The last thing I want to do is
start a fire on the lathe.

Yes, I should be using gouges for hollowing, but I absolutely suck
at this (although I anticipate improvement with practice).
----------------------------------------------------------------------------
"woodchucker" wrote:


Larry, you are probably not feeding fast enough #1,
try candle wax, at least if you light it, it will be a candle.;-)
no seriously, I use wax sometimes, but I find burning a result of
not feeding fast enough. I used to think my friend abused his tools
as he always pushed the things to the point of bogging down, but he
never burned anything, so there was something to his madness...
__Now that you have smoked the bit, take it out, sharpen it__, then
try again with more feed speed.
-----------------------------------------------------
SFWIW

Cerritos college, in their WMT courses teach to feed forstner bits as
fast as possible to prevent heat build up and resultant burning.

It works for me.

Lew

Forstner lube
 

"Gramps' shop" wrote in message
...

I'm boring into some hard end grain using a pretty big forstner bit. This
is on a lathe at a pretty low speed. Lot of smoke and heat with the first
1/4 inch, so I thought I'd stop and ask if I should lube the bit. I seem to
recall seeing a demo where the guy used a light brush on of WD-40. The last
thing I want to do is start a fire on the lathe.

Yes, I should be using gouges for hollowing, but I absolutely suck at this
(although I anticipate improvement with practice).

Any thoughts?

Larry
++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++=
Forstner bits have no clearance so they create a lot of heat. Go very slow
and use paraffin wax for lube. Pull it out of the hole frequently to clear
chips and apply more wax.

Forstner lube
 

"Gramps' shop" wrote:
I'm boring into some hard end grain using a pretty big forstner bit.
This is on a lathe at a pretty low speed. Lot of smoke and heat with the
first 1/4 inch, so I thought I'd stop and ask if I should lube the bit.
I seem to recall seeing a demo where the guy used a light brush on of
WD-40. The last thing I want to do is start a fire on the lathe.

Yes, I should be using gouges for hollowing, but I absolutely suck at
this (although I anticipate improvement with practice).

Any thoughts?

Larry

If using a bit larger than 1" you are probably turning too fast.