Dry Lube

[kruzzer]

My wife recently asked me to re-make a letter opener with a longer handle. I had a extra log 7mm tube laying around and decided to use it. The problem was drilling the 7mm extra long hole in the wood (yellow heart) blank. It kept binding regardless what speed I use. I was wondering if anyone has used a dry lube like RX-50 on the bit?? I use water as a coolant and lube for acrylic blanks and don't seem to have any problems with it but
the longer wood blanks give me fits..

 

[Curly]

What speed are you drilling at. Try the lowest speed your drill press or lathe has. Make sure you have sharp quality drill bits and clear them often. If you have compressed air you can blast the tip of the drill and down the hole to cool them when chip clearing. Make sure you have eye protection on if using air. Pretty much every lube will contaminate the hole and interfere with the glue when you put in the tubes.

 

[Rockytime]

Would not the water in a wood blank cause a bind as it swells?

 

[kruzzer]

Pete,
I was drilling on my lathe and tried slow to moderate speed. Also use air to clean out.
I get it done but it is just difficult, not impossible.
Les,
I only use water on acrylic blanks to cool and lube not on wood...
I guess I'm looking for some "magic"..

 

[CREID]

Ok, bear with me, i'm winging it here. But!! If you have a fairly straight piece of wood or whatever you are making your letter opener out of. You can just drill in a little from each side and then glue in a short brass tube (I know, I know, there is a little thing as a mandrel that usually goes through) but after gluing in the shorter brass tubes you can forego the mandrel and turn between centers. Like I said i'm winging it, but I think it will work.

 

[Dalecamino]

Rich, you could try a bar of soap. Then run a wire brush through the hole with the lathe on to, clean it out. Just a thought. I have never tried this. But, my mom used it on the chest of drawers.

 

[jttheclockman]

Hello Rich

I will give you my opinion on this and there will be others that disagree but that is OK. never use water to drill a wood blank. It will swell the wood and make drilling more difficult and also could ruin the size of the hole after it dries. and shrinks.

Now wood is best drilled with an auger bit especially end grain such as what you are doing. With an auger bit it has larger spaced flutes to allow the swarf eject better. You can find them in sizes we use for pens. These are different than brad point bits.

Now you can use standard twist drill bits as most of us do. As mentioned slow the speed down but it will require you to pull the bit out more often to clear it. As far as a lubricant you can use a linseed oil. Some use a walnut oil. Small amount sprayed in the hole. I can see it now all the fire inspectors jumping on this but your goal is not to get the bit so hot because if you did you run the risk of splitting the wood anyway. This will not interfere with the glue when left to dry. You should always wait to glue a blank in anyway to let it dry and cool.

One other thing that could be of help. Use a smaller bit first and work this through and then switch to the proper bit after the blank has cooled. Something a size or two below what is needed. Keep the bit steady when drilling and advance slowly but evenly. Pen blanks are not long so this should not be a problem. You run into problems when drilling heavy grained woods because no matter how hard you try a drill bit could follow a grain vein and go off center. Straight grained dried wood is the best. Yellowheart is an oily wood which makes for a harder wood to drill and the swarf will bind to the bit.

Good luck.

 

[randyrls]

Ok, bear with me, i'm winging it here. But!! If you have a fairly straight piece of wood or whatever you are making your letter opener out of. You can just drill in a little from each side and then glue in a short brass tube

With the short tubes, one can use TBC bushings too!

As JT said, no water on wood blanks.

 

[KenV]

Need a really sharp bit. Freshly reground if already in hand.

 

[kruzzer]

Curt, Randy, I thought about that but was just looking for an alternative.

Chuck, never thought about soap. Maybe first drill slightly under size then clean up with correct size drill to get the soap residue out..

John, I would never use water on a wood blank... Might try to linseed/walnut oil next time I have to drill an extra long blank.

All good input and thanks to all.

 

[monophoto]

The cutting edge on drill bits is at the very tip. As the bit cuts, the swarf flows into the flutes. If the hole is shallow and the wood is reasonably dry, the swarf flows through the flutes and is carried out of the hole. But if the hole is deep, swarf can accumulate in the hole, causing friction, overheating and binding. And if you are drilling wood that is wet or oily, the tendency for that to happen increases because the swarf is sticky.

So that suggests four things that you can do. First, make sure that the drill bit is sharp. If ;you have a Drill Doctor, use it. Otherwise, use a diamond paddle to 'tune up' the cutting edge at the tip of the bit.

Second, you need to frequently back the bit out of the hole to clear the accumulated swarf in the flutes. How often depends on teh depth of the hole, the diameter of the hole, and the depth of the flutes. I generally try to not drill more than 1" at a time.

Third, you can lubricate the bit, but that raises the concern that if you are planning to glue a tube into the hole, you want to use a lubricant that won't interfere with adhesion of the glue. When I don't need to glue anything into the hole, I use paraffin or candle wax. Soap would also work. If you are going to glue something into the hole, the ideal solution is to not use any lubricant, but if you must, use something that will cure thoroughly and leave a surface that the glue will adhere to. Brian Stemp, a flutemaker from Austrialia, suggests using BLO, and I suspect that would be fine if you are going to use something like epoxy or CA that doesn't rely solely on surface adhesion, but also cures and hardens to form a solid mass that conforms to the irregular surface of the wood inside the hole forming a mechanical bond.

But you need to understand that lubrication can also lead to a 'sticky' swarf that will tend to clump in the flutes of the bit, and you will need to back the bit out and clear that swarf.

Finally, make sure the bit is straight. If it is bent, the tip of the bit will cut a hole, but then as the bit moves into the wood the sides will attempt to enlarge that hole. That can lead to both heating and binding.

 

[smik]

Check if your drills have any back taper, no taper will contribute to binding. If not enough chip clearance you can try clearing the land towards the backend or use parabolic drills.

 

[Skie_M]

I would say drill undersized first, with a wax lubricant and a freshly sharpened bit, making sure the bit isn't bent....

And then move up to the full size bit, drilling slowly, to remove the wax residue and enlarge the hole to the final size.

This would enable you to drill from either side with the long 7mm bit provided by PSI's kits, for example, and then finish drilling with the standard sized 8mm or 3/8ths bit you need for final sizing.