Drill press

[GaTurner]

Is it ok to wet a Forster bit while drilling
to keep from getting to hot.
Sandra

[BobW]

If it's getting too hot, it's probably turning too fast. Max speeds are printed on the shanks of my forstners. Range is max 870RPM (1/4") to 620 RPM (2")

[bubba]

BobW said:

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If it's getting too hot, it's probably turning too fast. Max speeds are printed on the shanks of my forstners. Range is max 870RPM (1/4") to 620 RPM (2")

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Too fast, as above, or the bit is too dull, or both.

I would think that adding water could just compound your problem. Water will cause the wood fibers to swell, increasing pressure around the circumference of your bit and leading to more heat production.

[iclark]

That is an interesting question.

It would need to be a fluid that does not interfere with the finish.

Are you thinking horizontal or vertical boring?

Is this a continuous flow with a catch basin and pump like a metal milling machine or just an occasional squirt from a bottle/can?

If you are thinking vertical and occasional squirts, the liquid might actually make the heat build up worse since a wet swarf might compact in and hold heat better.

If horizontal on a lathe, then the continuous flow from a pump could do some good, but the catch basin is going to be difficult to implement.

My gut instinct is that it would be better to set up a compressed air nozzle to blow on the backside of the cutter. That would help cool and also help blow the swarf out of the hole.

I would be happy to have someone else tell me that I am wrong, though, with an explanation of how to do it right.

[fredhargis]

I wouldn't. If it's a good high speed steel bit, the heat won't hurt it. Turning tools made of HSS can turn a little blue on the grinder and not be damaged, I'd bet the forstner isn't getting anywhere near that hot. But running it slower as suggested may help it run cooler.

[Routerman]

Would not use water, but would use air, vacuum essentially.
Get that chip otta the hole now; that's the major contributor to heat if you have the right speed for the material, cutter diameter and feed rate.
Clamp things down and vac. that chip out of there as it's created. & it wouldn't hurt to retract the cutter every couple of seconds.
The Essentials

[GaTurner]

Thanks. I think it may be a little of both
turning to fast and a little dull.

[T.J.]

GaTurner said:

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Thanks. I think it may be a little of both
turning to fast and a little dull.

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I actually ran into this issue recently while finishing my tool cabinet and making hangers for my chisels and such.
I lubricated the forstner bit with bees wax. I have a big chunk of it that I just press against the bit between plunges. Worked like a champ.

[Timberwolf]

Try "peck" drilling....drill a little, raise the cutter out of the wood for a few seconds, then repeat.

[MarkSingleton]

Jack for the win. If you cannot slow the bit down, that will keep it from heating up too much.