Thread: drilling out resin blanks

Note: I've never drilled resin blanks on a lathe before.

But I know when drilling/reaming very hardwood (Gidgee, African Blackwood) blanks on a lathe in that same configuration I have the lathe set to the lowest possible rpm.
I also use auger bits, not twist drills.
And I frequently add a smear of vaseline to the bit (just the tip and cutting edge) every couple of minutes usually when I do the next few steps.
I also remove the bit after an inch or so of cutting to allow both the bit and the blank to cool. It can take awhile.
And I also re-tighten the drill chuck frequently in case of slippage.

Hope that is any help at all?

V

For resin I slow the lathe right down and after covering the lathe bed to keep it dry, I squirt water with a drop or two of dish soap in the hole as I peck drill it. Peck drilling is going in a short distance, 5mm to 10mm, withdraw the bit to clear the chips, squirt a bit of the lubricant (soap and water) and repeat until done. It keeps the bit and blank cool so they don't melt into one. You might as well also get into the habit of leaving the blank long and not drilling through the last little bit. Helps to stop blowing out the end of the blank. Cut it to size when done. Once you get a few under your belt you can change speeds or amount you peck drill if you must. Also some tell you to use penetrating oil or tapping fluids. I don't because some plastics will react to it by crazing, fine cracks. Oh, rinse the soap out of the blank before glueing.

Pete

I did turn on the lowest speed, but I used a normal drill bit, didn't lubricate. I thought I did it in small steps, but perhaps too big... after blowing tge bottoms out of a few drilling by hand I was hoping this would be safer....

Originally Posted by Hangfire

I did turn on the lowest speed, but I used a normal drill bit, didn't lubricate. I thought I did it in small steps, but perhaps too big... after blowing tge bottoms out of a few drilling by hand I was hoping this would be safer....

If your also blowing the bottom outs.
Use a piece of scrap timber as a backer board,
That way the drill bit exits the Timber.

But like others have said go slow clean the waste, chips often, an water helps too.

Cheers Matt.

Fingers crossed!! This turning stuff is addictive.

The other thing to make sure of is that the drill is very sharp and good quality. If the drill has been used previously for drilling steel it may have lost that super sharp cutting edge and will need to be resharpened. If it's not sharp it will heat up the resin where the drill is trying to "wear" its way through and the deformed shavings will not slide out easily along the flutes of the drill and get bound up causing more heat, and possibly melting your blank onto the drill.

what i do when drilling blanks whether resin or timber is to use compressed air as i am drilling
it cools and cleans the hole as you drill it and as others have said use low speed
also back the drill out a bit every 1/2" or so seems to work on even very hard wood like gidgee and
beefwood