How do you sharpen a Plug Cutter?

[capetown]

Trying to cut some 10mm plugs in mahogany today, I only managed to cut two cleanly, then the cutter got hot, so then had to feed the cutter intermittently allowing it to cool.

Was using a pillar drill @ 150RPM, wood clamped with sacrificial wood under it.

The cutter is a cheapo parallel type, can this be sharpend? I only need about 20 plugs.

 

[Poignard]

Trying to cut some 10mm plugs in mahogany today, I only managed to cut two cleanly, then the cutter got hot, so then had to feed the cutter intermittently allowing it to cool.

Was using a pillar drill @ 150RPM, wood clamped with sacrificial wood under it.

The cutter is a cheapo parallel type, can this be sharpend? I only need about 20 plugs.

If it's a cheapo it was probably never hardened and tempered ( and probably made of low-carbon steel that could not be), in which case file it sharp with a small fine file, making sure you keep the same cutting angle.

However, if it is hardened a file will not bite so you should sharpen it with a small slipstone.

When using one of these cutters you should withdraw it from the workpiece frequently to allow the cuttings to get clear, otherwise it will overheat and ruin the temper.

 

[fergie_mac66]

ONLY touch the inside face of the cutting surfaces small slip stone...You can do it with a small grinder in a dremmel type tool

 

[lenseman]

Your words "then it got hot" suggests that it is very,, very blunt.

It will be cheaper in the long run to buy new.

 

[fergie_mac66]

had a set of 5 cheapish ones for 15 years sharpened 2 off them, the most used , at least 20 or so times over years the others just a few times . Importantly they still make plugs well.
so it can be done you have to preserve the cutting angle only touch the cutting faces NOTthe outer ,inner and the bottom /back clearance .. similar to sharpening forstner, sawtooth or auger type tools

 

[capetown]

Ok, Thanks Guys,
Job done, but I think I've overdone the cutting angle, it's a tad aggresive now, but I've made enough clean plugs.

I ground the cutter so it was more like a drill bit, it is hardend, cleaned it up with the Dremmel, then used a diamond slip to tidy up the leading cutting edge.

Thanks for the tip about withdrawing often.