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I've got the sharpening "blues"...

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Forum topic by Thrakintosh posted 10-19-2014 11:58 PM 963 views 0 times favorited 8 replies Add to Favorites Watch
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Thrakintosh

52 posts in 3232 days


10-19-2014 11:58 PM

Hi all,

Newbie turner here who just received a One Way Wolverine and various jigs this week. Set everything up according to plans with my Delta grinder (1725-3450RPM). My low grit wheel is a stock Delta 80 grit aluminum oxide. The high grit is a Norton 150 grit also aluminum oxide. Tools are an assortment of HSS tools from Sorby, Bodger and PSI.

It seems I’m having a real touch time not blueing any of the tools. Even using a light touch. Am I spending too much time on the wheel? I’m not using 3450RPM setting – always the low setting. Of course the problem is exaggerated when I am regrinding. For instance, regrinding a bowl gouge from 45 to 60 or using the Vari Grind to turn a standard grind into an Irish grind lead to my blueing the tips and wings.

While we’re at it… Any recommendations on basics or sharpening videos (YouTube or DVD)?

Thanks!

Adam

-- Adam - Red Hook, NY


8 replies so far

View Pezking7p's profile

Pezking7p

3097 posts in 1116 days


#1 posted 10-20-2014 01:08 AM

I’ve never used a wheel to sharpen, but I did stay at a holiday inn express.

Are you using water to cool while grinding? Other than that, just take it really really easy, especially when changing bevel angles because you have to take off a lot of material, obviously you know that already but just reiterating.

-- -Dan

View Crank50's profile

Crank50

173 posts in 1041 days


#2 posted 10-20-2014 01:47 AM

Are those the friable wheels, the white ones, or the standard grey or green.

You need to use the white wheels.

You need to move quickly and not spend any time at one spot on the tool.

And you need to use a light smooth moving motion.

Finally, dip the tool in water frequently.

If you hear a sizzle you are moving too slow and are about to burn the tool.

After the tool is burned you have already softened it and the edge will not last.

You have to remove more material to get to hard metal again. Hard to do without burning again.

A belt sander will grind away material better than a wheel without burning as bad.

Use very coarse belt or wheel to make drastic changes in angle or shape.

Only use fine abrasive to finish up.

View exelectrician's profile

exelectrician

2327 posts in 1892 days


#3 posted 10-20-2014 04:18 AM

Grind for two seconds or less, then dip in water for four, that is a rule.

-- Love thy neighbour as thyself

View bobasaurus's profile

bobasaurus

2672 posts in 2649 days


#4 posted 10-20-2014 05:06 AM

I second Crank’s answer. Get the white wheels that won’t load with steel particles and quickly burn your tools. Regrinding different edge profiles requires dipping in water frequently. Edge touchups can be done dry, just be quick about it and keep the edge moving.

-- Allen, Colorado

View kaerlighedsbamsen's profile

kaerlighedsbamsen

1177 posts in 1178 days


#5 posted 10-20-2014 07:02 AM

Grinding without blueing the steel is not particularly difficult if you follow a few rules:
- Go with the FAST setting on the grinder. Slow takes more pressure and makes more heat. Fast helps rotate air to help cool the steel.
- Use a stone dresser regularly. Either one of these or a diamond one. Both works fine.
- Hold the tool with a finger CLOSE to the cutting edge and keep a finger on the tool support on the grinder as well. That way you have max controll and feel the metal heating up.
- Use minimal pressure. Make sure you relax in your arms and shoulders. It is essential that the grinder is at a comfortable height (higher than most tables) and has good light.
- Move slow (fast makes for loss of control) but touch only the stone for 1-4 seconds at the time. Dont move the tool from the tool rest but only move it a mm. or so back. That way the moving air cools the steel and you continue grinding at the right spot and at the right angle.

Follow these rules and you should be able to grind without blueing.

Let us know how it goes!

-- "Do or Do not. There is no try." - Yoda

View hairy's profile

hairy

2384 posts in 2997 days


#6 posted 10-20-2014 12:57 PM

https://www.youtube.com/watch?v=31pzViUhJuQ

https://www.youtube.com/watch?v=9WGw4fYplkY

These are the best I’ve seen on Wolverine. Thanks, Curtis Turner !!

-- stay thirsty my friends...

View Wildwood's profile

Wildwood

1886 posts in 1599 days


#7 posted 10-20-2014 09:41 PM

You are pressing too hard, try holding the Vari-grind jig with two hands while sharpening instead of jig and tool handle. I do not quench my tools in water when resharpening tool does not get that hot where burns my fingers. I do not quench my tool in water when redoing bevel angle just air cool, tool does get hot but never blues.

People smarter than I say quenching HSS in water changes structure of HSS. People do it all the time so have no idea who is correct. I stopped quenching tools years ago. I stopped over heating my tools years ago too. Have a six inch 3400 RPM grinder been using for past twenty years. You have a good grinder so back off on the pressure while sharpening or regrinding bevels!

I use a medium 46 grit K-hardness to redo bevel angles or repair damage tool (don’t ask). I go right from the grinder to turning, will resharpen on an fine 80 grit k-hardness wheel.

Doug Thompson had a great video on sharpening no longer on the web but there are still some great one still around.

-- Bill

View gwilki's profile

gwilki

121 posts in 938 days


#8 posted 10-21-2014 02:39 PM

Adam: I’ve sent a private message.

-- Grant Wilkinson, Ottawa ON

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