Thread: Cleaning Help Chisels

Originally Posted by delbs

Does anyone use a CBN wheel on a bench grinder that has the higher rpm? Or it's not really suitable?

Yes, CBN wheels are fine on the higher rpm.

Originally Posted by delbs

Scotch Brite pads look super useful. Yup @BobL I just picked up a 2nd hand Abbott and Ashby 8" grinder with a few different buffing wheels. Looking forward to it helping me finish off with some plane cleanup I have left to do

Does anyone use a CBN wheel on a bench grinder that has the higher rpm? Or it's not really suitable?

Recommended speeds for 8" CBNs are between ~1450 and 2850 RPM
For 6" wheels its between ~1900 and 3800 RPM.
This is for dry use

For wet use on 8" it's between 2850 and 3600 rpm, for wet use 6" it's between ~3800 and 4800 rpm.

see https://graffdiamond.com/files/commo...tes-013522.pdf

Thank you. This is great. Is freehandling a chisel or plane iron with a toolrest set at the right angle the best method for a CBN wheel on a bench grinder or can something like trugrind or some jig make them repeatable?

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Perhaps this would be a good base to add to a grinder to help setting new angles on restoring chisels

https://www.timbecon.com.au/baladoni...l-toolrest-kit

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Originally Posted by Bushmiller

I would use a fibre wheel on a bench grinder for the flat chisels. The concave side of the gouges may not be easy to do this way and if that is the case wrap W & D around a suitable size piece of dowel. Just go lightly with the wheel on the back towards the cutting edge on all the chisels as you don't want to compromise the flatness. In fact, as you will probably have to "flatten" the back of the chisel anyway, don't treat the last 25mm at all. It will polish up in the flattening stage.

Regards
Paul

Many thanks Paul - appreciate the thought and was thinking the same thing -


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Originally Posted by Mountain Ash

Hi Brenton. I have had good success with citric acid for removing rust but your steel looks pretty good. I would spend more time restoring the handles. Great score by the way.

Many thanks for the reply, re the handles - light sand and then do you have an thoughts on what to use to put on the handles? Spray on clear? Water base poly, shellac or does not matter?


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My recipe for all wooden tool handles (from where it came I can't remember)
1) a liberal wipe of BLO and leave it to soak in for a few hours,
2) then a light wipe of BLO and leave ON,
3) Then using the same rag as for above wet it with a small amount of BLO and a drop of shellac and rub onto hndle. This should dry a bit quicker.
4) Then repeat 3) with 2 drops of shellac
5) Repeat 3) with 4 drops of shellac

This should leave a silky smooth feel but if you hold the handle firmly it will grip surprsing=ly wee.;

Originally Posted by delbs

Thank you. This is great. Is freehandling a chisel or plane iron with a toolrest set at the right angle the best method for a CBN wheel on a bench grinder or can something like trugrind or some jig make them repeatable?

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Whoah! Stop! No bench grinders on wood chisels or plane irons! Thats basically guaranteed to ruin the edge and draw the temper. CBN wheels and the like are for HSS turning chisels, NOT carbon/alloy steel wood chisels. You can use a charged buffer to resharpen/polish an bevel that's already established.

The only time I resort to something that drastic is to help speed up the manual jigged grinding process (on sticky back sandpaper) with the initial angle if something is a problem. Say it's skewed, pitted, or badly humped.

I'll lay a strip of sticky back 80-grit on my surface plate, run the jigged chisel or plane iron 8 or 10 strokes, then have a look-see. If the edge is badly damaged or convex, I'll use a dremel or bench grinder to *barely* touch the steel halfway between the edge and back where it's hitting hardest on the jig. Then go run another 8-10 strokes, and repeat, until the edge is uniform.

Originally Posted by truckjohn

Whoah! Stop! No bench grinders on wood chisels or plane irons! Thats basically guaranteed to ruin the edge and draw the temper. CBN wheels and the like are for HSS turning chisels, NOT carbon/alloy steel wood chisels. You can use a charged buffer to resharpen/polish an bevel that's already established.

truckjohn

My understanding, and indeed experience, is that a bench grinder is perfectly acceptable to establish a primary bevel. I tend to bring this primary bevel to within 1mm of the edge. Of course if you are ham fisted and a little on the impatient side you will overheat the steel and turn it blue. That is to be avoided at all costs. The trick is to go slow and constantly dip the tool in water to keep the temperature down. As the bevel reaches towards the cutting edge it may be necessary to go slower and cool the blade more often by dipping in water. I am pretty certain that Terry Gordon (HNT Gordon tools) has demonstrated this on his website.

This is a brief exert, but somewhere I have seen a video: Just can't locate it for the moment.

How to Sharpen Your Plane Blade – HNT Gordon & Co. Classic Planemakers Australia

I agree that the final edge is best done by hand and here there are many different techniques: Just use the one that works best for you or the one that you have.

Regards
Paul

I should have added some more context to my previous posts

The chisels i have to restore are very similar to the OPs and essentuially have no edge to begin with. I have tackled one of them through all the grits of sandpaper but am not interested in doing it for all of them.

Agreed finishing on a fine stone by hand and leather etc as I intended to do.

I've got a bench grinder on the way with wire wheel and polishing wheels but I thought a cbn wheel used lightly to put a new bevel on them would be preferable efficient method not intending to generate much heat at all

Then when it comes time for lathe turning again ill look at a trugrind for the hss turning tools





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Originally Posted by BobL

My recipe for all wooden tool handles (from where it came I can't remember)
1) a liberal wipe of BLO and leave it to soak in for a few hours,
2) then a light wipe of BLO and leave ON,
3) Then using the same rag as for above wet it with a small amount of BLO and a drop of shellac and rub onto hndle. This should dry a bit quicker.
4) Then repeat 3) with 2 drops of shellac
5) Repeat 3) with 4 drops of shellac

This should leave a silky smooth feel but if you hold the handle firmly it will grip surprsing=ly wee.;

Dear Bob

Many thanks for the advice will definitely give this a go,


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Originally Posted by bbarrett

Dear Bob

Many thanks for the advice will definitely give this a go,


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I second that, great advice thanks!

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Originally Posted by delbs

I should have added some more context to my previous posts

The chisels i have to restore are very similar to the OPs and essentuially have no edge to begin with. I have tackled one of them through all the grits of sandpaper but am not interested in doing it for all of them.

Agreed finishing on a fine stone by hand and leather etc as I intended to do.

I've got a bench grinder on the way with wire wheel and polishing wheels but I thought a cbn wheel used lightly to put a new bevel on them would be preferable efficient method not intending to generate much heat at all

Then when it comes time for lathe turning again ill look at a trugrind for the hss turning tools





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I have some bad news, you will possibly get quite tired very quickly of swapping between one wheel an another on a bench grinder.
If you can in the future, I would try for a second grinder dedicated to just the CBN wheels.

Cheers Matt.




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Originally Posted by Simplicity

I have some bad news, you will possibly get quite tired very quickly of swapping between one wheel an another on a bench grinder.
If you can in the future, I would try for a second grinder dedicated to just the CBN wheels.

Swapping actual wheels can be a right PITA especially if you bother to true them up to remove runout, and rotate them to minimise vibe. Both are well worth doing but once done, you don't want to be repeatedly doing this every time a wheel is removed.

After a while even using quick change polishing mops and buffing wheels becomes a nuisance.
Mops should not be left anywhere near grinding wheels so they have to be distanced from other wheels to avoid the possibility of collecting cross contamination by grit .

Today I was sanding and polishing the very faint machining marks off a newly machined steel telescopic sight mount for a rifle.
First I tried fine and then medium fine Scotchbrite mops (these mops screw on to a spiral threaded grinder spindle) but they did not even touch the marks.
Then I tried various grit belts using a multitool on a grinder, started at 360 and end up needing 120 before working my way back up to the 360 then the fine scotchbrite and finally a cloth polishing mop.
Only then was the result acceptable to the client - my very fussy nephew