I swear there's something wrong with this iron

Okay, probably not, but ... it's only been a recurring problem with my Luban No. 5.

Re-ground the primary on the electric bench grinder, then half an hour going through three wetstones (mostly because I didn't get quite on 25° on the grinder so had to remove a lot with the 300 grit with the Mk II), back in the plane, then test it out - it's sharp right along the cambered blade, but has three nicks in it that couldn't possibly have survived the bench grinder, which means I made them while sharpening the blade.

This keeps happening. It's only my No. 5 so nicks aren't life or death but it's bloody annoying.

Any over-heating on the bench grinder should make the steel softer not more brittle so I don't know what's going on.

Sorry, no photos, it's a bit hard to take decent photos of something that small.

The blade may need grinding back a bit a few because of poor heat treatment. Hollow grind the blade then instead of trying to hone the hollow bevel on the stones place the bevel down on the first stone and slightly lift the blade so the heel of the bevel no longer contacts the stone and put a small micro bevel on the cutting edge only, proceed to the next stone & repeat until you have finished honing. It normally only takes a half a dozen swipes on each stone to et a razor sharp edge and touching up when it gets blunt is a quick exercise as well. From grinding the blade to final honing should take less than five minutes when you get used to it and it also negates the need for setting angles in jigs etc.

Derek Cohen gives some illustration and advice on this technique here. I like it because it takes literally only a few short minutes to go from nicked blade to back to work.

http://www.inthewoodshop.com/Woodwor...gStrategy.html

I suspect I need to spend more time truing my grinding wheel - I suspect it's getting nicked from high spots on the wheel - the fact that things often go bouncing off the table from vibration is giving me a clue that there's an opportunity for improvement there - so I've just got one of those T-shape diamond dressers and going to see what that does, spend more time balancing the wheel and seeing if I can replace the plastic bushings with steel ones, and also planning to restore an old hand-cranked grinder I just got off Gumtree.

Anyone know if we can get the Geiger Solution's Tru N Dress diamond point grinding wheel truing jig here in Australia? Though I'm guessing it'd be close to $200 ...

Be very careful, your grinding wheel may be failing. Check it thoroughly for cracks, chips or nicks. Mr. Dodds, HS welding teacher, told us that grinders were the second most dangerous shop machine.

It's a brand new aluminium oxide wheel so shouldn't be failing; I wasn't familiar with the concept of truing grinding wheels till recently.

Grinder shouldn't be hopping around. If you've used the new wheel under those conditions please have a look. https://www.youtube.com/watch?v=iaoVqUpOrPs

You need to dress Alox wheels often. If it is a white, blue, pink alox wheel, you can see as you use it not only does it lose its shape, but dark grey bits begin to fill the surface. This dark grey stuff is steel grindings. Eventually you end up rubbing rather than grinding. Before you put a new wheel on a grinder, loosely hold it with one finger and give it a soft, and I do mean soft soft soft, tap with something metal...I use a spanner, not a hammer because I'm used to hitting hard with a hammer (even a soft hit with a hammer is still pretty damn hard). The sound it makes when you hit should be a clear ring, rather than a dead thud. If it is a thud, it means the grinding wheel has a hairline crack in it and should be discarded. But I doubt this is the problem.

Thanks I'll do that too. I've just been using one of those carborundum sticks till now. When I say "Brand new" well, 6 months but used infrequently.

Quote:

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Originally Posted by rob streeper

Grinder shouldn't be hopping around

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No no, grinder is bolted to bench. I mean vibration is causing things on the bench like angle gauge etc to fall off the bench.

Also, that video is gruesome. But sobering.

If it's only happening with the one blade, repeatedly, then replace it. Those Luban blades cost what, $20? I know it's a poor tradesman who blames the tools, but sometimes it really is the tool's fault.

Fix the grinder problem but first the wheel dresser for $200, if the grinder is powerful enough you can buy a CBN wheel for close to that and never have to dress it.

https://www.cwsonline.com.au/shop/ca...rinding-wheels

Buying the CBN wheel will not necessarily fix the vibration, that is more likely down the the grinder itself but it is fixable. The cheap Asian grinders have poorly made shafts and nuts which when tightened push the wheel off centre and even making steel bushes for the wheel lessens it but does not eliminate it altogether, been there and done that already so I am speaking from experience. Whichever way you choose to go with the wheel you need a matching set of these self aligning washers between the nut and the wheel, they are simply magic

https://www.youtube.com/watch?v=uH7SU2ntPLU

The washers Self Aligning Washers | Jergens Inc

What type of sharpening you do will dictate the type of CBN wheel to buy if you choose to go that way, rounded edges for wood turners and flat wheels for flat iron sharpening so keep that in mind. If you keep the wheels you have buy the washers and watch the problem disappear if the wheels are properly dressed. McJings have perfectly good wheel dressers for a few dollars if you need to buy one.

Thanks Chris, never heard of CBN wheels. Will look into it, although I use my bench grinder for all sorts of things so don't want to put something on it that means it's not all-purpose, though I'm forever switching wheels, different grits and diameters, wire wheel, stitched rag, hard felt etc. It's a decent machine IMO, Abbott & Ashby.

I have a 200mm Abbot and Ashby I bought about 3 years ago. Runs as smooth as silk. I have a tin of water, for cooling, on the same base and you can barely see a ripple. It replaced an AEG unit I had for all of 10 minutes - I couldn't fit a wire wheel with the guards on and it rattled the shed windows. I'm also looking at acquiring a CBN wheel for it.