Bench Grinders

[cskrimshire]

Hello,

I'm of a mind to buy a bench grinder for general sharpening purposes - knives, chisels shears etc, but also to do some polishing/buffing of metal.

a. For sharpening, is a standard dual-wheel unit with one coarse and one fine grit (plus manual dunking in water) be OK, or would a wet/dry machine be worth it? b. Are the grit sizes likely to be standard as supplied? And is materials choice important? c. Are 6" grit wheels generally adequate? d. Is it possible on most machines to easily swap wheels and/or fit buffing discs for polishing, or is there more to it than that? (I'm thinking that replacing a heavy grit wheel with a light buffing disc might not work.) e. Any advice on makes/models? As a fairly low-usage tool I'm against spending too much.

Many thanks for your thoughts.

Regards,

Chris

[Dave Plowman (News)]

I've got one of those combination wheel and belt jobbies. To me, it's more useful than a twin wheel type.

[newshound]

I'd say that the classic "workshop grinder" either with two wheels, or one wheel and a buffer, is one of the more dangerous tools that is readily available to the untrained DIY-er.

Excuse me if I am wrong, but from your questions it sounds to me as though you have not had workshop training on grinders.

It's not the right tool for shears at all, IMHO: for those you are better off with a hand stone, or an angle grinder if they are really damaged.

For wood chisels, the type with a *low speed* wet disk is ok, you can also do knives on them although I prefer a static stone and/or diamond laps.

There are several different types of wheel for different materials, grit size is not the only variable. There is more skill involved in changing wheels than in changing disks on an angle grinder.

[Dave Liquorice]

A grinder will be a bit vicious from knifes and chisels, they really need hand sharpening on oil stones. Shears you might get away with if you are *very careful*. For polishing/buffing the rotational speed used for grinding is far too high.

A grinder is a useful tool but not ideal for sharpening most things. The only things that get sharpened on mine are the rotary mower blade and cold/bolster chisels.

[Tricky Dicky]

Your bog standard bench grinder is OK for cold chisels, drills, general gri nding of steel just do not go anywhere near it with a plane iron or wood ch isel, you will draw the temper in a blink not to mention the difficulty of producing a sharpened edge perpendicular to the length of the blade.

When the 16" horizontal grinder at my last place of work became uneconomica l to repair it was replaced with one of those smaller wet wheel types which seemed to do as good a job as the grinder for putting the sharpening angle in albeit a little more awkward setting up. As far as using the leather st rop wheel with grinding paste to put the honing angle on, I cannot say I wa s impressed and much preferred using my India stone by hand.

Richard

[Bill]

Ditto. I bought a cheapy from Wickes about 4 weeks ago to put an edge on a rotary mower blade, and again as you say great for taking the mushroom off bolsters and sharpening them too. I was surprised at how well I did on the mower blade, not having used a bench grinder for about 40 years! I feel safer using one of those than an angle grinder!! Not as much fun though :-)

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