I am currently considering buying a powered means of re-grinding the primary bevel on my chisels and plane irons. To date I have done this by hand on a diamond stone , and sometimes an oil stone, but I'd like to save myself some time in the future. For honing, I plan to continue to use my waterstones, so I am not looking for a powered grinder that will give me a finished edge (although it could be an advantage sometimes I guess).
I have searched through the archives which, as ever, yielded a lot of very useful information and some excellent reviews of some of the options available. I see that there are a variety of products in use, from the Tormek machines, to Rexon "specialised" grinders, to belt sanders, and the occasional mention of a common-as-muck bench grinder. For now, my needs don't really justify the likes of a Tormek (in terms of cost), although answers to some of my queries below might lead to a "simple" grinder solution being more expensive that it looks at first.
So, to my questions:
1. Wheel diameter. Views seem to vary as to whether 159mm/6" is too small. Is a 150mm wheel likely to lead to problems and therefore is an 200mm/8" wheel a better bet?
2. Thickness of wheel. Am I correct in believing that a good jig (which allows the blade to slide back and forth across the wheel, for wider blades) means that a 20mm wheel is more than adequate?
3. Speed of grinder. Seems to be a heavily debated topic in the woodworking and metalworking worlds. I was thinking of opting for a full speed grinder (3,300rpm or so) and relying on an approrpriate wheel, and care and attention, to avoid excessive heat build-up on the tool. As I have never used a bench grinder before though, am I underestimating how easy it is to ruin a blade?
4. Wheel colour and grit. I was thinking here of something like an 80grit wheel, possibly a red one, but maybe even a pink or blue one from Peter Child. Is this overkill, and would a white wheel be adequate?
5. Water or not. I'd prefer not to use water, if I can avoid it, just to avoid additional mess. Obviously though, without the cooling benefits of water, I'll have to exercise more care, so this assumes that I am not grossly underestimating the level of skill I'll need (as per question 3 above). Is dry grinding really less messy though (e.g. does water help keep the metal filings from going everywhere?), or does it even pose any kind of fire risk in the workshop if the filings end up on the bench and/or floor?
6. Guide/jig. I am presuming that a basic bench grinder comes with an inadequate guide/jig for holding and controlling the blade being sharpened. The following Veritas Basic Grinding Set looks good though, and might be ideal. Has anyone used it, or has anyone found that a home-built guide/jig is more than adequate?
Lots of questions, I know, and it may well be that a Tormek deals with all of the issues/worries that I raise in one fell swoop. However, if a basic bench grinder fits the bill, and doesn't require a lot of expensive accessories to make it effective, then the money that I'd save could be put to good use elsewhere. As an example, I recently saw a Powercraft 150mm grinder in Aldi for the euro equivalent of about £14 - it seems like the basis of a very cheap grinding solution, but subject to whether I'll have to pay twice that for a decent wheel, etc., and also assuming that all basic grinders are created equal (e.g. it certainly wouldn't compare to an industrial grade "basic" grinder, but at this price range could it prove to be a bucking bronco when turned on!).
Any advice gratefully received.
I have searched through the archives which, as ever, yielded a lot of very useful information and some excellent reviews of some of the options available. I see that there are a variety of products in use, from the Tormek machines, to Rexon "specialised" grinders, to belt sanders, and the occasional mention of a common-as-muck bench grinder. For now, my needs don't really justify the likes of a Tormek (in terms of cost), although answers to some of my queries below might lead to a "simple" grinder solution being more expensive that it looks at first.
So, to my questions:
1. Wheel diameter. Views seem to vary as to whether 159mm/6" is too small. Is a 150mm wheel likely to lead to problems and therefore is an 200mm/8" wheel a better bet?
2. Thickness of wheel. Am I correct in believing that a good jig (which allows the blade to slide back and forth across the wheel, for wider blades) means that a 20mm wheel is more than adequate?
3. Speed of grinder. Seems to be a heavily debated topic in the woodworking and metalworking worlds. I was thinking of opting for a full speed grinder (3,300rpm or so) and relying on an approrpriate wheel, and care and attention, to avoid excessive heat build-up on the tool. As I have never used a bench grinder before though, am I underestimating how easy it is to ruin a blade?
4. Wheel colour and grit. I was thinking here of something like an 80grit wheel, possibly a red one, but maybe even a pink or blue one from Peter Child. Is this overkill, and would a white wheel be adequate?
5. Water or not. I'd prefer not to use water, if I can avoid it, just to avoid additional mess. Obviously though, without the cooling benefits of water, I'll have to exercise more care, so this assumes that I am not grossly underestimating the level of skill I'll need (as per question 3 above). Is dry grinding really less messy though (e.g. does water help keep the metal filings from going everywhere?), or does it even pose any kind of fire risk in the workshop if the filings end up on the bench and/or floor?
6. Guide/jig. I am presuming that a basic bench grinder comes with an inadequate guide/jig for holding and controlling the blade being sharpened. The following Veritas Basic Grinding Set looks good though, and might be ideal. Has anyone used it, or has anyone found that a home-built guide/jig is more than adequate?
Lots of questions, I know, and it may well be that a Tormek deals with all of the issues/worries that I raise in one fell swoop. However, if a basic bench grinder fits the bill, and doesn't require a lot of expensive accessories to make it effective, then the money that I'd save could be put to good use elsewhere. As an example, I recently saw a Powercraft 150mm grinder in Aldi for the euro equivalent of about £14 - it seems like the basis of a very cheap grinding solution, but subject to whether I'll have to pay twice that for a decent wheel, etc., and also assuming that all basic grinders are created equal (e.g. it certainly wouldn't compare to an industrial grade "basic" grinder, but at this price range could it prove to be a bucking bronco when turned on!).
Any advice gratefully received.