Bench grinder for primary bevel

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pooka

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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.
 
Over the past 40 years a jam jar with some water and a bench grinder has been all I ever used and I have never thrown a chisel or plane iron away.
 
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 (

I think it is very difficult to avoid losing the temper of the steel without using coolant, even with a light touch. Because the edge in contact with the wheel is so thin, heat transfer is very limited and you must always dip the tool edge in water every few seconds. As you want a low-cost solution, a simple bench grinder will suffice. Ideally an 8" wheel rather than a 6" wheel. I'm sure that there are sturdy and still cheap 8" grinders on the market.

The slow-speed grinders are more expensive but less cooling is required.

Even cheapo grinders will run smoothly as long as the wheel is dressed.



Ike
 
Thanks for the responses, and the advice on keeping a container of water at hand.

Would either of you recommend any particular colour of grinding wheel (white, red, pink, blue, etc.)?
 
Hi pooka, hope this helps,

The larger the weel the better, as when you use a grinder you get what it called a hollow bevel. That is basically the radius of the grinding wheel being ground into your chisel or iron, so it is better to go for the bigger wheel as you will get a flatter bevel.

As long as you keep the tool moving there should be no problem with the width of wheel

It is difficault to keep the edge of a tool cool with any high speed grinder, especially chisels less than 6mm wide as the heat builds up very very quickly.

With the wheel colour, basically most of the red wheels or cool running wheels are just a softer compound. They will need re-dressing more often than a white wheel. I have only used industrial ones so i cant compare with the ones on the market now. A redressing tool is a must if you are doing some serious grinding though.

Water is an absolute must. You will blacken a blade very easily without keeping it cool, it tends to steam off the tool anyway so not to much mess.

Most grinders do come with rubbish tool rests so an extra fence would be advisable.

Personally i use a tormek, i find it hard to get a nice clean bevel on a tool with a high speed grinder, plus the risk of overheating.
If you do buy a high speed grinder just make sure you dont overtighten the wheel onto the machine and always perform the ring test before putting a new disk on.
 
Hi Pooka,
I'll warn you now, you'll probably not like my response :). I've got a Tormek 1200 and would really very strongly recommend it. I agree, it is quite pricey, but it's a great piece of kit. I don't have experience with any other grinders, but I don't think you'd feel like you wasted your money if you bought one. If it helps here's a review on it I wrote a while back.

My only other comments are with regards to hollow grinding. If you are planning to use a normal stone for your secondary bevel, then a deepish hollow shouldn't cause a problem as the second flat bevel should give support and strength to the edge. I guess as long as you keep away from a spoon shaped profile it'll be fine!

Andy
 
orangeth, thanks for the advice and info. What is the ring test that you refer to?

Andy, I found your review of the Tormek 1200 in the archives (excellent review by the way!), and it certainly did make me stop and consider that particular machine. You mentioned that it can tend to splash water about though, which would probably rule it out for me - have you managed to find a way around this ?
 
Pooka,
Yes, it can slop water about a bit. However, it can be minimised, quite a lot, by not having quite so much water in the trough. Just have enough so the wheel is coated. Also, placing the unit on a folded tea-towel helps.
It is a shame that Tormek, didn't really pick this up, and add some kind of lower tray to the unit. I guess there is no reason why it couldn't be operated in a seperate tray, as long as water wasn't able to get into the device. As I said in my review, I'm a little wary as it's mains powered.
Andy
 
AndyG":245a1ik6 said:
However, it can be minimised, quite a lot, by not having quite so much water in the trough..... I guess there is no reason why it couldn't be operated in a seperate tray, as long as water wasn't able to get into the device....
Or by sitting it in one of those old-fashioned catering trays with a drain hole in one corner leading to a bucket?

AndyG":245a1ik6 said:
As I said in my review, I'm a little wary as it's mains powered.
How about installing an RCD in the power supply? Just a thought

Scrit
 
scrit":383499y5 said:
Or by sitting it in one of those old-fashioned catering trays with a drain hole in one corner leading to a bucket
Now that is an idea, might have to pay a visit to one of our canteens :wink:.
As for the RCD, well all the garage's power runs through its own RCD anyway, but a good suggestion none the less.
 
no problem pooka, a ring test is to check if the grinding wheel is cracked. What you need is a something plastic through the hole in the middle, but so the wheel is loose and just haging off it. Then you need to tap it with a not metallic piece of... something... and if the wheel rings like a bell then it is fine. If it makes a dull thud then the chances are it is cracked
 
its boring to say, but for no problems with losing the temper, then Tormek is the way to go. i use mine to sharpen tools for others so it is quick too.

high speed grinders were designed for metal working tools, and
will always cause you a problem when you least expect it. i know lots
of people have good results, but it does require a fair investment in
other wheels etc, whereas Tormek has the wheel and the hone.
yes it could be messy, but so can an oilstone, or indeed a water stone.

the other thing is that the tormek means you can sharpen other tools more easily too. just look at the manual. mine is a 2006, but hey if you are not running it for more than 30 mins at a time the 1206 works well too.

the other good thing is that the results can be repeated frequently because of the jig set up, and the size of the wheel.

remember John Brown who used to write in GWW and make chairs always used a hand driven wheel.

paul :wink:
 
engineer one":368woz0j said:
its boring to say, but for no problems with losing the temper, then Tormek is the way to go.

Surely this is not quite accurate, ANY water cooled, slow speed grinder will grind without losing the temper on the tool.

Tormek seems to be loved by all who own one for good reason, but I got a Rexon clone for about £35 and I find it does all I would want once I knocked up my own rest from a few offcuts - and I don't lose the temper on any tools I grind on it.
 
sorry tony, my bad use of grammar.
you are right slow speed no real loss of temper, except your own.

one other thought in my past life when i used to machine and sharpen
then temper things i found it was always at the end of a session that
you forget how long since you started grinding, and then you let it ge that
little bit too hot, and there you go.

once it turns to straw then you are b*******d cause it goes so quickly.
anyway go for slow speed, and where the best jigs are.

paul :wink:
 
Many thanks for the responses.

The (relatively) high cost of the Tormek is one of the main reasons that I have put it near the end of my list of options. However, I am making the large assumption here that I will be able to avoid ruining blades with the bench grinder solution from the outset. If I made a mess of two or more chisels with a bench grinder, then it may prove to be a more expensive solution in the long run. So, at the risk of asking how long is a piece of string, is a novice user of a bench grinder (even with a white or red wheel) very likely to burn metal i.e. is learning to use a bench grinder correctly a very steep learning curve?
 
i know i seem to be working for tormek, but i am not,
like everyone re-starting i had a lot of blades to sharpen or
re-sharpen, and i found hand work to time consuming.

the thing about the tormek is the good quality tool rest and support.

if you read many reports, you will see that they all complain about
the lack of a good tool rest, so you have to factor that into the cost
of a higher speed grinder, red wheel or whatever.

with the tormek, the learning curve is steep, but easy. i think with all the things you have to think about with a higher speed grinder, the curve is steeper, and more dangerous.

anyway as with all posts, this is a personal view.
but would suggest you consider the values of the honing wheel as well.

all the best
paul :wink:
 
Thanks Paul. I have been looking at the grinding jig, and guide, from Veritas (this one). I am not sure how it compares with the rest that comes with the Tormek, but it certainly does add significantly to the cost of a solution based around a basic bench grinder.

I have a couple of local sources of bench grinders to check yet, but it is looking like a 200mm grinder will be more expensive than I expected, so the cost is certainly getting closer to a Tormek 1206. Hmmm, this is going to require more thought.
 
recently checking articles in F&C i notice that DC uses a tormek to
rebuild edges.
if the guru uses it, then who knows.
but remember it is just the starting point for sharpening.
paul :wink:
 
I wonder if David Charlesworth uses one because of the variety of blades (chisels, gouges, etc.) that he has to sharpen? I don't do any turning (well, not as yet, but maybe I'll catch my credit card off guard some day...), so I expect to be dealing only with flat edged blades for the forseeable future.

So far, of the local places that I have checked, the cheapest 8" bench grinder is the Record Power RPBG8, for 99euro - these are £49.99 RRP (approx. 73euro) according to Record's site, but I have come to expect very little of good value from this particular local retailer. For example, the same retailer have the Tormek 1200 for 299euro (approx. £205)!.

I know that Record's reputation has taken a hammering in recent years, but there are a few things to recommend this grinder:

Pro's:
- it has a 40mm white wheel fitted.
- it is light (10kg) so easy to move around.
- there are two reviews of it on the Record Power website, both positive.

Con's:
- the tools rests look terrible (just bent steel bits).
- it is light, so it might like to try to move itself around during use!

Another issue is that the price of this grinder here, plus something like the Veritas grinding jig and guide, brings the overall cost to something not far off the cost of the Tormek 1206 (well, the cost of the Tormek in the UK, not the evern more exaggerated cost of it from the shower that sell it here).

Can I make a loud plea for Axminster to open up a branch over here?? :(
 
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