School Me on Bench Grinders

[Gilmourisgod]

I don't use them much in bass building, but my Son has gotten addicted to all kinds of metal work, mostly using just a course wheel and a wire wheel, but occasionally a buffer pad. I bought him a cheap little Wen 6' grinder a few years ago, and it's a piece of junk. The shaft has gotten a little bent, so it vibrates badly, and you can bog it down with heavy hand pressure on the work. Looking for something better as a replacement, probably 8" just to get something more powerful and robust. I've been looking at a few, hoping to spend around $150 on it. been looking around for a used Delta or Jet too without much luck. My brother has an old Delta that just refuses to die, but they are more like $300+. Thoughts or advice? Some have variable speed, is that useful/necessary?

https://www.amazon.com/DEWALT-DW758-8-Inch-Bench-Grinder/dp/B0000224J4/ref=sr_1_6?crid=LPV8NCMJV4IZ&dib=eyJ2IjoiMSJ9.pbijl1zYS2asUoG70uJzlKZURbjVfvQ3eY3sgPq6dBOPV8nGpA996WxHKcWOIvL6sDbvHjJ5Xq9rrHvcdUsCGwZB9QibhV0RORqRjnTBf1OZIKIB8UlCt3ZDYI9eH1Er8Kpae7V9M7pXFegQY4LMoLY8FncT7dT-6GA-1nXpBAAzMLpcyq7VrN7gEq_OreYMT9zuz4Q6mChTkvVm4tx6wYX6o1nnK2CjOOLiRu7PjVLNPfwIMWuqIPga7iiFgz901k71iSRkRQmldqvWDF2QOKFg4W2K-84Yn54VsJg0GOw.ptqgp6xVZvtPMe3-_Xl8z5V0a6fJuPvh84wEfw5Rh_g&dib_tag=se&keywords=8%2Bbench%2Bgrinder&qid=1762887316&sprefix=8%22%2Bbench%2Bgrin%2Caps%2C128&sr=8-6&th=1

SKIL 3.0 Amp 8 In. Bench Grinder with Built-in Water Cooling Tray & LED Work Light - BI9502-00 - Amazon.com

SKIL 3.0 Amp 8 In. Bench Grinder with Built-in Water Cooling Tray & LED Work Light - BI9502-00 - Amazon.com

www.amazon.com

And then of course, there's Harbor Freight. I'm thinking it's hard to screw up an electric motor, but some reviews online say the variable speed dial tends to fail.
Invalid Link Removed

 

[buldog5151bass]

I've had the same Delta for the past 20 years to keep my lathe tools sharp. If it os something you expect will be used for years, its worth a few bucks more.

If he doesn't use the variable speed, get a model without that option.

 

[Bruce Johnson]

I recommend that you invest in a Belt Grinder, rather than a better old-style Bench Grinder (with the spinning stone wheels). A modern abrasive belt takes off metal so much faster than a stone wheel. And you can quickly change belts when they get dull, or change belts to different grits over a wide range. Even a cheap little tabletop 1" x 30" belt grinder is more useful for general metalworking than a 6" bench grinder. With a few exceptions.

I have several decent quality 6" bench grinders sitting in shelves and back corners, and I never use them any more. I have one with a 4" white fine grit stone that I use for final grinding of edges on small cutting tools and drill bits. But I do most grinding of bevels and angles of tool bits on the belt grinders.

Also, belt grinders are much safer. Blowing up a sanding belt isn't likely to hurt you. I've tossed a few over the years. An exploding grinding stone wheel can be fatal.

 

[Bruce Johnson]

By the way, what type of metalworking is your son doing on the bench grinder? Do you/he know that you should not be grinding aluminum on a grinding wheel? That's actually dangerous. It can cause the wheels to crack and explode. Aluminum should be shaped on belt grinders.

 

[frets4ever]

I don't use them much in bass building, but my Son has gotten addicted to all kinds of metal work, mostly using just a course wheel and a wire wheel, but occasionally a buffer pad. I bought him a cheap little Wen 6' grinder a few years ago, and it's a piece of junk. The shaft has gotten a little bent, so it vibrates badly, and you can bog it down with heavy hand pressure on the work. Looking for something better as a replacement, probably 8" just to get something more powerful and robust. I've been looking at a few, hoping to spend around $150 on it. been looking around for a used Delta or Jet too without much luck. My brother has an old Delta that just refuses to die, but they are more like $300+. Thoughts or advice? Some have variable speed, is that useful/necessary?

https://www.amazon.com/DEWALT-DW758-8-Inch-Bench-Grinder/dp/B0000224J4/ref=sr_1_6?crid=LPV8NCMJV4IZ&dib=eyJ2IjoiMSJ9.pbijl1zYS2asUoG70uJzlKZURbjVfvQ3eY3sgPq6dBOPV8nGpA996WxHKcWOIvL6sDbvHjJ5Xq9rrHvcdUsCGwZB9QibhV0RORqRjnTBf1OZIKIB8UlCt3ZDYI9eH1Er8Kpae7V9M7pXFegQY4LMoLY8FncT7dT-6GA-1nXpBAAzMLpcyq7VrN7gEq_OreYMT9zuz4Q6mChTkvVm4tx6wYX6o1nnK2CjOOLiRu7PjVLNPfwIMWuqIPga7iiFgz901k71iSRkRQmldqvWDF2QOKFg4W2K-84Yn54VsJg0GOw.ptqgp6xVZvtPMe3-_Xl8z5V0a6fJuPvh84wEfw5Rh_g&dib_tag=se&keywords=8%2Bbench%2Bgrinder&qid=1762887316&sprefix=8%22%2Bbench%2Bgrin%2Caps%2C128&sr=8-6&th=1

SKIL 3.0 Amp 8 In. Bench Grinder with Built-in Water Cooling Tray & LED Work Light - BI9502-00 - Amazon.com

SKIL 3.0 Amp 8 In. Bench Grinder with Built-in Water Cooling Tray & LED Work Light - BI9502-00 - Amazon.com

www.amazon.com

And then of course, there's Harbor Freight. I'm thinking it's hard to screw up an electric motor, but some reviews online say the variable speed dial tends to fail.
Invalid Link Removed

Have you looked on Facebook marketplace. I have gotten a couple Blador grinders cheap one for $50 and the other $70. So $150 you can get him several items.

I am in Chicago area there are plenty of quality metal working and machinist tools. It seems a large number of machinist are retiring about the same time and have gotten for under $100 100s of taps and close 100 almost of them unused vintage Nicholson metal files and etc. Most of my equipment is used for a fraction of the cost of new.

It will depend on your area.

You will see prices that are too good to true but it’s due to people wanting the stuff out of their homes.

Best of luck.

 

[buldog5151bass]

Harbor freight is so hit or miss. I've seen absolute junk. I have a bench top 12" disc grinder that I've used for over a decade.

 

[Gilmourisgod]

Yeah, I've had a couple decent tools from HF, and a couple junk ones. the only reason I included them is they seem to be the only source for an 8" grinder with variable speed under or close to $150. I don't know if the variable speed is something I "need", only ever used single-speed grinders. Those seem to come in 1750 or 3250 RPM, does it matter much for general purpose? The Facebook marketplace idea has merit.

 

[Smith357]

I recommend that you invest in a Belt Grinder, rather than a better old-style Bench Grinder (with the spinning stone wheels). A modern abrasive belt takes off metal so much faster than a stone wheel. And you can quickly change belts when they get dull, or change belts to different grits over a wide range. Even a cheap little tabletop 1" x 30" belt grinder is more useful for general metalworking than a 6" bench grinder. With a few exceptions.

I have several decent quality 6" bench grinders sitting in shelves and back corners, and I never use them any more. I have one with a 4" white fine grit stone that I use for final grinding of edges on small cutting tools and drill bits. But I do most grinding of bevels and angles of tool bits on the belt grinders.

Also, belt grinders are much safer. Blowing up a sanding belt isn't likely to hurt you. I've tossed a few over the years. An exploding grinding stone wheel can be fatal.

I concur with your assessment that a belt grinder is a better tool for metal working. I differ only in getting something bigger than a 1x30. I make knives as a hobby and find the 2x42 to be a good compromise between the little 1x30s and the very expensive 2x72 grinders. Variable speed is a huge plus, as it can keep temps down and not draw out the temper of the steel. or burn wood end grain. Though if I had 4k burning a hole in my pocket I would get this KMG.

 

[Stylee Mousse]

I lucked out getting a mid century Craftsman professional bench grinder from my in laws estate.

A fine white stone wheel is what I use to re-profile knife edges.

I agree the sander, we have a jeweler’s belt sander and it is really nice to use for smaller things

 

[Gaolee]

My take on all kinds of tools is that you get what you pay for. I have a bench grinder I don't use these days, mostly because I don't have a bench to attach it to at the moment. It is one that was older when I got it in 1988. It weighs about a zillion pounds and will probably still work just fine when archaeologists dig it up 3500 years from now.

 

[Pocket Dave]

By the way, what type of metalworking is your son doing on the bench grinder? Do you/he know that you should not be grinding aluminum on a grinding wheel? That's actually dangerous. It can cause the wheels to crack and explode. Aluminum should be shaped on belt grinders.

This is massively important. In 1987 a guy died on the shop floor where I worked after doing this using a hand-held wheel with a disabled guard.

Also, @Gilmourisgod - please tell us you trashed that Wen grinder with the bent shaft. That needs to be taken out of service permanently.

 

[SoonerBill]

I have an older Craftsman bench grinder with pretty equal specs to the DeWalt in the OP. It's worked very well for everything I've ever used it for.

 

[Fender_Bender]

By the way, what type of metalworking is your son doing on the bench grinder? Do you/he know that you should not be grinding aluminum on a grinding wheel? That's actually dangerous. It can cause the wheels to crack and explode. Aluminum should be shaped on belt grinders.

About 25 years ago I used my single point diamond dresser to de-clog a grinding wheel that the father of an acquaintance had used to grind aluminum. I had to pull my shirt up to my eyes because I was getting pelted with aluminum debris.
That’s another thing with a wheel grinder, you’ll need something to dress and true the wheel, and may as well throw away the cheap grey wheels that they come with in favour of a free cutting white wheel. I still use my Taiwan bench grinder for grinding lathe bits.

 

[tr4252]

In addition to all the good advice here, I'd like to stress safety. There are many ways even a simple bench grinder can hurt you, and full knowledge on how to operate any given type of machinery is essential. Search How to use bench grinder safely or something like that. Look at several sources, and understand what you are reading. My advise would be; until you've done that, don't even plug the grinder in. I'd tell you about a one-eyed guy I used to know, but I don't want to get long winded here.

Learn how to do ring tests, dress your wheels, select grades and materials, what mistakes to avoid, etc.

As always, good luck.

Tom

 

[frets4ever]

If you want to speed control you can get a belt driven grinder then add a two speed pulley with the ratios of your choice. Also plenty of good used motors able for cheap to make your own belt or direct drive grinder.

 

[Bruce Johnson]

I concur with your assessment that a belt grinder is a better tool for metal working. I differ only in getting something bigger than a 1x30. I make knives as a hobby and find the 2x42 to be a good compromise between the little 1x30s and the very expensive 2x72 grinders. Variable speed is a huge plus, as it can keep temps down and not draw out the temper of the steel. or burn wood end grain.

Oh, yeah. I have a '90's vintage Grizzly 2 x 72 Knife Belt Sander. I think its the most-used power machine in my whole shop. Still going strong. I have two of the little 1 x 30 belt sanders, both Deltas. They are useful for smaller stuff, but they are limited on HP. I was recommending the 1 x 30 to Alex, because I know he's looking to spend more like $100 than $1000.

While scanning Amazon, I saw this cute little belt grinder. Like a miniature version of a Burr King, and only $200. That's an impressive looking little machine. I may get one.

Belt Sander, 30 x 1-Inch VariableVariable Speed Belt Polisher with VFD, 110V 550W Electric Grinding Machine with 2 Grinding Moulds & 3 PCS Sanding Belts for Metalworking, Knife Making - Amazon.com

Belt Sander, 30 x 1-Inch VariableVariable Speed Belt Polisher with VFD, 110V 550W Electric Grinding Machine with 2 Grinding Moulds & 3 PCS Sanding Belts for Metalworking, Knife Making - Amazon.com

www.amazon.com

 

[Bent77]

My take, as a machinist/ mechanic more than luthier

Harbor freight electrical sucks
Belt sanders are better for most all things
I like sharpening drill bits on a wheel
The wire wheel on a bench grinder is the parts tosser 4000
I’ve never needed variable speed

Using a 40yo alltrade and 50yo Craftsman, both 6”

If I were to buy a new bench grinder, it would probably be a Dewalt at the lower price end, or the JET

 

[Gilmourisgod]

I had actually looked at a couple combo grinder/belt sanders online. My son bought the cheapest belt sander thay had at harbor Freight, which he doesn't use, of course, because it's a complete piece of crap, but he TRIED to use it. Weirdly, he's gotten into buying old antique rusty axe heads and polishing/sharpening them up, and then re-handling them. he got some hickory handle blanks and used his favorite axe handle as a pattern to make a couple new ones, I helped him with the woodwork part of it. Aspiring Lumberjack I guess. He's also has gotten into collecting and restoring old huge ball-peen hammers, 5 lb sledges, etc, rusty junk he finds at the local fleamarket for $2 and restores. He uses the wire wheel constantly, to the point he's worn one down to the nub, so a combination belt sander/wire wheel setup would probably be ideal. I'm going down that rabbit hole! I'm a bit handicapped in that as a family we agreed on a $150 cap for Christmas presents, my (4) sons are all adults now, and perfectly capable of accumulating too much of their own junk (and leaving it in my garage), but maybe I can cheat a little on that and find something that would work for axe grinding (or whatever the NEXT hobby is).

 

[T_Bone_TL]

Data point.

Nigh onto 20 years ago most of the wood lathe community switched to AlZn belts (typically on a 4" "wood-type" belt sander used only for grinding metal, mounted so the belt was running up relative to the tool point.)

For rust removal I prefer electrolysis or a citric acid bath, (phosphoric if money's no object, not the case in my house) but if using a brush-type thing, a cup wheel in a hand-held angle grinder. But a flap disc (also AlZn) in the same tool works well too. Brushing on a fixed wheel is more awkward, especially if it's mounted in a typical bench grinder.

 

[frets4ever]

I have used Zep CLR to remove rust. It’s inexpensive and takes about and 1-2 hours of soaking. Rinse, scuff pad and WD40 dry lube. I just started to use Boeshield T-9 excellent however there is a chemical smell and gassing off period which is why I only apply it in the garage.