A Word To The Wise For Newbies

[Zonie]

I haven't mentioned this for a long time and we have enough newbies on board that I think it's worth saying.

By Newbies, I'm thinking of those of you who haven't had a lot of metal shop training and who own a bench grinder.

Bench grinders are great for a lot of things like grinding off unwanted material but something that is not known about them is a danger that is not immediately obvious.

Sure, everyone knows they need to keep the wheel guard in place and it doesn't take long to learn that the rest that is next to the wheel should be up real close to the wheel but not touching it.

Having the grinder throw your part across the room and embed it in the drywall will teach you that in a hurry.

When you grind a steel or iron part, not only do a lot of sparks fly but a small amount of the grinding wheel wears away. All is good (assuming you have some water handy to cool the part and you keep the object on the grinding rest).

In fact, it's so neat you automatically think of using the grinder when you get your first brass or bronze raw castings that has all sorts of blobs sticking out of it that need removing.

That is where the trouble begins.

Remember when I said the wheel wears away while your grinding iron or steel?
That doesn't happen if your grinding brass, bronze or other soft materials like aluminum.

Instead, much of the brass, bronze or aluminum will embed itself into the grinding wheel. This is called "loading".

So, aside from having a fouled grinding wheel, what's the problem?

Many bench grinders like mine are spinning at about 3450 rpm.
The surface of a 6 inch grinding wheel at that speed is moving at over 60 miles an hour.

The wheel is built to take this kind of speed but when the soft material embeds itself between the pieces of grit the wheel is made from, it tries to push them apart.

That can rapidly overstress the wheel and cause it to literally explode.

Most of the wheel will be caught by the wheel guard (if you were smart enough to leave it in place) but often, chunks of that wheel moving at high speed will fly out and hit your hand, arm or body.

Needless to say, this can cause some serious damage to you.

OK. So what's the solution for "grinding" soft materials like brass, bronze or aluminum?

The answer is, "sanding".

There are inexpensive sanding drums that can be mounted in a hand drill or a drill press. These have replaceable cylindrical drums of metal and wood cutting sandpaper that can be easily replaced, are not very expensive and most important, they won't "load up" and explode when you use them to "grind" brass, bronze or aluminum.

A Belt sander is also handy for trimming off unwanted metal too.

Have fun.

 

[Billnpatti]

Good advice, Zonie. :thumbsup:

 

[Grizzly Adams]

Sage advice for sure! One of those 1x30 belt grinders does the trick pretty well if you can't stand just using a file :hatsoff:

 

[Eric Krewson]

I use a face shield while grinding, the thought of removing metal slivers from my eye gives me cold chills.

I also worked almost 30 years in a coal fired power place. No matter how careful you were you would eventually get a piece of coal ash in your eye, like having a jagged piece of glass in you eye. I remember those days well.

 

[MSW]

Thanks for the post, Zonie ... it is a sad but storied fact that many of us never took a high school shop class, and were simply never told about the potential hazards of the tools we use.

 

[tiswell]

Zonie and all,
I would like to piggy back here and add that a wire wheel should NEVER be used without safety glasses, face shield would be better. Once you see someone with a wire from the wheel stuck in their eyeball you will never need to be told again!

Blessings, Bill

 

[Col. Batguano]

I wish some of our politicians wold load up and explode.

 

[Billnpatti]

It has been said and repeated more than once on this thread but the importance of personal protection equipment simply cannot be overstated. I can relate a story about having relaxed my safety consciousness and paid a price for it. I was using a Dremmel tool with a wire brush to polish a piece of a gun that I was building. I was wearing safety glasses but had pushed them up on top of my head to better inspect my progress. I picked up my Dremmel tool and started again but forgot to put my glasses back down from the top of my head. A piece of the wire brush flew up and stuck in my eye. The pain was terrible and I had to go to the ER to have the piece of wire removed. Fortunately, my eye healed but for several days I had a constant reminder of the mistake I made by not paying more attention to making sure that I had proper eye protection when doing anything that could result in an eye injury. This same need for safety consciousness applies to anything that we do and especially when shooting our guns. Before starting any project, think safety and use proper safety equipment.

 

[fischereco2]

Some great points, well worth remembering. I think most people associate danger with the more obvious tools, bandsaws, table saws, etc. The thing is, when you are aware that something is extremely dangerous you always exercise caution. Not so with many of the seemingly innocuous tools.

Another major culprit in my experience is the buffing wheel. I make pipes, knives, etc, and use a flannel buffing wheel on a motor. On the surface it seems like there is no way such a tool could be dangerous, but when the wheel catches a knife blade and flings it violently across the room it's a different story. I mounted my buffing wheel in a wooden box on my workbench so any caught objects can't go flying too far, and I always wear protective gear.

 

[44-henry]

As a teacher of lab classes I can definitely support what has been said. When students ask me which power tool is the most dangerous I have always responded that they all can be dangerous if not used properly, approaching one tool with less caution than another is a sure way to invite injury. With that being said I have had more close calls on belt grinders than any other power tool (I don't like buffing wheels but they would be in the same category). The belt grinder has a nasty habit of snatching work pieces from the uninformed hands rather unexpectedly. I had a student a few years back that was operating our belt grinder in the lab without a guard (which is against our lab policy) and also without a face shield (again against our policy) when the belt broke. Though no serious injury thankfully resulted, he did have a 2 inch wide red welt running from forehead to chin where the severed 2"x48" grinding belt struck him between the eyes. He survived and became a very quick believer in shop safety in the aftermath.

 

[RonRC]

I was just getting ready to take a piece of sand cast brass to the grinding wheel.
Thank you for that timely lesson!
Ron

 

[kaintuck]

OH those wire wheels on the grinders have 'cleaned' my thumbs in my ill-spent youth!!!! :shocked2:

I use a belt sander with 150grit, take it slow, and carefully get sprus off of BP and other stuff~ dremels for TG, then file it!!!

and put the kat outta the shop while running electrical stuff..........!
kat safety is important too! :grin:

marc n tomtom

 

[Zonie]

Thanks for all of the added comments and other warnings.

My reason for posting about the dangers of loading a grinding wheel is it is not an obvious danger.

Everyone (with 3/4 of a brain) recognizes the obvious danger of a high speed grinding wheel or a spinning wire brush, although more than a few have lost pieces of their fingers while using them.

Loading up a grinding wheel with soft metal isn't so obvious. The only clue is the wheel doesn't seem to be grinding stuff the way it did a few minutes ago.
That usually ends up with the person pushing the soft metal part harder against the wheel until either they give up or POW, all hell breaks loose.

 

[Captjoel]

On another note of safety. I was taught many moons ago during my USAF mechanical training to always use the right tool for the job! Not having a metal lathe or horizontal milling machine in my shop, I got by many a time using a power hand drill for barrel breeching. On my LAST attempt doing this a couple of years ago, I had a very large drill bit catch and fracture sending the broken piece aloft like a rifle bullet. It zinged past my head hitting the ceiling, wall, and then shop window. I was very lucky and very stupid. There is no protective safety equipment made for STUPID! I patched the hole in the window with duct tape and leave it there to remind me of that ignorant incident!

 

[Tinker2]

Jim
As always good advice, thank you. :hatsoff:


One of my habits is when I first turn on the grinders I stand to the side and not in front.
I have seen wheels come apart, they can kill you.




William Alexander

 

[BigBoreBLR]

Two other things. Power tools remove material quickly. I have regreted using a power tool many times with numerous different types of projects.

The other thing, the dust. Metal and wood dust can get you sick. Maybe not something really bad for a hobbyist. However, a good grinding session or a lot of snading always makes me feel a bit unwell the next day. Maybe a headache or a small stomache ache. That's your body's reaction to getting mildly poisoned.

A lot of welders don't make it to retirement. It's the grinding more than the welding.

A little ventilation and a dusk mask goes along ways.

 

[Claycow]

I am fairly certain i inhaled terrible things while scrubbing my late 1880s trunk. Same with my wood stocks for my gun. I am definitely buying a mask, i just felt like cheaping out before but it isnt fun to get that all inn the sinuses

 

[BigBoreBLR]

Look at the Netti Rinse at the pharmacy. A rinse for the sinuses. For hayfever season, it's one of the best cures for sinus problems with virtually no side effects. Right after anything overly dusty I rinse my sinuses out.

Home Depot and other major outlets all sell dust masks. Nasty chemical fumes is another story, but plain old dust and particles, all you need is a basic face mask from 3M. However, get the one with the exhale check valve. Makes a big difference.

Here's a 10 pack for $21, they also sell a 2 pack for $6.
http://www.homedepot.com/p/3M-Part...Pack-8511PB1-A/203030486?N=5yc1vZc5c7Z1z0t827

Cartridge filters work better, but the one above is mosty of the way there. I find this one not too burdensome to breath through even when lawn mowing with a walk behind mower on my hilly home.

 

[thecapgunkid]

I'm actually going back to tools with not more than two working parts because of issues like this.

I used to always work by hand, then began to use a Tippman Boss on the gunbelts I made. Now I am either going to sell it or take a happy hammer to it, because machines move too fast and errors can be as dangerous as you have shown here.

Besides, being retired, any project I undertake is couched in a lot more time that I have to spend on it, and I am not worried about recompense beyond cost and a little for new materials..

 

[Claycow]

I took off the old "wallpaper" of my wooden trunk from decades maybe centuries ago. I once again have a stuffy nose : / Or maybe its the alcohol.