Shocking Grinder

Ember Knives

Well-Known Member
Anyone have grinders that shock them and ways to combat this? I'm guessing electricity builds up from the friction the belt causes? I was grinding three blades at a time, which is a lot of grinding for me, and when I touched the aluminum tool rest, I sometimes got zapped. I have a Grizzly 1x30 by the way. Is there a way to stop this? Thanks!
 

bladegrinder

Well-Known Member
This has been brought up a few times, I think most of us have got zapped. it only seems to happen using the flat platen, I usually hollow grind so it doesn't get me much...but when it does...DAMN o_O that'll wake you up.
I've read a lot of remedy's to get around this but all I ever use is a spray bottle with water and some dawn dish washing soap.
A couple short sprays on the inside of the belt and drive wheel while it's running knocks out the static.

I work on polyethylene natural gas lines that usually always have some amount of static on them from the gas running thru them, and while we do use pinch off crimpers with ground rods attached, it's industry standard to use soapy water on the lines before cutting them. on large 6" and 8" pipe we wrap the pipes with burlap where the pipe contacts the ground and saturate it with soapy water.
I've seen static sprays in a can and even had samples come thru our company but in my opinion soapy water works just as well.
We don't use dawn, it some soap that's non corrosive and blah blah, but it's still soapy water.
 

John Wilson

Well-Known Member
Grounding does help, but as Steve says static is a beast all its own and grounding doesn't always get all of it. Static will do things it's just not supposed to do. Everyone believes that static is a product of dry air. Well, that's ONE cause of static, and I'll be the first to tell you that high humidity does not eliminate static. The soapy water trick is definitely the way to go.

In the manufacturing/packaging world, we used to deal with static all the time, especially on machines that cut and wrap film around a product. We spent thousands of dollars on grounding, bonding, tinsel, whiskers, ionizing bars- you name it. Sometimes they even worked... slightly. Static can charge up on only one side of a film and you end up with a capacitive effect. That's where a charge builds up on one side of an insulator (the grinding belt) and the charge builds until it's strong enough to jump over to the grounded machine, or more likely you get close enough to take the zap.

It got way worse on my machine when I put the glass on the platen, but the glass is so much better for grinding that I'm more than happy to live with it.
 

Ember Knives

Well-Known Member
Started grinding today and in the first coupla minutes got shocked. I stuck a nail in the ground and connected wire to it and the machine and didn't get shocked for the whole rest of the time. Thanks.
 

EdCaffreyMS

"The Montana Bladesmith"
Gosh I hate that static shock thing at the grinder!! I didn't read through all responses, but can tell you that it has a lot to do with humidity. At anything less then 45% static becomes huge issue in my shop, with any machine. Either grounding as has been mentioned, or what I do is a humidifier in the shop. Sometimes that's a loosing battle because here in Montana, it's rarely more then 30% humidity...... and in the winter that number drops into the teens or single digits.....just like the temp! :)
 

Sean Jones

Well-Known Member
Gosh I hate that static shock thing at the grinder!! I didn't read through all responses, but can tell you that it has a lot to do with humidity. At anything less then 45% static becomes huge issue in my shop, with any machine. Either grounding as has been mentioned, or what I do is a humidifier in the shop. Sometimes that's a loosing battle because here in Montana, it's rarely more then 30% humidity...... and in the winter that number drops into the teens or single digits.....just like the temp! :)
Interesting. As in Montana the humidity here in the Salt Lake City area gets in the single digits on a regular basis. Yet I've never had a serious problem with static. Not quite sure why. I'll have to pay attention more and see if notice any static build up.
 

tkroenlein

Well-Known Member
Sometimes here in SE IL the humidity will fall single digits below 100%.

Today, for example, it was plumb comfortable. The nicest day we've had in weeks. I just checked, right now, the RH is 88%.

I have never been shocked on my grinder.
 

John Wilson

Well-Known Member
The belt material will make a difference, too. When I run a Scotchbrite belt you can hear the static discharge from across the shop. SNAP SNAP SNAP... sounds like a projector when the film reel ends! I hate using those belts for that reason.
 

Drew Riley

Well-Known Member
I normally don't have much of a problem with static on my grinder, but I was sharpening a scraper a couple of days ago and was getting lit up! I saw a couple of bright blue sparks jumping from my fingers to the grinder from nearly an inch away.

If I keep a finger touching the back of the platen, it doesn't seem to be an issue. I probably need to double check my ground, as the machine SHOULD be grounded back to the panel, as the motor chassis is grounded, and directly connected to my grinder. I remember one time I kept feeling a zap every time I bumped into my metal workbench while grinding. I had been grinding a lot of carbon fiber, and there was so much dust it was creating some continuity from a power strip on my bench to the metal top. Turns on the outlet also had a bad ground. o_O


BTW: Another solution often mentioned for static shock, is to spray some anti-static / cling guard spray on the back of your belts, every once in a while. You should be able to find it next to the dryer sheets at your local grocery, if I'm not mistaken.
 

gudspelr

Well-Known Member
Yup, what was just said above about the static cling spray. When I put anew glass platen on a little while back, I got some meaningful snacks while grinding. Found someone mentioned somewhere the anti-static spray so I gave it a try. I sprayed it on the inside of the grinding belt before I started grinding. Worked like a charm. Next grit belt, did the same and it’s been fine ever since when I do that.

Jeremy
 

tkroenlein

Well-Known Member
Welp...I spoke too soon. Our humidity plummeted to 55%. I experienced what @John Wilson described. I put my fine belt on to touch up the spine on a finished knife and I thought I had got ahold of the spark plug wire on a lawnmower. That thing was lit! It spark in time with the flupp flupp flupp of the belt. I tried three times to power through it and couldn't get it done.
 

bladegrinder

Well-Known Member
Rubber gloves may help, I’ve never tried that. But don’t think that humidity is the only devil in the cards. Static cling spray is mostly made for clothes. Like I said earlier I’ve seen static spray come in our shop as demos from salesman and it usually gets laughed at. It’s no better than dish washing soap and water for suppressing static. I live near John Wilson and our humidity is over 80% most of the year with a lot of rain and static is still there, our machines are generating it. High humidity doesn’t negate static electricity.
 
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