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Another Blasting Question

Posted: Fri Feb 24, 2006 6:50 pm
by RadDavis
I've been blasting since last Thursday afternoon with no problems.

Today I made a pipe and when I began blasting, I was feeling a little stinging sensation around my chest area where it was touching the cabinet. At first, I thought there was a bug biting me or something, but then as I moved back, "POP" a blue spark arced into my chest and stung me pretty good.

I thought I'd try keeping in contact with the cabinet while I was blasting to see if that helped. You know, to see if it would keep a charge from building up. I leaned into the cabinet with my chest and pulled the trigger. I could feel little shocks traveling all over my chest, and it was *not* comfortable.

I finished the pipe by standing back and trying not to touch anything as I pulled the trigger.

I've seen some anti static mats online. Do these things work? The ones I've seen say they reduce static. I don't want it reduced. I want it gone.

Any of you more experienced blasters have any suggestions? Is there anything available at Ace or Wally World?

Rad

Posted: Fri Feb 24, 2006 7:01 pm
by KurtHuhn
I just put a grounding strap on my forearm, and attached the other end to the metal shelves that my blasters sit on. That seemed to take care of it well enough. Prior to that it was my elbows that kept getting shocked since they were closest to the shelf uprights.

BTW, this only started when I began using my Cyclone blast cabinets. They're made of heavy duty molded plastic, so I'm thinking that they're self-insulating. The Grizzly never did this to me - the only thing it ever did right the first time....

Maybe stop by your local CompUSA or other computer repair place, and see if they have grounding bracelets designed for working with the innards of computers. That's the kind I used, since I have a pile hanging around.

Posted: Fri Feb 24, 2006 8:13 pm
by RadDavis
Thanks, Kurt!

Should I attach the grounding strap to the cabinet? There's nothing else metal around it.

BTW, I've been blasting all week and never had it happen. A front passed through last night, and the air dried out and the temp dropped. I guess that makes all the difference.

Rad

Posted: Sat Feb 25, 2006 1:06 am
by KurtHuhn
Yeah, the first time it happened, it was *way* drier than normal, and cold. I imagine it was sort of like rubbing your socked feet really fast on the living room carpet. :)

Considering you were getting shocked by the cabinet, I would try ataching it to that. Failing that, maybe finding a good ground somewhere.

You know, there's a joke in there somewhere about electric nipples, but I just can't figure out what it is....

Posted: Sat Feb 25, 2006 9:10 am
by bscofield
KurtHuhn wrote:You know, there's a joke in there somewhere about electric nipples, but I just can't figure out what it is....
I thought the joke was about rad blasting naked....

Posted: Sat Feb 25, 2006 3:01 pm
by ScoJo
Blasting naked sounds extremely dangerous. Remember, there probably ain't going to be nice looking growth rings in that thing, Rad, so be careful!

Posted: Sat Feb 25, 2006 5:44 pm
by custom300
This may be totally ridiculous, but what kind of shoes were you wearing? If you wear rubber soles, it may reduce the chance for static shock. As an example, during the winter when you slide out of your car, with regular leather soled shoes you can get a pretty good jolt, but if you have rubber soled shoes you usually won't. The electricity is trying to find a way to ground...obviously you are creating the conduit to ground. The rubber soled shoes should eliminate the path of least resistance. Again, I may be way off, but it might be worth a try.

Posted: Sat Feb 25, 2006 5:45 pm
by custom300
This may be totally ridiculous, but what kind of shoes were you wearing? If you wear rubber soles, it may reduce the chance for static shock. As an example, during the winter when you slide out of your car, with regular leather soled shoes you can get a pretty good jolt, but if you have rubber soled shoes you usually won't. The electricity is trying to find a way to ground...obviously you are creating the conduit to ground. The rubber soled shoes should eliminate the path of least resistance. Again, I may be way off, but it might be worth a try.

Posted: Sat Feb 25, 2006 7:19 pm
by RadDavis
I did try that, and you *are* way off. :P

I not only wear rubber soled shoes, but I dragged a 3/4" thick rubber mat from in front of my lathe over to the blast cabinet and stood on that. I still got zapped really good.

Rain moved in this morning. I blasted all day with no problem.

Rad

Posted: Sat Feb 25, 2006 9:59 pm
by JHowell
I'm probably missing something, but why wouldn't you give the cabinet a path to ground rather than grounding yourself? I use a plastic cabinet, too, and sometimes experience the shocks, but don't find it unpleasant.

Posted: Sun Feb 26, 2006 11:12 am
by RadDavis
JHowell wrote: I use a plastic cabinet, too, and sometimes experience the shocks, but don't find it unpleasant.
That sounds kinky, Jack! :P

My cabinet is metal, and the shocks are quite strong when conditions are right.

I don't know nothin' about no 'lectricity. How would I give the cabinet a path to ground? It's already standing on it and has metal legs. Would something else be required?

Rad

Posted: Sun Feb 26, 2006 8:41 pm
by JHowell
I dunno, I guess electric shocks just remind me of my childhood. Anyway, I'd run a wire from some bare metal point on the cabinet to a water pipe, if that's possible. When discussing electricity I usually save time by declaring right up front that I don't understand it, but things rubbing against each other (dry things, anyway) generate electric charges. Wool sweaters and leather seats are one combination for those who remember the term "sparking." The ancients generated electricity more or less for kicks ("Hey, Socrates, put 'er there. *spark* HAHAHAHAHH) by rubbing silk or wook and amber together (the root for "electricity" comes from Greek for amber). Denied a path to positively charged particles, the negatively charged particles accumulate. Evidently your cabinet isn't making good contact with the ground, so you and your electrolytes offer a path once sufficient charge accumulates. The more resistant the path, the greater the accumulation, so you are probably making things worse for yourself by wearing rubber shoes and standing on a rubber mat. The grounding strap Kurt suggests would, if properly grounded, reduce the shocks somewhat by improving your conductivity to ground and lessening the voltage at which the transfer would occur, but the charge would still have to go through you. I understood that the straps were required for computer work to prevent you from accumulating a charge and zapping the computer rather than the other way around, which is your current problem -- your work accumulating charges and zapping you.

I don't know the particulars of your system, but I'd try running a ground wire to various points. Those whirling particles are notorious for generating static -- same as dust collection systems and thunderstorms. It may be that the cabinet is fine but the charge is accumulating in the gloves or attached equipment or something. Electricity can behave strangely. Try grounding the gun itself, and the dust collector. Or just learn to enjoy the shocks. They're ont htat dab once ouy etg sude ot meth.

Posted: Sun Feb 26, 2006 11:02 pm
by RadDavis
Thnaks orf all rouy hep, Jak.

I ma gttnig udse to ti swloy utb slurey. Nda yrou'e rtigh. ti's nto thta unpslenta ta lal.

Rda

Posted: Mon Feb 27, 2006 1:56 am
by carthagena
Hu ?? :think:
:dunno:

Lol !
Rad, I'm happy you're doing sandbasted pipes, there are fine !

Best Regards
David

Posted: Fri Mar 24, 2006 7:57 pm
by BriarBrian
I had the same thing with my blast cabinet Rad. I just attached a long wire to the trim ring around the glove on my right and then attached an alligator clip to the end of it and just clip it on the edge of my jeans where it will touch my skin. I havent had a problem with it since then. I also had the same problem with my belt sander and did the same thing. You ground yourself to the unit and it doesn shock ya, dont know why but it works.

Brian
www.briarart.com

Posted: Sun Apr 02, 2006 3:33 pm
by RocheleauPipes
Until about a week ago I had forgotten about this forum, and never seem to get much time to chit chat, but I was just going through some threads here.

I don't blast, but my belt sander builds static charge. I just run a copper wire from the metal of the table to the nearest good ground. A ground can even be the concrete floor, metal electrical box, etc. I'd experiment with grounds. I don't like those shocks.

John

Posted: Sun Apr 02, 2006 11:31 pm
by JHowell
Yeah, I'd forgotten about this thread. It occurred to me that what needs to be grounded is the gun -- the potential is between the gun, which is insulated by a rubber hose from ground, and the cabinet, which is grounded. Running a wire from the gun to the cabinet would do it.

Posted: Sun Apr 02, 2006 11:40 pm
by RocheleauPipes
Well, if it's anything like an airless paint sprayer (something I actually know about), the static charge is from the material sqeezing at velocity through the orifice, so Yeah what you say makes sence--ground the gun.

John

Posted: Sun Apr 02, 2006 11:54 pm
by bscofield
RocheleauPipes wrote:the static charge is from the material sqeezing at velocity through the orifice
John
I could take away so much from just that phrase...

Posted: Mon Apr 03, 2006 2:48 am
by mahaffy
Ben, this is serious, grown-up stuff here. Besides, I'm sure the rest of us can cut to the hot parts OK without direction. I think the topic is kinda static, anyway. Next time it starts, Rad, try rubbing a cat briskly through your hair and see if it'll stick to the ceiling. Great parlor trick.