common sense is not that common afterall

[Zahid Naqvi]

Let this be a lesson to all who think they are too smart to make any mistakes in the shop.

Since I don't have a grinder I frequently use my belt sander as one by mounting it upside down in a vise. Even since I got a set of used Robert Sorby bench chisels I have been wanting to convert one of my old blue Marples to a skew chisel. Well I was doing it last night. Since it required a considerable amount of grinding it generated a considerable amount of sparks, but I was very careful to keep cooling the chisel every 5 secs or so. For the first 5-10 mins (Not sure how much time it took to do the whole process) I kept an eye on the vaccum bag to make sure it doesn't start smoking, no such thing. So I complete the creation of the skew bevel and am getting ready to line by my jig for scary sharping the edge, and boom in a flash the vaccum bag is on fire. I guess the saw dust had been smoldering all the time and suddenly decided to catch fire. Good thing I had the cup of water I was using for cooling the chisel nearby. I think I'm going to get that fire extinguisher for the garage after all. Here are the remains of the bag
bag-smc.JPG

But it wasn't a total loss I did get this out of the deal
chisel-smc.JPG

[John Miliunas]

Whew! You got lucky, Zahid! But, thanks much for that reminder! I think of all the things which can happen in a shop, a fire is what I am most paranoid about. I have 3 fire extinguishers in there and parts of my cement floor which aren't covered with pad, typically have one or more rags/towels spread evenly out to dry from applying oil!

[James Owen]

Let this be a lesson to all who think they are too smart to make any mistakes in the shop.

Since I don't have a grinder I frequently use my belt sander as one by mounting it upside down in a vise. Even since I got a set of used Robert Sorby bench chisels I have been wanting to convert one of my old blue Marples to a skew chisel. Well I was doing it last night. Since it required a considerable amount of grinding it generated a considerable amount of sparks, but I was very careful to keep cooling the chisel every 5 secs or so. For the first 5-10 mins (Not sure how much time it took to do the whole process) I kept an eye on the vaccum bag to make sure it doesn't start smoking, no such thing. So I complete the creation of the skew bevel and am getting ready to line by my jig for scary sharping the edge, and boom in a flash the vaccum bag is on fire. I guess the saw dust had been smoldering all the time and suddenly decided to catch fire. Good thing I had the cup of water I was using for cooling the chisel nearby. I think I'm going to get that fire extinguisher for the garage after all. Here are the remains of the bag
bag-smc.JPG

But it wasn't a total loss I did get this out of the deal
chisel-smc.JPG

Zahid,

As John said, you are indeed lucky. The sawdust in your bag could have waited to catch fire until after you had gone back in the house...then you could have had a REAL BIG problem. Thanks for the reminder to pay attention to the little things! If not, Murphy will get you every time.....

Gald that nothing worse happened!!!

James

[tod evans]

zahid, i use my sanders to sharpen on a regular basis, but knowing i do this i did not hook them into my d/c system, maybe not so healthy but neither is fire! glad you caught it.....02 tod

[Jim Becker]

Ouch....'glad you are ok.

Rule of thumb is never run any kind of DC or vac when working with metal on a sander or other tool (including grinders) unless it was designed for metal. Disconnect the hose, even, so you don't accidentally ignite dust in the hose.

[Bob Noles]

Zahid,

Sorry about the vac, but a cheap lesson learned, I'm sure. Looks like the chisel turned out nice despite the scare.

Thanks for sharing the experience and reminder.

[Zahid Naqvi]

zahid, i use my sanders to sharpen on a regular basis, but knowing i do this i did not hook them into my d/c system, maybe not so healthy but neither is fire! glad you caught it.....02 tod

So what do you do just leave it open blowing dust into the air? How about if I loosely wrap a soaked (with water) fabric around the exhaust.

[Dave Anderson NH]

I grind steel regularly with my big Jet disc/belt sander to make marking knife blades. I do NOT hook up the machine to my dust collection system. I wear a mask and use a paper bag taped to the collection fitting. The bag gets inspected for sparks. If it should catch fire there is plenty of water right next to the machine. Kinad Mickey Mouse, but it works well.

[Dean Lapinel]

One of this months wwing rags discusses this risk. There is a comment about not ever connecting a DC to a grinder.

The hot metal seems to have a fondness for wood dust.

Good reminder for us all....Thanks!

[Doug Ketellapper]

The issue other than fire is the risk of explosion from the dust. I get annual training on grain dust handling, and the power of dust suspended in the air is incredible. Sawdust isn't as strong as grain dust, but is explosive just the same. In your dust collector you have all the ingredients needed to cause an explosion. Dust suspended in the air (fuel), oxygen, ignition source (your hot metal), and containment (the dust bag). It's quite sobering to see the demonstrations of these explosions and the aftermath of a grain silo accident. It really isn't something you want to take even a slight chance with.

[Don Baer]

The issue other than fire is the risk of explosion from the dust. I get annual training on grain dust handling, and the power of dust suspended in the air is incredible. Sawdust isn't as strong as grain dust, but is explosive just the same. In your dust collector you have all the ingredients needed to cause an explosion. Dust suspended in the air (fuel), oxygen, ignition source (your hot metal), and containment (the dust bag). It's quite sobering to see the demonstrations of these explosions and the aftermath of a grain silo accident. It really isn't something you want to take even a slight chance with.

I was going to say the same thing. When my son was taking his courses for his Fire Science degree one of his classes required he do a demonstration showing som hazard. When he asked me about it I got a tuna can, and put some cooking flour in it (Fuel), then I took a bycycle pump with a small hose and inserted it into the flour. Next I covered the tuna can with a 3 lbs coffee can to contain the fine dust. By pumping the bycle pump a few time and match we were able to launch the coffee can several feet in the air. He got an A in the class

[Zahid Naqvi]

I grind steel regularly with my big Jet disc/belt sander to make marking knife blades. I do NOT hook up the machine to my dust collection system. I wear a mask and use a paper bag taped to the collection fitting. The bag gets inspected for sparks. If it should catch fire there is plenty of water right next to the machine. Kinad Mickey Mouse, but it works well.

Aha! that sounds like something I cal pull off, a wet brown bag, and a bucket of water close by.

[tod evans]

So what do you do just leave it open blowing dust into the air? How about if I loosely wrap a soaked (with water) fabric around the exhaust.

yes, before grinding metal i blow the sawdust out of the machine(depends which one i`m using) then go to town...the machine i usually sharpen on is the 6x48 and being homemade it has no dust provisions anyway. the last thing i would do is attach a rag(fuel source) in line with the sparks! if you`re using a handheld belt sander, first remove the residual dust from the machine, blow/vacuum, etc, then if your unit was equiped with a vacuum bag, have the exhaust blowing freely at/into a non flamable object like a cookie sheet or piece of tin. when done grinding let the machine cool and check for sparks, also the surrounding area. it pays to keep fire extinguishers handy and use common sense,(i know the title!) just think before grinding....a piece of sawdust imbeded cloth in stream with the sparks just ain`t a good idea .02 tod

[Peter Gavin]

I was grinding something (forgot what, not important) and the sparks ignited a buffing wheel I had placed behind the grinder. So even without sawdust or other contaminants sparks are dangerous. Keep your eye on everything for at least a half hour when making sparks.

[Ken Fitzgerald]

Thanks for the reminder Zahid! It's not a matter of common sense....it just having a casual attitude towards what's probably an everyday occurance!