Goofs & Blunders You Should Avoid.

[master53yoda]

I had a nerve on the outside of the cut that finally callused over but for probably 5 years it was just like getting shocked with 110 every time i touched it

 

[Bill Gruby]

Been there bdone that. It isn't close to being funny.

"Billy G"

 

[brino]

man I wish there was a "delete post" button on this site!
or at least a way to add quotes during an "edit" of a already posted response.
-brino

 

[brino]

Why would one use a volatile, flammable liquid as a coolant for a tool that has an open ignition point (that is, the spark)?

The kerosene works extremely well as long as the ignition point is kept submerged.

exactly why I decided on distilled water for my EDM.......I can't be trusted!
(@savarin, it is not meant as a gloat or "I told you so", just as a example of a compromise/substitute for safety's sake).

Yes my EDM vise is rusty, I want to try a wax coating or something......

-brino

 

[brino]

Lots of things are flammable in a dust or powder form----try a little coffee creamer powder--burns well

Even many things that are not flammable can be explosive when in dust form.

I've never seen it for myself but I remember a story about a table saw being used for cutting steel & apparently pine dust is much like gasoline.

I spent some school-time summers working mechanical maintenance at a plant producing diapers. They had large towers for both storage and processing("fluffing") of talcum powders. They went to great lengths to make sure that even a static spark could not ruin everyone's day.

Myth Busters did a huge fireball with "coffee whitener".......and saw dust, and other common powders.

Be careful out there!
-brino

 

[Glenn Brooks]

Reading through the thread, saw a couple of posts about welding sparks pitting windshields on cars in the garage. This reminded me of a small welding project I did two or three summers ago. I always wear protective gear when cutting or welding -summer and winter. So took off a nice new fleece pullover, and put on my old leather welding jacket. Buttoned it up to the neck, doned the gloves and hood and went to work. About 10 minutes later I had welded the fixture up and took off the leather coat to put everything away. As I turned around, I noticed my nice new pull over fleece I had folded up and placed behind me on the ground, out of harms way, had turned into a small synthetic bonfire. The flames had burned a nice hole right thru the center of my garment, right down to the pavement. Somewhere along the line, welding sparks had somehow bounced into the fabric and ignited. I stamped the fire out. But holding up the pullover, could see nothing left except the arms, neck, and zipper, and a bunch of ragged, burnt and melted fabric around the edge of the garment, with avery large hole burned clean through the body.

 

[SapperDave]

When using an angle grinder on an I beam on the floor, do not kneel down when your cutting. Having a diamond blade run up your inner thigh hurts, Stitches in your inner thigh hurt even more, especially if you do it the day before your first holiday in years. It was fun explaining to my wife why I was in the medical centre.

 

[mephits]

Apologies to all for taking so long to respond. My wife had surgery at the beginning of the week and I've been a little preoccupied. It was a routine endoscopic procedure that went beautifully, but she still had some recovery to do afterward. She's fine now!

Liquid kerosene will not burn. Like gasoline, and diesel, it needs to be mixed with oxygen to support combustion. Gasoline appears to burn, because it vaporizes easily, and that is what you see burn when you toss a match in a bucket of gas. Unless it is a super hot day, you can toss a lit match in diesel or kerosene, and chances are the match will burn a few seconds, then go out. You need the vaporization of the fuel to get the flames. That's what Savarin caused by slowly adding kerosene to hot metal with sparks.

All true, but kerosene's flash point is only around 150ºF. That's not much hotter than water from the hot tap. And on top of that, it's autoignition point is only around 425ºF! The cutting point on an EDM is going to be much higher than that. And it's true that ignition requires oxygen, but it still feels like tempting fate to use kerosene around an open spark, even totally flooded. Seems like all it takes is one mistake...

And a lot of automotive fuel pumps are submersed in the fuel tank and the fuel flows right over the commutator and brushes.

Also true, but there we're talking about an automotive electrical system. Much lower wattage than an EDM. On top of that, if you're getting sparks in your motor, it's destroying itself. Those sparks will erode the commutator and rotor just like they erode metal in the EDM.

exactly why I decided on distilled water for my EDM.......I can't be trusted!
(@savarin, it is not meant as a gloat or "I told you so", just as a example of a compromise/substitute for safety's sake).

Yes my EDM vise is rusty, I want to try a wax coating or something......

Interesting. So the EDM doesn't push enough wattage to crack the water into free hydrogen and oxygen? That would create a whole new set of flammability issues!

So as a question to all and sundry who actually have EDMs. What about standard cutting fluids like emulsified synthetics makes them less desirable here? Conductivity issues? Cost?

 

[brino]

There were some comments above about removing swarf.
Here's a shot of the acid brush I use to remove swarf and apply cutting oil to the work area:


The milling cutter grabbed it, pulled it thru and spit it out the other side.
I am so glad it wasn't my fingers.

I still use it.....keeping it as a reminder......

-brino

 

[brino]

Interesting. So the EDM doesn't push enough wattage to crack the water into free hydrogen and oxygen? That would create a whole new set of flammability issues!

So as a question to all and sundry who actually have EDMs. What about standard cutting fluids like emulsified synthetics makes them less desirable here? Conductivity issues? Cost?

Hi Hurley,
I want to respond with what I know, but this page looks like my soliloquy.
In order to keep this thread on topic, I'll respond here:
http://www.hobby-machinist.com/thre...hine-version-2-edmv2.49689/page-2#post-443894

-brino