Meet in Commons area. Just submitted, won’t show for 48 hrs on calendar.
@LisaSelk FYI
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Metal shop has re-elected Chuck by near-unanimous decision (with only Chuck voting against).
Topics covered include:
Upcoming class on the Plasma Cutter. The actual cutter unit has suffered some damage due to misuse, so we are exploring a new cutter unit. We are hoping to have individual logins required on the computer so that only trained operators will be able to use the machine.
Personal Storage of any materials is not allowed in the Metal Shop. Only store your materials in the project storage area. We will be going through and cleaning out the ‘scrap’ bin as well. Metal shop members (including the chair) have removed the non-functional hydraulic press that was never accepted by the Chairperson and placed it into its proper place in large item storage (sorry Eric).
Welding: We have been going through a LOT of welding supplies as of late and are considering/planning on implementing a cost per minute (much like the laser) for the welders in order to recapture some dollars to pay for consumables.
The handheld plasma cutter has an air leak and may be offline (Tim was working on it).
Metal Shop will be implementing a wood-shop-like 101 training course, required by all who want to work in the shop. It will primarily be a safety based course, but will also likely cover specific DMS rules (eg. no grinding aluminum).
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Handheld plasma cutter is repaired & operational.
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So if we have taken the welding safety class, and paid for the welding classes we are going to be required to take another class to continue to use the metal shop? (Just to clarify).
Let me know when the new classes will be! I am very interested in attending. I wanted to catch the last welding classes, but was out of town.
Some folks may wonder about this and why it would be so dangerous. Here’s a link to a letter that explains and links to events that have happened because of aluminum grinding.
Keep in mind that thermite is made with aluminum powder and ferric oxide so rust and aluminum grindings can be a very nasty combination on a shop floor.
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That’s a question for Chuck @dallasmagna
As to grinding aluminum, I think our first reason is that it gums up the grinders surface. Safety issues notwithstanding.
The thermite issue is really why you don’t grind/cut/sand aluminum in the same area as steel. Once going, thermite is extremely difficult if not impossible to put out.
Actually, a more common reason is that the loading caused by non-ferrous materials (think brass as well) causes the grinding wheel to load and then overheat. This process can cause the wheel to litterly shatter (small pieces of wheel propelled at high speeds)… This is a near certainty with brass/aluminum. The thermite reaction is less likely since thermite is quite difficult to ignite. You can use a propane torch on thermite and it will not realiably ignite.
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That"s why I always alternate a small chunk of magnesium with my aluminum and iron grinding.
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Personally I’m more concerned over the thermite. Yes we should not be using non-ferrous metals on it to keep it from getting loaded. But since it is a welding shop with all sorts of arc’s & sparks, it could be ignited without is knowing. I have read several instances where this has happened.
What I find funny about this, is the time we tried to ignite a pile of VW case shavings. We had just line bored it, so we had a nice pile of oily shavings from the infamous “burning magnesium” case made by VW for like, a zillion years. Whilst making said cut, much discussion ensued concerning their infamy, and reasons therefor. It was determined that the best course of action, once completed, would be to test the stories. We placed them on a ceremonial alter (concrete pad) in a prominent place of natural energy flow (the bottom of the hill in the back) and took a propane torch to said pile. Nothing. Burnt the oil off nicely, but nothing doing on the “magnesium” shavings. So we rolled out the oxy/acetylene rig. Never did get ignition…
This is not to say these things aren’t of concern, but I still go back to that attempt at validation of one of the old “shopman’s tales” and its abject failure.
Thermite on a grinding wheel is VERY unlikely. Thermite is not steel and aluminum. It is RUST and aluminum… Sparks from welding are not going to ignite thermite (and should be on the other side of the welding curtain anyway).
Loading resulting in shattering is orders of magnitude more likely, and a concern even with brand new unused grinding wheels–that is why one should never stand inline with the wheel when you start a grinder.
Shattering is my general fear with grinding too. I would think that under load would be the primary time that it’d go off, as opposed to startup. More reason for me to take the Metal Safety class!
Grinding wheels are pretty loosely bound aggregate (that is how they grind). It can certainly shatter under load, but only if your not using them properly (generally), but if the wheel was subjected to microfractures (during manufacturing, shipping, or when the last idiot used it) those fractures can result in shattering when subject to the sharp acceleration of start-up.
Safety gear for grinding; facemask, heavy apron.
You can check a grinding wheel by doing a ring test. While it may not be perfect but it’s another way to check for cracks in the wheel.
Walter my point was that it was possible. Yes I know iron oxide & aluminum oxide make up thermite in a specific blend. But how do we know that the iron shaving/powder has not been oxidized enough to cause the reaction. While yes welding curtains are there, there still are sparks that can continue.
AWS states that normal welding sparks can travel up to 35 ft & still be at 2,500 degrees. The temp of the arc itself can be 10,000 degrees.
Then there is plasma cutting. It can have an arc of up to 50,000 degrees, plus there is the degree that the dross/slag is being shot out by compressed air.
Knowing my luck, I’d get a reaction. This is why at home when I work with aluminum I’m very cautious.
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Because we’re all so studious, carefully sweeping up all grinding residue immediately upon completion of our day’s work…
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