Fire Safety in the Lab

[charlie1218]

Originally Posted by lukevanoort

This is news to me. I'm curious why that is? I can see why it might be an issue with some kinds of insulation (like paper... ugh). However, I don't understand why the temporary heat would be affecting the copper in that manner, except for possibly adding energy that could speed up the oxidation reaction.



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As you heat up any metal with intense heat, especially at a gauge that small, you cause it to rapidly expand, and contract, which causes finite cracks. This causes the wire to become brittle and greatly weakened, so that when the electric current passes through, its heat, which a normal wire can stand, is now too great and will cause a short in your wiring, which causes high heat. This heat will in turn compromise your remaining insulation and further damage the conductor. Essentially a giant Cluster*^%&

[lukevanoort]

Originally Posted by charlie1218

As you heat up any metal with intense heat, especially at a gauge that small, you cause it to rapidly expand, and contract, which causes finite cracks. This causes the wire to become brittle and greatly weakened, so that when the electric current passes through, its heat, which a normal wire can stand, is now too great and will cause a short in your wiring, which causes high heat. This heat will in turn compromise your remaining insulation and further damage the conductor. Essentially a giant Cluster*^%&

Wouldn't soldering do that too?
EDIT: Wait a minute, shouldn't a wire act as kinda like a short anyway since it is supposed to have as low a resistance as possible and a short is a low resistance path? A short inside a single conductor wire would simply imply that the electricity has found a lower resistance path through the wire, which would then imply that rapidly heating and cooling the wire would in fact improve its electrical performance?

[MrForbes]

I doubt using a lighter or torch to strip wire would damage the wire itself, but the insulation probably releases toxic fumes when burned....and using open flame instead of the proper tool for the job (wire strippers) is just not good practice.

[charlie1218]

It may not be as serious with a lower gauge wire, but 24 gauge will get very hot very easily when heated. SO DONT USE A TORCH.
Yes, but the heat up is not as rapid, and the solder will fill any cracks. Use a wire stripper. Similar idea, just with aluminum:

[Alan Anderson]

Originally Posted by fimmel

last year my team bypassed this by taking an extra Anderson connector and completely removing the alligator clips and connecting the connector to the charger with crimp connectors, solder, and heat shrinking it worked great.

I expect that most teams did that last year. The Kit of Parts included a plastic bag containing the components and instructions for doing it.

[Roger]

What kind of fire extinguisher would you recommend for a metal shop? And for our large "field room" which has computers, shelves of leftover stuff, and some boxes of paper (copier room next door stores extra paper here).

Originally Posted by charlie1218

Don't place any item in front of the access or, blocking the visibility of fire extinguishers or exits...

We (the construction company I work for) used to do a clothing chain store (long gone minor chain, for those who worry) that would store all their extra clothing racks in the rear egress hall. I would shudder every time I see that, but once we them got their Occupancy Permit, it was on their heads not ours.

[Engineer]

Originally Posted by Roger

What kind of fire extinguisher would you recommend for a metal shop? And for our large "field room" which has computers, shelves of leftover stuff, and some boxes of paper (copier room next door stores extra paper here).

You want a fire extinguisher rated for Class C fires. Class C is for electrical fires. Don't use water on electical fire. Most of the fire extinguishers mounted on the wall are rated for Class A, B, and C.

Class A is for 3D fires like houses, boxes, and structures.

Class B is for 2D fires like oils and liquids.

There are other sub classes (Charlie will know about these) but we don't need to go there.

[charlie1218]

Originally Posted by Engineer

You want a fire extinguisher rated for Class C fires. Class C is for electrical fires. Don't use water on electical fire. Most of the fire extinguishers mounted on the wall are rated for Class A, B, and C.

Class A is for 3D fires like houses, boxes, and structures.

Class B is for 2D fires like oils and liquids.

There are other sub classes (Charlie will know about these) but we don't need to go there.

I would Recommend a CO2 Extinguisher for your computer equipment, as it will not damage it, and Class ABC dry chem as well for your standard cobustibles. Is your metal flamable (lithitium, sodium, etc) if so you need a Class D extinguisher. If it is just steel, aluminum, etc, go with a large ABC dry chemical extingusiher ( 1 10-15 lbs extinguisher for every 100 sq ft)

[charlie1218]

Originally Posted by Roger

What kind of fire extinguisher would you recommend for a metal shop? And for our large "field room" which has computers, shelves of leftover stuff, and some boxes of paper (copier room next door stores extra paper here).


We (the construction company I work for) used to do a clothing chain store (long gone minor chain, for those who worry) that would store all their extra clothing racks in the rear egress hall. I would shudder every time I see that, but once we them got their Occupancy Permit, it was on their heads not ours.

PM me

[charlie1218]

Fire extinguishers guide http://www.fire-extinguisher101.com/

PM me for assistance with selections.

[MrForbes]

Originally Posted by charlie1218

( 1 10-15 lbs extinguisher for every 100 sq ft)

Could you elaborate? I doubt I need 13 extinguishers in my garage....

[charlie1218]

In an area you should have one extinguisher on the wall within 35 feet of every point. So if you have a room 100 x 100, you should have roughly 8 extinguishers, to per wall placed 35 feet from each corner. I recommend that they be 10-15 lbs because that is quite a bit of supression. If you have alot of stuff crammed in there, get more or heavier extinguishers. In general use ABC dry chem. For electrical that you dont want harmed, get CO2 have a dry chem to go with it. this is b.c CO2 cant be used on Class A (wood, paper, rags, trash, etc)

[MrForbes]

Ok, that's quite a bit different from one extinguisher per 100 square feet...100 square feet is a 10' x 10' area.

I have 3 extinguishers in the 30' x 44' shop, by each of the doors. Although they're getting old, should they be replaced periodically or inspected or what? the gages all show pressure, and there is no fire suppression company in our small city.

[charlie1218]

Inspect guages every month. replace every 10 years, or when rust shows, or paint chips

[Kyle]

Originally Posted by charlie1218

Inspect guages every month. replace every 10 years, or when rust shows, or paint chips

and of course if ever used, I have met some people that used them and put them back thinking they recharge them selves.