Range oddity....

[Bob Wright]

Have you ever been in a welding or metal fabricating shop and noticed little pock marks in the concrete floor?
These were made by holding a torch too close to the concrete floor. Concrete always contains some moisture, and when a concentrated heat is applied, such as a torch, the moisture turns to steam and a little explosion occurs, blowing out a plug of concrete.

Recently I noticed a large area of spalled concrete in front of the firing line at the local indoor range. I asked about it, and this is what happened.

Unburned powder from firing drops to the floor, and the draft from air conditioning and dust control caused little swirls of powder particles to accumulate. A spark from a round being fired ignited this powder, the resulting fire caused the consurface to explode. The range owner pointed up to the acoustic ceiling tiles above which showed several holes from concrete fragments.

Houskeeping is very important to indoor ranges.

Bob Wright

 

[JohnKSa]

Interesting. I've accidentally damaged concrete with a large magnifying lens on a sunny day; I guess any type of applied heat can be equally problematic as long as it gets hot enough.

I have heard of indoor ranges having fires from accumulated powder. Until your post, I hadn't thought of the possible implications that you describe.

 

[Mrgunsngear]

That is interesting..... Thanks for posting that; learn something every day.

 

[mrt949]

A few years ago we were shooting a action pistol match indoors . Did a range prep before the match.One of the shooters was shooting a 357 DESERT EAGLE that was MAGNA PORTED when he got close to the wall FLASH AND FIRE That will get your attention.

 

[bedbugbilly]

My degree is in Industrial Education - a fancy word for "shop teacher". When working in the foundry area, we were taught and I always "hammered" it in to the heads of my students that when pouring, you always wear the asbestos (at that time) apron, gloves and leggings as well as goggles. If any molten aluminum (or other metal) gets spilled on concrete, it does the same thing in less than a heartbeat.

In college, we had a lab assistant who "thought he knew everything". He was working alone (a big "no no") in the foundry lab trying to get his aluminum lab project poured. When he picked up the crucible with the tongs out of the furnace and swung over to pour his sand mold, he spilled a portion of the molten aluminum on to the concrete floor which instantly caused a small explosion of the concrete (moisture in concrete turning to steam as mentioned). The idiot hadn't put on the asbestos leggings and the result was that molten aluminum blew upwards from the floor and hit his pants, setting them on fire and the aluminum ran into his shoes. I will not describe what fully occurred as a result but it wasn't pretty. I worked ambulance/rescue while going to college and I just happened to be on duty and was dispatched to the scene.

This experience is one that I have never forgotten and it has always reminded me to 1. never take short cuts and 2. when doing something that could be dangerous or hazardous, always have another person nearby in case something goes bad.

Bob - thanks for the interesting info. When I'm in AZ during the winter, I shoot at an indoor range. You can bet I'll be looking at the floor the next time! Thanks for sharing.

 

[mete]

As an engineer I've studied many industrial 'accidents' .Most were caused by people who didn't follow safety procedures or use safety equipment.
In heavy industry like steel mills that meant heavy injuries, even death !!

 

[Koda]

This is true. It is often the impromptu, get it done, can't wait for the safety devices attitude that will get you. I'm an engineer for a car company and one of the things they do right is make SURE you follow the safety stuff.

If you feel unsafe, you will not be faulted for calling it out.

Craziest thing I saw was a chunk of concrete crack loose because it had had about 50 things bolted to it over the years, and the studs just pounded flush once each piece was removed. Eventually, you have to cut and repour.