lamp heat

[duke]

i have made a blasting cabinet which is 4ft H, 4ft W, 2ft D.
i will be using black beauty (coal slag). my question is, will a flood light connected inside the cabinet, get to hot & cause fire or explosion hazard from coal slag dust created by blasting ?
cheers

[non-stick]

generally speaking I'd say no as I've had those types of lamps in blasting rooms before but yours is a little smaller of a volume. Is it an option to cut a cole in the top or such and put a piece of plexi or lexan there and have the light on the outside? I think you'll find you get longer life out of the bulb that way as well.

[duke]

hmmm, back to the drawing board . or should i just use normal 60 watt bulb work light?
cheers

[non-stick]

no drawing board.... just "adjust" to suit your needs. Most commercial blasters use a hole in the top and shield it with either safety glass or plexi and have a small fluorescent tube light so they can see with. It serves two purposes.... first of all it take the risk of having anything in the way while you are flipping the part around and possibly breaking. Second.... if it's up and out of the way and a fluorescent tube, no heat is generated and therefore... you won't be sweating while you're already laboring moving grit and steel around.

Nope... a hole in the top with a small fluorescent is probably the easiest/cheapest way to go in this case I'd guess. Of course... if anybody else has a better idea, I'm all for it,natrually...... Russ

[duke]

thanks again russ, that makes a lot of sense.
cheers

[Fireblade]

Actually you can use the bulb inside the cabinet with no problems. If you look around at some other places that sell the cabinets, alot of them come this way, and these are commercial duty. I for instance, have 2 cabinets, one 8' long, the other 4' both have light assemblies in them in which I bought at Lowes for outdoor floodlights. The larger cabinet I designed mine after also has floodlight assembly in them, the smaller one which I bought, did not build myself, had a flourescent light tube, which really did a lousy job, and the tube themselves are not cheap. You can pick up a new halogen flood for $5.00, much better, cuts through dust, and cheap and easy to replace for nearly anywhere. You could however do as Non-stick said with hole and plexiglass, just you would have to either replace the plexiglass or buy film protectors to protect it. Either way will work fine.

[duke]

thanks fireblade, my main concern was if floodlight gets to hot while blasting with coal slag. as we know, coal burns.
you have used them. do you think coal dust would ignite in 4FTX4FTX2FT
cabinet?
cheers

[edclark]

I'm going to throw in my two cents, duke, 'cause I think you're getting ready to do something fairly questionable. From a safety standpoint, if the dust isn't combustible, it doesn't make a hoot whether the bulb is inside or outside the cabinet. However, I'm not familiar with coal dust slag, but if it's combustible and it sounds like it is, do not put an electrical source within that cabinet - particularly a bulb - unless it's very specially designed.

Combustible dust such as coal dust has a little property associated with it called the LEL (Lower Explosive Limit). You don't have to worry about it catching fire, you have to worry about it blowing your head off like a stick of dynamite.

I'm no expert, but it sounds to me like the dust concentrations in a blast cabinet could easily get above the LEL for coal dust. One spark and blooey!

If you were using sand or glass, no problem. Coal dust? Keep the lamp outside of the cabinet OR read up on the National Electrical Code for "Classified" areas which is what you are dealing with. Not trying to be a doomsayer, just trying to save your life here.

Good luck,
Ed

[non-stick]

thanks Ed! Always helpful and informative. Well said, bud.

[tomg552001]

I blast with coal slag all the time, and have a internal light, no explosions yet. I think you'll be fine, but if in doubt, cut a hole in the top, buy some lexan, and keep the lamp external. Good luck Duke.