# Doggone amateurs…

Someone on LE writes with a good question:

I have a “barley box” being made up for me and need to know the CFM’s necessary for proper ventilation. I can’t figure out these CFM calculators I’ve seen on some other sites.

The box is 17″ deep, 30″ wide and 30″ tall. I’m working on a Cheetah.

One of the new “know-it-alls” writes back in response:

… – this is the calculation for a 17×30 hood:

17 x 30 = 510 / 144 = 3.54 x 125 = 443 CFM

Since you will have the sides enclosed, you can use the 100 multiplier instead of 125, thus 354 CFM

So you need a fan between 354 and 443 CFM.

Ummmmm…the opening of the box is 30″ x 30″. The 17″ is the depth (or how deep from front to back) the box measures.

The correct calculations are:

30 x 30 = 900 / 144 = 6.25 x 100 = 625 CFM. Size the fan with a minimum 625 CFM fan, up to about 10% over (or about 700 CFM).

# What we have here is a failure to communicate…

From wonderful WetCanvas:

Has anyone used the AGW-300 for furnace work? It seems like a good product from the specifications but I’m not sure how well I’d be able to see in the hot shop with 60% visible light transmission. A packet about eye protection that came with the intoductory materials for a course I took in Corning suggested wearing flip up #5 welding filters but it would be nice to not have to deal with the flipping. The AGW-300s are pretty expensive at \$260 though so I’m not sure if it would be worth it even if I could see pretty well. Continue reading

# Rip off artists need not apply

About six-seven months ago, a “gentleman” by the name of Craig Bellinger appeared with a couple of websites entitled ‘The Glass Blowers Bible” and a series of DVD’s on torch worked glass.

Several of the glassworking fora took exception to Mr. Bellinger’s information and it was subsequently discovered that Mr. Bellinger’s DVDs were actually the work of another person whom Mr. Bellinger had actually taken but not paid for, then duplicated them and sold them as his own. Yep, we are talking outright copyright piracy here, folks…not pretty. Continue reading

# Protecting the walls of your studio

From a post on LE:

I’m working on a bench that is 38″ deep. I will have a phantom running on my side of it and a wood wall opposite of it. What kind of protection do I need on my wall, how much of the wall should be covered (as in how high). Is the distance great enough to leave the wall alone? What is the best way to go? Continue reading