The view from the naughty bench

The title of this piece isn’t meant to be snide or churlish, just what I’m feeling right now.

Did your grade school have a naughty bench? You know, the bench or chairs outside of the Principal’s Office? Where the ‘bad kids’ sat before getting lectured for their behavior?

Yeah, that place.

I admit it. I’m an ass. I’ve taken the first step: admitting to a problem. The next steps are even harder, but today I’m trying my best.

What does cataract surgery cost?

Per eye, approximately $7,200.

My mother, still “young” (in her early 70’s), just had cataract surgery in both eyes over a two month period of time.

$14,400 for both eyes. Plus not having perfect vision for up to 2-3 weeks afterwards, having to avoid bright lights for 6-8 weeks. If my mother had been a torch worker, she would have been out of work for close to 4 months.

Energy Radiance Information for Glassworkers

NIOSH and OSHA have determined that the IR TLV (threshold limit value) to the unprotected eye is 10 mW/CM2 for time periods greater than 16 minutes. (10 mW is .010 Watts)

Air temperature and altitude corrections for ventilation systems

Altitude and air temperature make a substantial difference in the performance of any ventilation system. The calcuations I have provided here: http://mikeaurelius.wordpress.com/2007/12/25/ventilation-basics-part-two/ are based on sea level and 70 degrees F.

In the calculations, the only variable that needs modifying is VP, Velocity Pressure. The standard calculation is (V/4005) squared.

When applying temperature and altitude corrections, use the following equation: VP = ((V/1096.7) squared) times ‘density of the air in pounds per cubic foot’.

Ventilation question

From the ISGB forum:

Hi , right now I’ve been using the system Vince described in the Drew Fritts book. I had been using a minor and everything worked well.
Recently purchased an Lucio torch from Carlisle. I noticed I needed to upgrade my ventilation system. So I like to start from scratch, build a new hood etc. My room is 8 x 24.
I have also read an interesting article, and would like to get your thought on it please. Here is a link.
http://andreaguarino.com/ventilation/

I took a look at Andrea Guarino’s website and the link on her ventilation system. If you are a regular reader of my blog, you know my feelings on open duct ventilation (I don’t believe they work and don’t recommend them).

Plumbing for propane

From LE:

My studio is a separate building and my propane tank and regulator are in a ventilated box my husband built sitting on a ledge attached to the outside of the building. He ran the standard hose that came with the torch (or I my have purchased it separately) through a small hole about a foot from the floor which is about 4 feet to my torch. The small hole has a pvc pipe inserted with the hose running through it and then a wood plate on the ouside and inside holding it in place. The hose also has insulation stuffed around it. Okay, now it all looks fine to us – but the experts out there, are we missing some important safety concern? Thanks in advance!

On the surface, this sounds like a marvelous idea. Make a hole in the wall, line it with PVC, insulate it, and run the rubber hose through it.

Unfortunately, it is an illegal installation. The National Fire Code (NFPA) states that all wall penetrations must be accomplished with hard wall metallic piping. The piping can be copper, black (iron) pipe or stainless steel. There must also be a shut off valve on either side of the wall. On the inside of the wall, the pipe must extend to within 5 feet of the point of use, and if the point of use is further than 10 feet from the inside shut off valve, the line must have an additional shut off valve at that point (torch valves do not qualify).