The Basics of Ventilation, Part Three: Overhead hood design

Overhead hoods have a problem: they are non-functional over most of the width of the hood. The only part of the hood that actually functions as designed is an area about 1-2” wide surrounding the suction duct. This is fine for small torches while making small beads, but what happens when you upgrade your torch and start working with larger pieces of glass?

Insertion of large pieces of glass into the flame plume deviates it and the open duct in your hood is no longer functional. And once you start working with powders, enamels and/or fuming, the only draw area is directly in line with the duct opening. How can the standard overhead hood be made to work more efficiently for the lampworker? Continue reading

Dry eyes – it isn’t always the heat or the air movement

As we age, the eye mechanisms age with us. And, on occasion, dry eye issues can crop up as well. As a group working with hot glass, we are additionally exposed to hot air plus air movement created by any ventilation we are using. Age + heat + air movement = pretty much everything needed for a good case of dry eye syndrome.

Note: I am not a doctor, nor do I claim to be one, nor do I play one on TV, the movies or the internet. However, I HAVE talked with thousands of glassworkers like you and from time to time they all experience episodes of dry eye syndrome that cannot be medically explained.

Here’s the consensus of what seems to work for most people:

  1. First and foremost: BLINK YOUR EYES. The brain will override the blink reflex when you are working on very small intricate work. You have to consciously override your brain and blink. The best way to remind yourself to blink is to make a sign for the back wall of your work area. Make it big, on white paper. Use a black marker and write the word BLINK on it. Don’t put anything else on it. Write BLINK in large letters. Place it in your visual range at the back of your work area.
  2. Get some good quality branded SALINE ONLY eye drops. DO NOT USE MURINE!! DO NOT USE HOMEMADE SALINE!! Murine and other similar products reduce the red in your sclera (white of the eye) by constricting the blood flow through the surface blood vessels. Homemade saline will contain bacteria and other harmful crap. Use only pure, sterile saline drops from a brand-name manufacturer. At the start of your glassworking session, put at least two drops in each eye, then blink several times to lubricate your eyes. During your session, take “safety breaks” every 45 minutes to an hour and repeat two drops in each eye, blinking afterwards. If you feel your eyes “drying out”, stop and add more drops.
  3. At the end of the session for the day, after you’ve safely shut down your work area, wash up, including your face and hands, then put two more drops in each eye.

Now, if the dry eye symptoms still continue after this, you may have an underlying medical issue and I strongly encourage you to visit your local eyecare provider.

Geeze, how many times do we have to tell you?

This isn’t rocket science, people!

I just called the welding supply shop that we got ALL of the equipment from (except the HH)…the brand spanking new tank, the brand spanking new hoses and proper fittings that were required to run the torch and spoke with THE owner…who has been in business for 40 years now. They are the best known and most respected welding supply here in the Tampa area. I told him the size of our shop/warehouse, the size of the office box, the size of the exhaust fan in the warehouse and in the office. He knows what torch is being used and what size tank and lines are running.

According to him (and I *think* that he might know what he’s talking about), it is NOT illegal [to keep propane inside]. They are used every day in many shops for all kinds of applications. He said the only time he’s seen any ‘rules’ about using one is in the situation of a jeweler in a mall or retail shop. And as for the insurance thing, he said that would be like telling someone they could not use their gas barbecue….that if something happened they would not cover it. Myth busted…..

Continue reading

What is the best location for my studio, continued

From another e-mail:

Where in the house would you recommend I put my glass studio? I have several options availble to me: a bedroom, the basement, part of the dining room and a section of the garage.

First of all, I don’t recommend using part of the dining room or the kitchen for glassworking of any kind. There are just too many ways that these areas can get contaminated with glass particles, and since these are food preparation and consumption areas, food and glass particulates do not mix. Continue reading

Ventilation questions

Can anyone give me an estimate of the temperatures one would expect in an 8 inch exhaust line from a minor torch. I have a baffled 4 sq ft hood about 2 feet above my work table and about 8 feet of pipe to the outside opening. My in line fan is not quite enough at 500 cft/min and I need a bigger inline but don’t want to melt a new one. An outside mounted squirrel cage is an option but not really what I need because of covenant restrictions. I can have a grill propane tank but no outside fans or a/c units -go figure.

Well, first of all, your hood is seriously underpowered. Standard overhead hoods should have at least 125 CFM per square foot, and at 16 square feet, you hood needs at least 2,000 CFM to properly exhaust the fumes captured inside. Continue reading