Technical Articles

Air-supplied face masks


  • Sump pump hose (black, corrugated, about 1 1/2″ d. (Canadian Tire)
  • Small vacuum cleaner replacement hose (Canadian Tire)
  • Small blower, squirrel-cage type best. (Used from Princess Auto catalogue or from a junked car’s air circulation system with a 12 volt plug-in adapter)
  • Duct tape (never go anywhere without duct tape)
  • Assorted PVC pipe connectors, hose clamps.
  • An old belt.
  • The Artist’s Complete Health and Safety Guide, Monona Rossol. Order through ACTS, 181 Thompson St. #23 NYC, NY 10012-2586 about 20 bucks (cheap).

Respirator. This is the part you’ll probably have to pay for although I can imagine adapting an old surplus gas mask. The respirator I base my units on is an MSA Comfo II Respirator, part #479860 black Hycar, medium (that’s what the catalogue says). It is a half-face respirator with an over-the-shoulder hose that is meant to attach to a belt-mounted cartridge carrier. I have ordered the face mask with the hose minus the belt and cartridge holder. That makes it somewhat cheaper. You don’t need the cartridge holder or the belt. Get a belt for 50 cents at Frenchy’s. Express yourself. The above unit complete runs $205 from Chandler Sales in Saint John, NB. They don’t have them in stock but can order them. They have managed to order just the parts I need for less than the complete cost in the past. 1-506-658-8000 but try 1-800-363-9611 first or find a local supplier.

I use my air-supplied face mask during dusty or fumy/smoky operations. This is a standard respirator with an over-the-shoulder air hose that attaches to a waist belt (so the hose won’t pull on the face mask). This hose is connected to a length of replacement vacuum cleaner hose (because vacuum cleaner hose is durable and can take getting stepped on), which is connected to a long piece of sump pump hose (cheap and easy to find).

The sump hose runs to a blower (squirrel cage type is best) that supplies fresh air under pressure to the hose. The blower unit is kept or placed in an area of the building where there is fresh, uncontaminated air ( be sure to screen the intake to prevent inhalation of insects). Because the face mask is under positive pressure, no air leaks in around the mask (even if you have a beard) and there is no strain on your lungs from sucking through filters.

You also don’t need to worry about having the wrong filter for the job. I use this system anytime I do anything where I should be wearing a respirator, even if I’m in front of an exhaust hood. Obviously, it isn’t a life support system and should be used with a good dose of common sense, but I find it extremely effective.

You should never use any respirator or air system in dangerous situations in which the failure of the system puts you at risk. They are easy and cheap to build. The only disadvantage is that you are connected to a hose that tethers your movements. A little planning before harnessing up makes this a minor inconvenience.

Disclaimer: I take no responsibility for any conceivable problems anyone might have using a system as I’ve described, remember that you are responsible for being sure you understand the system, how it works and what the dangers are.


I’ve got a bit of a problem about the following. I did not write it and don’t know who did, all I have is a handout with the information. I offer it in the spirit of sharing that I hope the unknown author will appreciate. If anybody recognizes it’s origins please let me know so I can attribute it. The work shown is mine.

“The raku style of pottery originated in Kyoto, Japan in the late 16th century with the potter Chojiro, a Korean immigrant. Bernard Leach in A Potter’s Book tells us that Chojiro’s parents, Ameya and Teirin, were the first to produce ware of the type we associate with raku, but it was Chojiro, under the guidance and tutelage of the great Kyoto tea master Sen-no-Rikyu, who brought the ware to the attention of the 


emperor Hideyoshi. Hideyoshi, in memory of Chojiro, bestowed a gold seal on Chojiro’s son Jokei. The work raku comes from the ideograph engraved on that gold seal. Loosely translated, it can mean enjoyment, pleasure, comfort, happiness, or contentment.

Raku was prized by the Japanese tea masters because it is unpretentious but aesthetically pleasing and embodies the ideals of Zen Buddhism and wabi. In Japanese aesthetics, wabi encompasses austerity, transience, seclusion, and tranquility. Wabi is the intangible essence of the tea ceremony. On the practical side, the porous clay body acts as insulation between the hot tea and the hand and produces a dull, quiet sound when it comes in contact with utensils or the table top.


The beginning of raku in North America beyond Warren Gilbertson’s introduction of the technique (in 1942) are unclear. The potter who is responsible for establishing raku as a popular, creative method of pottery making is Paul Soldner. Soldner began making his raku experiments around 1960 with only the information gathered 

from A Potter’s Book (Bernard Leach). Being somewhat bored and dissatisfied with the apparent bland nature of the colour development in the pots, Soldner spontaneously put a piece in some leaves to burn. Thus was born our contemporary incarnation of the raku process – ‘postfiring reduction’.”


I fire raku indoors in digitally controlled (GB4 by Digitry) electric kilns and do post-firing reduction in seasoned sawdust. Sometimes I quench in water sometimes I don’t. I wear an air-supplied face mask and have an industrial extraction fan going to keep the smoke moving. The controller allows me to have all the work ready for reduction at the same time and stay on top of at least some of the variables.