On 9 Jun 2005 10:49:49 -0700, wrote:

I am attempting to repair a gas-fired kiln that is used to fire the
shell moulds at a bronze foundry. The fire clay nozzles cracked and
caused heat to destroy the ignition transformers. The problem is I
can't find any supplier that carries these transformers. The brand is
Webster and I see many cross-references at other manufactures sites but
no one that carries Webster. This kiln was made at the shop from
commercially available (at the time) components, but the maker and his
sources are long gone. Any help with suppliers would be most
appreciated.
Thanks

Look for a "continuous duty ignitor". Beckett is a leading brand.
Beckett acquired Phelon, may have acquired Webster as well.
Grainger stocks some Beckett transformers. Honeywell makes a
variety of "spark plugs" for gas and oil ignition, or used to anyway.
The electrodes are just bits of kanthal rod.

"Gas ignitors" tend to be low-energy sparkers, OK for
naturally-aspirated flames (like stoves). In a forced-air burner, a
higher energy continuous-duty oil ignitor would probably be more
suitable -- and give longer electrode life as well. They are designed
to operate in an air blast, have a discharge that looks like a flame
in moving air.

For this application I'd avoid the electronic ignitors and go with a
conventional copper-iron ignition transformer. All of the various
electronic ignitors I looked at when designing ignitors ran too hot
for good life expectancy. This was nearly 10 years ago, though, so
they may be better now.