The early years were dominated by European cars,
primarily Lola, McLaren and Porsche with drivers
including Bruce McLaren, Mario Andretti and John
Surtees. By 1969 a revolutionary car designed by
Peter Bryant from the UK and built in the USA
made a significant impact on the sport. Bryant
recognised that weight and lack of ground effect was
holding back advances and a car emerged that used
lightweight titanium body parts for the first time.
Titanium components are stronger than the steel
equivalent and are barely half the weight. Called
the Ti22 (chemical symbol and atomic number of
titanium) the car set new standards in performance.
Bryant built two cars, the MkI in 1969 and the MkII
in 1970. They achieved several podium finishes and
over their lifetime scored more points in Can-Am
racing than any other American built car.
Recreated car, the Ti22MkII, manufactured by Bob
Lee. Image courtesy Melinda Stewart
The success of the Ti22 cars was short lived because
of funding constraints. Both cars were destroyed in
the Can-Am era
In 2015 Bob Lee in the USA acquired original Ti22
MKII drawings and rights to the MkII history. He
assembled a team of fabricators led by Ilia Burkoff
and began work to build a new car employing his
Burkoff’s expertise in fabrication of titanium. It
became apparent early in the construction that
a major hurdle to be overcome was welding. The
fundamental problem in welding titanium alloys is
the elimination of atmospheric contamination1 from
the weld zone. Contamination of the weld metal and
the adjacent heat affected zones will increase tensile
strength and hardness but only at the expense
of ductility loss. This can lead to cracking even in
conditions of only moderate restraint. The most
likely contaminants are oxygen and nitrogen, picked
up due to air entrained in the gas shield or from
impure shield gas, and hydrogen from moisture or
surface contamination.
The molten weld pool can be protected by the normal
gas shroud but the cooling weld and its HAZ will
need additional protection. The underside of the weld
also needs similar protection through the provision
of an efficient gas purge. Atmospheric contamination
however is best avoided by the use of a welding
Flexible enclosure purged with argon in use during
welding of titanium components for the Ti22 Mk II.
The enclosure is a Huntingdon Fusion Techniques 1.2
metres diameter standard model and the welder used
a GTAW torch with MultiStrike® electrodes for arc
stability and longevity.
chamber or glove box that can be filled with inert
argon. Metal glove boxes are available but these can
be very expensive.
Lee solved the problem by using a flexible welding
enclosure together with an oxygen monitor. This
combination allowed him to weld all the sensitive
titanium components in his car, the Ti22 MkII. They
included roll bars and braces, front and rear sub-
frames, suspension parts, brake throttle and clutch
pedals, engine firewall and mirror mounts.
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TUBE NEWS December 2017 9