The Forestry Contracting Association has recently reported the death of a fitter while welding a wheel on a tractor. The risk from tyre explosions during inflation have been well publicised and large/industrial tyres should be inflated within a restraint. The risk from welding wheels with tyres still in place is less well known. As the rubber is heated a chemical reaction known as pyrolosis, which liberates hydrocarbon gases creating an explosive atmosphere.
The FCA Report:
“There is a theory that tyres which have been in place for a long time, which makes forestry machines likely to be affected, can contain a gas created when air and something in the tyre compound react over time. This gas can explode if ignited. The recommendation is that tyres should be removed, not just deflated, before using a gas torch, stick or mig welder or a disc cutter or grinder during any repairs. We did think this was a tad difficult to believe at first but it would appear evidence is mounting so we will be doing further research and will be back with more information in the future”
Thanks to the FCA for bringing this to the industry's attention.
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