Insert the required "check with your local codes" here.
fwiw I have a extension cord that has 4 220 outlets on it, it powers my joiner/planer/dust filter and would prob work on the welder I have too.
But not all at the same time.
I does do the DC and joiner or planer just fine and is rated for more amps than they draw together.
Not saying you should do it, but its worked well for me.
I would probably wire them differently if I was in a more permanat shop, but the wife's car has to fit in the shop/garage from time to time also..
Al
Remember our vets, they need our help, just like they helped us.