certified roll cage
NHRA wants moly tigged.
The reason is the heat affected zone is much smaller when using a tig as you can control heat input better. Moly tends to crystalize when heated and you want to keep that area to a minumum if you can't bring the temp down slowly.
You can mig moly, done it plenty of times.
I know of a few certified moly cages that had multiple welds done with a mig. go figure.
In these pics of a friends work, you can see the outer ring. That's the HAZ area. It would probably be another 50-100% wider using a mig to get adequate penetration.
NHRA wants moly tigged.
The reason is the heat affected zone is much smaller when using a tig as you can control heat input better. Moly tends to crystalize when heated and you want to keep that area to a minumum if you can't bring the temp down slowly.
You can mig moly, done it plenty of times.
I know of a few certified moly cages that had multiple welds done with a mig. go figure.
In these pics of a friends work, you can see the outer ring. That's the HAZ area. It would probably be another 50-100% wider using a mig to get adequate penetration.
