[Clem1640]

Last two years we have used welded frames. Mostly 6061 Al MIG welded.

Before that, we used bolts.

Reasons for the shift to welding:
1) Weight! No connecting pieces. Reduced nuts & bolts.
2) Strength - a well-welded frame is nearly as strong as the native aluminum.
3) Durability & Maintenance - Bolts work loose. Our welds no longer break. There's a learning curve here.
4) Design - As head of the Design Team, I am well aware that it is easier and faster to design a welded frame than a bolted frame. Especially if you are paying attention to detail (and the devil always hides in the detail).

The other benefit is that frequent welding makes us better welders, and yields welds less likely to fail. It also becomes easy and fast. We are now able to weld on the fly.

Downside is that when a critical weld fails, you need to work out a field fix. This can be easy. This can be damned near impossible.

Still, for us, the benefits of welding (applied to the right places) overcomes the costs and dangers.