Plug welding thick metal onto thin

[Matt S]

Hi guys,

I am preparing to do some welding on my car, and am currently lining everything up and fettling for a perfect fit, and have noticed a potential problem.

When i weld the engine mount bracket back onto the top of the chassis leg i will be plug welding through 2 holes in the bracket (which is quite thick) and onto the closing plate for the chassis leg (which is quite thin). I can't do it the other way as there will be no access to the inside of the leg.

How exactly do i go about this? For plug welds i would usually start in the centre of the hole on the lower plate, and then spiral outwards to join to the top sheet and leave a kind of mini ice cream cone effect! Should i be trying to start on the top sheet where it can take the heat and gradually come in to join the lower sheet? Advice would be much appreciated! I have searched and not really come up with anything!

MIG welding by the way.

Thanks!

 

[cumbriasteve]

Although vehicle welding is not really my field, I would suggest that because you will be directing the heat to the edge of the thicker material, it would weld easier then it would if you were welding on the flat and attempting to get penetration...that may not be true but it tends to make sense to me.

I think I would try one as you normally do.