how to use weld-thru primer Options

[jmitro]

two questions about using weld thru primer, (assuming that proper usage is spraying primer on the backside of two adjoining pieces so that primer covers the bare metal that cannot be accessed once welding is completed);

1. Do you change the weld settings on the welder? It welds terribly with poor penetration. Or do you grind off the primer from the anticipated weld spot? If so, then it's defeating the purpose of weld-thru primer, is it not? it leaves bare metal.

2. After welding is complete, do you grind off the exposed weld-thru primer and replace it with POR-15 or primer of choice?

[r_towle]

I spray on the primer, then grind off the spot welds I an going to weld.
I feel better that there is some primer on the back side.

If I am doing a seam weld, Its all bare anyways so I can work the joint from both sides and hammer dolly it flat, grind it, then prime it when done.

The spot welded seams, like all over our cars, is where I use it.
Never use it anyplace else.

Cannot weld through it....
rich