Kevin, can you send me a picture? I will text it to Pete and see what he says. I'm going to guess that the pin holes are because of the crater that can be left when tig welding aluminum. If you just snap out of an aluminum weld it will leave a divot at the end of the weld. That divot usually cracks. You have to ramp down the amperage and kinda do a little swirly thing with your tig torch to prevent it.