Unstick left fuel tank

In the rush to rivet the left fuel tank rear channel before the sealant began to set, I forgot to cover the main spar flanges with loose plastic. The sealant squeezing out from the rear channel made contact with the front flanges of the main spar seriously locking the tank in place.

I was able to cut though some of this sealant with an extended exacto blade, but much of this adhesion was between the front facing edges of the main spar flanges and lumps attached to the rear channel flange.

After some thought I made a specialised right angle knife from stainless steel sheet, attached to a large wood handle which would provide close control and sufficient lateral force. This blade was slipped into the gap and dragged along, successfully cutting though the sealant top and bottom. No damage to the fuel tank nor main spar resulted and the fuel tank was able to be detached.