I have just carried out some panel repairs on an mgb that im restoring (slowly) but im wondering what to do with the panels that i have plug welded before i apply any paint, should i seal the flangers against water ingress and if so with what, i have seen brush on seam sealer and the stuff in the tube that you apply with a mastic gun but never having used any i could do with some advice, many thanks in advance, Vin