It's easy with a few tricks... Lay your weedgaurd on the mold where you want it on one half of the mold. With a ruler draw a slot with a sharpie. Then carve away with the dremel. Lay a piece of SS spinnerbait wire/similar in the slot and slam the mold closed. This transfers the exact location on the opposite side.... Carve away at that side... Then real close to the head in the mold, drill a hole in the slot on both sides and fill with http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_makers/auto_Permatex_Ultra_Copper_Maximum_Temperature_RTV_Silicone_Gasket_Maker.htm over full on both halves... After it dries, Cut off extra with a razor blade. Now you can pour your bait and get no flash and works like a charm... Been modifying molds for 20+ years and have found some tricks that really work good.