Finding single-sided edges preventing a Solidify
Anyone have any tips for finding the single sided edges of a merged surface which are preventing a Solidify? I have the upper and lower surfaces of a water jacket which ideally are supposed to merge and solidify so I can use it as a cut from the stock cylinder head. The surfaces merge but Solidify isn't available when you select the merged surface. It looks like there are multiple tiny single-sided edges but I can't find a way of identifying them all.

