.
I do have thin pieces of the same plastic covering where the corners overlap but that's just due to an earlier version with entire sides of the same plastic, and I didn't want to cut new sides so I just epoxied strips of plastic in the overlap areas so there would be no gaps, but it's a reasonably tight fit. Then I siliconed the remaining part of the sides and the full face of the end pieces.
This mold does not leak with normal soap batter, but during an experiment with transparent soap making--which is as thin as water--the transparent soap started leaking right out, lost at least one-third in the sink. Not a good mold for transparent soap. BTW the transparent batch was in a crock pot and right in the middle of gel the power failed--for six hours!!! I blame the power failure for the transparent soap failure. I'll try again.
So your hinge mold won't leak if it fits reasonably well and you don't pour at zero trace. I've never had ordinary CP soap leak out of it.
The silicone works great, seems to get less sticky each time I use it. Might even get to not needing mineral oil. Only problem I have is that I used the mold several times before applying silicone and a couple places may have had soap preventing the silicone from sticking right. But heck, I've got tons of silicone left over.
By the way,
ALL of my molds disassemble (except the pipes). It's a good way to go.
