I overtightened a new psi gauge at the top of my sand filter and now have a hairline crack. I was able to seal it for a couple weeks with some marine silicone I had at the house, but now the leak has found its way through the silicone. What should I use to seal this tiny crack in the plastic? I have some JB weld at the house, wondering if that'll bond to the plastic? Is there another epoxy, or sealant you guys would suggest to form a permanant bond with the plastic of the crack?