Best Material to Thicken CW Motormaster/Blackjack Posts?

If one were to try to fix the "loose Blackjack" problem on Combiner Wars Motormaster by thickening the connection posts on Menasor's chest, what would be the best material to do this with?
I've heard the idea thrown around the internet of using nail polish. I don't know anything about nail polish except that it stinks. Will it quickly wear down/rub off/come off inside Blackjack's ports when I detatch him? Will it deteriorate with age or heat?
I also thought about superglue or epoxy.
I'm leaning epoxy, because near as I can tell, the stuff IS plastic when it dries. But I've only ever used either epoxy or superglue to stick two things together. If I just use it as a coating instead, then after it dries, will it still be "sticky"? I don't want it coming off with Blackjack when I detatch him from Menasor...
Also, are there any better materials I don't know about?
I've heard the idea thrown around the internet of using nail polish. I don't know anything about nail polish except that it stinks. Will it quickly wear down/rub off/come off inside Blackjack's ports when I detatch him? Will it deteriorate with age or heat?
I also thought about superglue or epoxy.
I'm leaning epoxy, because near as I can tell, the stuff IS plastic when it dries. But I've only ever used either epoxy or superglue to stick two things together. If I just use it as a coating instead, then after it dries, will it still be "sticky"? I don't want it coming off with Blackjack when I detatch him from Menasor...
Also, are there any better materials I don't know about?