I thought sugru was okay, but it had a short shelf-life and was pricey. It’s especially good for remotes or other things you fondle with your hands, it has a good tactile feel to it when cured.
I probably wouldn’t use it to waterproof an enclosure, but I don’t think it’s a terrible choice.
Honestly after using butyl tape it’s hard to consider something else, unless the enclosure wasn’t a tight fit and I didn’t have a spacer, then I think butyl tape would not be good.
Thanks. I will try butyl tape next then.
Use up your sugru before it expires. 
The expiration date on the package is not a joke.
This is coming from the guy who disregards most expiration dates and will eat almost any food regardless of the date on the packaging.
I’ve been using butyl tape for over a year on a commuter board and it’s very good. It never hardens, so it flexes with the board and enclosure. The extra ooozes out a bit after installing, just scrape it away no problem. When I do need to pull the enclosure, it has a good suction to prove it’s still working 
Best of all, they have lots at the local hardware store sold as “window sealant”
My limited experience with it is really good so far as well. I wish I’d read a water resisting thread authored by @iamasalmon a year ago 
To be honest, I didn’t know how well it would work. I use it all the time to seal deck plates on boats, tho
Next thing you’re going to tell me is boat builders know a thing or two about waterproofing, eh?
You can remove the enclosure without destroying the butyl tape seal, or do you have to first take it away and seal the enclosure to the deck again? Although I haven’t tried yet, I would guess that with sugru you will have to do it all over again …
Actually more lax than you think about water intrusion. Boats let the water in then pump it out.
Wait… bilge pumps on skates? Could be the next big thing 
It’s like silly putty (probably is silly putty).
You’ll may deform the seal taking it off, but you can just squish/pinch it back into place or lay more down and cut the extra off. It’s super cheap, you get like 10 boards worth for $10.
Full confession:
I had it around the house and was too impatient to wait for the foam gasket to come in the mail.
edit: I swear I have posted about butyl tape before. Can’t find it now, maybe on the old forum.
Yes, if it’s a thick and strong fiberglass enclosure. I have to pry HARD to get the enclosure off. If it was ABS or even thinner fiberglass you’d probably destroy the enclosure trying to get it loose.
But as @iamasalmon said, you can mostly reuse it again, just squish it back into place, and I have added a little bit more new as well. It’s a lot like chewing gum or Silly Putty that never hardens but isn’t completely soft either, and is very sticky and malleable.
Magic stuff 
- will try!