Waterproof Pond Project

[PDubya]

Howdy!

Curious if anyone has ever used resin in any of their various projects, or waterproofed something to be emersed in water?

I've been asked to put together a small lighting setup using LED's for a pond. The thought was to create little lighting "pods" that would be, obviously, waterproof - and our first idea was to just encase them in little resin pucks. This doesn't have to be super-professional as it's for a few friends, so I've given thought to just using baby food jars and sealing them in some way - but the resin bricks would have the added advantage of sinking.

The actual wiring and what not would be external to the pond, so each puck would basically just have a handful of led's wired together with a single wire coming out of the puck and into a weathertight box.

Any past experiences, pitfalls, suggestions?

Thanks!

 

[DirtyLude]

I would suggest just using clear silicon, the kind you use as bathroom edging. You should be able to make a mold out of just about anything, like small bowls or something and create your 'pucks' with the LED's inside. Coat the mold with some type of release agent.

 

[The Mad Professor]

I've potted various devices over the years for use in adverse conditions, I believe silicone would work well for your application , another medium that may also be of use is "Polymorph" or "Friendly Plastic" if a more durable and hard wearing package is required.

"Cling Film" or "Sarin wrap" normallaly used for wrapping food is a quick and simple way of lining molds for use with epoxy or silicone.

 

[PDubya]

Will silicone be clear enough for lighting? I'm worried about it diffusing the light too much as most silicone I've seen ends up curing opaque.

 

[HarveyH42]

Leave the LED lens exposed, its epoxy and already waterproof. only the leads and wires need to be protected. For your mold, try modelling clay (the kind that doesn't dry out, $1.00/ lb(+/_ been a while, cheap though) at Walmart. If you want to make many of the same shape, make a plaster of paris dummy of your finished 'puck', so you can just press it into the clay, pull it out, set your circuit, and fill. The clay is reusable, and uneffected by most resins, silcones, epoxies...

 

[zevon8]

HarveyH42 has the right idea, don't worry about the LED's. You could just solder the wires to them, and get some "dual-wall" heat shrink. This is the stuff that has an adhesive lining that melts and seals on shrinking. I use it all the time on vehicles, connections subject to highway speed rain and winter salt spray look like new years later.

You can get the stuff at most automotive places like UAP, Pepboys, or any of the electronic part places also.

 

[DirtyLude]

Silicon is very common in clear see thru for bathroom molding. You will find it at any hardware store.

If yu just want to to the wire/leads attaching to the LED's, I would just use a simple hot glue and dab it around. I can't see the need for a mold in that case.

 

[BeeBop]

Hi,
I don't mean to be a 'thread-jacker,' but I'd like to know how one could distinguish the

"dual-wall" heat shrink

from the regular heat shrink.
My Korean language skills are not good enough to explain to sellers, and I'd really like to have some of this for sealing LM34s.
Regards,
Robert

 

[zevon8]

I guess you could tell them you want the kind that has the " glue " inside, or print out a web page with part numbers. Search some of the bigger manufacturers websites and see if they have a Korean version of their website, and print the page from there.

 

[BeeBop]

Ha ha,
I'm too much a shopper! I googled on "dual-wall" heat shrink, and the first site was action electronics. I think I had bookmarked that one for connectors. Well I just spent the last forty minutes there, and could have spent much longer.
Anyway, thanks for heading me in the right direction.
Regards,
Robert

Edit, Yes, I know enough to say glue inside; next time I go to the markets, I'm going to try.