Underwater wire repair

[Akronviper]

Any Ideas on how to fix a wire that is normally submerged. My urchin ate the sheathing off of my two korilas right above the power head. On one of them the wire is exposed. Any way to do a water proof repair. Also do you think the water got into the sealed motor by way of the wire?

[kenl1960]

Rest assured that saltwater has wicked into the wire.
It will corrode and may leach copper into your tank.

I strongly recomend you you remove it and buy a new one.

Ken

[kgross]

I would agree with Ken, remove it for safety. You could repair it, but the dangers of a small leak are just not worth it. You could use some silicone and heat shrink tubing to try and seal it up, but is it worth the risk, it doesn't take much copper to start loosing inverts.

Kim

[BeanAnimal]

I don't disagree often with Kim...

However, a proper heatshrink patch will work just fine. I have spent many an hour waist or neck deep in a mud hole or sump pit with high voltage pumps (480/575) with power leads spliced with heatshrink and butt connectors... Such splices are approved and common in the mining industry. 3M and several other companies make the splice kits, but your local electrical supply will have them as well.

That said, if you have any doubt, then by all means replace the pump. Copper leaching into the tank is certainly not a good thing.

You are using GFCIs right?

[titoreefs]

heatshrink tubig will do the trick.

[sabbath]

Regular heat shrink will not be 100% sealed.

You are going to have to use a underground splice kit. From HD or Lowes... It will have a glue in it that seals the ends when heated.

[GIJOE007]

I agree with bean and others...I've done many repairs also using heat shrink tubing and it seals 100%. I would personally save the $$$ and repair it, you wont have issues after that. Do you have a grounding probe on your system? might be a good investment just for reasons like this rather then sending your fish to the electric chair

[Akronviper]

Yea I will have to get a grounding probe also. I'm still torn on what to do. Only problem is I dont think heat shrink will work since its just a nick with a little copper showing 1/8" so unless I cut the wire I cant get the heat shrink on.

[SeaWeed89]

a nice glob of silicone will be fine just try not the move it by the wire and not to move it around to much.
goodluck

[GIJOE007]

all you have to do is cut the heat shrink so it opens up, wrap it around the wire, then shrink it...you could even double it up if your that worried, or silicone on top of the heat shrink, but I think you'll be fine.

[Frank AZ]

I would cover the area in silicone and then use an underground piece of heatsink myself.

[hebygb]

shrink wrapping will work, depending on your level of skill... Koralias are not that expensive, so while you may be able to fix it for $2, peace of mind of a new pump isnt a bad thing.

How are you going to prevent it from happening again?

[Akronviper]

I'm getting rid of the urchin, so this shouldn't happen again. If it was an old power head I would trash it but this one is 3 days old so it just makes me mad to toss. Hey who knew urchins would do that, esspecialy since I had him for year with no problem. Ill take a look at lowes and see. I thought about the silicone and tubing but thought there may be a resin or polymer repair kit for water resistant cords.

[BeanAnimal]

Though you can use silicone and regular heatshrink tubing with likely success, you can get the proper underwater splice kits from your local electric supply. The heatshrink has a heat activated waterproof glue inside of it.

The kits (little bag with a 3 short lengths of heatshrink and 3 butt connectors) should only be a few bucks each.

Some types of PVC shrink tubing are not really water tight, water can leak tough the plastic structure... so play it safe and use the proper supplies.

[ReefEnabler]

what about using liquid electrical tape around the heatshrink tubing?

is that stuff safe underwater?

[Rhodophyta]

<a href=showthread.php?s=&postid=12835407#post12835407 target=_blank>Originally posted</a> by RyanBrucks
what about using liquid electrical tape around the heatshrink tubing?

is that stuff safe underwater? I think they all claim to be... Look for some statement like this one: "Forms a protective, waterproof, UV-resistant dielectric coating
Provides a totally sealed joint that's flexible..." I would use just the LET and not combine the two, especially with what you may pay for LET.

[BeanAnimal]

I am not a big fan of the stuff... though I have heard good things about the 3m product. Some folks swear buy it :)

[ruarox]

i think that silicone on copper has some sort of ill effect

[SeaWeed89]

is this the 12volt model, if there is such a thing?

[Rhodophyta]

<a href=showthread.php?s=&postid=12836878#post12836878 target=_blank>Originally posted</a> by BeanAnimal
I am not a big fan of the stuff... though I have heard good things about the 3m product. Some folks swear buy it :) I like the old style splices that you filled with epoxy resin over the fittings then like a clamshell, bolted the body shut. Haven't seen those lately. The new ones are shrink wrap.

[Akronviper]

The epoxy splice kits are as much as a new power head and I cant find any for gauges larger than 10awg. I've also seen the underground shrink tube around with the silicone gell inside if them but the exposed wires are around the base of the power head so hard to get to. The nicked power head I put a thin layer of silicone over the bites then used liquid tape. I bought a new 3 I figured it wasnt worth my life for $50 bucks. I will try to repair it an use it for a QT tank or water mixing (limited use).

Seaweed- The new ones are DC now to go with the controller. The older ones are 120 volt, 9 watts.

[BeanAnimal]

<a href=showthread.php?s=&postid=12843820#post12843820 target=_blank>Originally posted</a> by Rhodophyta
I like the old style splices that you filled with epoxy resin over the fittings then like a clamshell, bolted the body shut. Haven't seen those lately. The new ones are shrink wrap.

In the mining industry we use (used?) tape splices... You prep the cable, splice the conductors (wester union style, or butt connector) then slather on adhesive and friction tape (now actually rubber tape instead of cloth) and then slather on more adhesive and more tape. Bundle the spliced wires together and then wrap with brass or steel mesh (to complete the shield/ground fault connection) and more adhesive and rubber but this time wrapping the tape over the cable sheath as well.

You end up with a water tight connection.

The traditional epoxy splices are just too large and too cumbersome (as well is inflexible) for trailing cables (mobile equipment power cables) and the like. The epoxy splices are around, and certainly becoming more common. I am not sure if MSHA still even aproves the rubber tape splice kits... I would imagine they still do.

3M Scothcast is more common than the "bolt together" epoxy splices. http://rock.thomasnet.com/ImgMedium/3MScothcastFlex.jpg

There are also many other 3m splices the "cold shrink QSIII" is getting to be rather common.

3M also makes a pretty cool flexible splice called the 82-F1, though they are expensive http://www.rshughes.com/images/products/images/2TUmXiiNV2ANvta4z58KHQ_img.jpeg

3M also makes waterproof "motor lead splices" or "connectors" that are heatshrink and have use a small crimp connector to grab the short leads off of a sealed motor. They are also kind of spendy (maybe $30) for a kit.

Sorry, I don't have the part numbers for the older (very common) 3M Scotch flexible rubber splice kits. I have a box full of them burried out in the shed, but am not about to dig them out :)

What does this have to do with the OP's question? Nothing of coruse! Just passing information along to anybody who is interested or may have the need to splice larger cables or has a general interest.

[JesseGnooby]

I am hoping I can get a straight answer from someone with experience, with heat shrink tubing . I have a mag drive pump that the outer insulation of the power cord is cracked on, but the inside insulation is not damaged yet. Just wondering if I can use heat shrink tubing to stop from further cracking the outer insulation, and to prevent the inner insulation from wearing also.
the crack is right were the power cord exits the pump housing so it will be submerged. just want to make sure heat shrink is reef safe before going ahead with this repair.
thanks for any reply's
Jesse

[BeanAnimal]

Heat shrink with adhesive lining (like the 3m products mentioned above) may work. The problem is that the cracking is going to continue over the rest of the cord based on the fact that it started cracking in the first place :)

[JesseGnooby]

What about heat shrink from home depot? Can it be confirmed reef safe? Wonld leach anything that will crash my tank?

[BeanAnimal]

Jesse,

I am not sure what products HD carries. The tubing MUST be rated for underwater use with adhesive inside. I would not be concerned about "reef safe" as they produt is a plastic with a common adhesive. Even if they have the product, you are dealing with insulation that has aged and is starting to crack. Your safest option is to replace the pump or at the very least, the entire cordset (not likely possible).