Repairing silicone wire insulation

[danielrlee]

Does anybody have any tips on how to repair silicone wire insulation where there isn't any room to heatshrink or tape?

As in the below example where the wire insulation is starting to split, I would like to prevent any further damage. I usually use clear nail varnish to add insulation where no movement occurs, but wouldn't have thought it would do much good here. Might give it a go if nobody has any better ideas, but thought I'd ask first.

Thanks

 

[dogman dan]

Good place to try one of the tougher than silicone caulks, such as rain gutter caulk. It would make sense to use silicone, but I find real silicone caulk kind of wimpy compared to other products out there. If you do turn to silicone, go with something like form a gasket engine silicone. Not household caulk.

But looking at that situation, I'd be tempted to try to cut away another tiny bit of the box corner, and get heat shrink on it. It looks to me like the real problem is chafing, so I'd cut back what it's chafing on.

 

[danielrlee]

Good place to try one of the tougher than silicone caulks, such as rain gutter caulk. It would make sense to use silicone, but I find real silicone caulk kind of wimpy compared to other products out there. If you do turn to silicone, go with something like form a gasket engine silicone. Not household caulk.

But looking at that situation, I'd be tempted to try to cut away another tiny bit of the box corner, and get heat shrink on it. It looks to me like the real problem is chafing, so I'd cut back what it's chafing on.

Thanks Dogman, some good suggestions there.

The damage to the wire has been caused by both the green heatshrink and the white plastic lining used at the manufacturing stage. I have already cut this back to help avoid more damage in the future. Hopefully I have removed enough. I don't think that my own lipo armour has caused this as I made sure it didn't rub when first fitted.

I do already have some silicone sealant that I will probably try, but as you say, might be a bit wimpy. I'll have a look in the hardware store for an alternative when I get an opportunity.

EDIT: What I missed out, is that these are new lipo packs (six of them) that have seen no action yet. This damage has occurred either in storage in the warehouse, during transit, or while fitting the packs and optimising wire runs by myself.

 

[Gregory]

If you want to go the silicone route, maybe try Liquid Electrical Tape/Plastic Dip.
I've never used it, but it looks good.
Personally I'd use heatshrink.

 

[nutnspecial]

The liquid tape/ plastidip could be good, but I've also never used.
I have used tripolymers and plenty of latex and 100% silicone though. Silicone is great for very specific applications, and could work here to shield wire from further abrasion/ degradation; but it will likely act more as grommet that stays due to it's mechanical shape, not from a great bond to the silicone wire and plastic. Maybe that could be beneficial, I don't know. It doesn't bond to like materials or itself.

Hence: tripolymer: http://www.ebay.com/itm/Geocel-26117-Pro-Flex-Tripolymer-Sealant-Terra-10-Oz-/391269641675?hash=item5b197cedcb:g:SS0AAOSwFnFWATOd For a really great bond and seal. Stays flexible, can bond to itself, and bonds to other rubbers/ polymers. Similar makeup across the geocel line.

Lap sealant is also another interesting product I've recently been using. It's used mainly on rv roofs over the tripolymer I think, and let me tell you it's nightmarishly messy to caulk with. Good for rubber, metal, fiberglass, paint, plastic, in high wear situ's.The self leveling stuff is pretty cool, but only holds up for a few years, and removal is a pita. http://www.ebay.com/sch/i.html?_odkw=lap+sealant&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xlap+sealant+no+sag.TRS1&_nkw=lap+sealant+no+sag&_sacat=0

Also, I did use black urethane roof caulk for the wires exiting top side of my controller. I chased them thru an innertube section and bonded the innertube to controller metal and existing rubber wire grommet. Worked great for that, but I'm thinking geocel might be the best for your application though.

 

[fechter]

I'd suggest getting some heat shrink in there. This may require re-terminating the end of the wire to get the shrink over the wire.
One problem with silicone is nothing really sticks well to it. Sort of like Teflon. If you can get some heat shrink over it, you can glue to the heat shrink afterward. I suppose if you can get some silicone glue all the way around the wire, it will act like a sleeve even if it doesn't really stick to the wire.

 

[danielrlee]

Thanks for your suggestions everyone.

I quite like the look of the plasti dip, so may order some in for use in future. For now I've gone with the silicone sealant I already had.

I've removed all the causes of abrasion I could find, so shouldn't need any heavy abrasion resistance. I'm mainly concerned about possible electrical shorts, so hopefully the silicone will suffice. I'll run the packs for a while and re-evaluate the situation in a few weeks.