Tinned Wire

[thinwater]

Originally Posted by psneeld

yeah... in the perfect world...but I too have seen that dielectric grease covering the end is night and day even over a "proper" crimp..even the glue kind and shrink wrapped kind. One is easy to do the other has "more" things that may not turn out prefect.

The only difference for me is I dip or smear AFTER crimping or tightening.

I have uncovered bus bars in the shallow, wet bilge of my workboat that look new after 2 years.

True enough. Terminal grease isn't "pretty", West Marine doesn't sell it, but it WORKS. Sprays don't, not by comparison.

[Maine Sail]

Originally Posted by psneeld

yeah... in the perfect world...but I too have seen that dielectric grease covering the end is night and day even over a "proper" crimp..even the glue kind and shrink wrapped kind. One is easy to do the other has "more" things that may not turn out prefect.

The only difference for me is I dip or smear AFTER crimping or tightening.

I have uncovered bus bars in the shallow, wet bilge of my workboat that look new after 2 years.

I have no problem coating the open ring end after the crimp is made and I do this. I have personally & purposely submerged factory made heat shrink crimps by FTZ for well over a month and they remained bone dry. This does not mean however that corrosion of the tinned ring can't begin to creep its way under the adhesive lined heat shrink so a terminal grease applied after it is connected is a good measure.. Silicone applied before the adhesive heat shrink only serves to inhibit the sealing of the adhesive glue to the wires jacket and terminal.

[delmarrey]

And now that we're on silicone, ya'll should know that the standard marine silicones are corrosive. e.g. http://multimedia.3m.com/mws/mediawe...9lxtD7SSSSSS--


Liquid electric tape is best for sealing off ends and splices.

[psneeld]

Originally Posted by delmarrey

And now that we're on silicone, ya'll should know that the standard marine silicones are corrosive. e.g. http://multimedia.3m.com/mws/mediawe...9lxtD7SSSSSS--


Liquid electric tape is best for sealing off ends and splices.

regular old dielectric silicone doesnt seem to be corrosive and I can see through it to see if there IS corrosion forming.

I don't believe a thing I read about products...as a pro captain and boat maintainer...I've seen most of them in use and disassembled electrical systems protected all different ways. I've settled on the easiest, cheapest and longest lasting combo I've seen work....plain old crimps, dipped/smeared in dielectric silicone. I use junction blocks for nearly everything...including bilge pump/float switches mounted in the bilge. Years later they look new and when/if they look bad...I can tell long before the pump/switch fails due to a connector failure.

[GordMay]

Originally Posted by psneeld

regular old dielectric silicone doesnt seem to be corrosive and I can see through it to see if there IS corrosion forming.

I don't believe a thing I read about products ...

Dielectric grease is a non-conductive, silicone grease designed to seal out moisture and, therefore, prevent corrosion on electrical connectors. Being non-conductive, it does not enhance the flow of electrical current. This property makes it an ideal lubricant and sealant for the non-metalic rubber insulating portions of electrical connectors.

But, I don't suppose you'll believe what I've written.

[psneeld]

Originally Posted by GordMay

Dielectric grease is a non-conductive, silicone grease designed to seal out moisture and, therefore, prevent corrosion on electrical connectors. Being non-conductive, it does not enhance the flow of electrical current. This property makes it an ideal lubricant and sealant for the non-metalic rubber insulating portions of electrical connectors.

But, I don't suppose you'll believe what I've written.

never said it was...the crimp takes care of the resistance the grease takes care of the moisture...couldn't care less if it's conductive or not in the fashion I use it or explained how it can be used. The method works well, is cheap and simple so that anyone can do long lasting electrical connections without a masters degree...

[capbillh]

Delmarrey, you linked to 3M 4200 sealant material sheet. It contains 0% silicone! it is Not your typical marine silicone sealant product.

[Maine Sail]

Originally Posted by psneeld

regular old dielectric silicone doesnt seem to be corrosive and I can see through it to see if there IS corrosion forming.

Silicone dielectric grease is usually a non-acidic product unlike many of the standard tub & tile or "marine" silicone products which can be acidic.

[um saudade]

No crimp on any terminal (let alone an insulated terminal) will crush the wires to the point where there can be no ingress of a liquid!

I have a little experience in doing submersible well pumps and cables. All of these are butt spliced at the pump so we are talking at least 60 feet if not 150 feet below the water line. I have spliced up to 480volt connections with the following method and never had a failure, even in hot salty mineral water at 140F.

Un-insulated butts (always use solid barrels, no split barrels, hand crimped with the trusty old T&B’s on smaller wire, a coat of Scotchkote not quite allowed to dry and then wrapped with Super 33 Plus. This includes taping the crotch of drop cable with a sheath to prevent ingress of water under the sheath. About 4 complete passes over the bulk of the splice with 50% elongation and 50% overlap. If it needed additional mechanical protection, as in a rough well casing, then an outer rap or two of 130C.

I have pulled a severed 480 volt mine cable out of the drainage ditch when a mucker cut it with the bucket and put it back into service in a few minutes with the same technique and the same results; done properly a taped joint will not fail!

There are some cases when self-fusing tape is better but seldom needed for most applications. Either Super 33 Plus or Super 88 Plus will fuse to itself if it is properly stretched (technical term: 50% Elongation).

What delmarray showed in his post is not a substitute for Scotchkote! I don’t know of any sealant that has a UL stamp other than Sckotchkote. I have tried some of the other, including Starbright and find it to be almost worthless in sealing.

On marine connections I don’t use ANY insulated terminals, as I don’t think they crimp uniformly when you try to crimp the plastic. You don’t have any arc potential anyway with 12 or 24 volts. I crimp with the T&B’s, (a non-insulated type of crimp, mostly), use some anti-oxidant (kool-aid) if non-tinned wire. Encapsulate with Scotchkote and cover with regular heat shrink (in this case the heat shrink is simply a mechanical protection for the Scotchkote).

Tinned or not tinned: Use tinned wire in most cases, as it is just added protection and the make-up less exacting. In case of big runs of long cable (anchor winches come to mind) use MTW or even THHN. If the ends are subject to moisture or need be changed out often for some reason then butt splice a nice whip of tinned wire to the end of the run. Saves big bucks and lasts forever.

Use no sealant with acetic acid around copper!

Even if you can use the crimped connection for a dog leash or to pull the Queen Mary behind your sloop, don't! It is an electrical connection not a tow rope!

Dielectric grease or kool-aid? I prefer kool-aid but anything to prevent that does not corrode and prevents ingress of moisture. Keep it clean on the outside if you use Scotchkote over all. Strain reliefs, drip loops, all good ideas. A few good tools, the right parts and some common sense.

um saudade

[delmarrey]

Originally Posted by capbillh

Delmarrey, you linked to 3M 4200 sealant material sheet. It contains 0% silicone! it is Not your typical marine silicone sealant product.

Marine sealants are not silicone. Silicone is a synthetic material, once use, it's really hard to get a marine sealer to stick on the same spot.

Most marine sealants are fairly close to each other as far as ingredients. I use 3M 4200 more then anything so that's what I just happen to use as an example.

Most inexperienced boaters usually refer to marine sealant as silicone so I was just using laymans terms, and I assumed that's what Maine Sail was refer to in post 47. Sometimes it's hard to get what some are really saying. Grease - silicone- silicone grease?

I'll stay out of it now!

[capbillh]

DAP® Auto/Marine Sealant

Long-lasting 100% silicone rubber seals and bonds for automotive and marine maintenance and repair applications. Provides a waterproof and weatherproof seal. Stays flexible, won't crack or shrink. Resists vibration, expansion and contraction.



3M™ Marine Grade Silicone Sealant is a high quality silicone designed for the harsh marine environment. It forms a mildew-resistant, non-yellowing seal that remains flexible even after years of exposure.

Dielectric Silicone Compound Ancor Marine Dielectric Silicone Compound . A silicone "grease" that's great for waterproofing coax connections, butt splices, and other sliding .

[Maine Sail]

Originally Posted by capbillh

3M™ Marine Grade Silicone Sealant is a high quality silicone designed for the harsh marine environment. It forms a mildew-resistant, non-yellowing seal that remains flexible even after years of exposure.
.

From the 3M Marine Silicone Technical Data Sheet:

"-Do not use with electronic circuitry. Acetic acid liberated during cure may corrode electronic circuitry."

[Maine Sail]

Originally Posted by um saudade

No crimp on any terminal (let alone an insulated terminal) will crush the wires to the point where there can be no ingress of a liquid!

Considering I let a crimped one piece cast battery lug sit in a bucket of water for over 6 months before drilling open the closed end to find absolutely no water I find that statement of fact rather interesting to say the least...





Six months submerged and no water past the crimps.

[capbillh]

Maine Sail, I only quoted the first 2 sources to refute a statement that was made re. marine sealants not using silicon. Then the 3rd source for the use of silicon as a grease and as a dielectric with electrical connections.
I use silicon sealeants for hardware fittings and a dielectric grease for connections which could get wet. Also, I use a small tub of silicon grease for insertion of the knot-meter paddle wheel seasonally since the hoist straps come across the sender. Other boats have had damage of the unit.

I am sure you know the statements that I am referring to so that I do not have to line them up.

[hellosailor]

Gents, siliCON is not siliCONE. And the common silicone RTV (room temperature vulcanizing) sealants, are not the same as the greases. One has a chemistry that changes from goo to solid as it cures in the presence of air, and it emits chemicals as part of that curing process. The other is manufactured and delivered as an inert grease that doesn't emit much of anything. (Yes, it will emit some things and it will outgas but not in any meaningful way under our normal environmental conditions.)

Y'all got the apples and oranges all mixed up. Can't make omelettes out of either one, no matter how round they may be.