Amen! We've needed this for years!!
P.S. Did you get my PM..?
Yes I did, but it must have been lost.
In case it does not go through...
"Thanks for the compliment! I learn from your posts too.
Yes, the tests included adhesive lined heat shrinks on MTW and SAE wire; in all cases the wire under the seals and near that end of the wire was in exactly the same condition as new.
No, I saw no certain evidence, after stripping the wires, that water or air traveled through the insulation on tinned, SAE, or MTW (THNN) wire. All of the damage (black wire) seemed to be caused by wicking from the end and was limited to a few inches. SAE wire suffered the most, as it had the finest strands (better to wick) and was not tinned. It was also darker that the THNN wire, though I am not clear why that would be.
Would air and water go through the insulation on lamp cord, for example? On old boats I have seen wire that clearly suggests this is true, but I did not test that this time.
I'm not a believer in heat-sealing every connection, though I certainly do in all exterior and damp locations. I should add that I have a dusty bilge and no water leak source (packings or through-hulls) in the main compartment; if I had a wet bilge I would heat seal a lot more!
I am a believer in ratchet crimpers; properly done I have NEVER had a failure either in a boat or industrial setting, and that is a LOT of connections, many in wet or vibration-prone areas. I cannot believe that a non-ratchet crimper could deliver that level of quality control. To assure I have it adjusted properly, I commonly (everytime I'm looking at a new or different brand of crimps or wire) crimp a ring fitting on a length of wire, clamp it in a vise, and pull it apart; if nothing is damaged, I re-adjust."