I personally think the need for tinned DC wiring is over rated. Its absolute need should be driven more by location, how dry the boat is and budget
rather than being the unbreakable rule
many proclaim on forums
Inside a dry boat, as many modern boats are, it is not necessary at all in my opinion and for wiring inside main/distribution panels
should not be required in any boat (because if wet/damp in there one has a bigger problem than whether the wiring is tinned or not). Notably most equipment
one buys, including things such as float switches and bilge
pumps do not come with tinned cable. Tinned is obviously preferable for runs inside the mast
and outside where it is likely to be exposed to water but an expensive waste of money
for large interior
cabling such as from batteries and alternators.
One commonly sees the claim that coaxial cable for radios should be tinned. In my opinion that is not needed at all, the reason being that if the shield is wet enough to need the tinning to prevent corrosion
then the cable is already lossy for RF and should be replaced - perhaps any corrosion
from lack of tinning is a valuable indicator of such wetness. The tinning serves no purpose other than to instill a false sense of confidence.
What has not been stated in this thread is that all runs of DC cabling should be sheathed ie the two conductors insulated and that all contained in another insulating and protective sheath (along similar lines to the TPS AC cable that Alan mentioned). For safety
reasons this is far more important than tinning but the requirement is rarely mentioned. It is not possible though to get sheathed large cables
such as used for charging
and main conductors from batteries and probably not desirable for free airflow and the good concept
of giving some seperation to the +ve and -ve cables
in order to reduce the possibility of arc
accidents in the future due to insulation fretting.
In our own boat which was specified by me all DC cabling is, however, tinned (its cost and availability was not an issue) except for that in the DC panel and large x-section area cables such as for the high output alternator
, the batteries, invertor, windlass
, etc. All AC cabling is untinned. After 11 years there is no discoloration on any of it, but the boat is a dry one. For the high quality commercial
builds for others I have managed I have expected similar from the builder
I trust that has been useful to some.