Nothing wrong with Copper lines used for steering , how ever here's few items concerning Copper and the feasibility of using Nylon Lines
1)Always use only
FULLY ANNEALED tubing and the following rules should be strictly adhered to:-
1) Use compressed air and blow out all tubing to remove dust and debris
from storage.
DO NOT CUT WITH A HACKSAW - USE ONLY A PIPE CUTTER.
2)
Avoid brazing or soldering joints as this introduces scale and burnt
flux into the tubes. Use commercial hydraulic joining fittings to avoid this. If you cannot, or will not, avoid soldering, then you MUST air-test each of the joints and flush the system using kerosene or similar to remove the solder, flux and scale BEFORE CONNECTING it to the steering unit.
3) Where the tubing is to be bent, you should use a proper tube-bender to
avoid kinking the tubing, which could result in firm steering.
4) Do not use Copper tubing on Aluminium boats unless it can be installed with isolation washers/ Nylon saddles/clamps
5) COPPER tubing can be substituted with either
steel or stainless steelhydraulic tubing. IT SHOULD NEVER BE SUBSTITUTED WITH HIGH PRESSURE FLEXIBLE HYDRAULIC HOSE.(except for flexible end connections).
6)
DO NOT USE Teflon Tape as it can be introduced into the system by
inexperienced installers. THIS MAY CAUSE VALVE FAILURE.
USING NYLON TUBING:
1)1) USE ONLY THE SEMI-RIGID NYLON with a MINIMUM burst pressure of 2500 PSI. DO NOT SUBSTITUTE for any other material, even if the rated burst-pressure is higher.
2) USE ONLY BLACK NYLON as the black material is U.V. stabilized. White, opaque or other colors may/ will harden in the sun.
3) It is most important that cones be fitted exactly square to the hose fitting to ensure proper sealing. Cut the tubing with a sharp knife SQUARELY and UNDER NO CIRCUMSTANCES use a hacksaw.
Cheers Steve