This is an excerpt from the ABYC Standards for Marine Cabling:

"Solder shall not be the sole means of mechanical connection in any
circuit."11.16.3.7.
You need to catch up on your reading....
and #10 / 20a ?

2 Conductors 105° C (221° F) 3 Conductors 105° C (221° F)
4 to 6 Conductors 105° C (221° F) 7 to 24 Conductors 105° C
(221° F)
Conductor Outside Inside Outside Inside Outside Inside Outside
Inside
Size Engine Engine Engine Engine
(AWG) Space Space Space Space

18
20 17.0 14.0 11.9 12.0 10.2 10.0 8.5
16
25 21.3 17.5 14.9 15.0 12.8 12.5 10.6
14
35 29.8 24.5 20.8 21.0 17.9 17.5 14.9
12
45 38/3 31/5 26.8 27.0 23.0 22.5 19.1
10
60 51.0 42.0 35.7 36.0 30.6 30.0 25.5
8
80 68.0 56.0 47.6 48.0 40.8 40.0 34.0
6
120 102.0 84.0 71.4 72 61.2 60.0