Making rock-solid connections that will hold up to harsh marine environments and keep you electrical components and electronics operating reliably for decades all boils down simply having the right stuff. Here is a 2-part breakdown of the most common wiring connections you're likely to run into and what you'll need to make it easy to do the job RIGHT.
For the record... you're going to need a heat gun for just about every electrical job you do in a boat, so I'm not going to list it over and over in every section below.
I'll also mention that I have used the electric "hair dryer" looking heat guns as well as the small gas-flame ones. I preferer the electric heat guns because for me it's way easier to control the temperature and heat the tubing and insulators just the right amount without going too far. The gas torch versions were super convenient because I you aren't fighting with an extension chord or trying to find an outlet that isn't already taken, but even after playing with all the adjustments and shielding attachments it was just too easy to screw up. After the third or fourth time I melted my heat shrink or the wire insulation I switched back to the electric heat gun and never looked back.
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| Electric Heat Gun | Gas-Flame Heat Gun |
Ok, moving on to the specifics...
#1. Large Terminations Like Battery Cable Lugs and Trolling Motor Wiring (8 AWG to 1/0 AWG)
What you need if you want to make life easy:
- Crimpers -
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| Premium Crimpers #8 - 4/0 AWG | What I Suggest on Amazon for 1/4 of the Price |
Since these large wire connections are almost always associated with providing the proper amount of juice to your primary modes of propulsion (e.g. your outboard motor and trolling motor) it's incredibly important that these terminations are bulletproof. The key to that is using the right size and type of crimpers, and of course terminals/lugs as well.
I had a pair of the expensive premium crimpers above as well as the $40 hydraulic crimpers off of Amazon on the right. I'll just say that I have no idea where the expensive ones are now. The hydraulic units make light work of any large cable crimping job, and you can hang the boat from your battery lugs they're crimped so tight.
- Lugs and Terminals-
I'm not going to spend a lot of time talking about these. As long as the wire size rating of the crimp or lug matches the wire you're using then it's hard to screw it up. Also, be sure you double check the post diameter for the lugs. Most wet cell lead acid and AGM batteries have 5/16" posts, and most lithium batteries have M8 bolts, but there are certainly exceptions.
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| Terminal Lugs (8 AWG x 5/16" shown) | HD Butt Connectors (8 AWG shown) |
- Heavy Duty Wire and Cable Cutters -
I don't think I need to explain what these are for or why they're important to have when you're working with heavy gauge wiring. However, I will say that I totally use these for stripping the heavy gauge wire insulation too. Just LIGHTLY clamp the cutters where you want to strip the wire back to and slowly spin them around the cable a couple of times. After 1 or 2 passes around the cable remove the cutters and gently bend the tip of the cable back and forth. You'll see the cut you just made open up and if there is any insulation still hanging on. You can usually just nick the one or two remaining strips with a pocket knife and you're all set.
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| Heavy Duty Cable Cutters (22 - 2/0 AWG) |
- Adhesive Lined Heat Shrink-
Last but not least you're going to need a quality adhesive lined heat shrink tubing. These have a layer of glue inside that melts as the tubing shrinks and completely seals moisture out of your crimp. If you notice most of the lugs we carry are marine grade and have closed ends which in combination with the adhesive in the heat shrink completely prevents moisture from reaching the internal wire stranding. This is not a trivial difference either.
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| Marine Grade Adhesive Lined Heat Shrink Tubing |
*I'm going to add some step-by-step photos and examples of some large cable crimps here soon.
#2. Making Smaller Wire Connections for things like Sonar Units, Pumps, Etc.
Coming soon!