Easiest and probably best solution is to order the correct tool for the job.

Heavy Duty Crimping Tool for Battery Lugs & Terminals 6 AWG - 250 MCM Genuinedealz.com

 

Sure. A huge $240 tool for four crimps.

What's "right" for tradesmen using it every day, is often not economically feasible, no particularly desirable, for occasional use.

Not the first time someone here has said that, is it?

 

If a bit of grinding will do it, why not? How about a Swage-it tool? I've done large electrical crimps with one of those. The #8 hardened bolts on those can exert lots of pressure, more than the metal can take before it extrudes and probably as much as any $250 crimper.

 

I've got one of the swageits, or something similar...IIRC this one is actually a tool for flared plumbing fittings (G) so grinding them down to AWG sizes would be a bit more work. Anyway, that's in the plumbing box, not a boat box.

 

I think the largest swage hole on those tools is .25, pretty close to a #2 AWG wire. Might be just right?

 

Dunno. Also remember that you need to allow for the thickness of a "standard" lug itself, not just the wire. And every maker seems to just say "Use our lugs with our tool" rather than discuss whether there are any standards.

So you take a dull chisel and a maul...(G)

 

I've never been able to justify buying one of those expensive crimpers just to do an occasional cable end either. Sometimes you just have to make something functional and forego "perfect."

 

"Sometimes you just have to make something functional and forego "perfect." "

Only if you're a pragmatic Yankee. (WEG)

 

I've used the nicopress swage tool on electric cables and it works pretty well, but not a "perfect" crimp. The bench mounted one at your local West Marine is quick and easy, especially of you bought the wire or lugs there. They might get a little upset of you brought your own parts in to do it.

 

I can hear the gasps already... I just solder them.

Use proper lead based solder (not the crap at big box stores) and I have never had an issue!

 

Soldering with a lead based solder would be terrific long term but if you have a slightly oversized crimper a slice of shim cut from a beer or pop can wrapped around the outside of the terminal should result in a good crimp from a slightly oversized die.

 

Shoving a copper brad, or a piece of extra wire, into the wire bundle before crimping it would do just as well, with less cutting & fiddling needed. And either more math ( to add specific mm2) or less precise crimping.(G)

Elevator motor cables are soldered onto their lugs, and those are way bigger than anything we play with. Apparently "elevator solder" must be the magic difference.(G)

 

I usually solder them anyway. To me it's a kind of "tinning" if nothing else. I wouldn't trust solder of any type (silver/tin, etc.) for any strength as it would quickly melt if the cable heated up. The toughest thing is sealing the cable ends to keep moisture out over time. There doesn't seem to be any kind of wire insulation that effectively protects the wire for years either. The rubber coating on marine wire and TW type wire all seems to let enough moisture through to corrode internally over long periods of time. THHN in some kind of conduit where possible is probably the most moisture resistant but THHN is not as flexible'fine-stranded as marine rated wire. For the big cables that run through bilges and around corners, flexibility is more important. Too bad they have that lousy rubber insulation that lets molecular moisture in.

 

Bear in mind that even with the best sealing, moist air already has been in there since it was manufactured. And wire strands, rough edges, etc. can put pinholes in the insulation. So...there's tinned wire.

Some types of rubber/vinyl sealant also are just not going to stick to some kinds of very good insulation, like Teflon. Or PVC that's bleeding plasticizers. But good crimps, good sealant, good wire, and the Creeping Crud doesn't seem to get in unless you really encourage it.

I'd like to "do it right" but I think sometimes we overthink and obsess about just how precise a "good enough" electrical connection has to be. Somehow, I don't think Mr. Edison or Mr. Tesla lost much sleep over that.

 

"good enough" is a connection with very low resistance, that maintains very low resistance during my ownership of the system.

 

Check Nigal Calders book on Electrical & Mechanical Bot Maintenance. Think he had a conversion chart I used when I crimped the AWG 2 cables when I converted to Electric Propulsion. That was eight years ago and have not had any problems with the crimps.

 

AWG and mm2 cable sizes just don't match up. The existence of conversion charts just "proves" a certain amount of mismatch in crimping diameters and tensions is perfectly normal and acceptable, at least to some.

I like it best when a manufacturer hints that crimps will only work if you use THEIR tool and THEIR crimp, because no one else knows the correct gauge of metal to make the crimp with, or how to form and plate it. (Ahuh, sure.)

 

Bought a hydraulic wire crimper from Harbor Freight. There was slight size issue with one of the dies but not enough to worry about. Don't have it near me but seem to remember it went down or up to '0' gauge wire. Used it in rewiring my boat and it has worked through the refit and is still working fine.

Not fond of HF power tools, have burned up a number of them in short order but the Wire Crimper/Swager seems to fit the needs of the one boat rebuilder: Hydraulic Wire Crimping Tool

 

My HF hydraulic crimper left "ears" on crimps. I started rotating it 1/6th of a turn once an earlet started to form and then crimping again. It took four or five rotations to get a clean crimp.

The crimps ended up looking pretty good, but their "00" kit only really goes down to 2AWG.