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Posted By Topic: Epoxy joining 16mm cable - underground

Jun 27 2019 13:02

Question around this topic. Been a while since I did one of these.

Is it better to crimp and not shrink sleeve the joins prior to using the epoxy kit or shrink sleeve the individual crimps/joints then epoxy the join.

Or is there a better system now-a-days with joining cables for underground use. Not in conduit, cable is a 2C screened.


Jun 27 2019 16:47

You would heat shrink each conductor before using the epoxy kit.

Make sure that the epoxy kit has good coverage to the outer insulation, and the surface is clean.

As the resulting joint will no longer be "screened", you probably should have additional mechanical protection above the join.

Jun 27 2019 22:22

sikaman, what do the manufacturer's instructions say?

Jun 27 2019 22:24

Usually says something like stagger and tape or stagger and heatshrink.

Jun 28 2019 22:13

I dont have the instructions. I have used Epirez 324A in the past but I was wondering if other types of resin can be used either epoxy or polyester.

Jun 28 2019 22:28

The whole point of epoxy joints is to never need to dig them up again. I think a few $$$ on a proven system is a worthwhile investment. Customers agree.

Jun 29 2019 15:37

I used an epoxy Kit about 25yrs ago on my rental property. Staggered joints, crimp links, sleeving and epoxy kit. Still going strong

Jun 29 2019 16:24

just use heavy wall heat shrink,way quicker and easier and quite possibly cheaper than an epoxy joint

Jun 29 2019 21:19

I like to wrap an epoxy joint in self-amalgam tape, a few cm up the cable each side. This would waterproof the joint if earth movement loosened the PVC-epoxy bond.
I never had one fail.

Jun 30 2019 20:13

This I can actually help on as I regularly do submersible cable joints. What method
You use depends on the time frame and where you are doing the joint.
If I have time and am in the yard I'm doing an epoxy joint. I will use Plasticast 2 part with heavy duty conduit as a sheath. Go about 50 mm past the stripped part of the joint on each side. Eg 150mm exposed cores 250mm sheath. Crimp joints, heavy duty shrink with 20mm overlap Self amalgamateing tape over the raychem, make sure to keep tension on the tape and overlap each wrap by about 1/2. Then fill sheath with resin and leave for at least 24 hours self amalg then vinal tape each end.

If in the field I will do a raychem joint on each core with a self amalg cover then raychem the lot with self amalg at each end.

For it needs to be fixed right now or tricky joints like singles into a multi I tend to just do everything in self amalg With vinyl, as warm raychem glue can form gaps if moved too much.

Notable tricks are use some fine grit sandpaper to rough the cables and rub around the cable not along the length (have seen water get into a joint that way.)

Self amalg has has been wound on too tight and exposed to direct sunlight can part.

ALLWAYS use the vinal tape to protect the self amalg. People will tell you it's not needed but it saves joints.

Jul 01 2019 08:24

Hey man,

Everyone will have a different way they like to do it, one I've found is good, which sounds pretty half cast lol is stagger the cores and heat shrink them, wrap the whole joint in thread tape, overlapping a few times and then use the heavy heat shrink with the glue.

Haven't had one fail yet and we do joints in damp situations quite often.

Jul 01 2019 08:29

I still put it in conduit though if it's in the ground