Suggestions for repairing ABS/Plastic stress cracks

[Solstice]

my Victron shunt has developed stress cracks around the area where it screws down. Not sure if the material is nylon, ABS or plastic, but I’m looking for suggestions on repair.
I’ve never had luck with ‘Super Glue’ type products for cracks.
I know the cracks have developed due to the weight of my big 2/0 cables and difficulty with strain relief due to the height of the shunt, but I plan on trying to alleviate this.
I’m tempted to simply keep the ears together with Rescue tape!
Any suggestions would be appreciated....thanks

 

[jssailem]

I hear what you say but without a picture it is difficult to put the issue in context.
An image of the part would help. I know what mine looks like and what the manufacturer sent to me.

 

[Solstice]

Thanks. I will take photos today and post...

 

[Solstice]

This is a photo of the shunt. The area around the screw is showing stress cracks emanating from the screw hole...I’m also thinking of creating a sleeve to reinforce the entire shunt??

 

[jssailem]

So your saying the circuit board is cracking at the screw holes holding the board to the main connectors?
Someone tighten the board down with too much force?
I have not seen anything like this on my unit. I will check next time I’m at the boat.
Cracks in a circuit board will likely cause faults in the data. You should contact Victron and ask them about the issue.

 

[walt]

The shunt itself is nothing more than a very low value precision resistor. Likely a twisted pair of wires go to the monitor which just measures the voltage across the shunt resistor and determines current from this. Its a differential analog signal hence need for the twisted pair.

If the shunt itself is cracked.. it either probably no longer works or is not accurate and can not be repaired. You could verify its accuracy by turning on a single load, measure the current of that single load with an accurate DVM and compare to what the battery monitor is reading.

If its just a crack in the plastic mount.. a wild guess is that JB epoxy might work.

 

[Solstice]

Thanks. It’s not the circuit board but just the attachment point. I’ve verified that shunt works fine...

 

[jssailem]

Well that’s a horse of a different color.
Your sleeve idea, epoxy, pretty much anything that will give you a structurally sound base should work.

 

[CharlieSea]

The screw used is a problem since the oval head is wedge shaped where it penetrates the hole and the tightening force tends to crack the fitting. Use a truss head or a pan head and also a washer to spread the load. To reinforce it now you can try a piece of heat shrink tubing, the sticky shiny type, then re-drill and use a pan or truss head with as big a fender washer as possible, you can file one side if need be. If the pull is down you could also try using a strip or block of wood or plastic as a ledge for the shunt to sit on. It could have two fingers pointing up to hold the shunt. This could be a block shape as thick as the copper shunt fittings.It is not important for the shunt to be rigidly mounted.