Transformer air gap mating

[electrocircuit]

Hello all,
I am working on some power electronics using a split core transformer. I am having issues with contamination of the air gap faces, and poor mating. I was wondering if anyone had experience with this and what the best cleaning solutions are? Are there any good thermal pastes or something similar that can be used to maintain a good connection when the split core is closed?

Thanks,
electrocircuit

[mtwieg]

I'm guessing you meant the core should have no gap, and contamination is creating a small gap? Or is this for clamp-on ferrite beads?

Anything you try and add to "fill" the gap will only make things worse. Even a thin layer of superglue can cause a large increase in core reluctance. You need to keep the cores clean, handle them carefully, and assemble them with proper clamping force.

[electrocircuit]

I am using a split-core current transformer. The two gaps where the halves meet keep getting contaminated and corroded with time as I open and close the CT. I am looking for advice on the best way to clean these (ie acetone?) and if there is any kind of high-permeability grease or paste that is used for a good bond?

[mtwieg]

I see, it's for a split-core current transformer. Is the core ferrite or iron/steel?

Cleaning the surfaces of the cores every now and then is a good idea, I would just use 70% IPA. But this will not remove or prevent corrosion.

I've used high-end current probes where the magnetics had some sort of passivation on their surface to prevent corrosion. But I'm not sure what process/material was used.

Are you sure the contamination/corrosion is actually affecting performance? If the device is meant to be opened and closed frequently, then it should be designed to be tolerant of a small air gap.