So I went in search of a core from a solar inverter (this was a Clenergy 5Kw jobbie) so
![In Search Of Large Ferrite like (ICH) U100/57/25-3C90 8304-0](https://www.anotherpower.com/board/index.php?PHPSESSID=r2dhnr7otgs7mme0h8p8miq5n0&action=dlattach;topic=1369.0;attach=8305;image)
Ripped it open and removed the transformer block (this was a rubber encapsulated block) and this looked promising (turns out this was three separate blocks that looked like one-so how to remove the rubber
![In Search Of Large Ferrite like (ICH) U100/57/25-3C90 8306-1](https://www.anotherpower.com/board/index.php?PHPSESSID=r2dhnr7otgs7mme0h8p8miq5n0&action=dlattach;topic=1369.0;attach=8307;image)
Well Acetone effects most rubbers so soaked it in that for 3-5mins
![In Search Of Large Ferrite like (ICH) U100/57/25-3C90 8308-2](https://www.anotherpower.com/board/index.php?PHPSESSID=r2dhnr7otgs7mme0h8p8miq5n0&action=dlattach;topic=1369.0;attach=8309;image)
and it peeled off pretty easily - BUT NO FERRITE - BUGGER! - Just three iron cores -The search continues ;thinking microwave oven inverter power supplies (so if you have any old 1200w ones and can part with the power supply board let me know)
![In Search Of Large Ferrite like (ICH) U100/57/25-3C90 8310-3](https://www.anotherpower.com/board/index.php?PHPSESSID=r2dhnr7otgs7mme0h8p8miq5n0&action=dlattach;topic=1369.0;attach=8311;image)