After reading following Bob Boyce post on another forum; I am going to remove or replace metal scrubby that I bought and used from Dollar store. I will look around for plastic now.

==== Being of Bob Boyce Post ========

Despite the limited successes that some have had with metal wools, that is the worst possible material to use for a hydroxy gas flashback filter! Hydrogen Tap, like most of the other marketing driven sources, is not a very reliable source of highly experienced information. They will tend to put sales profits over customer safety or needs.

1. A flashback filter MUST NOT BE CONDUCTIVE! Anyone that uses a conductive media does not understand the nature of hydrogen / oxygen combustion. There is a high voltage discharge that occurs from the rapid release of electrons (why a hydrogen fuel cell works like it does), and that discharge occurs VERY fast during hydroxy gas detonation. This discharge can pass right through a conductive flashback arrestor, and create an electrical discharge into the hydroxy gas on the other side, igniting it!

2. Metal wool does not filter out ANY of the caustic aerosol that can be produced at higher power densities. For this reason, the use of a > > scrubber bubbler is recommended. THEN you can follow up with some
sort of flashback protection. I prefer a dense plastic based filter media.

Bob

==== End of Bob Boyce Post ========