My OWB got a makeover this summer (major rust out, hole the size of your fist on the top of the water jacket). I'm in the middle of getting it up and running again and noticing a lot of left over rust particles in the water. I'm going to try to flush out what I can, but I got thinking, wouldn't it be a good idea to have some kind of filtering system on these things? Sooner or later, every boiler is going to see some level of internal rusting, and I imagine those little bits of rust play havoc on the pumps. I've got two new Tacos on this thing and don't want to waste them if I can't get all the debris out. There's a braided steel line connected to the circulator pump, I'd love to rig up a filter there to catch the worst of it. The only question is, what kind of filter could I use? I'm tempted to try an oil or hydraulic filter. I figure water is a lot thinner than oil so flow shouldn't be a problem, run it a few days then pull the filter apart and check how bad the paper is. What do you think?