Obtainable filter material. That is affordable and adaptable to my process. That is the problem.
I just have not had the time or resources. To go any farther with it. I did it as a one time thing to filter my .223 rifle alloy.
The material I used to filter with was an industrial grade smelting filter material used in the aluminum manufacturing process. Ceramic. I got leftover trim scraps, from where I work. But stainless would be fine for lead working temps.
We no longer make filtered aluminum alloy. So no more source for the ceramic filter or stainless scraps.
I can't find a source where you don't have to have a business, and buy thousands of dollars of the stuff (like 400 SQ ft of the stuff) to obtain it.
The material I used to filter with is used in the aluminum smelting process. For high grade alloy. At aluminum smelting temps
There are stainless mesh screens on Amazon and such that could be used possibly.
Stainless has been used in the aluminum smelting process also. We have used both mediums. They just do not last as long as the ceramic filters.
This should not be as much an issue at lead pouring temps .
Stainless will not degrade at the melting point of lead.
But I have had no time or ability, as of late to work with the process. To obtain a filter agent affordably, and develope it to be feasible on a smaller scale. Feasible for the average caster, hobie smelter.
Saw dust and wax are working just fine for my current needs. And I have a good bit of pre smelted lead on hand.
The process is pretty simple if you go back to my previous posts. Just basically stretch the mesh screans in three different layers from large mesh screen to finer mesh. Over a cut out metal can. Keep it warm (almost starting to glow but not quite) with a rose bud torch or two. This keeps the lead from (freezing in the filter) Then pour the melted lead thru it from one pot to the next.
I believe the mentions of microns and such are in the other posts