Hello! Does anyone have problem with N4 Overcoat Flux from Ninomiya? I fire mine in thin layers, I sift and wash it several times, BUT its coming out milky and not transparent in some places. Wondering what else can help. 

I use this flux for an overcoat, and grind it fresh every day. I guess I would suggest getting it in lump form, and using an agate mortar and pestle, and only using what you need for that day. To help the grinding, I set a few lumps somewhere hot, and then drop the in cold water in the mortar, where they fracture like the marbles we used to put in frying pans. That makes grinding fast and easy. Also don't try and fill a lot, maybe only up to three coats, too much of any fill seems to dilute the color or fog. Also, I use distilled water.

Thank you for response. I have it already in grinded form (I see retail websites in US suggest only in this form).  Since I tried many times, I believe it was a bad portion of enamel. Wondering if there is any other enamel brand have nice overcoat flux?

Over unleaded, I've tried the Thompson clear 2020, and did not have good results. I rarely overcoat, maybe is not necessary? Usually I use light tints on final layers and factor in the loss of color that comes with grinding.

I agree there is no need in some designs , but you know in some cases you want to keep lighter shade. Thank you for advice!