My best results were letting it sit in the acid for about 6 hours. I've used KNO3 and NaNO3 with the same result. I've found that my nitrocellulose gets extremely hard during the process, but after cleaning (washing in cold water and boiling in NaHCO3 solution), it's more like cotton again. It's probably been bout 6 months and I don't recall the ratios that I used, but I do remember cooling the acid before the cotton was added and letting it raise with the addition.
If your cotton dissolves, you may be using too much H2SO4. You should be able to use RFNA. H2SO4 protonates HNO3. No water is necessary. |