Next time I do something this big I think I'll use the cauldron and fire outside! Wonder if the cast iron will act like a mordant and change the color??? I'll have to research that one.
YES it will, but just a tad.
I have been using walnut hulls for years, though I use a less efficient method. I pick them up in the fall, green, stomp on them to break them up, then put them in the hot water in an iron kettle. The iron kettle has a rusty interior when it's used.
IF I don't have access to a large kettle and am doing a large garment or perhaps dying linen to make some oil cloth, I will use a plastic brewing bucket no longer used to ferment beer. In that case I take 4-0 steel wool and let it rust up in a mason jar of water, and then do the dye and add the iron oxide to the water.
You get a "sadder" color..., duller, tending a bit darker than what you achieved when using iron oxide. Over time the walnut will fade if used plain, and using iron oxide it usually lasts a good year or so of regular outdoor use before a bath is needed..., or not...depends on the opinion of the wearer. :wink: I don't know how colorfast your mordants will be with the walnuts.
I really liked your results! :hatsoff:
LD