solar oven dyeing?

I've seen people dyeing with jars of water in the window, but what about an actual solar oven?

When the dyestuff is at its peak, it's too hot to cook in the house.  I don't like using outdoor burners or fire because of the wildfire risk.  So I thought maybe I could make my dye baths with a solar oven?  


If I leave the house in the sun, it gives me about 2 gallons of water at 120-140F.  Maybe hotter as sometimes it burns my skin.  

The greenhouse averages 130+F+ in the heat of the summer (the thermometer only goes up to 130F).

There seem to be lots of heat around.

I know nothing about solar ovens except it needs sun and it produces/captures heat to cook stuff.

So... possible?

If it's not possible, what would it look like if it was possible?

Interesting question. I'm brainstorming, but have come up with this: Get a solar generator (the kind with a solar panel and a deep charge battery). Charge that, then plug an induction cooktop into that outside. No flame needed! You would need a dye pot that attracts magnets, though, so the induction cooktop would work.

oh I like that idea.

It's just that my marketing strategy for yarn and fibre is low impact.  Electronics aren't all that low impact in the long term.  

Also, some dyestuff we have to heat for 12 or more hours a day over several days.  Can a solar system do that?  

Let me start by saying I know very little of value when it comes to solar. Total newbie here.

But...could you do the dyeing inside the greenhouse, maybe surrounding your dyeing container with insulation akin to a haybox or something like a decent sized rock/boulder with a hole drilled in to fit your container exactly? I'm trying to get at combining the heat with some thermal mass to keep it from cooling too much overnight, but not sure if this would be how to go about it. The rock thing may not be remotely practical, but I figure any crazy idea is worth mentioning.

r ranson wrote:oh I like that idea.

It's just that my marketing strategy for yarn and fibre is low impact.  Electronics aren't all that low impact in the long term.  

Also, some dyestuff we have to heat for 12 or more hours a day over several days.  Can a solar system do that?  

I get that.

I think the solar set up could last 12 hours. While the sun is out and the panel is collecting, the energy would go to the cooktop with the excess going to the battery. Once the sun set, the excess that has been stored in the battery will take over. I'm not sure, though, how much would get stored if you were using it while charging. That would take some experimentation.

Now you've got me curious. What needs to heat for 12 hours? I've only made a few natural dyes, and none of them took that long. I'm thinking you're working with something pretty cool!

Roots, wood and bark may need to simmer or boil for days.

Some flowers and leaves give different colours at different temperatures.  

The greenhouse isn't making the water simmer, so I'm only getting a limited range of colours.

I made a solar oven a few years back; it was constructed of pallet wood (inner and outer crate) and insulated with scrap wool and wadded phone book. It had a flat lid made of a pane of glass I found on the side of the road. All this to say, it was a pretty average piece of kit. It did, however get water to 60C (140F). I tried using this for dying, as well as jars in the glasshouse at the flat I was staying at at the time, and I got good results. I was dying with field madder, however, and this sort of set up (heat, cool, heat, cool) is actually ideal for both true madder and field madder. I didn't have enough field matter to do a huge dye batch, but I did get a lovely pinky-red colour with this method. Maybe it's a matter of choosing the right dye to use? Also, a better constructed solar oven will be able to boil water by midday if set out on time and tracking the sun. You may need several solar ovens to get enough water to do a big dye batch.

Have you experimented further with this? I'd think that pre-heating the water to 50-70C in a solar oven would, at the very least, significantly reduce the energy to boil water for dyeing.

If my crop of woad is successful, I'm considering building a haybox for my dyepot so that it doesn't use so much energy (and steam up the house!)--these are usually quite effective for all sorts of things that need a long simmer. I'd be keen to hear from anyone who's tried it to know if it worked or not!