Here’s another idea for a cheap and quick sulfur burner.
Get a cheap laundry iron, clamp it to something flat and upside down, make an aluminum cup, and get some sulfur to vaporize.
I used a temperature meter to check temperature, but you can probably skip that step. My old iron was turned up to max temp, and I found that it cycles on and off between 260 and 380 degrees F. Never went over 400. I believe sulfur vaporizes in the 300 degree range. Your iron temperatures may vary. Don’t use an iron that you would use on clothes again. My iron is used to wax skis, and a little sulfur is OK on that.
I got sulfur for my test from an existing bag of garden sulfur. I saw this on YouTube. I separated the light colored “split pea” sulfur from the other pellets. I’ll probably buy a bag of real sulfur, and that should last me many many grows.
I’ve got powdery mildew in my grow room, and 2 weeks from harvest. I don’t really want to risk using this on my flowering crop, but when I clean out the room I will scrub with bleach and vaporize sulfur, and then maybe use it a few times in veg on my next run.
Once the sulfur melts, it runs into a pool in the lowest part of the cup. I think I need maybe a teaspoon of dry sulfur for a 2 hour treatment of my small grow room. So, having the cup tilt a little might be good. I suggest NOT putting sulfur directly on the iron, or directly on any hot plate, electric frying pan, or George Foreman grill. Also have a mat under it to catch any drip or spill.
Does that really burn the sulfur or just vaporize it and let it get deposited all over the room as elemental sulfur? I know when you burn it, it makes sulfur dioxide, which is a gas. It does not change back to sulfur, and when you air out the room it is gone.
Can you just dust the leaves with sulfur to kill the mildew? Or does it take sulfur dioxide?
BTW burning it also makes SO3, which is sulfuric acid without the water. VERY DANGEROUS! VERY BAD to breath. This is what they used to use for termites, so you might want to move out of the house for a couple of days. Don’t forget to remove pets and fish.
My hope is that this will vaporize the sulfur, but not burn it. I don’t know what temp sulfur burns. My understanding is the sulfur vapor is distributed throughout the room, and leaves deposits on the plant leaves and stems as well as all the cracks and gaps in the structure where spores might hide. Some sulfur compounds (maybe sulfuric acid) are acidic and lower the pH to the level that mold and spores don’t grow.
I have outdoor roses, and there are many fungus problems and treatments for roses. However roses are not consumed, so more toxic methods can be used. I would not use rose fungicides on my weed.
The recommended procedure, is to turn off lights and fans, seal the space as well as possible, then vaporize the sulfur for 2 hours, let it sit in the dark for 4 to 6 hours before ventilating while still dark. Light causes a chemical reaction that can be toxic to plants.
There are other methods to treat mold and mildew in plants, but this is considered low cost and effective. Sorry but I can’t give a more scientific explanation of sulfur states or sulfur compound byproducts.
Note that there are many stories in the forums where growers have lost their plants from improper sulfur treatments.
Sulfur forms polyatomic molecules with different chemical formulas, the best-known allotrope being octasulfur, cyclo-S8. The point group of cyclo-S8 is D4d and its dipole moment is 0 D. Octasulfur is a soft, bright-yellow solid that is odorless, but impure samples have an odor similar to that of matches. It melts at 115.21 °C (239.38 °F), boils at 444.6 °C (832.3 °F) and sublimes easily. At 95.2 °C (203.4 °F), below its melting temperature, cyclo-octasulfur changes from α-octasulfur to the β-polymorph. The structure of the S8 ring is virtually unchanged by this phase change, which affects the intermolecular interactions. Between its melting and boiling temperatures, octasulfur changes its allotrope again, turning from β-octasulfur to γ-sulfur, again accompanied by a lower density but increased viscosity due to the formation of polymers. At higher temperatures, the viscosity decreases as depolymerization occurs. Molten sulfur assumes a dark red color above 200 °C (392 °F).
(Wiki) Elemental sulfur is one of the oldest fungicides and pesticides. “Dusting sulfur”, elemental sulfur in powdered form, is a common fungicide for grapes, strawberry, many vegetables and several other crops. It has a good efficacy against a wide range of powdery mildew diseases as well as black spot. In organic production, sulfur is the most important fungicide. It is the only fungicide used in organically farmed apple production against the main disease apple scab under colder conditions. Biosulfur (biologically produced elemental sulfur with hydrophilic characteristics) can also be used for these applications.
Standard-formulation dusting sulfur is applied to crops with a sulfur duster or from a dusting plane. Wettable sulfur is the commercial name for dusting sulfur formulated with additional ingredients to make it water miscible. It has similar applications and is used as a fungicide against mildew and other mold-related problems with plants and soil.
Elemental sulfur powder is used as an “organic” (i.e. “green”) insecticide (actually an acaricide) against ticks and mites. A common method of application is dusting the clothing or limbs with sulfur powder.
A diluted solution of lime sulfur (made by combining calcium hydroxide with elemental sulfur in water) is used as a dip for pets to destroy ringworm (fungus), mange, and other dermatoses and parasites.
Sulfur candles of almost pure sulfur were burned to fumigate structures and wine barrels, but are now considered too toxic for residences.