Hot plate

[Orange]

did you notice the difference before/after secondary air installation?

[martyn]

Well I had a P plate before but it was too thin and got pushed out of shape, I made this one from 2mm s/s and it definitely works better than my first attempt.
I need to do a few more fires to test various potential settings, it has been a really hot summer and it has been uncomfortable testing the fire but winter is coming!

There is a big difference between the high mass and low mass riser though, I am not even sure what the difference is but the fire behaves in a different way.
I know the low mass heats up the system quicker but it also drops the temp quicker..... I liked to see the high mass riser glowing red and orange.
There is more to it though, I need to test both risers again especially now I seem to have a more effective P plate.
There is something I don’t like about the blanket riser....
One thing is for sure, I love looking down the riser, when it is hot, you can see the secondary air sort of pulsing.
There is a picture right need the end of my last vid that just catches a pulse of secondary air.

[martyn]

A bit of an update... I had the stove going with the high mass riser back in place.
It most definitely takes a lot longer to get to 500c but it still gets to 220c in around 15 mins or in about the same time as the blanket riser.
However once I get that flame right up high in the riser I can reduce the burn rate and still maintain that amazing colour flame just lipping the top.
With the low mass riser I can only get that to happen with a continuous supply of wood and full air flow, or a lease I have not found a setting to keep the flame high without a full fire.
I will have another swap around next weekend....

[Piet]

Hi Martyn.

What kind of steel do you use for the hot plate? Is that 'regular' steel seasoned with oil? And what's the thickness? Does it bend or warp at all?

Cheers!
Piet

[martyn]

Hi Piet, the top plate is made in two rings of 6mm mild steel.
The 30”outer ring is bolted in place to the cement ring around the barrel top, I then have an inner 20” ring that is bolted to the outer ring with 15mm fire rope in between.
I think you definitely need two pieces to avoid over warping , the outer ring will noticeably concave but the inner ring remains pretty stable.
This system seems to work very well as any food juices run toward the centre, I don’t think a single piece of steel of that size would work.
The top has an oiled finish that cleans up fine when hot, I would love a Stainless steel top but unfortunately that is outside my budget!

[wiscojames]

Saw your post at permies. Have you got any photos that detail the new core?

[martyn]

No sorry, I was really busy and rushed so I did not take any but I will make a new vid (easier to put up on this forum than pictures)
Certainty a powerful stove now, of course I don’t know if the vortex or the big fire box is responsible for the improved performance or if I am producing more or less pollutants!
However from my perspective it seems to be working extremely well.
I won’t have a proper chance to test it out for a few months though as the weather is warming up fast and I tend to cook outside as it gets to hot inside the summerhouse.
I made the box useing the same method as the previous one, cast refractory and a wood and foam mould, I am using my original refactory riser.
I think the highest temperature I recorded on the first version was 520c on the top plate, we saw around 610c on the first run with the new model.
However, I don’t need more heat but, to sustain it at a more constant temp for longer periods, so I need to play with the air supply and see what other adjustments I can make.