What type of steel for grate ?

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Mike Rometer
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Re: What type of steel for grate ?

Post by Mike Rometer » Sat Dec 09, 2017 12:08 pm

ianrichards wrote:Excellent, I’d rather go thinner.
The grate’s outer frame is made of angle and have fitted to the fore and aft angles a row of spacers to drop the bard between.
These spacers provide a gap of 15mm.
So, what section steeldo you reckon I should use, bearing in mind that it needs to be 15mm wide?
Thanks
Ian
I have 6mm x 25mm on edge. I stack them and drill them through then part off spacers to the required size, again drilled through, and then assemble with 5mm rod nutted on the outsides, like Mike I make sections.
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Re: What type of steel for grate ?

Post by ianrichards » Sat Dec 09, 2017 1:05 pm

And what size spacers would you suggest ?
Ian
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Re: What type of steel for grate ?

Post by Mike Rometer » Sat Dec 09, 2017 2:21 pm

ianrichards wrote:And what size spacers would you suggest ?
Ian
Minimum, the same as the bars. I worked it out from the size of the 'box, to give as near 50/50 as pos. Last one I made I finished up with slightly more 'air', as it didn't divide exactly.
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Re: What type of steel for grate ?

Post by Mike Cole » Sat Dec 09, 2017 3:25 pm

What are you going to burn as fuel, wood or coal. I would think that for either of these the biggest spacing between the bars as you can. More gap = more air= better combustion
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Re: What type of steel for grate ?

Post by Mike Rometer » Sat Dec 09, 2017 4:31 pm

Mike Cole wrote:What are you going to burn as fuel, wood or coal. I would think that for either of these the biggest spacing between the bars as you can. More gap = more air= better combustion
More gap = more falls through before it's burnt away. 'Tis literally a balancing act!

For wood you can use bigger gaps.

I (and some others) have come to the conclusion that really you need a different grate for every fuel, and that includes different coals. Steam coal seems to like 50/50.

Another option if you burn wood is a rosebud grate. I've never experimented with one because I can't be ar$£d drilling all those holes and then tapering them.
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Re: What type of steel for grate ?

Post by ianrichards » Sat Dec 09, 2017 6:30 pm

Wood will be the main fuel.
I’m a little confused as to the spacing as if it is the same as the thickness of the bars, then that a hell of a lot of steel if you are using 25x3 section.
My firebox has a surface area of 400x420.
If I was using stainless steel, what would be the best solution based on wood?
Very happy to make it in sections so that it can be changed if burning coal.
I just want to get it right ... if at all possible.
I’ve designed the firebox in such a way that things can be altered at a later date according to experience.
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Re: What type of steel for grate ?

Post by ianrichards » Sat Dec 09, 2017 7:40 pm

Rather like this method.
What size angle would you suggest and bearing in mind that I’ll mostly be burning wood, what space between the VVVs would you suggest?
Thanks
Ian

Coal fires are quite hot, so mild steel will not work very well at all as you know. 316 is quite resistant to high temperatures, so will likely last for a while. One method that has protected the steel and helps prevent clogging w/ slagging coal is to use stainless angle rather than bars; the tip of the angle is pointed down. The grate ends up looking like this: V V V V V V V V

Ash will collected in the 'V's, helping to insulate the stainless steel from the worst of the fire, and once a piece of slag falls between the bars, it will end up in the ash pan rather than cooling off and getting stuck. Note that the highest temperature conditions will be obtained when the damper is closed suddenly after steaming hard; letting the fire cool off more slowly should help prevent sagging grate bars. If a support can be rigged in the middle of the grate for the angled bars, the chance of sagging will be much reduced.

If you can figure out how to make one fit, stock cast iron drain grates can be used with good success - that's what it's in Rainbow, stuck in a round Scotch furnace. After it sags too much or rusts out, they're readily available at non-bespoke prices for many years as they're stock sizes.

https://www.google.com/search?q=olympic ... 88&bih=785

Note also that there still various sorts of grates and grate bars available in the UK, from which it would seem possible to construct a proper cast iron grate w/ replaceable pieces:

https://heatingpartswarehouse.co.uk/pro ... are-front/

Note the grate bars are available in 10 and 12 inch lengths:

https://heatingpartswarehouse.co.uk/pro ... -iron-bar/

- Bart
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Re: What type of steel for grate ?

Post by ianrichards » Sat Dec 09, 2017 8:01 pm

Bart pointed out these.
I could easily make this fit.
what do you reckon guys?

https://heatingpartswarehouse.co.uk/pro ... are-front/

Note the grate bars are available in 10 and 12 inch lengths:

https://heatingpartswarehouse.co.uk/pro ... -iron-bar/
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