Grate help - Flexing expanded metal, are my supports wrong?

[dmac]

I made the standard cooking grate for my pig roaster with Expanded stainless steel flat 3/4 diamond #9 and 1x1 1/4 angle iron. This is the standard grate like many smokers have

The diamonds point the length of the grate. The grate is 2x5 and I have supports, running the width every 10" or less.


My issue is I have added 6 burners to turn it into a grill and when Iheat it over 400 degrees, the grate bows up and down like a wave. There is at most like 9" betweent eh supports and it is still flexing when hot.

All I can think of is to cut the supports out and put in at least 3 length wise. All the pictures I see on the web don't have this many supports and I know some have to use high heat. Is this a common issue? I had supports wider then it flexed then when I added more, it was worse.


Maybe is the way the run of the diamonds length way that means it's how I have to support.



Anyone use their grates with high heat and have this issue. The below link is to the grate type I made.

http://www.smokymtbarbecue.com/avactis/ ... ker_24.jpg


So, will the length wise helo this? I don't see any google search grates with it this eay.

[dmac]

No one has had this issue? No ideas?

[DATsBBQ]

Most of here are LowNslow, wood/charcoal types.

[k.a.m.]

Does the frame bow up as well or just waves in the expanded metal?

I would like to see a pic of the grate in question if you can post one.

[dmac]

I'll get a shot of it. it's just the expanded

[dmac]

This unit is 2' x 5'


http://prntscr.com/677438
http://prntscr.com/677325

[RWBTEX]

Yes that will always happen with that type of grate after a certain temp point, very common on grill type cookers, the metal expands with the heat even if your brace it very sturdy.

[dmac]

since the expanding /wave is length wise, I am thinking of removing the width supports and adding length supports, 3 so I only have 6" of space to each of them

I will change from 3/4 angle int he middle to 1" and because 3 it will be okay that it hangs 1/4" below the frame, it will be able to sit well

I hope that will cut the wave.

[RWBTEX]

Hope that helps, I have had the diamonds both ways and it still happens with high heat. They always go back to original form though unless they are older and have stretched a few times too many. I use a pear burner to clean my gratse at times and you can see the grates bulge and flex then they settle back as they cool off.

[k.a.m.]

I agree with RWBTEX, putting that much heat to #9 flat expanded is going to cause waves no matter what way it is placed.
You would be better off using raised expanded for this application, the metal is thicker and a lot more sturdy. If you go with raised make sure the long end of the diamonds run with the width and not the length.

[bullypitbbq]

Thts very typical with stainless steel, moves twice as much as carbon steel with heat. U will be a little better off putting ur cross members long ways as u were saying but u will still get alil warp