Methods for cutting the Cook Chamber door in a RF propane tank build

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seenred

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I'm in the middle of a build - 24"x48" RF from an old propane tank. I'm about to the step where I'm ready to cut the door in the main CC. My tank has a 5/16" thick wall. My original plan was to cut the door with my plasma cutter, but I'd like to minimize the chances of warping. Any advice or experience from ya'll regarding this? I've got angle grinders and cutoff wheels, but I'm hoping to avoid making such long cuts with that method. I've also got a sawzall and a jigsaw, but I've never had much success making clean, straight cuts with those. I'm also not opposed to purchasing a metal cutting circular saw if that's the best option - like maybe this one:


Those of you who've done propane tank builds, what is your go-to method of cutting the CC doors?

Thanks in advance for any insights.

Red
 

civilsmoker

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I have that saw above, but I would use a 4.5-inch angle grinder with a quality thin cut off wheel. I would clamp or tape a metal straight edge as a guide and cut away. Once you get through the initial skin then run the cut off "1/4 in" and it will move quick. Using the saw above would work but it could burn up a $35 blade real quick if it tips or binds..... Oh and I run the stainless blades in the saw as they tend to run way longer than the standard.

PS there is always a risk of the door section springing, if you are really worried then pre-weld some shaped stiffeners on the outside first.
 
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seenred

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I have that saw above, but I would use a 4.5-inch angle grinder with a quality thin cut off wheel. I would clamp or tape a metal straight edge as a guide and cut away. Once you get through the initial skin then run the cut off "1/4 in" and it will move quick. Using the saw above would work but it could burn up a $35 blade real quick if it tips or binds..... Oh and I run the stainless blades in the saw as they tend to run way longer than the standard.

PS there is always a risk of the door section springing, if you are really worried then pre-weld some shaped stiffeners on the outside first.

Yeah I understand there’s always the chance of the door springing if the steel‘s under any strain…I mainly just want to remove variables like heat warp from the plasma cutter.

Thanks for the insight on that saw.

Red
 

civilsmoker

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Yeah I understand there’s always the chance of the door springing if the steel‘s under any strain…I mainly just want to remove variables like heat warp from the plasma cutter.

Thanks for the insight on that saw.

Red
Ah got ya.... by the way I love the saw above! It is a keeper for sure. I use it for all my flat cuts. I have cut 3/8's plate with it but 1/4" is the practical max....., it rips through 3/16" and 1/8" like butter.... If you are ok with burning up a blade, then it will produce the least amount of heat doing the cut. Be warned it is LOUD!!!....and I mean LOUD!

I'm cheap and a have used an angle grinder so much its practically a 6th finger on the hand.....
 
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seenred

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Ah got ya.... by the way I love the saw above! It is a keeper for sure. I use it for all my flat cuts. I have cut 3/8's plate with it but 1/4" is the practical max....., it rips through 3/16" and 1/8" like butter.... If you are ok with burning up a blade, then it will produce the least amount of heat doing the cut. Be warned it is LOUD!!!....and I mean LOUD!

I'm cheap and a have used an angle grinder so much its practically a 6th finger on the hand.....

Well, if the max on that saw is 1/4”, then I’ll have to go another way. The wall thickness of this propane tank is 5/16”. I’ve certainly known I could get the job done with a grinder…but not looking forward to going through a dozen or so cutoff wheels on such a long cut. Reckon I’ll just suck it up and get it done. :emoji_cold_sweat:

Rec
 

JckDanls 07

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I agree with the cut off wheel... but let me suggest.... Cut across the top first and then spot weld the hinges on before cutting the rest of the door...
 
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phathead69

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I made this one from a German built compressed air expansion tank. actually over slightly 1/4" thick. I tacked in door frames after vertical cuts. didn't have any problems. all plasma cut with straight edge guide.
 

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YooperSmoker

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the plasma cutter is designed to cut steel and reduce the chance of warping
instead of using a cutting torch
Id use compressed nitrogen instead of air also purge the tank with nitrogen
Ive used this torch on many pieces of flat stock stainless steel with out any warping
if concerned about warping make short cuts and let it cool

Mike
 
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seenred

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I made this one from a German built compressed air expansion tank. actually over slightly 1/4" thick. I tacked in door frames after vertical cuts. didn't have any problems. all plasma cut with straight edge guide.

Thank you...that's how I'm probably doing it. Good looking smoker!

Red
 
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seenred

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the plasma cutter is designed to cut steel and reduce the chance of warping
instead of using a cutting torch
Id use compressed nitrogen instead of air also purge the tank with nitrogen
Ive used this torch on many pieces of flat stock stainless steel with out any warping
if concerned about warping make short cuts and let it cool

Mike

Appreciate it. I've pretty much decided to make the cuts with my plasma.

Red
 
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boykjo

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May I suggest this. This will produce little to no heat and your cuts will be superior. It's a little pricey now but I got mine for $280 back when I did mine.
 

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seenred

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May I suggest this. This will produce little to no heat and your cuts will be superior. It's a little pricey now but I got mine for $280 back when I did mine.

That's a saw I looked at briefly...but it's a bit more spendy now than 2013. Around $350 if you can find it in stock.

I'm assuming it'll do plunge cuts into thick steel? That's one limitation that steered me away from the Evolution saw I was considering - it apparently doesn't handle plunge cuts very well.

To be honest, I've pretty much talked myself into just making the cuts with my plasma cutter and saving the extra bank.

Appreciate the input!

Red
 

zwiller

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Dream of building one someday and noob to metal working so mostly lurking here. That said, pretty sure I could rent that Milwaukee for a day for cheap. I live in small town and have 2 good rental places.
 

seenred

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Dream of building one someday and noob to metal working so mostly lurking here. That said, pretty sure I could rent that Milwaukee for a day for cheap. I live in small town and have 2 good rental places.

Hey now...I didn't think about renting a saw. I'll keep that in my back pocket if the plasma cutter doesn't do the trick.

Thanks!

Red
 
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boykjo

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IMO your still going to get some heat warpage from the plasma cutter although it will be the least of other options.
The Milwaukee did plung into the 1/4 inch plate easily.