Scuba tank mini reverse flow - first build

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I have welded 1 1/2" thick steel with 0.030 wire .....  So you do remove, or change out the gas nozzle.....   I guess that answers my question...  
 
now y'all really have me confused.. being a novice welder myself... at work we have a VERY OLD miller wire feed... So my partner and I tried to hook it up to this new portable welder we just bought... the portable is set up for stick or wire feed... we hooked the positive lead from portable to the wire feed... turned the switch on portable to wire feed... used some flux core and tried welding... it was doing ok but had problems with the wire slipping... after further investigation we found it has .035 gears on it and we were using .030 wire... so we changed the wire to .035 and it worked better... still having minor slipping problems but not as bad....

my confusion comes on the polarity and the nozzle... your saying that we should use the Neg. to the wire feed ? or does it switch the polarity automatically when you turn the switch on the welder from stick to wire feed ?

it is set up for gas but we don't have a regulator yet for the bottle... so your saying there are different nozzles when switching from flux core to non? what's the difference in the nozzles ?

I did notice there is a lot of spatter with the flux core.. really hard to clean up in areas you can't reach with a grinder...

:hijack: I guess
 
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Dave, the air tank build was how I found this forum. The two mini builds I have seen are BBQDad and Huntington County Customs. Not sure if they are same person but I had found a video on Youtube when I was researching mini smokers. I could not afford a nice offset and there are none to be found in California anyway. I'm usually just cooking for me and the wife so I wanted to go small. Ideally something like  RibWizzard's #22 but now I am committed to finishing this build.
 
now y'all really have me confused.. being a novice welder myself... at work we have a VERY OLD miller wire feed... So my partner and I tried to hook it up to this new portable welder we just bought... the portable is set up for stick or wire feed... we hooked the positive lead from portable to the wire feed... turned the switch on portable to wire feed... used some flux core and tried welding... it was doing ok but had problems with the wire slipping... after further investigation we found it has .035 gears on it and we were using .030 wire... so we changed the wire to .035 and it worked better... still having minor slipping problems but not as bad....

my confusion comes on the polarity and the nozzle... your saying that we should use the Neg. to the wire feed ? or does it switch the polarity automatically when you turn the switch on the welder from stick to wire feed ?

it is set up for gas but we don't have a regulator yet for the bottle... so your saying there are different nozzles when switching from flux core to non? what's the difference in the nozzles ?

I did notice there is a lot of spatter with the flux core.. really hard to clean up in areas you can't reach with a grinder...

hijack2.gif
I guess
read the book that came with your welder. or google it.

hope that helps

David
 
Got to borrow a friends welder today (220 MIG)  and got half the firebox done. Just as I was starting to make some nice beads it ran out of wire.  I should be able to finish the firebox and get it welded to the cook chamber/Scuba Tank next week. I am still looking for a small stainless beehive spring handle for  the firebox door so if anyone knows of a supplier please let me know.
 
Got to borrow a friends welder today (220 MIG)  and got half the firebox done. Just as I was starting to make some nice beads it ran out of wire.  I should be able to finish the firebox and get it welded to the cook chamber/Scuba Tank next week. I am still looking for a small stainless beehive spring handle for  the firebox door so if anyone knows of a supplier please let me know.
th_nopicsye3.gif


What is a beehive spring? I have bees
 
Mule, not sure if it's called a beehive spring but it's a spring handle that is fat on one end and skinny on the other. I should have some more pics up today or tomorrow after I get the notch cut in the tank for the tank to firebox opening. I also received my tricycle wheels from Radio Flyer so I should be able to post some mockup pics.  Stay tuned, we're getting close to making smoke!!!
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as far as the spring handle goes... you'll probably have to buy a chipping hammer that has that kind of handle and then cut the head off... looking good so far
 
Hi all, I am hung up doing the opening between the firebox and the cooking chamber . Aside from trying to draw straight lines on a curved surface  I need to cut the opening in the tank and the firebox and want to make this tiny thing to actually cook.

1. The cook chamber is 21" x 6.750" I.D.

2.The Feldons bbq pit calculator says - 1.71" diameter half moon opening! and that seems really really small .  Is there a rule of thumb for tank/firebox cutouts?
 
Hi all, I am hung up doing the opening between the firebox and the cooking chamber . Aside from trying to draw straight lines on a curved surface  I need to cut the opening in the tank and the firebox and want to make this tiny thing to actually cook.

1. The cook chamber is 21" x 6.750" I.D.

2.The Feldons bbq pit calculator says - 1.71" diameter half moon opening! and that seems really really small .  Is there a rule of thumb for tank/firebox cutouts?
Do not use the Feldon's calculator for the CC to FB opening.....   Use the circle calculator in my signature line......   Dave

Volume of CC X 0.00266 = Square Inches of Area for FB to CC opening...
 
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Thanks again Dave!
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, I got 2.186" (2-3/16") using your formula, wondering though if the dynamics change on something this small, should I think about some 1/2" tuning plates?.  Not sure at this point if I will actually go reverse flow, just not a lot of room in there. I did offset the door to make room for the chimney on the firebox end, but I could go direct flow. Trying not to rush through and mess it up at the end. I did figure out how to draw straight lines on the curve and I have a new blade for my hacksaw.
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Toby, morning.....  When I look at the build, with the small cooking chamber, a RF will give more uniform temps in that small cooking space...

The 2.186 area may be correct, BUT..... looking at everything, the surface area of steel....  RF and walls of the tank, the friction loss in that size smoker would be too much.....  I think the calculator needs to be thrown out here....  Using the circle calc and plugging in various Segment Heights ED..... Chord AB is the width of the RF plate....     making the RF plate 5" wide out of 1/4" plate... That would sit 1.1" above the bottom of the tank CC.....  leaving 3.8 sq in area under the RF plate....  OR using the same ideas, 5" wide X 3" long sections would be good for tuning plates.... Measure the actual dimensions after cutting the tank....  

either way, here is one way to cut into the tank....... Lay on a flat surface and scribe the cut line.....    Dave

          ....click on pic to enlarge .........

         
 
Behive handle , its actually called a barrrel spring.

Ive seen recently that they dont like links to other sites on here, so just go on Amazon and google spring handles or BBQ handles, the place with a River in the name is trustworthy, so is the one with the letter K, scroll on down because they come in many sizes, stainless or nickle plated. Some fit 3/8", 1/2" and 5/8" round rod. The longer ones are really sloppy.

Or....buy yourself some stainless round stock, and make a jig to wind them yourself, its not hard and you dont even need to add heat if you put a long enough crank on it.
 
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Behive handle , its actually called a barrrel spring.

Ive seen recently that they dont like links to other sites on here, so just go on Amazon and google spring handles or BBQ handles, the place with a River in the name is trustworthy, so is the one with the letter K, scroll on down because they come in many sizes, stainless or nickle plated. Some fit 3/8", 1/2" and 5/8" round rod. The longer ones are really sloppy.

Or....buy yourself some stainless round stock, and make a jig to wind them yourself, its not hard and you dont even need to add heat if you put a long enough crank on it.
RibWiz do you have a photo of what a jig would look like? My dad used to make all his but being young I don't remember what he used to make them. My google search only turned up information on gun barrels!!!
 
Basically just take a pipe the same as the inside diameter, support both ends with some kind of bearings ( can be fancy roller bearings or just pipe big enough for the first piece to slip inside of,) then mount a big crank on the end. Ideally you would mount it on a table with the center pipe being just a few thousands higher than the diameter of the rod your using, drill a hole in the pipe to stick the rod in , and hold the rod at the angle that will give you the wrap you want. Start cranking.

Or pay $10.00 a piece for each of them.

th
 
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