$40 DIY Conical (+ keg, no welding)

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outside92129

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After pricing out some of the SS conicals out there i thought i could just kinda sorta maybe do it myself. Maybe. But after looking at the prices of the parts required i thought it would worth the experiment. Here's what i used:

$20 - 24ga stainless steel sheet, 304, 24"x48" (from the local metal supplier)
$17 - BCM14WLMP-G200, 2" tri-clamp ferrule (dump port)
$13 - BCM14WLMP-G100, 1" tri-clamp ferrule (racking port)
http://www.jmesanitary.com/item.aspx?itemid=100711

The end product was a SS conical with a 2" dump port, 1" racking port, 2" top port for wort fill/thermowell/blowoff (using the original sankey port).

tools used:
2 vise grips
solder gun (not iron)
stainless flux (lennox)
silver solder
step bit + drill
saw
angle grinder

Keg prep: 30 min
I cut the *bottom* of the keg off with the angle grinder + cutting wheel at the weld seam and saved the bottom ring for the stand. Sand/grind down any rough areas. Prep the keg first so you'll have exact measurements for the cone.

research and calculations: 1 hr (should take you less with the info below)
The most mentally taxing portion of the job were the cone calculations. I found the following math instructor/prof's website extremely helpful as it's been a while since i took geometry.
http://jwilson.coe.uga.edu/emt725/CarlCone/CarlCone.html
Mr Wilson has a nice spreadsheet you can download. I wish everyone could use my numbers but every keg is a little different, where you cut the keg affects the cone, and cone/keg attachment method also affect the cone values. For me i cut out of the sheet an outer radius of 15.8", inner radius of 2", and 179 degrees. Note that 179 isn't 180 and 1 degree makes a difference a 16" away. But 179 is less than 180 so you can use part of the flat edge of the sheet from the factory.

sheet cutting: 1 hour
I cut the outer radius with tin snips, 24 is just thin enough to cut by hand. The inner radius was too tight to do by snips so i used a dremel. As you can see in the pics i did practice models with paper, good thing too as it took a few tries to get is just right (i found out my keg wasn't a round as i thought and initially used the shorter diameter for my cone calculations).

sheet bending: 1 hour
The next step was to bend the sheet into something resembling a cone. I just used gloves and SWMBO's kitchen rolling pin. Actually it was "ours" since it was a wedding gift. Anyways i spend the next few nights slowly bending the sheet in between diaper changes, etc. 5-10 minutes at a time.

cone soldering: 1-2 hour
Once the sheet is more or less cone-like, i lightly cleaned and sanded the edges to remove the oxide layer then clamped the two ends together with vise-grips. A light coating of flux and the solder adhered like a champ. I soldered inside and outside of the cone. Note that solder isn't the strongest joint but the addition of the ferrules + keg join will make it pretty durable. Just don't drop it. Also note that you can't use a electronics soldering iron, they just don't put put out enough heat. A torch will work as well but i liked the control of the soldering gun.

Ferrule/tri-clamp port additions: 1-2 hr
The ferrules come pretty long from JME so i shortened them down with a saw. I pre-wetted them (flux, solder) and the cone attachment areas to make sure i had a good bead. A few times in the past i noticed that i didn't quite clean an area and the solder didn't stick, pre-wetting (soldering) the areas tells me if i did it right without committing the entire joint, and it reduced the need for 1 less hand while doing the soldering (1 hand for the cone, 1 for the ferrule, and 1 for the solder wire). I placed the racking port in the middle of the cone joint to give the joint more strength, but the port also seemed the very delicate as there is significant leverage on the thin joint by the ferrule. I extended the ferrule 1/8" into the cone and added two strips of sheet on the outside across the cone joint to give the joint more strength.

Cleaning: 15 min
Thoroughly clean off all the flux! It starts doing weird things to the solder if you leave it on and it gets real hard to remove. You can remove burnt flux with fresh flux, and rinse it off with boiling water (per Lennox). Clean off the cone and ports as access later on is much harder.

Keg Join: 2 hr
I pre-wet all the joint areas for the cone/keg join as well. The harder part was getting the cone perfectly on and to stay still while i soldered. My keg wasn't perfect, and my cone was much less round than the keg. But the cone radius was larger than the keg opening (overlap) so i was able to insert the cone and pull up on it until it got stuck. It took a few times to get it just so. With the overlap there was a small gap above the keg/cone point of contact and i just filled it it with solder. The overlap was just over 1/4" for me so the joint is quite strong, it just takes a lot of solder to do. I opted for this overlapping joint instead instead of a butt joint primary for strength, but it was also significantly easier to do and is more forgiving in workmanship (of the cone and keg cut).

Final clean: 15 min
lots of hot water on the inside, maybe some PBW and/or oxyclean.

Things i would do differently:
1) I originally decided to solder the bits together as i could not reliably MIG the 24ga SS. Since doing the build i've dialed in my welding and would weld for strength, i am nervous when handling this conical. I'd grind down the nasty SS welds and probably solder over them for sanitary purposes. MIG welds can be especially porous and the solder would take care of that.
2) Yuri_rage has a DIY SS conical build too and i like what he did with the corny lid. That would make getting inside possible.
https://www.homebrewtalk.com/f51/diy-chilled-conical-keg-fermenter-123770/


Future additions:
1) Cooling- I'm toying around with the idea of wrapping the keg with copper tubing and running cold water through it.
2) better stand. Right now the conical is on a wheeled stand made of out of 3/4" angle and the bottom keg ring. It's not as stable as i like. But it is portable and removable for storage.

Concerns:
1) solder joint strength. I'm reasonable confident in the joints. I accidentally dropped the completed conical on the cone without damage. I've filled it to the top without leaks. However i did drop the cone during construction and the joint did break. The ferrules and keg join provide stiffness that a rolled up piece of sheet metal cannot do on it's own.
2) sanitary- the same as a sankey fermentor.

IMG_1514_md.jpg


IMG_1517_md.JPG


kegjoin.JPG


DSC04955_md.jpg


DSC04961_md.jpg
 

bhamade

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That's brilliant man! Great job! I totally am doing this when I get to that point.
 

JJWP

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Awesome! it just so happens that I have a 50L euro keg sitting around that would be perfect for something like this. Thanks for sharing.

I do not have any soldering experience (or equipment) I wonder what the local welding shop would charge if I cut the keg and cone myself and just asked them to weld it together..

How hard was it to cut the keg ring off and keep a straight line? I assume the keg seam made a pretty nice guide, but I know from experience cutting tops out of keggles that one wrong move can botch the job. Did you do it by hand or rig up some type of jig?
 

Bobby_M

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Is there solder filling the gap between the cone and keg on the inside? I'd be really worried about any nooks, pits, etc and I think heat sanitizing is the only sure way to reduce the risk.
 
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outside92129

outside92129

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I used a Weller D650 soldering gun, 200/300 watts all electric, i didn't have any issues with the keg wicking away all the heat. I tried a few sections with a propane torch but IMHO it was too much heat for sheet metal work.
http://www.cooperhandtools.com/brands/CF_Files/model_detail.cfm?upc=037103129925

If you're looking to take it to a welding shop they'll do it right with a TIG welder. But you'll be using butt joints so you'll have to be spot on with the calculations and cone cut. Welders make $15-$35/hr, then there is shop overhead, materials, and capital costs. Expect fully loaded fees of $75/hr for welding work. Maybe you might know someone and can sweeten the pot with brew! Paying cash for this work is going to bump you up close to commercial offerings, you'll still need fittings, etc. The Brewhemoth is $439 and includes fittings, blowoff, etc.
http://brewhemoth.com/brewhemoth

The cut was pretty easy to make, much more so than a keggle. There are no turns to make, it's just a longer straight line.

There *shouldn't* be a gap on the inside between the cone and keg, the gap should be accessible from the outside and i believe i filled it all in. But with a 48" circumference there is a good chance of operator error, and i have no way to verify the insides. But i'm prepping it with boiling water before each batch. Can't use a torch as it'll melt the joint. I attached another drawing of the joint and gap location with a little more magnification.

gap.JPG
 

ChuckWeiser

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I love the idea of soldering over the weld problems that can happen with a mig welder and stainless steel. He is a little trick that have helped me reduce the number of bad welds on SS. I am NOT a professional welder, so if there is a better way please speak up.
I read that SS must have shielding gas on the back side of the metal as well as the side being welded. Based on this, I took a large coffee can, put a small hole in it and taped it to the backside of the area to be welded. Then I would pumped in argon gas into the coffee can to shield the back side. If you pull out the argon tube and tape that shut it will likely hold the argon in the can during the weld time. But instead of that, I simply split the nylon tube in my mig welder that supplies the gas when the trigger is pulled. This is the 1/4 inch line inside the mig welder that supplies the hose that runs out the the welding gun. Where i split it with a Y, i took the new line and ran it over to the coffee can. Now when the trigger is pulled, argon is flowing. It reduced my bad welds significantly. Something worth trying if your having troubles.
You guys may already know this so I am sorry if i wasted your time.
Chuck
 

forcabrew

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i would deffinately be willing to try this, but ill wait to see how yours holds up for a while first
 

mattd2

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I love the idea of soldering over the weld problems that can happen with a mig welder and stainless steel. He is a little trick that have helped me reduce the number of bad welds on SS. I am NOT a professional welder, so if there is a better way please speak up.
I read that SS must have shielding gas on the back side of the metal as well as the side being welded. Based on this, I took a large coffee can, put a small hole in it and taped it to the backside of the area to be welded. Then I would pumped in argon gas into the coffee can to shield the back side. If you pull out the argon tube and tape that shut it will likely hold the argon in the can during the weld time. But instead of that, I simply split the nylon tube in my mig welder that supplies the gas when the trigger is pulled. This is the 1/4 inch line inside the mig welder that supplies the hose that runs out the the welding gun. Where i split it with a Y, i took the new line and ran it over to the coffee can. Now when the trigger is pulled, argon is flowing. It reduced my bad welds significantly. Something worth trying if your having troubles.
You guys may already know this so I am sorry if i wasted your time.
Chuck
Yep that pretty much how I have seen back purging done where you don't/can't want to fill the whole vessel. The other thing is if you can split the argon it off after the reg but before th welder and control it with a ball valve, that way you don't have to waste wire pulling the trigger and not welding to fill the can. Also if you don't completely seal the can to the plate (at the top) you can make sure that the whole can is filled prior to welding.

Another way I have seen it done is just a diffuser (basically a socket with some scoring pad sort of stuff in it) nozzle pointed at the back of the weld plumbed up like you described (not so good in windy situations :eek:) or a solid block of stainless to draw the heat out of the back of the weld fast enough that you don't get sugaring, not the best way but good enough if there is no room to do anything else it would be better than nothing.
 

mattd2

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...If you're looking to take it to a welding shop they'll do it right with a TIG welder. But you'll be using butt joints so you'll have to be spot on with the calculations and cone cut...
The way I would get it welded would be to oversize the cone, then tack it to the cut keg, then trim the cone to suit for butt welding. But I agree unless you can do this yourself or pay someone in homebrew you probably may as well buy an off the shelf conical for the money you will spend doing it this way.
 

lumpher

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very nice. hope it works out great. $50 for a conical is killer (20+17+13). wish i had those skills :mug:
 

mattd2

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Outside - Do you have any pics of the inside of the joint?
 

hammis

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Outside, this project is amazing, well done!

I've been planning on doing something similar for a while now and will definitely be using yours and Yuri's as inspiration.

CHEERS!
 
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outside92129

outside92129

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I couldn't get a good pic of the internal joint, the camera kept focusing on the wrong area. I was able to dangle a flashlight inside to inspect the solder and of the entire circumference "only" 1/2" has a flaw/bubble/gap. More than enough to cause a problem w/o proper care but I fill it with boiling water + starsan to sanitize it. No problems yet.

I also made a blowoff cap with a thermowell for about $10. Much easier to make than the conical and it'll save you $60. I'll post pics of that in a little while, right now it's all being used for a nice stout.

The unit is on it's 4th batch and has held up quite nicely. I am really careful with it though, i'm pretty sure if i drop it when it's full of beer it'll pop like a water balloon!

I wish i had a TIG welder but for now diapers take precedence for family expenses : ) But the conical was pretty darned easy to make. All you need is a soldering gun and time.
 

ChuckWeiser

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Hey Outside, :mug:
I was thinking about your "only" 1/2". If your worried about it and want to make 100% sure no nasty stuff is growing there where you cant see it. As an example would be a small piece of hop leaf or something caking up over time which would prevent the hot water / starsan from penetrate the caking. I would suggest the trying the following.
Much like I use a lighter to sanitize the rim of my test tubes when propagating my yeast strains, you could mark the outside of the conical fermenter where the flaw is on the inside. Then just before loading the fermenter with sanitizer, take a soldering torch (the small bottle type would work for household pipe soldering) and hit that area to heat it up. That would guarantee no nasties and would likely burn off any caked on material.
Just a thought...
 

bbognerks

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Why not cut the top off like you would a normal keggle conversion. Size it to a pot lid and use a sheet silicone gasket from McMaster to seal it? Then you could ensure no problem spots by soldering the inside.

McMaster P/N 8525T41 or 8525T43.
 
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outside92129

outside92129

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So after a year and a half of use and abuse I'm happy to report the conical has worked out nicely with no problems. No infections, no cracks, no leaks. Summer of 2012 we moved and somehow the conical broke free in the back of the moving van and bounced around. On the way to the ground it smashed a 809 pump, pump head was DOA but the conical survived intact. I have a nice IIPA in there right now!

Keeping it clean wasn't as hard as i thought it would be, after each batch i hose out the insides and let it soak w/ PBW and it's clean as a whistle. On brew days i rinse out the inside with a 212F Starsan solution, it might be overkill but better safe than sorry.
 

Atl300zx

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congrats! good job on this project. any pics of the finished product on a stand?
 

Aschecte

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Believe me I like this build ALOT and just yesterday I was taking about doing this but had little direction. My only concern as a hvac and union metal worker is that most stainless unless specifically noted food grade stainless will be coated and even sometimes depending on the supplier will be coated or impregnated with zinc oxide and other oils to prevent metal sticking to one another and to keep it from pitting and getting mineral build up.
 
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outside92129

outside92129

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Aschecte - thanks for the note. The steel looked clean but i took the precaution of cleaning beforehand. A bit after the fact but i called the metal supplier and it turns out the stainless i used was clean w/o oil or zinc oxide.

MM- Thanks for the heads up. I called FiveStar to confirm and they say not to use Starsan above 120F. I'll have to come up with a alternative plan, i still like the idea of filling it with boiling water, but maybe i'll drain it then spray down the insides with normal starsan. Most likely overkill, but i'll spend a few minutes to save all the work on a brew day.
 
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outside92129

outside92129

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Update - 3 years on and it's still going strong. Once i forgot/got lazy and didn't clean out the fermentor after kegging. A month or two later i discovered the nasty mess inside and just filled it with boiling water and PBW. The next morning it was clean as a whistle. The joints are still holding up, it's fallen a few times (moving truck) too.
 
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poptarts

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This thread needs way more love then its getting, this is pretty sweet.
 

NewBrewB

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Fantastic contribution to the DIY forum. I have been thinking more and more about somehow using an inverted snake for fermenting my 10gal batches but if I can make friends with a welder, this would be great.
 

SleepyCreekBrews

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The unit is on it's 4th batch and has held up quite nicely. I am really careful with it though, i'm pretty sure if i drop it when it's full of beer it'll pop like a water balloon!
This post is old, but I suspect almost any conical available these days would pop like a balloon if it somehow hit the ground full of beer. My Blichmann almost fell over once, and I had some pretty vivid images of the thing bursting open and spilling 12 gallons of beer on the floor.

I'm glad to hear it's holding up well.
 

Spellman

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Not sure how I missed this thread until the diy forum got reorganized, but this is pure awesome. Any way we could get a couple shots of the "welds" if you get a chance? I think this may go on the list of things to do!
 

NewBrewB

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I just bought an extra keg to do this but I need to make friends with a welder that works for beer (or teaches welding for free and will loan out equipment for beer)
 
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