Ongoing Review: Custom Blichmann G2 Bottom Drain 15-Gallon Recirculating Electric (240v) BIAB System from brewhardware.com

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Hi All,

I wanted to make a post detailing & reviewing the custom Blichmann bottom drain BIAB system that @Bobby_M at brewhardware.com offers: Premium Recirculating Electric (240v) BIAB Package (Blichmann Bottom Drain Edition). I had been looking to make a significant upgrade to my basement brewery and ended up settling on this system after investigating pretty much every AIO rig available under the sun. I was previously brewing on a 10 gallon Anvil Foundry for the last four years and I knew I wanted to do it big and upgrade to a larger 240V electric system that could do split 10 gallon batches since I recently started brewing with a friend from work. I wanted to have all the bells in whistles available to start exploring as consistent as possible brewing techniques via investigating extremely precise temperature control and LoDO brewing practices as well.

I was considering the Spike Solo, SS Brewtech SVBS, Bräu Supply Unibräu Brew System, and the Clawhammer Supply AIO rig all until I found this system via the recommendation of other users on this forum. At first I was actually going to go with the Spike Get Tanked bottom drain rig but after briefly chatting with Bobby on the phone I realized that the tanked rig was likely a bit too cumbersome due to the tanked leg height and my low basement ceilings which wouldn't get along. I figured it would be best to take his advice and go the custom Blichman G2 bottom drain route and also just bore a hole through a stainless steel table. What really sold me on Bobby's custom rig was the unit's bottom drain/ease of cleaning and also the dual recirculation feature for flowing fluid both on top of and underneath the grain bed during mashing. I am very surprised other manufacturers aren't offering the split recirculation feature - it seems like such a straightforward improvement for maximizing heat transfer during heating, maintaining consistent temperatures during mash rests, as also increasing the efficacy of the mashing process in general.

After speaking with Bobby I thought about my options and I ended up just purchasing this system directly through the brewhardware website. I settled on going with the custom 15 gallon bottom drain G2, a Blichmann Brewcommander 240V controller, and a 1.5" TC Blichmann Riptide pump for maximum overkill. After purchasing the rig it took roughly two weeks to ship out, and everything arrived at my house in a single shipping day (shipping from NJ to MD). Everything was packaged very well and setup of this unit was a breeze (aside from boring through that stainless steel Vevor table, which was somewhat of a powerdrill nightmare). After literal hours of soul-crushing hole boring I was able to pass the kettle through the table and TC couple the pump while adjusting the height of the bottom table rack to have the bottom drain and pump sit flush on the table's rack, which ended up looking so sick. With the 5500W element I went from 130F to 140F in 3 minutes and 20 seconds (heating 10 gallons of water), so the heating rate was about 3.3F/min at this 10 gallon volume which is quite good. One snafu was I didn't realize that the Brew Commander needs to have two seperate power inputs, one for 240V and another for 120V, hence at first I couldn't figure out how to get the pump working. Eventually I realized the 120V cable sticking out of the back of the controller wasn't just for aesthetics and plugged it in and everything worked great.

Its worth noting that the bottom drains and added TC ports on the G2 are very well done; the bottom drain smoothly curves/transitions from the kettle floor to the pump drain and the fabrication team (Bobby?) did an excellent job making this extremely slick. I also really like the adjustable valve and sparge arm system that is included with this package - it seems like a great way to get very precise mash recirculation control and I can't wait to try it out.

For this setup I figured I would use some of the computer monitor arms I had in lying around to attach my controller and my brewing recipe tablet to the table, and also setup a crane hoist/pulley system for lifting out the bag, which actually came out looking great. I had a 35lb monitor on it originally so I am praying it can handle the bag's weight in all its worty glory. The final system looks like some kind of Frankenstein'esque brew android that's about to just make the beer without me if I look away too long. I just went to my local homebrew store today and bought all the grains for a Belgian Tripel T-58/BE-256 co-fermentation, since I figured that would be a great way to christen this thing.

So far I am quite impressed with how everything came together, but the proof is really in the actual brewing process and final beer. I am unbelievably stoked to make my first batch on this rig and I'll report back with how it goes! I'll also include some photos of everything below, too. I hope this helps anyone who is interested in this system or considering purchasing it.

System Photos:
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I'm always tickled to see a unique take on the pump flow split. There's only so many ways to slice it, but this is the first time with the big sight glass on there. If it ever becomes cumbersome, it can easily be moved to the bottom drain in place of the 6" spool and that might be extra cool with an LED backlight.

I'm disappointed to hear the trouble you had with the table drilling. I've had good luck with the cheap tungsten carbide hole saws on all kinds of tables.
 
I'm always tickled to see a unique take on the pump flow split.
Oh man the backlit LED idea and bottom drain sounds insane - I might have to try that haha. I actually just moved everything around after finishing my first brew day, which went well aside from a stuck mash at one point. I think I had the recirculation through the locline going too fast and I also didn't wait for the grain bed to settle long enough. I went ahead and added a flow meter inline with the recirculation arm to try to lock in the mash recirculation rate more repeatably and prevent issues in the future.

I also realized having the hard line triclamp tubing to the pump isn't ideal because you can only use the pump by feeding with fluid going out of the bottom of kettle. I switched it up now so I've got quick connects on the kettle outlet and the pump inlet with the hopes of being able to start a LoDO batch with boiling the water in the G2 and then moving the solution to a second holding vessel. I want to add the dry grains to the G2 then pump the fluid back in to slowly fill the kettle from the bottom up. The only thing is I'm not sure if doing the kettle fluid transfers would actually be valuable as it could potentially introduce more oxygen then it actually saves. Anyway, here is the new configuration:

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I'm also fermenting and serving in these Chinese 6.5 gallon kegs. I really like these things and right now I just have a tripel fermenting without any pressure. Just racking the entire post boil volume into this thing and still having headroom for fermentation is great.

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I'm disappointed to hear the trouble you had with the table drilling.
The problem I ran into I think was specific to this particular Vevor table. It had about 3mm of stainless steel on the top with about a cm of very dense paper/cardboard mounted to the bottom of the steel. Everything was going fine until I got completely through the stainless steel and then the thick paper material underneath kept lighting on fire even with a ton of cutting oil present. It also made it seem like cutting was taking WAY longer than usual, which I think had to do with the oiled paper gumming the bits up to some degree.

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Eventually I was able to get the hole bored wide enough by rotating through my regular bit set and a stepped bit up to a 3/4 diameter, and at that point I just used a steel punch and a torque wrench which went through both materials like butter.

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Below you can see there is a significant amount of thick paper material in addition to the steel that was causing issue. That being said I actually really like this table (Amazon Vevor 24x34) and I think it's a good deal for around $100. I would recommend that before anyone even assembles the table they bore the hole using a drill press first.

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It looks like you changed the connection from the bottom drain to the pump from all stainless fittings to a silicone hose. Why did you change that? Also, for drilling stainless steel, I have found that a 1/8 inch titanium bit for a pilot hole works well even without cutting oil. After that pilot hole those step drills work pretty well. What size punch did you use for the hole?
 
It looks like you changed the connection from the bottom drain to the pump from all stainless fittings to a silicone hose. Why did you change that?
I wanted to be able to feed the pump inlet with something other than what is in the kettle itself. With the quick connects and flexible hosing I can close the butterfly valve below the kettle and then rig up the pump to intake fluid from another vessel. Ideally this would be good for filling the kettle from the bottom up with water that has been oxygen purged for LoDO shenanigans.
I have found that a 1/8 inch titanium bit for a pilot hole works well even without cutting oil. After that pilot hole those step drills work pretty well. What size punch did you use for the hole?
My pilot hole went in easily once I used a Dremel to etch in a nice starting point but it was widening that pilot hole that got hairy. I used a 2" conduit knockout punch with a true diameter of 2.416" to punch all the way through to the larger hole size once I got the initial hole bored wide enough to thread the punch through (3/4").
 
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It's all done now, so consider this just some fodder for future readers. The thing that kills drill bits is overheating and it happens in seconds when you combine stainless and high speed drills. Here's the rule of thumb. If the bit turns one full revolution without cutting a ribbon of metal away, it's turning too fast or the down pressure is too light (or both). It sounds hyperbolic, but it's true. Every time the bit just RUBS against the metal, it work hardens the metal you're trying to drill. Now the second revolution has an even harder time starting to cut and so on until the bit is fried and the surface you're drilling is like tool steel.

High pressure
Low to medium speed (slower the bigger the hole gets).
Any cooling liquid from water to cutting oil.

If you're wondering if the hole is taking too long, here's is my typical expectation.

1/8" pilot hole takes 5 seconds. Push as hard as you can without feeling like the bit is going to snap (dont leave the bit sticking out all the way).

Going from 1/8 up 1-1/8" with a Dewalt step bit takes 15 seconds or less.

If I need a hole bigger than 1-1/8" I use inexpensive tungsten hole saw bits and I can do 1-3/8 up to 2" in about 20 to 30 seconds of medium speed drilling.
 
It's all done now, so consider this just some fodder for future readers. The thing that kills drill bits is overheating and it happens in seconds when you combine stainless and high speed drills.
Wish I read this before I drilled haha! I'm definitely going to try cooling better next time. It's so rare that I drill thought metal and the last time I did I was going through aluminum which was not a problem so I just did tried the same thing with this attempt. I agree and I think I just killed my bits to some degree right at the start (the smoke was flying lol).

One thing that I would comment is for a small guy like myself it was really hard to put enough pressure on the drill to get it going, I think mostly because I was trying to drill through the already assembled upright table at a weird standing angle. This made it awkward because I had to lean over the table and try to hold the drill stable and also try to put a bunch of weight on it which put me at a awkward hovering position over the table which didn't work well. When I finally got things working it was just because I found an angle where I could just push REALLY hard on the drill.

I'm wondering if it would have been better to turn the table over on its side and put it against a wall so I could lean into it really hard versus trying to push down on it while holding everything steady. I am by no means a drilling pro and I really only bust it out for random one-off projects so I'm sure there has got to be a better way than what I did for this.
 
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It's all done now, so consider this just some fodder for future readers. The thing that kills drill bits is overheating and it happens in seconds when you combine stainless and high speed drills. Here's the rule of thumb. If the bit turns one full revolution without cutting a ribbon of metal away, it's turning too fast or the down pressure is too light (or both). It sounds hyperbolic, but it's true. Every time the bit just RUBS against the metal, it work hardens the metal you're trying to drill. Now the second revolution has an even harder time starting to cut and so on until the bit is fried and the surface you're drilling is like tool steel.

High pressure
Low to medium speed (slower the bigger the hole gets).
Any cooling liquid from water to cutting oil.

If you're wondering if the hole is taking too long, here's is my typical expectation.

1/8" pilot hole takes 5 seconds. Push as hard as you can without feeling like the bit is going to snap (dont leave the bit sticking out all the way).

Going from 1/8 up 1-1/8" with a Dewalt step bit takes 15 seconds or less.

If I need a hole bigger than 1-1/8" I use inexpensive tungsten hole saw bits and I can do 1-3/8 up to 2" in about 20 to 30 seconds of medium speed drilling.
I once had to drill through a 1/2"-thick carbon-steel tabletop using a hand drill. I remember needing to climb on the table and basically lean my whole body weight on the drill. I think it still took over half an hour, but memory is fuzzy. Good times.

The drill survived. The bit, not so much.
 
It's all done now, so consider this just some fodder for future readers. The thing that kills drill bits is overheating and it happens in seconds when you combine stainless and high speed drills. Here's the rule of thumb. If the bit turns one full revolution without cutting a ribbon of metal away, it's turning too fast or the down pressure is too light (or both). It sounds hyperbolic, but it's true. Every time the bit just RUBS against the metal, it work hardens the metal you're trying to drill. Now the second revolution has an even harder time starting to cut and so on until the bit is fried and the surface you're drilling is like tool steel.

High pressure
Low to medium speed (slower the bigger the hole gets).
Any cooling liquid from water to cutting oil.

If you're wondering if the hole is taking too long, here's is my typical expectation.

1/8" pilot hole takes 5 seconds. Push as hard as you can without feeling like the bit is going to snap (dont leave the bit sticking out all the way).

Going from 1/8 up 1-1/8" with a Dewalt step bit takes 15 seconds or less.

If I need a hole bigger than 1-1/8" I use inexpensive tungsten hole saw bits and I can do 1-3/8 up to 2" in about 20 to 30 seconds of medium speed drilling.
 
The only thing I would add to this is to make sure you start with a 1/8" titanium drill bit and make sure you have a couple of them. You need more than one because if you apply too much pressure you will break it!
 
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