The Keezer Build: Pt 2

It took me long enough to finally get to writing up the second part of my keezer build. What the hell was the holdup? Well, it was a number of things, laziness, life getting in the way, spending time outside versus on the computer…take your pick. I’ve got an excuse for why it took so long.

In my last post (found here) I started off with the Keezer build and gave a general overview of how I build my keezer. I left off having finished the PVC tubing circulation system. There wasn’t a whole lot more after that. It was surprising how easy it was after that to get the keezer up and running.

Placing the Collar

Once the collar was all stained and ready to go, I slid it overtop of the keezer. While I thought I had everything aligned nicely, I noticed there was a slight gap at one of the corners where the wood interface met the top of the freezer. Even though I put some weatherstripping on the bottom of the collar for a better seal against the freezer, there was still a gap. In retrospect, I should have been a bit more careful in my alignments.

 

Collar Fitted with Taps in Place

 

After doing a bit of reading online as to the best way to seal the collar, I got some clear silicone caulk, then lined the inside edge of the interface where the collar met the freezer top. Once it dried a couple hours later, I checked the seal with the small fan that would go on top of the reducer of the air circulation piping. The seal was great!

 

Corners and Edges Sealed with Silicone Caulk

 

Test Fitting

I had to test fit the kegs and the CO2 tank along with the reducer to make sure everything fit. Luckily, it looked like everything was going to fit nicely. I was a little disappointed I wouldn’t be getting 4 kegs in, but I think I can do with 3.

Even with only 2 kegs, a 3rd wasn’t going to be an issue 🙂

Insulation

Prior to adding the insulation, I mounted the manifold to the back of the collar so I could cut my insulating pieces to size.

Manifold in place (I took this after the build was complete, realizing I’d forgotten to take the picture)

I made cut outs for the faucets along the inside of the front face. I started placing strips of aluminum tape over the corners and the top side of the collar to seal the interface between the insulation and the wood. I had thought about covering all the insulation with aluminum tape, but figured it was more effort than necessary. 99% of the time the lid is closed.

Once I had all the cutouts for the faucet bars and the manifold in the back, I sealed the bottom each with silicone caulk to prevent any air from escaping. It seems to have worked pretty well.

Setting up Air Circulation

I initially had a few issues trying to figure out how I was going to mount the fan to the pipe reducer at the top, however, after thinking about it, I figured I would use the silicone caulk to hold it in place.

One thing I noticed with just the basic computer fan is that it didn’t move as much air as I wanted. After doing some investigation between axial fans versus centrifugal fans, I decided to purchase a centrifugal fan and mount it to the reducer instead of the axial fan. I used the silicone caulk to seal the fan and reducer interface.

There’s a lot more engineering behind selecting blower fans along with the air filtration systems, such as the draft angle of the reducer to the pump, the pressure differential in a compressor fan to move the ideal amount of air, pressure loses due to bends in the air movement system, and so on and so forth. My approach was pretty basic: take the compressor fan wires, hook them up to the correct wires on a 12 V wall wort power supply (an old phone charger) and then plug it in. So far, it works pretty well moving the cold air. Plus, it moves the cold air horizontally towards the taps versus upwards right into the lid.

 

Centrifugal Fan Wired up and Ready to Go

 

Finishing Touches

What I noticed with the CO2 tank with the double body regulator on it is that it’s very prone to tipping. With a full CO2 tank it’s not much of an issue, but as it gets empty, it becomes a problem. My fix for this was to use a chain, 2 carabiners, and two eyelet screws. With the eyelet screws in the collar, the chain retains the CO2 tank at the neck to prevent it from tipping.

 

A Good Retaining Solution for ~$3

Then there were the last few little things to do before I prepped my first keg. With the manifold added prior to the insulation, I mounted the temperature controller at the back of the collar behind everything, so that it looked clean from the front.

Temperature Controller Mounted and Ready for Action.

 

The temperature controller probe was placed in a cup of water. I had read it was a more accurate way of measuring liquid temperature versus measuring the air temperature. I placed it next to the small dehumidifier in the space underneath the CO2 regulators.

Temperature Probe and the Dehumidifier on the Compressor Hump

Then there was attaching all the hoses to the barbs and making sure all the connections were sealed. I did this by mixing some dish soap in a spray bottle and squirted at all the connections while the system was pressurized. If any bubbles showed up at the connections, I knew there was an issue.

Hooking up the System

The way I hooked up the system was I plugged the temperature controller into the wall, then plugged the power bar into the temperature controller. The power bar had the fan plugged into it, so this way the fan only turns on when the freezer is cycled on. It’s a noisy fan, so I didn’t want it running all the time.

Prepping my First Beer

Once I checked all the connections and fixed any leaks, it was time for my first beer to be kegged! I ran some beer line cleaner through the hoses a couple of times to ensure the that the hose lines were clean, then I cleaned the keg with some dish detergent. There’s better cleaners out there, but it was a brand new keg that I’d already cleaned an sanitized.

My first keg was a force carbonation test to see how well force carbonating worked.  I followed the process detailed on homebrewing.org. (Click the link to see it).

The Finished Keezer

It’s finally finished! My keezer is finished and producing lovely carbonated beers!

Inside All set up (I only have  beer on at the moment. More to come 🙂 )

 

The Keezer. Finished at Last.

Producing Wonderful Draft Beer

Future Upgrades

There’s always more things I can do to tweak and improve my keezer. A few things I had thought about include the following:

• Adding a dolly to the bottom to move the keezer around.
• Making custom tap handles.
• Adding a drip tray under the faucets.
• Incorporating some nifty electronics, such as a scale or load cell to determine the amount of beer remaining in each keg.

But that’s my keezer build. If you have any questions, leave a comment!

The Keezer Build: Pt. 1

It took me long enough, but it’s high time I wrote up my keezer build. I seemed to to a lot of talking about it, but finally it’s time to at least write up a general “how I did it”. I built my keezer in a similar fashion to the keezer that’s detailed on Homebrew Academy. It’s your best source of information if you’re looking for specifics on building a keezer.

It’s easy to drive yourself mental with the options you have when it comes to kegging your beer. I’ve discovered there’s no shortage to how much control you can have over your homebrewed beverages. For my keezer, I wanted to be able to do the following:

• Serve three different types of beer
• Carbonate a keg while serving with other kegs.
• Keep the construction relatively simple.

After much debate in terms of whether I build a collar versus building a more elegant bar style keezer with the coffin box on top, I decided in the end to do a collar style build. This build is already a step past what I’m used to and considering I’m making a draft system for the first time, the collar style build is the easiest way to go.

Planning

One thing I find is that I try to plan things to the n’th degree. I like to know exactly what I’m getting into when I take on projects like these, since ones like these tend to come with a price tag. With a general idea for keg sizes and the dimensions of some freezers I had in mind, I made a 3D model in Google Sketchup to see what my collar build would look like in terms of dimensions.

Isometric view of Keezer

Better Idea of Spacing Between Kegs

View of PVC Network for Air Movement

This gave me a good sense of realistically how many kegs I was going to be able to fit in. I had tried to convince myself that possibly I could fit all four kegs on the bottom, but it was going to be really tight. Basically, I had to accept that I was likely only going to be able to fit three on the bottom and maybe a low profile or 2.5 gallon keg on the compressor hump.

Since I’m a neurotic engineer, I try to estimate my costs as accurately as possible, but if there’s anything I’ve learned from the wisdom of others would take on projects and document them on the web, it’s that no matter how hard you try, you’re always going to spend more than you think. Taking this into account, I made an initial bill of materials, then multiplied the total cost by 1.2. Not surprisingly, I spent more than this. That being said, the actual cost was relatively close to the 1.2 multiplier on the estimated cost. I was only over by about $50. Good lessons to remember for the future.

With a digital representation of the keezer, it was time to jump into the real build.

Getting the Materials

To build a keezer, you need the main ingredient: a freezer. You’ve got a number of options, there’s usually a good number of people looking to get rid of freezers on craigslist, however I have a $100 gift card to Lowes and they had the size of freezer I was looking for. In the end, I picked up a Idlyis 7.1 Cu-ft freezer for $109 after the gift card.

I had struggled to find exact dimensions of the insides of freezers online. One good way to easily determine how many kegs will fit in a freezer is take some cardboard and cut out circles the size of the keg diameter. Then, go to Lowes, or Home Depot, and put them in the bottom on the freezer. This quickly tells you how much space the kegs are going to take up in the freezer you’re looking to buy. The image below shows using the templates on the floor models at Lowes.

Keg Cardboard Templates in Idylis 7.1 CU Freezer

 

Loaded and Ready to Go

Considering now I had a freezer and two kegs, I was committed at this point. I took a trip down to the local homebrewing store Adventures in Homebrewing. It’s wonderful living so close to Adventures in Homebrewing, the team there is incredibly knowledgeable and helped direct me to everything I needed for the keezer build.

Below is a rough bill of materials. Since I bought some tools for the first time while doing this, my costs were a little bit out of whack, but below is a fairly good review of how much the Keezer cost.

Material/Component	Cost
2 x 6 Lumber	$          5.83
Beer Line (15 ft, 3/16″ thick)	$           13.13
Beer Line Disconnect (x 3)	$           15.87
Beer Shanks (4-1/8″, SS)	$           79.47
Carbonating Beer Line	$           16.42
Castors	$           11.51
CO2 Tank (10 lb) – Reconditioned Tank and Fill	$           90.10
Computer Case Fan	$             5.17
Computer Scroll Fan	$             7.09
De-Humidifier	$           31.75
Double Body Regulator	$         105.99
Fasteners	$           11.26
Faucets (Perlick, 630SS)	$         114.48
Freezer	$         109.88
Gas Ball Locks (x3)	$           15.87
Gas Line (12 ft, 9/16″)	$           10.05
Gas Manifold	$           41.33
Hose Clamps	$           11.72
Insulation	$             5.81
Miscellaneous	$           17.30
Oak Trim	$           31.86
PVC	$           18.54
Shelving	$             5.24
Swivel Nuts (1/4″)	$           12.69
Tail Piece Assembly (x 3)	$           15.87
Taps Handles (x 3)	$           12.69
Temperature Controller	$           61.42
Wall Wart	$             5.30
Weatherstrip	$             3.47
Wire Connectors	$             2.52
Grand Total	$         889.61

The above doesn’t account for the fact that I needed some extra tools and materials as well. If you don’t do much woodworking, you’re probably going to need a good palm sander, along with a wood stain and a varnish. My total cost after materials ended up being about $100 more than what’s listed above.

There’s places you can save money, like finding a freezer on craigslist for less than $50 if you really look around, or by going with chrome material instead of stainless steel. The double body regulator is a big cost, if you don’t mind carbonating a keg then serving it separately, you can save about $45 going with a single regulator. Depending on what you want, you can probably do this a little bit cheaper. I wanted to be able to carbonate and serve at the same time, the double body regulator lets you split off two separate pressures, so I can have a high one for carbonating, and a low one for serving.

My Trip to Adventures in Homebrewing

Building the Collar

The first steps involved getting the collar built. Removing the lid is a bit of a challenge because the hinges on the back are spring loaded, so I had to be careful when taking the screws out. Once they were out, I measured the top of the open freezer and cut the 2 x 6 lumber to create the base of the collar. I used basic screws to hold the collar together.

Then, I reinstalled the lid onto the back of the collar, since I wasn’t going to be putting any oak trim on the back. If you really wanted to go basic, you could stop here with the collar, seal the insides, and drill faucet holes. However, the nice thing about the oak trim is that it creates a glove for the keezer that gives it a nice polished look when combined with the staining.

Oak Trim Installed

Using brass nuts and screws, I fastened the oak trim to the 2 x 6s. The oak trim hangs about 2 inches below the bottom of the collar and lines up with the top of the 2 x 6 interface with the lid.

One of the issues I ran into is that I discovered after I attached the oak trim was the the front face had a crack that ran right though the center. This irritated me as oak trim is not exactly cheap. Oh well, first hangup. No biggie, back to home depot more oak.

There was a silver lining because I used the cracked piece as a template for mounting my beer shanks. I used the cracked piece to determine the size of spade bit I needed to use (I think it was 7/8″, though I forgot to take down the size I used!) & I got a chance to see what the taps would look like on the trim. I also used the cracked trim piece as a template when I made the mistake of using a spade bit for the beer shanks that was a little bit too small. As I said, the cracked piece ended up working out pretty well 🙂

Silver Linings Cracked Trim

Test Fitting the Faucets

Once I got a new piece of oak trim, I drilled the holes and attached the taps to test the fit. So far pretty good!

Test Fit of Faucets.

Staining the Collar

The whole reason I got the oak is that I wanted the outside to be stained. I like the stained look of oak, so I ended up getting a cherry red stain and glossy urethane finish. This took about a week to do, since I did 3 coats of stain and 4 coats of urethane.

Staining the Collar

Urethane Coat Drying

 

I like the red color, and I didn’t want to go too dark with the stain as I wasn’t planning on doing anything to the fridge. I had originally thought of painting it black, but it’s something I can do in the future if I really want to.

Air Movement

While the collar was being stained, I built the network of PVC tubes that would move the air. In retrospect, doing the PVC tubes is overkill, but I wanted to go the extra mile. If I really want to I can always remove it later.

I wasn’t able to find the exact PVC tube sections I had in my sketchup model. So I improvised and made the PVC network a little more curved with a few extra 90 degree elbows and a four way connection.

Cutting the PVC

In the end, I think it turned out alright. The PVC size I use was 1-1/2″, but the truth is you can use any size you want, you just have to make sure to account for the keg height change with respect to putting the PVC in the bottom. So if you use 2″ PVC tube, the top of the keg will be 2″ closer to the top (plus a little bit if you put something over the PVC). If you’re collar height was based on the keg sitting on the floor, the lid might not close!

Once the PVC sections were cut and fitted together, I tested out how the fan would sit on top of the reducer section right at the top of the PVC network.

PVC Network All Assembled

For the wiring the sits on top of the pipe network, I found some cheap wire shelving at home depot. I used a dremel to cut out the sections of the shelving to fit above the pipe network. It was a cheap solution, but it worked great!

Shelving Sections Cut to Shape

The Shelving Fits Perfectly!

One thing I noticed (which I’ll discuss in part 2) is that the fan hardly moved any air at all. For the time being, it worked as a good surrogate part to place everything so it fit.

For Part 2

In the next post, I’ll go through some of the smaller details as I finish up the build, such as insulating, routing hoses, and sealing, along with plans for the future. I’ve got two beers finishing up fermentation, so I hope to be enjoying some nice draft out of the keezer soon!

More to come soon!

Looking Ahead

Once again, I’ve let my blogging lapse due to the trials and tribulations of a busy life. It has been far too long since my last post. Other than being able to say I’m 1 class closer to getting my master’s degree, not too much is new. …only 7 more courses to go…

If there’s anything I’ve discovered in the last four months, it’s that as a mechanical engineer, I certainly did not get the background necessary during my undergraduate degree to fully understand all of the content involved in signal processing. While the course is meant to be a signal processing course in the context of being for mechanical engineers (AKA “For Dummies”) I found that to really understand the significance and theory behind concepts such as Discrete Fourier Analysis, Fast Fourier Transforms, Short Time Fourier Transforms, or Wavelet Transforms, a background in higher level mathematics, complex algebra and mathematical functions is really helpful.

What I struggled with in the course is the deeper understanding of what’s really happening with some of the concepts. Take for example the concept of convolution. This is the basis behind the short time Fourier Transform, because the mathematical definition of the short time Fourier Transform is understanding that in order to get a closer look at a signal time segment, we “convolute” the window function times the complex exponential with the original signal to get a windowed segment of a signal. This allows us to see the frequency contents of a smaller section and we can see how the signal contents change over time.

Don’t worry if absolutely none of the above made sense (in fact I sure some savvy engineer with a strong signal processing background could call me out on this. Please be kind 🙂 ) All I was trying to get at is while I can talk to it at a basic level, I still really don’t have a good understanding of what “convolution” in a mathematical sense is. There’s many, many resources online which will try to break down in layman’s terms what it is, but right now, while I can implement what I’ve learned into a nice Matlab script that will punch out a beautiful looking spectrogram of the frequency contents of a signal, I still struggle to understand the mathematics behind some of the concepts (I will say Daubechies wavelets made my head explode in this sense). In short, a couple higher level math courses would have been really helpful.

So now that I have a few months with a bit of extra time, what’s the plan?

During the last month, I built myself a nice little subfloor in the garage of the place I’m renting. What I found this last winter is that the absence of having a good place to skateboard was one of the few things that makes me really crabby and disgruntled in general. Since my garage doesn’t have the smoothest surface, I decided to build a little subfloor to skateboard on.

While I had planned on doing a write up on it, it’s actually really quite simple. You take a bunch of 2 x 4s, some OSB sheets, masonite sheets, and a whole crap load of screws, and basically build a frame from the 2x4s. Then you lay the OSB sheets on top, and then masonite on top of that.

I probably didn’t need nearly as much lumber as I used, but it’s nice and sturdy. It’s not perfect, you can tell where the 2 x 4 sections are separated as it creates a bit of a hump in the masonite. That being said, it works pretty well for my purposes.

Sketchup Rendering

Sketchup Rendering

Building Phase

It’s Finished! There’s space for my truck and for skateboarding.

The nice thing with this setup is now I have no excuse not to do some kind of skateboarding. Even if it’s only a couple of kick flips or 360 flips for 20 minutes at the end of the work day, I have a place to go. I’ve discovered that sometimes at the end of the work day, I either need something else to focus on or just some way to get rid of some of the pent up energy I get from sitting at a desk all day.

Upcoming Projects

As I’ve constantly referred to in the past, I still do have plans to make my homebrew draft system (or “Keezer” as it’s referred to in the homebrew community). What I’m struggling with at the moment is figuring out exactly what I want. While I have a pretty good idea of the quantity of kegs, types of faucets, CO2 tank size, etc… I’m trying to figure out what kind of overall design I want. One style is the “collar” design, which is pretty easy to implement. You remove the freezer lid, take some 2 x 4 or 2 x 8 wood and create a square collar in between the lid and freezer, then drill holes to mount the faucets on the collar. An example is shown below.

Collar Keezer – Source: http://www.homebrewtalk.com

The other style is known as a “coffin” keezer. In my opinion, this style looks a lot more refined and more like a bar setup, however it does come with some challenges. One is that you have to take a bunch more steps to ensure you have a low temperature difference between where the taps are and the bottom of the freezer. If you have a higher temperature at the taps than in the freezer, you end up with a lot of foam when you pour your beer. This equates to lost beer (not cool!). This usually means you need to insulate the coffin box really well and you need to wire a fan to move some air through the bottom of the freezer up to the coffin box to keep it cold.

Coffin Keezer with 3 Taps – Source: http://www.homebrewtalk.com

Also, I know if I went this route, I’d want it to look polished and refined, more like a bar setup. This would probably mean more money put into materials to make it nice and a lot more construction work to make it look nice. If I’m going to go to all the trouble to construct a coffin style keezer, I want it to look nice as well.

So while that’s coming up at some point, I want to hash out exactly what I want to do with it before I start putting it together, as I don’t want to be changing my mind after I’ve started down a specific direction.

As per usual, it’s a balance figuring out what to do next as I only have so much money to work with. While I have a pretty good idea of what the keezer is going to cost, I am constantly trying to get over the fact that it costs a decent amount of money and jump in.  We’re not talking thousands of dollars, but enough to stop and think. The usual questions of “maybe this money could be better used elsewhere” come up. Maybe I should buy the TV first while it’s on sale at Bestbuy. Maybe I should focus on paying off my truck. Maybe I should get a Tonneau cover for my truck. Maybe I should invest in the stock market.

What I constantly forget is that material possessions are not the basis for happiness. Money, possessions, and wealth do not equal happiness. So while it will cost some money up front for the keezer project, it’s the planning and execution that’s the fun part. Plus I know the end result will grant me many a good pint.

Photography, Electronics, and the rest of my life.

My photography has taken a bit of a back seat in the last couple of months. At some point I hope to get that back up and running as I still want to work on my time lapse rig that I spoke to in previous posts. It’s been quite a while since I’ve done anything with my Beaglebone Black, so if I look into that again, I’ll probably be starting from the beginning while I refresh my memory on how to program it and make it work.

Going Forward

As I go forward, I probably will find that it takes me longer than normal to get my projects up and running. I only have 4 months until classes start up again, so my goal is to make the best use of my time since once school starts, the posts will stop.