SK brewery update log

It is that time of year again!

I have the brewery completely torn down. I am doing my annual deep clean but also taking this time to swap the function of the big and small pots. Both pots need new holes drilled for fittings and both have holes that need to be plugged. It is going to be interesting figuring out how to pull that off.

Also, I got a fancy new stainless steel fermenter in the back of that picture. Merry christmas to me. I will be setting up a glycol cooling system for temperature control in the fermenter.

I’m going to document the rebuild of the brewery in this thread.

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So for the first thing I wanted to tackle was plugging holes that were already drilled. I picked up some small stainless steel strips to cut some blanks out of

Here is a picture showing the hole i am trying to plug.

I ground the plug to be as close of a fit as I could.

This is the first time i have tried silver soldering and I ended up putting a little too much heat into the pot so it got a little discolored. Luckily a little wash with vinegar cleared most of the discoloration up.

I got too much solder on it but it did fully solder and it is water tight which is what is important.

I’m planning on taking a flap wheel to it to smooth it all out. Since that will ruin the oxide layer ill have to re-passivate the pot. I’ll wait till I’m done with all the soldering to grind everything and do the passivating.

Overall I think it went alright for my first attempt. It is surprising how little heat is actually needed.

Ok so next up was trying to solder a valve fitting into one of the holes.

I pre cut a small ring of solder then threaded the fitting into the kettle and applied flux to the joint.

This was a bit different from the plugs I did earlier as the valve fitting is far more mass. I had to basically focus the torch directly on the fitting after a gentle heating of the surrounding pot.

Overally I’m happy with the results. The solder looks clean and it made a good fillet with the pot.

This silver soldering is turing out fantastic. Some of the parts that I know I will never unscrew I am soldering their threads.

For example, here is an elbow for a volume sight glass that mounts to the side of one of my kettles.

Here is the dry fit with some 0.5" steel rod to simulate the sight glass.

And here it is all soldered up with the sight glass. This pot is starting to come together!

In an attempt to clean up the excess solder and make things look nice I took a die grinder with a sanding disk to some of the joints.

The grinder certainly got rid of the discoloration but the soldering is a bit obvious. Oh well, This is a practical tool. I’m not trying to win any beauty pageants with it.

Next up on the brewery rebuild is figuring out how I want to go about installing my recirculating heat exchange coil.

This is 50’ of stainless steel tubing wrapped into a coil. The coil is submerged in a warm water bath and the beer is pumped through it. This allows for gentle and continuous heating of the beer without applying direct heat

The end of the coil is intended to be mounted to a kettle fitting with a compression fitting.

I really don’t love compression fittings. They seem tricky to get right and my track record with them leaking or getting dirty is poor. I think that instead of threading them on with the compression nut, I will silver solder them directly into the back of the fitting. There is a fairly substantial barrel where solder can wick in and make a seal and a good mechanical bond.

The kettle side threads are just under 0.75". Wearing ear plugs while drilling this hole is pretty much necessary as the kettle rings like a bell.

Here is a dry fit of the external coil fittings and a picture of the coil inside.

I dont love that the coil sits quite a bit offset from the center of the pot. I think I am going to cut the coil tube down a little to make it sit closer to center. This pot has water constantly circulating via a pump. I want to make sure that there is plenty of room behind the coil for water to flow.

After cutting about 3/4" off of each end of the coil it sits a little better. I could go further but I think that this will be fine.

In the next post I will solder the coil to the kettle fittings.

The compression fittings soldered onto the heat exchange coil easily, however the solder tended to pool at the bottom of the joint which made me a little suspicious. Before tightening them down and soldering them into the pot I figured it would be a good idea to do a leak test.

I pulled the coil and fittings through the pot and soldered on the cam lock nuts at the end of the compression fittings.

The idea was to connect my pump and push water through the coil while looking for leaks. I hooked up all of the hoses to the pump and coil then to a small pot of water.

After firing up the pump I inspected all of the joints around the compression fittings and I found this on the bottom fitting:

The leak was pretty slow so it must be pretty small. With the water pumping the upper fitting had zero leaks.

I did a further inspection of the solder job on the lower compression fitting and found that there was some area where the solder did not fully fill. As I mentioned earlier, as I was soldering these fittings it looked like the solder was flowing to the bottom of the joint from gravity. This can be pretty easily seen in this next picture.

I am out of flux right now so I cant make more progress but I have another bottle on its way. I think I am going to have to get creative and make a jig to hold the pot up while the compression fittings are vertical. This way when the solder flows it will want to flow down into the barrel of the fitting and make a solid connection completely surrounding the coil.

Luckily, the flux arrives on Friday so I can make more progress over the weekend. This pot is nearly complete. The other pot that I will solder fittings to does not have anywhere near as much complexity to it so I expect it to be a cakewalk compared to this one.

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Try putting some sandpaper in a block and match the brushing of the original stainless. Will help hide this.

Yeah my plan is to finish up all the solder jobs across the project then take a brass wire wheel to all the heavily heat affected areas.

Ill focus on cosmetics after that.

I grabbed a new bottle of liquid soldering flux so I can continue working on the brewery. The flux I am using is called Stay-Clean by Harris. It is very aggressive and a little seems to go a long way. I typically apply a little to the joint I am going to solder then heat the surrounding area until the flux boils. I may apply more once the solder flows if I have noticed it not sticking well.

So to fix the leak I had from the last post I needed to reflow the solder on the rear barrel of the compression fittings. This time I did the soldering with the fitting horizontal. this time I balanced the pot on its side so the fitting was vertical which would hopefully allow the solder to more easily flow down and surround the tube.

Here are the results of the first fitting. I would say that it came out great.

I used a brass wire wheel on a drill to scrub off all of the caked on flux and generally clean up the area. I think the results are fantastic.

So now it was time to repeat the leak test to see if I got it the second time around. I set things up just like before and fired up the pump and was happy to see that there were no leaks!

Since I had everything set up I figured it was a good time to try to clean the inside of the coil in case any of the flux had solidified and burned inside. The manufacturer of the flux recommends a mixture of TSP and baking soda to remove he flux. Luckily I keep both of these around for various cleaning jobs.

The pot that I was using to hold the water I was pumping was on the stove so I cranked up the heat, added the cleaners and let it circulate for 15 minutes.

I honestly expected the water to look more mirky but I suppose that there was not a lot of flux residue in the fitting. I had previously put a small pipe-cleaner like brush in the end with some acetone so I may had already got rid of the bulk of anything that was in there. I will certainly be doing more cleaning before anything I intend to drink touches the coil but it is nice to know that there is probably not a lot of stuff in there.

The pot is now ready to have the coil soldered in place. I installed the nuts on the back of the compression fittings and cranked everything down tight such that the fittings sat as flush as possible with the pot.

Flipping the pot on its side made the soldering a bit easier and ensured that the solder would flow equally around the joint.

Since these joints are going to be under the constant stress of holding the weight of the coil I decided to go a little overboard with the amount of solder I applied to them. If one of these joints were to fail on a brew day that would spell the end of that day and I would have to toss the batch.

Here is an image right after soldering both the top and bottom fittings. There is a ton of burnt flux that needs to be cleaned up as I applied flux multiple times during the soldering.

While I was waiting for the two coil fittings to cool, I decided to also solder down the eye bolt that accepts the sight glass tube.

This pot now has all of its fittings soldered on! Here are some pictures after some TLC with the brass wire wheel to clean up the excess flux.

One remaining item with this pot was to cut the threaded portion of he eye bolt that stuck out inside the pot. I used a cutoff wheel then a die grinder with 80 grit sandpaper to smooth it down to the inner wall of the pot.

There is more I would like to do with the brass brush in terms of cleaning residue but overall I am very happy with how it all came out. The solder feels very strong and I don’t fear that there will be any leaks. Time and use will tell if the work I have done here will last but I am optimistic.

Here is a picture of the pot with the sight glass in place.

So now this pot has changed duty and is configured to be my hot liquor tank. Next up is setting up my 15 gallon pot to be a boil kettle.

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Looking great! I think you should polish those pots :smiley:

Mirror finish polish?

wax GIF

One of the reasons for tearing down the brewery every year is to do an inspection on all of the parts and see if anything needs replaced. One of the parts that are not easy to inspect without breaking things down are the heating elements. They are buried down in the bottom of the pot and obscured by a big nut.

Here is the heating element that I pulled out of my old boil kettle.

I would say that it has seen better days. The white build up on the coil doesn’t really bother me as that is just caked on minerals. It is easy to clean. The part that is annoying is the threaded portion of the body which has some pretty significant rusting going on.

I really thought that I had purchased a stainless steel version when I first installed this but I supposed the presence of rust shows that I had not. The portion of the element that has corrosion on it were in contact with the beer in the boil kettle which doesn’t make me too happy. I have not been making bad beer so I don’t think this was a huge issue but since I know about it I have to fix it. I guess a little bit of extra iron in my diet isn’t a bad thing right?

I have already purchased a replacement element that is stainless steel so this should not be an issue going forward. The other pot in my system has a stainless steel element and it has had just as much contact with water as the one in the images above and it has zero rust.

rust remove GIF

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Happy new year everyone!

I took a break from the brewery project during the holidays to work on some other projects but it is time to get back to it. If I wait too long then I might run out of homebrew in my fridge and not have a way to replenish it (gasp!)

I got a new 5500W stainless steel heating element in for the hot liquor tank to replace the one from the last post that had rusted.

In the images, the new one looks just a little crusty but that is because I saved a few bucks and purchased a non-polished one. This is stainless steel from the element casing to the threads so it should last a lot longer than the old one and not rust. The duty of this heater is to heat a pot of water that is not intended to be consumed so it is less important that everything be immaculate. This water will be used to indirectly heat the beer and to be used for cleaning.

Over the break I cleaned up my large workbench so now I have a big spot to do assembly of the brewery. I still have a lot of fittings to figure out. Most of these I want to solder in place.

All said and done, I would like to end up with as few non-soldered joints as I can. I am tired of rebuilding everything every year with pipe tape and hunting down leaks. Hopefully this is the last time I do a full system tear down. The goal is that my cleaning efforts on brew day are enough with perhaps an occasional deeper clean of the ball valves.

Given how much solder I had left and how many more fittings I have to go I went ahead and snagged some more along with a big boy bottle of flux.

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So it has been 5 months since I last posted an update to the brewery. I am itching to brew again but with all the equipment torn apart I have to finish all of the updates to actually brew.

In all honesty, I have picked this project up a few times since my last post but each time I ran into some serious issues and frustration led me to shelf the project. I am now at the point where I have to power through to get things wrapped up. I have already done all of the hard work (or so I thought) since I finished all of the soldering on the hot liquor tank.

The soldering that I did on the first pot all seemed to go well with very little issues so I was under the assumption that it wasn’t that hard and I had enough skill to just keep moving forward with the second pot. For whatever reason, the first hole that I went to solder has now taken me months to complete because every time that I attempted to do a task that I had by now done multiple times it just would not cooperate.

I did not take photos of the first few times I attempted this repair because it looked more and more gnarly with each attempt. Similar to some of the holes in the hot liquor tank I did back in December, I was just trying to plug the hole with a patch. With each attempt, the pot would just refuse to solder. No amount of cleaning, grinding, and fluxing seemed to work. This pot was made of 304 stainless just like the first pot so I expected it to be just as easy to work with but this has been a nightmare. It got to the point that the sheet metal was splitting from the heat of multiple soldering attempts.

This leads to today. I decided to do a completely different approach. I got out the dremel and notched out a rectangle from the pot so I could attempt an easier shape.

All of the discoloration around the hole is from the multiple previous solder attempts. I will have to go after those with a brass wheel when this pot is all done.

The idea with this next attempt was to cut a rectangular patch to fill the hole. My thought was that matching a rectangle of new material to a rectangular hole would be easier than trying to cut a circle to match a circular hole.

Here is my sad face plug that I cut for this hole.

I was a little upset that I had to go to these lengths to fix this issue, but I want this project to move forward and I am not terribly concerned with the pots looking amazing. They are intended to be functional first and pretty second.

From the work I did on the first pot I learned a few things that makes soldering easier.

  1. Both the pot and the plug must be clean.
  2. Both the pot and the plug must be heated as evenly as possible.
  3. The plug must match the hole as close as possible. In other words, the gap between the plug and the solder needs to be as small as possible.

Points 1 and 2 are easy to achieve. Just hit the pot and plug with a sanding disk on a die grinder, and wipe them with acetone just before soldering. This is similar to welding. Point 3 is a bit more tough to achieve. I have been using sheet metal snips to cut circular plugs to fill the holes which has been a challenge. Every plug has required some love with a belt sander to get it to fit. This is why I thought that a rectangular plug would be easier to fix.

I ended up being right about a rectangle being easier to cut and fit, but I was wrong about this being the fix. For whatever reason, even with following the three rules above I was just having the worst time soldering a plug into this hole. For whatever reason, this hole just did not want to solder.

I was not going to let this one hole best me however so I decided to go with a more sure fire but uglier method. I overcut the plug such that I could do a lap joint instead of trying to fit a perfect plug. This did end up working after a few attempts.

Here are the post results. The pictures actually make it look a bit worse than in reality. There is more work to be done with the grinding/cleaning effort but the plug is holding.

You can actually see that I had to do two separate plugs that are soldered together from the inside of the pot. There was a split in the sheet metal that was too large to fill with solder. I ended up cutting an additional strip to fill this gap.

So the hole is finally plugged. It only took 5 months and a few very frustrating attempts. I am a bit baffled since I had excellent success with all of the work I did on the other pot. It seems as though the solder gods were just upset with this hole and would not allow it cooperate. This pot isn’t going to win any beauty pageants but its one job is to hold water which it is one step closer to now.

In the future, I may revisit this to make it look better but for my sanity sake I am calling this hole complete.

There are only two more holes that I need to patch. I think I may try cutting the plugs on my cnc to see if I can my plugs to be more accurate without having to shape them to fit on the belt sander.

In an attempt to make better plugs I turned to the cnc. This machine was originally designed to cut plywood and perhaps some light aluminum so I had not even considered cutting steel a possibility.

The stock I had was 0.031" thick. I figured this isn’t too bad to attempt. Here is an image of three circles that I cut.

The first cut was not deep enough so I left it on the stock and moved onto the other two. The circle in the back has a different surface finish because I hit it with a sanding wheel before taking this picture.

The first circle was designed to have a diameter of 0.88" to match the hole size in the pot (7/8ish"). It came off of the machine a little larger than this around 0.89 indicating that the bit had some flex.

My cut parameters were 0.005 depth of cut and 60ipm with a spindle speed of 10k which is very aggressive for steel on a machine like mine so I am not surprised that I had some errors. The only coolant I was using was compressed air blown directly on the bit while cutting.

The second circle was cut a tad larger to fit another hole in the pot. This circle came out looking alright but it was nearly 0.03" larger in diameter. This is 3x the error of the first circle. Given that the same cutting parameters were used as the first circle, I would expect a similar error. I figured that something else must be happening.

I pulled the end mill from the machine and immediately found the issue.

The bit on the right is the bit that was used to cut and the bit on the left is a newer bit. Both are 0.125" diameter 2 flute up cut. You can see that the cutting edges of the bit on the left are completely non existent. Cutting the steel broke the forward cutting teeth clean off. By the end of the second circle, the bit was not really cutting the steel but more like pushing it out of the way. This is likely why the circle came out 0.031" larger in diameter. The bit was probably flexing that much as it attempted to cut with no cutting edges.

Oh well, I got the two circles cut that I wanted and I learned that my machine cant really cut steel. I was under no delusion that it could but it was a fun experiment regardless.

The first circle fits pretty nicely in the hole that it is destined to plug.

The second circle will need some more love to get it to fit.

Finally after 5 months of frustration I have the 4 holes in the big pot soldered.

Now I have to put two new holes in the pot for the sight glass then I have to solder the valves on.

I am not sure how I am going to handle the ugly look of the pot. I may go nuts with some brass wire wheels and see where that gets me.