Building PVC Liebig

[zirtico]

Up to now, I've had my 1/2" copper pipe submerged in a leaky bucket of water, which does not submerged the entire 3' of pipe and has no flowing water, both of which render it inefficient. It takes FOREVER to run a single batch because if I try and run harder, heating power quickly exceeds the low condensing capacity, so I've decided I gotta build a PVC condenser around my copper. I was thinking of using 3/4" PVC around my 1/2" pipe and having the PVC enclose all the 3' of copper. Once I get the two caps for both ends of the condenser and drill the appropriate holes, will PVC cement be sufficient to create a decent seal between the copper and PVC? And between the hose barb (in/out) connections and the PVC? I want to have a good idea about this before I go out and build it.

[StillLearning1]

Save the extra cash and use copper to jacket your liebig. It will last forever and you will be glad you did. It shouldn't cost you all that much extra.

[S-Cackalacky]

I would advise that the best solution is all copper. That said, I built mine with PVC (1") over 1/2" copper. For the initial part of the build, I used PVC cement on all the connections. I then used an epoxy putty (2 part) that you knead together, roll into about 1/8" strips and work into each joint. It still leaked a little, so I used silicone sealant and generously applied it. I've been using it for about 8 or 9 months with no problems. Another problem with PVC is that it expands and contracts at a different rate than the copper vapor tube. That can also cause leak problems over time. I think my saving grace is that I pump a lot of water through the jacket and that keeps the PVC/copper fairly cool and avoids some of the expansion/contraction differential. If I were to run a proper heat gradient, along the length of the liebig, I think I might have a problem.

So, the long and the short of it - PVC will work if properly constructed, but copper is better.

[thatguy1313]

Just built a PVC liebig. 1" PVC over 1/2" copper with a turbulator (#4 copper wire wrapped around the copper in a spiral) . I drilled holes in the two PVC endcaps so that it would be very snug to the copper and sealed with JB weld. I also used JB weld to seal two 1/2" couplers in the PVC to run the cooling lines in. Worked like a charm. No leaks and didn't get near hot enough to affect the PVC. I use an pond pump in a cooler of water with just a trickle of water coming out of the output. No huffing or anything. Very happy.

[zirtico]

Nice. Which parts exactly did you use for water inlets/outlets? Hose barbs?

I considered using copper for my Liebig but I don't want to have to buy more 6' piping just to use 2-3' of it, as it's not cheap out here. I was just wondering what would bond the PVC to the copper so if JB Weld works, I'll just use that. Should be a very simple build, but I do want to have the right stuff when I start so it doesn't create more problems rather than solving existing ones...

[S-Cackalacky]

For my cooling water connections I used 1/2" nylon elbow fittings from Lowe's. One side is threaded and the other is barbed. I drilled my holes where the end caps overlap the PVC tube, applied PVC cement and threaded the fittings into the holes. I used an epoxy putty that's similar to JB Weld to seal around all the connections. I like the putty because I can roll it out into spagetti strands and work it into the connection joints easily. The hoses I use (clear vinyl) slip onto the barbs fairly easy and I haven't had to use hose clamps. Before applying the putty, I roughed up the PVC, nylon and copper to get a good bond.

Like I said in my previous post, I still had some small leaks around some of the joints and had to apply some silicone sealant. If I had thought about it at the time, I would have used a spray sealant like Flex Seal or Rust-O-Leum. The stuff from the tube is a messy application.

One thing I don't like about the PVC build is that you have to be somewhat gentle with it. If you torque down on a fitting to hard, the epoxy will break and leak. I had that happen soon after I finished my build. I'll probably end up rebuilding with all copper at some point just because of the fragile nature of the PVC build.

[thatguy1313]

I JB welded some 1/2" copper couplers into the PVC then shoved some hose barbs in that. Don't ask me why the copper couplers. Just seemed like a good idea at the time. You could probably just drill holes in the PVC and JB weld the hose barbs in.

[Hound Dog]

Seem like after you buy the JB Weld, the silicone, the Flex Seal, the extra fittings, you could just buy one piece of 3/4" copper and two fittings and have a liebig that will last a lifetime. Just thinking out loud......

[NZChris]

Drill out a compression fitting so that the condenser pipe goes right through it.

That goes into a tee. Put a barrel on the other end of the tee so that you can push a clear flexible PVC water jacket tube over it. Silicone will help to seal the tube to the barrel.

Put whatever water fitting you want on the inlet to the tee.

You can do exactly the same for the top of the Liebig, but if you want cheap and quick, you can just poke the condenser pipe through the wall of the outer PVC as I did with one that is still ok thirty years later. The top will only leak for a few seconds until the siphon takes over. If it leaks, it will suck air, which you can consider an annoyance, or a tell tale that the water is still running ok. I let mine leak.

[zirtico]

So I took the advice and built an all-copper Liebig. My inner pipe is 1/2" and outer is 3/4" copper. I essentially soldered two 3/4"-1/2" reducers onto each end of the 3/4" pipe, drilled a small hole on each reducer/pipe joint, and soldered brass hose barbs into each hole on either end. I then pushed the 1/2" pipe through the 3/4" outer jacket and soldered the 1/2" and 3/4" pipes together at each end.

I've seen much more complicated plans, but all my joints are soldered up and should last a long time and provide effective cooling (or at least MUCH more effective than having wet towels and only 1' of my pipe submerged in a bucket)!!!! Being able to up the water flow to control cooling is also very welcome as is the 6x increase in heat transfer coefficient! I used to be lazy to do a run because my damn still used to take an exceptional amount of labour to keep the wet towels wet and run the still slower than I'd like on stripping runs due to limited condensing power. I'm so glad I can now just focus on collecting product and making cuts rather than sweatily toiling away for hours to keep wet towels wet.

[DAD300]

1.5" pvc over a keg spear...tight drilled caps and JB Weld...has never leaked! More than three years old...maybe 30 runs

[nomoon]

I know I'm digging up an old post but does the heat from the condenser melt the PVC at all? The hamsters in my head are running about with an idea...

[DAD300]

No the pvc will not be melted. At the top joint it may be exposed to ~180 deg F...

[still_stirrin]

....The hamsters in my head are running about with an idea...

I just hope they don't take a "crap" in there!

[S-Cackalacky]

I've never had a problem with mine. I run fairly low heat on the boiler, but I suspect that no matter how hard you run it, it's only going to get as hot as the liquid that's boiling. I was warned by other members here when I built it that the heat expansion differential between the PVC and copper might cause it to leak, but I have never experienced that.

It's a less expensive build, but I remember it being a PITA. It's a matter of the cost of two or three feet of 3/4" copper pipe and 2 copper tees. In hindsight, it would have been better to spend 20 or 30 dollars for the parts to make it an easier build.

[still_stirrin]

The advantage to the design is that it takes the copper out of the descending vapor line...certainly something to consider. But fabrication complexity is, or can be a big concern too, especially for some builders.

Copper is very efficient at heat transfer and much easier to solder. PVC..well, it just doesn't seem it would be robust enough. But the proof is in the pudding...."pudding" it through run after run!
ss

[S-Cackalacky]

1.5" pvc over a keg spear...tight drilled caps and JB Weld...has never leaked! More than three years old...maybe 30 runs

PVC Jacket Liebig.jpg

Dad, I'm a little stumped by the design. I'm familiar with the other ss keg spear liebig w/csst that you've posted here on the forums, but I'm puzzled about how this one works. Is there a link to a build thread for it, or a design drawing?

[thecroweater]

I really can't believe you guys are promoting a really B grade way of going about this. Fact is sooner or later PVC and/or the seals or both will fail and it is likely to happen at the worst time. Just because you might get away with some short coming for awhile does not make it a great idea and this most certainly is not a great idea

[nomoon]

....The hamsters in my head are running about with an idea...

I just hope they don't take a "crap" in there!

My hamsters have treated me very well thank you. They have helped me construct some pretty cool things (and some really tasty cider and wine). I built something but it needs to be tested before I post anything. If it works then I will not have any issues. If it doesn't, then the hamsters and I go back to the drawing boards.

[Tater]

I really can't believe you guys are promoting a really B grade way of going about this. Fact is sooner or later PVC and/or the seals or both will fail and it is likely to happen at the worst time. Just because you might get away with some short coming for awhile does not make it a great idea and this most certainly is not a great idea

Plus 1

[S-Cackalacky]

I really can't believe you guys are promoting a really B grade way of going about this. Fact is sooner or later PVC and/or the seals or both will fail and it is likely to happen at the worst time. Just because you might get away with some short coming for awhile does not make it a great idea and this most certainly is not a great idea

Are you speaking from experience there Crow? As I said before, If I had it to do over, I would go with copper, but I've been using my PVC liebig for two years with no problems. I've had to repair or replace other things on my still and I'll do the same with my liebig if it becomes necessary. I would suggest that if something works and works well, it's not "B grade" - it's just different. The only reason I would discourage anyone to try it would be because of the difficulty in using PVC compared to copper - NOT because it's somehow an inferior material.

Posted while Tater posted.

[Tater]

The only reason I would discourage anyone to try it would be because of the difficulty in using PVC compared to copper - NOT because it's somehow an inferior material.

Posted while Tater posted.

But compared to copper pvc is a inferior product.Hell Id at least thought if someone was going to try it they would at least used cpvc .When dealing with a vapor that's flammable Id be very very careful.What you use is your business .

[thecroweater]

C'Mon mate be serious, by your own admission it has from time to time sprung leaks, I guess ya can just keep patching it up with glue, putty and silicon. So how bout the new guy that reads this and makes his great plastic elastic and parks in full sunlight, seen what happens to PVC in full sunlight say behind a window . It goes as brittle as candy fairly. Quickly. It IS an inferior material and there is absolutely no question of that. Use what ya like but I'm sure I'm not the only member that would call bullshit on it being equal to copper or stainless, hell even steel would be safer .

[S-Cackalacky]

Tater, I imagine if you got flames coming out of your still, you have a lot more to worry about than your water jacket melting. Hell, it might even put out the fire - being full of water and all. To be clear - having done it myself, I don't recommend building a PVC liebig. But, if you do, I wouldn't consider it to be an inferior liebig as long as it's well built.

[Tater]

Tater, I imagine if you got flames coming out of your still, you have a lot more to worry about than your water jacket melting. Hell, it might even put out the fire - being full of water and all. To be clear - having done it myself, I don't recommend building a PVC liebig. But, if you do, I wouldn't consider it to be an inferior liebig as long as it's well built.

people water and electricity don't mix well either

[S-Cackalacky]

C'Mon mate be serious, by your own admission it has from time to time sprung leaks, I guess ya can just keep patching it up with glue, putty and silicon. So how bout the new guy that reads this and makes his great plastic elastic and parks in full sunlight, seen what happens to PVC in full sunlight say behind a window . It goes as brittle as candy fairly. Quickly. It IS an inferior material and there is absolutely no question of that. Use what ya like but I'm sure I'm not the only member that would call bullshit on it being equal to copper or stainless, hell even steel would be safer .

I don't think I said that it has "from time to time sprung leaks". It leaked when I first used it and I fixed the leaks and it hasn't leaked since. I'm not sure why there's all this animosity about using PVC for a water jacket. It seems to be coming from people who have no experience with it and have some kind of aversion to all things non-traditional. All the things that folks here warned me about when I first built mine just simply haven't proven to be true. Maybe because I could possibly drop something on a copper liebig and put a big kink in it, I should avoid using copper to build a liebig - that's just as ridiculous as your reasoning about PVC. It's just a friggin' water jacket.

[S-Cackalacky]

Well, let's see what other far fetched reasoning you can come up with to support your POV. I won't be arguing with the unreasonable - done.

[thecroweater]

Not exactly animosity just calling bullshit on bullshit. Some here have claimed that PVC is not inferior and very frankly (and I would have thought obviously ) it is. The plastic is not in contact with the spirit and with a bit of ginning around it can be made to work but it is a cheap arsed ghetto fix when for a few bux more you can build a Leibig that would last for a number of life times

[DAD300]

I have built two, with a pvc jacket over a SS Keg Spear for a vapor path. The descending ethanol never touches the PVC or any copper!

New builder has a keg. Everyone here pushes keg. That means he has a keg spear. It is easier to put a PVC jacket over a SS keg spear than copper jacket over a keg spear.

Not everyone can solder. Everyone can mix glue.

It's an alternative with dif pros and cons...and not for everyone! Just like copper is not for everyone.