Once there was a lengthy and informative post on this.. now it has vanished. If anyone knows where that post went, plese move this there.

I am nearly finished with building my ethanol still. However, I am having major problems attaching the copper piping to the pot/boiler. The pot is aluminum, which I bought foolishly not knowing aluminum's notoriety for resisting welds, but stainless steel is about the only other pot I can find and it is equally hard to bond. I've tried the lead free solder, I tried copper brazing, I tried aluminum brazing, I tried copper and aluminum brazing at the same time. Nothing will make them stick to each other. I was also told that mig welding wouldn't work but I can't remember if I ever actually tried and I can't afford a TIG welder even if it would work. Does anybody have any suggestions for how to make and air-tight seal that will hold the copper pipe securely to the aluminum lid? If not, where can I find a type of pot that is easier to weld to copper? The only thing I've thought of so far is buying brass plate and drilling 1" holes in them(somehow?) then screwing them to each other on both sides of the lid and brazing the brass to the copper. I'm not sure this is the best solution though.
Any suggestions would be greatly appreciated?

Also, its a reflux still. How densely should I pack the pot scrubbers?

Get a brass, compression type tank fitting.

You drill a hole in the ally lid, but the threaded part of the fitting through, secure with the backing nut. Then the copper pipe slide into the fitting on the other side of the lid and is tightened down with a spanner.

Seal the thread on the inside of the lid with some PTFE tape. The entire fitting is brass construction so nothing will melt of contaminate your ethanol.

The best way to solve your problem is like you said yourself. Or get a fitting like Anthony suggested. I'm rebuilding the lid of my still now as well. I used the regular lid that came with the pot(foodgrade) but the edges have been damaged so it's far from airtight now. I'm attaching a 2mm thick plate big enaught to cover the pot to the column, since it's quite flexible it will easily adjust itself so that no leaks occur. The edges on the pot have been coated with a layer of silicone to improove the seal. On top of the plate there will be a wooden 20mm thick "plate" that will be put under pressure which in turn will preess the metal plate against the pot. I use 2 component chemical metal to assemble my still, it's most likely not healthy so all parts of the CM has been coovered with silicone to prevent toxic chmes from leaking out of the CM.

Dont press the SSscrubbers into the still, it will most likely choke. Fasten them lenghtwise along a thin metal rod and push them up the column, that has worked best for me.

<a href="http://w1.478.telia.com/~u47804009/SSscrubbers.JPG" target="_blank">http://w1.478.telia.com/~u47804009/SSscrubbers.JPG</a>

How will you bee heating it?

I'll most likely be heating it with a hotplate or a propane camping type stove. Where would I go about getting that brass tank fitting? Also, I used lead free solder and copper brazing to connect my pipes. Do I need to coat everything with silicon like you said? I already put the pot scrubbers in and I'm not really excited about taking the pipes apart again if not neccessary. If water will flow through does that mean that it will not choke? Or will I save myself a lot of trouble later just by doing what you said? What's a good way to get a 1" inch hole in a brass plate without using a cutting torch? My torch skills are less than accurate.

Any DIY/hardware store that caters for domestic plumbing will have the tank fitting. A typical use is for the input and overflow pipes for the water tanks that go in your loft and feed your cold bathroom water.

If you used lead free solder then it should be suitable for fresh water plumbing, and thus safe for your drinking alcohol.

The best way to get a 1" hole in a brass plate is with a 1" (or slightly larger) drillbit. Not the size of drill you want to buy to use one though. A rough and ready, and rather laborious method is to draw a 1" circle on the plate, then using a small drill bit (1/8" or so) drill a series of holes inside of the line. Drill them close together and then join them all up and then knock out the raged edged disc of metal. Use a round or half-round file neaten up the hole and take it out to your 1" circle line. It's a lot more work, but it is cheap.

You'd better pull them out and fasten them on a rod. The scrubbers shouldn't be compressed, they should be put in so that they have the same lenght in the column as they had before. How else are you going to cleant the still? the SSscrubbers get very rusty very fast if left wet. How long is the column and how many scrubbers are you using?

The column is about 3.5 feet(105 cm I think?). I put 8 scrubbers in that length but they're not stainless steel. They're copper. Will this hurt it? I put some pictures of it at <a href="http://www.sensorystatic.com/still/" target="_blank">http://www.sensorystatic.com/still/</a>

I'm going to have to undo the "weld" that holds the two pipes together anyway so I'll take some pictures of the scrubbers inside. Also, how do you make it so yours is easily cleanable? If i'm going to clean mine I will have to un-solder it everytime.

Edit:
I added pictures of the pot scrubbers(4-6). Also, subtract and inch from the height cause I just cut out the joint that was holding the two pipes together. Couldn't get the brazing to melt again.

<small>[ December 06, 2002, 05:26 PM: Message edited by: photonic ]</small>

Hi, I have also built a still and am having that exact same problem. What you could try is cuting through about 3cm of your pipe so that it is split down the middle ( imagin the pipe is verticle you cut down into it at the end it will join with the lid) then cut doen into it aging another 3cm so you can flare the end. You then put the pipe through the hole in the lid and flare the end. Then you could drill throught each bit of pipe that flares out (there should be 4)and through the lid then put bolts through these holes and do them up tight. sorry if this is a bit hard to understand.

Yors still doesn't look axcactly as mine, you have one of the reflux coolers at the top and one ate the bottom. I have all 4 at the top, that's what makes it so easy to clean, I have no obstacles in the pipe until you reach the reflux coolers. Spits out better EtOH as well. About 94%.

Your scrubbers seem a bit to muck compressed, have you just molded the round scrubber into a single "piece"? the best thing is to cut the "ring" at one place and "stretch" it to it's full length.

I'm putting on my new lid today, I might post some pics of later today.

Hey, i just decided those scrubbers were destroyed. I finished my still. I got a threaded female flange and just attached a male adapter to the end of the reflux column. Do you have an email or ICQ/AIM name where you wouldn't mind me contacting you? I now am somewhat confused on the actual fermenting process. Mostly just on the "yeast nutrients." I heard somewhere tomato paste can be used, is this ture? Also, do you think a hangar would work to attach the pot scrubbers to? Thanks for all the help.

Drop me a mail at: dbsp_monte@hotmail.com

Does anybody else around here who has a still have any advice on cleanliness? I'm a little hesitant to drink from something that's been everywhere these pipes have been. Also, i need to attack some copper pot scrubber to a coat hangar without destroying them, but with them secure so i can pull the coat hangar out of the pipe and the scrubbers remain attached.

If you're concerned with cleanliness, why didn't you use new piping?

Bacteria wise, the heat and the alcohol will kill anything, so now worries there.

General dirt/grime/dust wouldn't generally be harmful if you gave the parts a clean before using them in the construction. So if your alcohol is visible clean (no particulates/colouring) then it should be ok.

If the piping was ever possibly contaminated with toxic chemicals, then even thorough cleaning would guarantee the alcohol being safe. But then you'd have to be crazy not to use new piping + fittings if there was even a remote risk of that.