flak stand dimensions

[Dirge]

Sorry about this I don't believe it's not there somewhere but I can find lots of nice pictures of flake stands but is there a minimum diameter tube you would recommend? This is to go on a home made all copper 6 gall pot still with a lift off head which i expect to seal with paste so I've no serious concern about the danger of it blocking and pressurising beyond the mess it would make.

Thanks!

[Usge]

1/2" to 3/4 nominal. (add .125" for OD size) is what I would use.

[Dirge]

Oh that's quite big. Have to organise my bending!

Thank you.

[Usge]

Get the soft/annealed coil. It's already going in a circle to start with and annealed for bending. Use a cylinder or tank or etc? and bend slowly. Some people fill it with sand, salt and/or sugar before this capping both ends to keep it from flattening too much. Then blow out (air pressure) the stuff after..which isn't always easy. Some people use salt/sugar and dissolve it after with water.

Make sure the rungs drop evenly each turn or you'll get flat spots. You can build a template for that, or just mark it out on whatever you are bending on. Then solder supports on 3 sides tacking each rung measured distance from the previous as you go. Some people cut equal lenghts of 1/4" tube pieces to act as spacers...between each rung in 3 different vertical locations. Lots of different ways you can do it. The main thing is make sure there aren't any flat spots in it. You don't want one rung hanging or bent lower than others...or following a different curve downwards...where the distillate can "pool" inside the worm.

[Dirge]

This condensor business has suddenly become complex. The cost of tube for a coil is extortionate. I don't like the idea of running a tap full on for hours; we're not really short of water here but it goes against all my upbringing somehow. A liebig won't work without that rate of feed, right? The 'trad' still I'm building probably needs a flake stand just for completeness but I can change it later. I need an economical solution to get me going.

In a coil, presumably the same rules still apply as earlier up the vapour path; as large a bore as possible so the vapour travels as smooth as silk? If I go down to 1/2"OD in a coil it's going to increase smearing? (I can get 1/2"OD relatively easily but still a hell of a price.)

And as the vapour is (hopefully) condensing I could do a couple of turns of larger tube then step down but only if i was very careful to leave no step at all in the bottom of the join and a gentle taper round the rest of the tube. Don't like the sound of trying to do it but all options are being chewed over

Learning to waste water happily is becoming more attractive...any advice on this one?

[Prairiepiss]

Use a tank and recirculate the water with a pump. Less waste.

[Usge]

Not 1/2 OD...1/2 nominal (which is 5/8" OD). You can run 3/4 "nominal" which is 7/8" OD as well. That's a pretty typical range. Personally, I think a 1" nominal worm would be overkill for a 6 gal pot. 1/2 to 3/4 nominal is plenty if you ask me.

You don't have to build a copper flake stand. That's not a requirement. So long as the bucket/container for your worm is at least as large as your pot, you should be able to complete a run without having to recirculate it. Some people just use a trash can (10-15 gals) and hang/suspend the coil with a cross at the top. Push the business end out a hole towards the bottom using a grommet or ? to seal it up. And you are in business. When you aren't running, just put the lid on the trash can. If you need to touch up the cooling...run a garden hose down from top to the bottom with cold water and let the hot overflow top. You can always build a shiny copper one later reusing your worm if you want to.

[Dirge]

OK I'm sorted for tube. The trick was to contact a commercial deep freezer maintenance co. who had lots of offcuts of 5/8" OD. Once again a little cash and the deal was done.

So I know where I'm going on this one now.

Thanks again for your advice gents..