2" Diameter Shotgun enroute

[BigSwede]

No probs Scribbler.

The doubler plates do serve a function beyond eye candy. They are drilled and tapped for 1/4" Female pipe taper - The UK has a near equivalent, BSPP I think, which is also a tapered thread. Without the doubler, any female thread would only have about 0.055" / 1.4mm of actual copper to thread into. Not real secure, and hard to do straight without fixturing or machine tool type setups.

I made my doublers from regular 2" couplers. Their internal diameter is made to wrap around 2" pipe. They are about 5" long. I made a paper pattern and first cut a ring off from the coupler, then cut out the doubler shapes (roughly) from the ring. The paper pattern had punch marks. I taped it to the ring, center popped all the locations (6 rivets and one pipe connection) and then cut out the doubler from the ring. Hand tools, files, shaped it nice. I'd guess most guys here think it's machine tool stuff, but most of this is hand work.

Rivets - got to source some solid copper round head rivets. Not easy to find these days, but I know the UK has some. IIRC you are UK, correct? They are also on Amazon. I recommend 3/32" rivets. The ones I used are 1/8" stem, the hemisphere is 0,215" or so diameter.

You drill the rivet holes. The rivets go in from the inside out. Look at this thread: http://homedistiller.org/forum/viewtopi ... 17&t=48882

It has some riveting details. Unfortunately, you need the tools to fix the rivets and round the stems.

Once riveted, if done properly, it's tighter than hell and very strong. I solder only from the inside on top of the rivet heads in there, and it seals instantly. I don't solder the interface of the doubler on the outside. Not needed.

With all six rivets done, the center is drilled for the copper ferrules, which were already female threaded for the female pipe taper. There's plenty of copper meat to do a good job of it. The copper ferrules I turned from copper bar stock. But this isn't needed, you can simply thread those holes, leave them female taper pipe, and install brass hose barbs or whatever you want.

There are commercial fittings available, called "copper flush bushing adapters" which look just like them, simple copper rounds threaded female for a pipe taper. Like these:

http://www.zoro.com/g/Wrot%20Copper%20F ... 21783/None" onclick="window.open(this.href);return false;" rel="nofollow

HTH. It's an elaborate way to make what should be a simple device, but if it's something you want to pursue, I'd say "Go for it!"

And the ferrules:

[Scribbler]

Sweet! Thanks for the walk through! (I'm in Canada, but this isn't a rushed weekend project for me so I think I'm going to try tracking down the parts! )




Thanks for the thread you linked as well. Gonna have some reading to do!

[Scribbler]

Edit to delete: followed those links. Removing a redundant question.

[BigSwede]

If it helps, note in those pics that I drilled only two rivet holes initially. The rest of the locations have only a center punch. The plate is riveted on with just the two, and THEN the remainder of the holes are drilled. This ensures alignment of the holes.

PM me if you cannot resolve the rivet tool issue, and still want to do riveting. There are alternatives... brass round head machine screws of a similar size would look nice and not require tooling, just drills and a tap. Another alternative, I have thousands of stainless #6 "headless" aviation screws... picture a flat head screw with no screw slot at all. You countersink the hole, the screws are flush, and the underside of the screw head is knurled so it won't turn when you tighten the nut on the other side. You'd end up with 6 shiny round spots. I think they'd look nice.

[Scribbler]

Bigswede: I think you must have invented the Swiss watch in another life! Here is another thing you have me stumped on. (Yes... Sadly this implies I am pouring over your photos and thinking about what techniques I will need to make mine in the same aesthetic ballpark... It isn't stalking, HONEST!).

In these photos:

ImageUploadedByTapatalk1400887859.193674.jpg (23.21 KiB) Viewed 911 times

ImageUploadedByTapatalk1400887889.370726.jpg (51.37 KiB) Viewed 911 times

The ferrules have my eyes watering. I'll try to explain my trouble. As I see it, you have drilled and tapped the pipe. Then you threaded (is it still called tapping when you are threading a shaft?). The inside of the ferrule is also tapped for the waterline hookup.

The pipe is round, so the threaded hole should drop away on the sides, like a saddle on a horse. (Probably a technical term for this, but I don't know it.. Parallax maybe? Viewed from straight on, the hole should be a perfect circle. 90 degrees to the side you just see a mild dish).

So when the ferrule is twisted in, there should be threads visible to the sides right?

So I thought maybe you machined a should on the ferrule by cutting a smaller diameter shaft on the end befor cutting the threads... But if that were the case, the flat bottomed shoulder ought to overhang about where the pipe curves away. But I don't see it.

The problem could be solved by cutting/sanding the proper radius into the bottom or the shoulder of the ferrule, but again, I see another problem: the saddle effect would leave longer 'wings' to either side, and they would bind at top and bottom when turning the ferrule in to the pipe!?

Is that a clear description of my confusion?

[BigSwede]

I understand what you are getting at. You're looking at two different ferrules using two different methods.

The ferrule on the riveted plate does in fact have a male thread that penetrates the tube, and of course carries a female thread internally. The ferrule male thread is 3/8 MTP... The female thread is 1/4 FTP. The doubler provides adequate stock to get several turns, more than enough to secure. In fact, the male threads aren't more than maybe 1/4" long, they barely penetrate the tube.

Tapping the doubler 3/8" pipe, since it's a taper, allows you to thread the ferrule in far enough so you really don't see the threads on the side, especially when you run a bead of solder in there.

The lower ferrule is on a liebig. It has only female threads. The base is contoured to match the liebig tube, so when it's in place, and soldered, you get the nice interface. I contoured it with an end mill the same diameter as the liebig, bit it could just as easily be done with a dremel, or by wrapping 220 wet-dry paper around the liebig tube and having at it. A solder fillet covers a lot of uneveness.

Neither of these is optimum. The first is a lot of work. The second, it's hard to line up the ferrule and hold it for soldering.

Look at page 2 of my "MixMaster" build, where I mounted a ferrule for a temperature probe. This is easiest and works best. You create a ferrule with 2 diameters, major and minor, with the minor being short and barely entering the hole in the tube. I make these with a strong friction fit. They can be soldered just like that, with the fillet covering the curvature, or better, if you have the tools, give the big tube a spot face, a flat area, just slightly larger than the ferrule major diameter. This creates a perfect joint.

There's a lot of ways to do this sort of thing without fancy tools, it's just going to take more hand work.

Look for those "flush copper reducing bushings"... They are perfect for this sort of mounting.

Long post, HTH, good luck.

[Scribbler]

So I found this piece of copper and did some drawing. Does this make any sense? I was thinking that once I made the piece, I could then start rounding off the corners and giving it a bit of a 1950's futuristic spaceship feel...

[BigSwede]

That would be different and kind of cool... A tangential water input. I'd be tempted to leave most of it square or rectangular, maybe just round off the edges a bit.

Regular C110 copper is a major bitch to machine. There is a special copper that machines, cuts, drills and taps beautifully, but I can't remember the designation off the top of my head. I am out of town now, I'll check it out when I get home.