Finding a machanical way to extruder long hollow tubes that remain straight

[Portiss]

Hi all 😃

wondering if anyone has any recommendations for tools or equipment that can make hollow clay tubes such as the ones that I have attached. I currently build them by hand and it is a long and tedious process. I am looking to find a way to mechanise the process so that I can create more in the time that I am working. My main concern is that the clay will warp when fired and not achieve the straight formation I am after.

The tube's rough dimensions are 800mm x 100mm x 10mm however can be slightly altered. I know I will have to get a custom die created which is fine. Another concern is the length of the tube 800mm which is quite sizeable and that it may warp/break during the extrusion process.

I have thought of two methods to do this:

 

Wall Mounted Hand Extruder

- Vertically extrude the clay form and then once reach the desired length, insert a tube on the inside of the shape, cut and then carry off to dry.

 

Mechanical Extruder (Pugging Machine)
- This method is pretty straightforward forward and I was wondering if pugging machines can extrude if it has a custom die piece on the end. 

Additionally, are there any tips, production methods, or treatments to ensure that they do not warp? What I understand so far is using harder clay and ensuring that there is ample dry time.

Greatly appreciate some support

[Mark C.]

You will will need a power extruder like the Peter pugger with a die in the end to get that long of a tube. Or a custom longer barrel hand extruder that holds more clay. My brent extrude can make those all day except not that long as it only hold 10#s of clay you will need say -20#s of clay to make 32 inch long tube at 4 inch diameter.

The issue with a power one it the tube will come out horizontal which can make d=for out of round issues vs the down staright froma. wall mounted home made one which is cheaper to fabricate and use-just have a metal fab shop weld it up and make the dies which also require a center die thats held off for the hollow part. The dies are easy and you can have them custom made as well.

[Portiss]

@Mark C. thanks for the reply.

I'm trying to wrap my head around the use of a pug mill and its ability to extrude. So de-airing pug mills can extrude if you place a custom die on the nose? There are numerous pug mill brands out there: Peter Pugger, Venco, BlueBird Clay, Nidec etc.

Ideally, I would not like to spend a large amount on a mechanical extruder however the hand extrusion seems a lot more finicky and cumbersome when extruding vertically. Willing to purchase a mechanical extruder if it is best fitting. Will greatly support my studio and production staff. 

I guess a way to mitigate the horizontal issue is also place a tube into the clay tube as it comes out?

[Mark C.]

I own two peter puggers and you can bolt a reduction die on nose but keep in mind the more you reduce the slower output dial  ikt down as the restriction is more than an open end extrusion. I will add I never have reduced the output but they sell foe example a handle die 9I may even have one as I bought them used with items in some boxes. I have shot many a hollow tube in hand extruder with great results on a vertical plane. Your clay will have to have a thick wall and be on the hard side to stay round  with zero flat spots. Peter pugger makes a tile extruder-they are very costly. I would investigate a lot before buying one. Vencos are from your neck of the woods -if they have the deairing thay can work as well but I know very little about them . But they have a long history. You can call Petter Pugger as well as Bailey as they make a nice pugger as well and talk story with them about your needs. The Nidec have poor support and some chipping/rust issues I know about. Blue Birds I feel are not in the same league as the others . The die should be the easy part. Keeping it round will be the hard part. The diameter is near the machines barrel size to so thats and issue as well that need to be looked at.

[Mark C.]

There is a business near Sacramento Ca that makes sewer pipe in red clay up to two feet in diameter as well as smaller . Youi could talk to them as they extrude or mold the pipes ? not sure of their process but that do an art program as well every year. I can get you the  contact info I thnk if you want it. They are in the pipe/tube business for the last 100 years

[PeterH]

6 hours ago, Portiss said:

Wall Mounted Hand Extruder

- Vertically extrude the clay form and then once reach the desired length, insert a tube on the inside of the shape, cut and then carry off to dry.

Any relevance?

 

[Jeff Longtin]

Peter Pugger makes a de-airing hydraulic extruder that's very nice. Not cheap, and very heavy, but they make handles in no time. (The chamber is about 8" wide and 12" deep.)

At the pottery shop they were used in the vertical position to extrude handles.  They can also be mounted horizontally if that's your preference.

(The pugmill actually mixes the clay, before extruding, while the extruder does not.)

As far as maintaining the round shape I wonder if the tubes were extruded on to "half moon" shaped trays if they wouldn't retain their roundness? (Like baguette baking pans?)

 

 

 

[Dick White]

Bailey makes a pneumatic power extruder with a 9" square expansion box on the bottom that could have a 4" round die. It holds 27 pounds of clay - after the extrusion is complete, so it will start with much more clay in the barrel. It is a vertical extrusion, so the only limit on the length of the extrusion is how high off the floor you mount it. It is quite expensive, but cheaper than a good pugmill adapted to extruding (with all the problems noted above).

[Mark C.]

I have seen that Bailey power extruder as a potter I know has one. This may be your best option. They cost about $1,650 plus shipping-very reasonable I feel

Edited June 28 by Mark C.

[Denice]

When I was building my southwestern house I need 6 one foot wide 3 foot long red clay sewer pipe for decorative use.   Couldn't find them near by so I called a sewer pipe company a couple of hundred miles from me.   They were also out of business but would do custom orders  paid in advance.   The freight on them was expensive so we took a nice drive and picked them up.    You may have a sewer pipe factory near you that can help you or does custom work.     Denice

[Pres]

Another possible mechanical alternative would be the Bailey big die extruder barrel. This will hold extra clay and by using a smaller die than the big barrel usually uses of plywood the extra clay in the barrel. even constant controlled pressure with the lever bar is needed to not end up with "pump" lines. I used this barrel years ago while teaching HS.

 

best,

Pres