Extruders and WD-40

[JohnnyK]

I've occasionally come across the suggestion to coat the inside of an extruder with WD-40 before filling with clay. I tried it once and, after squirting the hollow form, the clay that's left in the extruder is contaminated with the WD-40. Is this leftover clay salvageable? How do you eliminate the WD-40 that's left on the clay? 

Not knowing the answers, I've gone to putting the clay in thin plastic bags that I get from the produce dept of my local grocery store. At least with the bags, I can salvage most of the leftovers to reuse, and the extruder tube stays fairly clean with little residual clay left in it...

[Mark C.]

oil burns out in clay and works fine. I do not like working with oily clay so I never do that myself  but do use spray vegetable oil a lot for release on glass forms for flat stuff and the oil burns off on those forms just fine

[neilestrick]

I don't know what effect WD-40 will have on the recycled clay. Since it's a water repellent I imagine it could do some strange things if it was in a high enough concentration. I would try wedging and using some of it and see what it does. It'll burn out in the firing, so it only matters how it behaves during use.

[Callie Beller Diesel]

I think it would depend on how much contamination there is. If you’re throwing a few hundred grams of contaminated clay in a 5 gallon bucket of reclaim, it’s probably fine. If you’ve been separating it all out, I’d use it for those jobs where you need a throwaway: cone packs, plaster moulds, maybe glaze cookies.

[Piedmont Pottery]

Instead of using a lubricant we put the clay to be extruded into a thin plastic bag open at the die end.  Clean up is just the die and the last few centimeters of the extruder tube.

[Denice]

I  used bags that the newspaper came in,  I no longer take the paper so I just put the clay directly in it.  My extruder is homemade so I think it has more areas for the clay to hide in.    When I am finished with it I take it apart and let it soak for a day before I clean it.     Denice

[oldlady]

mistake.  forgot the extruder part.

Edited October 8, 2023 by oldlady
remove

[JohnnyK]

On 8/11/2023 at 8:21 AM, Piedmont Pottery said:

Instead of using a lubricant we put the clay to be extruded into a thin plastic bag open at the die end.  Clean up is just the die and the last few centimeters of the extruder tube.

I've gotten to using plastic bags in the extruder as well as using reclaimed clay where I find the consistency of the overall slug to be less critical than when I'm throwing...