Friday, April 3, 2009

Perhaps I should have listened to my gut...

The past few weeks have been somewhat frustrating to say the least. I have recently changed clay bodies. Having had repeated problems with the one I had been using, I decided to try a new one.

Great. No problem. Until I opened up my pug mill to clean it out. Ughhhh!

So porcelain will react with certain alloys in metals. I knew this (although I confess I didn't exactly know what 'react' meant) and researched pug mills accordingly. When it came time to buy one, due to some injuries, the Peter Pugger VPM-9 was recommended to me. After reading testimonials, I decided 'sure, why not!' and that's the one I brought home. After about a month of loving this particular little machine, I started to find little hard chunks in my clay as I was throwing. These pesky, hard bits made throwing and trimming incredibly frustrating, and after firing, led to lots and lots of seconds. These bits bulged out and fired a different color. Grrrr! I figured it was just more 'stuff' in my clay, that I had been having issues with for some time, but when it was time to clean out Piggy (which the pug mill was affectionately nicknamed) I was shocked to find those pesky hard bits stuck to the inside of the pug mill. And they appeared to be stuck ONLY where there was some over-spray paint on the inside of the mixing barrel.

You'll notice in the image on the top, all the little bits stuck to the inside of the pug mill. When they finally break off, they take the paint with them. Turning your attention to the image on the bottom, you'll see that there is absolutely NO little bits stuck to the parts of the pug mill that have no paint.
I called Peter Pugger for some advice and they suggested Airplane Paint Remover so that's what we did. Sprayed the inside, waited, scrubbed out all the paint we could. And now we wait. I hope, hope, hope (finger's crossed) that these little chunkies don't return. I've got about three more weeks to find out. (Sigh) The most maddening part is, I WANTED the stainless steel pug mill from Venco, (which was considerably more expensive) but got the Peter Pugger on recommendations from my supplier and other users. Perhaps I should have listened to my gut...


  1. Agggh! It's a wonder there isn't a known syndrome, called something like Potter's Slow Descent into Insanity!

    Fingers crossed that your problems are over now.

  2. Wow! What a tough go for you lately Melissa. I'll keep my fingers crossed for you that things will be on the up and up for you!!

  3. dang pugmills! My clay supplier has been using an old one that is shedding large metal shavings into the clay.....and apparently doesn't want to replace the machine. My last 700 pounds of clay all came with "free metal". Guess I can't buy that clay anymore. Hope your issue is resolved.

  4. Well see now, I had no idea. I thought the peter pugger was the better pugger. I am going to remember this and when I finally save the $$$$, I'm definitely getting a venco or something stainless steel. I learned my lesson on non-stainless steel with my ebay homemade extruder. Thanks!

  5. I actually think the problem may be with the state of the clay you are feeding the pug. Porcelain is tricky sometimes to recycle and I have come across some bodies that need to be completely dried, crushed and slaked before reconstituting sucessfully. I use a peter pugger almost daily ( for stoneware) and I think they are meant to be left full, Are you attempting to completly empty the mill after use? Are you adding leather or drier scraps to the mix?

  6. Oh Goodness! Sorry ot hear that Melissa. I just bought my VPM-9 early this week and I hope I don't encounter this issue. I am using a stoneware though, so I don't know if this would be a porcelain issue. I got it on high rcommndations from several potters.

  7. Stoneware does not have this problem. So don't worry there. Other than this reaction, I've enjoyed the machine. And now it appears the company has resolved the issue. I've been impressed with their customer service.
    Enjoy your VPM-9!

  8. Why don't you throw the pugger at Peter. Sounds like the bits coming of are from the pug mill? Hence Peter should fix.
    Venco, made in Aus. must be the best.
    And the Aussie dollar is only 0.72USD a bargain buy.
    My fingers and toes are crossed for you.

  9. Where did you hear that "porcelain will react with certain alloys in metals"? just wondering...

  10. Well, that's just based on my own observations, the observations of other potters using cone 6 porcelain in aluminum pug mills, and the observatoins of the pug mill manufacturer. It's hard to find info on this, and hard to pinpoint exactly what is reacting. My own guesses are that it has to do with potassium (an active flux in mid-range porcelain bodies) reacting with the aluminum. But then, that's just my mildly-educated guess from what I can remember about high school chemistry....

  11. Hi Melissa,
    I am thinking of buying a Peter Pugger VPM20 (aluminium mixing chamber with a stainless auger)to process my porcelain with. I might be getting it for a good price, but still expensive compared to other pugs! From your experience, is this worth getting? And did you have any luck with your Airplane paint remover?! I'm amazed you even found such a thing for sale! All the best, Josh

  12. Hi Josh;

    If you're planning on letting your porcelain sit in the pug mill AT ALL, then you really need the stainless steel pug mill. (Peter Pugger does make a stainless steel version now and Shimpo also has one). I like the mixing feature that's unique to the Peter Pugger, but it definitely needs to be stainless.

    Mine has gotten to the point where if the clay sits still in there for 2 days or more, I get M&M sized hard bits that cause all sorts of problems when throwing, trimming and firing.

    While the airplane paint remover got rid of the paint on the inside of the chamber, it did not get rid of the problem. It's the actual aluminum of the barrel that seems to be the problem, and the chemical reaction between the aluminum and the porcelain.

    The amount of work that I have lost from the problems this has given me has more than added up to a brand new stainless steel pug mill. My two cents is to choke down the expense and get the stainless one!

  13. It is crazy that you continue to use this pugger. Given how fond potters are of this brand, you should be able to sell it for a good price and buy the one you want.

    1. What can I say? I'm persistent.
      My persistence paid off and I was able to resolve this issue.
      I'm glad I stuck this problem out until its resolution. I absolutely love this machine now and wouldn't trade it for the world.

    2. I have heard about the issues with porcelain..but I don't use porcelain and haven't had any issues. Heading over to the above linked post so I can read about the resolution. ;) I've had my "piggy" for about 8 months and absolutely LOVE it. <3