Cone Six Throwdown: Highwater Clay's Helios


This is a bag I grabbed from my colleague (or boss?) Todd Burns‘ stash in the U of L studio. Though not really marketed as a cone 6 clay, here it is, free, so I’ll give it a shot! Some distributor sites say it is inended for cones 6-11 while the actual site claims it is intended for cones 7-11. I actually fire at cone 7, basically because my clay body doesn’t quite fit my glaze unless I do, so I thought I might as well try it. Here is the description Highwater gives “This is our grolleg-based porcelain. It is very bright and a joy to throw. Believe it or not, Helios can be fired from cone 7 – 11 with fabulous results.” I know general wisdom is to stay away from range clays like this if you are a cone 6 firer, and this may be especially bad for my in particular because the bottom of my kiln hits cone 8 while the top is around cone 4-5, which for the time being is beyond my control as I don’t own the kiln that I depend on. My solution is to put all my many, many refires up in the top so they pop their bubbles but don’t run, and all the fresh ones go down below. Anyways, back to the topic, which is: how does Helios porcelain feel to throw?

Even before I crack open the bag, I notice that it is quite hard. Leather hard. I open it and cut off a chunk anyways. I start to wedge it and at first it is crumbly, but as soon as I work it a little, it relaxes, and is in fact quite soft. The texture is very smooth and quite dense. It dries very quickly and forms a skin of dry cracking clay on the outside. So this is the first “true” porcelain that I have worked with in this test. It is pure white. I almost feel guilty setting it down in my studio where every surface apparently has something on it that makes the clay look dirty or stained. I must say, I have never worked with a pure white no-ball-clay grolleg porcelain before in any capacity, but it does have an amazing visceral appeal in the raw state. Already, it feels precious. Once it has been woken up a bit, I find that it is pleasantly plastic, about the right consistency, but is sort of slumpy. When you set a wedged chunk down in a tall cylinder as I often do, it gets shorter as it sits there. It is actually slumping as small cracks appear on the surface.

I cut a chunk off and put it on the wheel to throw a bowl. It requires, when centering, that you ease into it. No sudden movements allowed, it simply doesn’t respond to them, stands defiant of them even. Relax, slow down, and there it goes. It is both hard and soft at the same time, depending solely on how hard you try to push it, in an inverse relationship. It has enough tooth to stand up for a while, It stretches nicely. I know that I need to be careful laying it down, because it has all of a sudden gotten really insubstantial between my fingers. Somehow I can barely even tell it’s there. I manage to get the right shape, but feel that I must be cautious and leave it fairly thick down towards the bottom. It collars well, but doesn’t like to stay where I leave it. There is a slight undulation on the lip. not sure if it’s the clay’s fault or mine, but man, I really don’t like it when my pots have that. As I suspected, the bowl does not transfer off of the wheel well at all. In the slight jerkiness of prying my tile/bat off the wheel, the bowl goes eliptical on me. ugh.

On to the tumbler. It is very easy to throw a tall and thin cylinder. When throwing vertically, the tooth in this clay really shines. As I alter the shape to my classic tumbler form, it does so gladly. This clay really likes metal ribs! It manages the transfer well, but I’m still a bit nervous. It feels like if I have shaky hands, the wiggling would revert this clay to a liquid (just kidding, but it very well might collapse).

This clay is completely different than the ones review previously. In the cone six throwdown Helios was the first true porcelain, being pure white, hinting at thixotropy, and a little bit short. If you are a porcelain lover and don’t mind a bit of “wonk” in your pots, this one is quite pleasant to throw. I, on the other hand, avoid wobbles at all costs. I like my forms to appear stiff and almost machined. I think Helios is just a bit too wabi-sabi for my work, but it was fun…



  1. keith says:

    Again, an excellent right up! I do not care for the helios, even though form wise it is good for my loosey goosey throwing. It doesn’t handbuild well at all, even pulling handles you have to be careful, pull one at a time, if you let the lugs sit they dry super fast and crack. Not sure if you shock your clay or not, but throwing the whole bag down hard on the floor really loosens this clay up. Although it’s not as pure as the Helios, I prefer their P-10 porcelain. It’s more forgiving, easier to build with and alter but sacrifices the whiteness (very grey in reduction, although still nice white in ox). Also, P-10 is waaaaay cheaper than helios – just sayin… cause I am cheap.

  2. Jeff Campana says:

    I am actually about to order a bag of P-5 from them. I think it is the cone 6-adjusted version of P-10. I really like Highwater so far, even though I haven’t found the right one from them, hoping P-5 is the answer. Whiteness is not my primary concern, but some firing tests I did are telling me my beloved #213 is gonna be too yellow for my bright glazes. :(

  3. John Bauman says:

    Interesting review.

    I have a box of Helios that I’ll be cracking open next week. From your description it sounds like the {cue Wagnerian music} anti-Coleman porcelain where throwing is concerned.

    I’ve been able to throw both Coleman and Turner porcelains to the same finished sizes as any plastic stoneware — with this one caveot: On a plaster bat it is really hard to reseat the base if it doesn’t start out close to the middle. And Coleman’s never gets too chalky or fragile either.

    But I don’t use porcelain for its whiteness. So, though it seems white to me, you might find it less so.

  4. Page Pottery says:

    We use to use Helios and it was great but had some issues. Our Studio mate Kim Dryden uses it and loves it.
    We use Highwaters 1/2 and 1/2 (half P5 porcelain & half Phoenix) Its pretty white with out the limitations.

    I would use B-mix or Coleman’s if I could afford the shipping. We are cheep too=)

    Good Luck we love this series of post!

  5. Page Pottery says:

    Oops! 1/2 and 1/2 is half P-10 and half Phoenix.

    It becomes vitrified from cone 6-10. Its is nice to be so versatile. I think its even a good Raku Clay Body

    Keep up the good work=)

  6. ellen says:

    have you considered Miller 550? it’s a laguna, cone 10, but likes cone 7 very much!

    It does bloat on refiring, though.

    I am using all different porcelains from a friend’s discards, but am missing my 550. it’s similar to helios, it’s a grolleg porc. and smooooth

  7. Jeff Campana says:

    I have fallen in love with Laguna #16 (Miller 617), so my search has ended. More on that in a couple days, when I get some time to write again.

  8. Jeff;
    Thanks for the post. I’ve been using Helios for 6 months and now that the boxes I have bought are finally gone, I will NEVER use it again. Glaze fit is horrible. I have worked with several of the low-med glazes from MC6G book and most craze immediately if not in a couple of weeks. Shame on me, I have lost many pieces to that blasted late craze. Firing it higher helps the crazing but it warps on thin pieces so badly that forget any lids. Unfortunately our local dealer (who is outstanding by the way) has it listed as cone 4-7. Looking for a cone six body that is still very white, smooth to the hand but behaves itself……… it a pipe dream! Time will tell

  9. Jeff Campana says:


    Laguna 16 (aka wc617) turned out to be a FANTASTIC clay. Translucent, Pure white, super smooth, great fit. I highly recommend it. I have gone through 2500 pounds of it. I have since gone back to mixing as I am now in a studio with a very nice pug mill, but I keep some of the 16 on hand for cups and smaller things. The clay I mix is ultra forgiving but not quite as beautiful. The glaze fit issues with helios are purely due to the fact that it is a Highfire porcelain. Glazes never fit underfired clay.

  10. What’s funny about this article is that I agree with just about everything written here, and still love to use Helios. I will say I haven’t had glaze fit issues, but that can be chalked up to the fact that I fire to cone 10.

    The thing about lids is absolutely true, and I usually let pieces get 1/2 way to leather hard before removing them from bats.

    I dunno, now you’ve listed off all the problems with this clay it’s harder to justify using it. I will say that it is the only bagged porcelain I’ve ever used, and I want to try that Laguna 16.

    …I’ve got like 200 lbs of this stuff kicking around though. They had a shortage when I needed clay for my undergrad thesis, so I had to purchase a 500lb batch.

    One day I’ll finish it all off…

  11. Janice Hill says:

    I agree with everything you’ve said too. To add to it, on the plus side, its thixotropic quality is amazing, which means that the more you manipulate it the more plastic it becomes. So if you keep to simple shapes and let it set up, you can manipulate the surface like there’s no tomorrow (Google Lora Rust!). On the minus side,
    Helios will NOT defy gravity. I flopped way too many bottles for it to be useful to me. Also I throw pretty thin; as long as I kept my shapes on the straight and narrow, it worked fine,but if I tied to alter the piece while on the wheel, it would flop in the most ignominious of ways.

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