Gek Posted April 14, 2020 Report Share Posted April 14, 2020 Hi everyone! I'm fairly new to the world of pottery and I like to explore unconventional combinations. I'm trying to make small objects that need to have a high weight. According to Google, fired clay should have a density between 1.5 and 2.0 g/cm^3 (gram per cubic centimeter). What I'm trying to achieve is a density between 2.5 and 3. I don't know if any special clay with that density exists, but I thought at some metods to increase common clay density. I could include in the clay metal chips, metal powders, metal oxide powders or small fragments of rocks with high densities. I use earthenware clay and could mix it with chips of copper or very fine iron powder, for example. The answer is if this is realistic or would result in a mess of cracking. I calculated that powders or chips would be 30% of the clay body in volume, or less. Could I fire something like this? tell me what you think and if you would try something different Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted April 14, 2020 Report Share Posted April 14, 2020 Off the top of my head: Mix some commercial clay body with a dense metal oxide such as iron oxide, titanium, or rutile. According to wikipedia: fired porcelain has density about 2.4 g/cc and titanium dioxide (TiO2) has density about 4.2 g/cc. so it should be a reasonable starting point. color is most likely to be near white: Other commercial clay bodies might be just useful if color is not a constraint. My suggestion is to get some porcelain clay body and some TiO2 powder and try blending them together, make some balls and fire to maturity of the porcelain. You should find a combination that would surer your purpose. alternative is to use porcelain clay body and mix rutile (a crude version of TiO2, ~2.3 g/cc) into the some and make balls and fire. If you can to for the color of the final object to be other than white: you can add iron oxide (~5.2 gm/cc) to porcelain, or to any commercial clay body. In either route, the clay must be fired to maturity, otherwise the open pores of the porcelain will lower the bulk density of the fired balls. Commercial Rutile composition implies it might be more reactive with porcelain. mixing solid metals into a clay body is not likely to be effective. most metals will oxidize unless heated in an inert environment and the metal oxides are generally less dense than the metal it self. soft metals (copper) will melt during the firing as well as oxidizing. LT Link to comment Share on other sites More sharing options...
liambesaw Posted April 14, 2020 Report Share Posted April 14, 2020 I'd go for zircopax instead of titanium following what @Magnolia Mud Research is saying. It is ceramic and may add strength as well as density. Density is 100lbs per cubic foot. You can also cast zircopax with 3% veegum binder, and fire. Not vitreous but very dense. Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted April 14, 2020 Report Share Posted April 14, 2020 according to mds zircopax density is 4.6 g/cc. http://www.aardvarkclay.com/pdf/raw_materials/SDS-Zircopax Plus-Endeka.pdf It should work also. zircopax is ceramic, but so are all metal oxides. Just not what most potters think about . take some clay add some heavy oxides and see what happens. LT Link to comment Share on other sites More sharing options...
Mark C. Posted April 15, 2020 Report Share Posted April 15, 2020 My back hurts thinking about clay weighing more than normal. Link to comment Share on other sites More sharing options...
neilestrick Posted April 15, 2020 Report Share Posted April 15, 2020 It all depends on what you're doing with these objects. Do they need to be vitrified? Will you be glazing them? Do they need to be food safe? Durable? Color? Thickness? Link to comment Share on other sites More sharing options...
Gek Posted April 15, 2020 Author Report Share Posted April 15, 2020 Thank to all of you for the suggestions. I know heavy ceramic is something very strange to think of, but this application needs weight. What i'm trying to realize are flat disks about 8 cm in diameter and 0,8 cm thick, no glaze, no decorations, no food-proof, not necessarily vetrified. You would probably laugh if i told you what those are for, so i won't hahaha. I think i'm going to try some metal oxides, starting with the cheapest, like iron oxide Link to comment Share on other sites More sharing options...
Chilly Posted April 15, 2020 Report Share Posted April 15, 2020 5 hours ago, Gek said: You would probably laugh if i told you what those are for, so i won't hahaha. If you trust us enough to accept our advice, you should let us be entertained (laugh) at your purpose. We are not the ceramic police (unless you want to fire glass chips in a ceramic bowl). Link to comment Share on other sites More sharing options...
neilestrick Posted April 15, 2020 Report Share Posted April 15, 2020 Get some zircon flour. Super dense. Link to comment Share on other sites More sharing options...
Gek Posted April 19, 2020 Author Report Share Posted April 19, 2020 On 4/15/2020 at 4:55 PM, Chilly said: If you trust us enough to accept our advice, you should let us be entertained (laugh) at your purpose. I'm trying to make some stone skipping stones. I'm a good stone skipper and i want to compete in championships, but taking away stones from rivers is illegal in Italy (i live there), so i want to make artificial stones to practice. Link to comment Share on other sites More sharing options...
Hulk Posted April 19, 2020 Report Share Posted April 19, 2020 My brother and I used to stand in a pile of rocks at pond's edge and practice skipping (also at seaside, along lake's edge, etc.) - at the quarry a few miles from our house - the rocks were all smooth discs, tons and tons available. You might find smooth rocks in bulk, e.g. https://milonstones.com/index.php/rumi-stones/ in Bergamo; they have a selection - see image, below. Get a truck load! No doubt you've found that a low release point, below the knee, shallow angle to the water, high velocity, and lots of spin all help to get many skips. My record is 58 skips - no more, too many injuries and don't have much snap left, haha. Our father could get over thirty skips quite often, which, of course, we wanted to beat; many many hours of throwing. Decades ago had 90+ mph fastball, wicked slider and late breaking curve ball. (we all had a good laugh as well!) Link to comment Share on other sites More sharing options...
Chilly Posted April 21, 2020 Report Share Posted April 21, 2020 On 4/19/2020 at 10:21 PM, Gek said: I'm trying to make some stone skipping stones. I'm a good stone skipper and i want to compete in championships, but taking away stones from rivers is illegal in Italy (i live there), so i want to make artificial stones to practice. I think that's a brilliant challenge. No ideas from me, but I wish you well in your quest. Link to comment Share on other sites More sharing options...
Gek Posted May 3, 2020 Author Report Share Posted May 3, 2020 On 4/20/2020 at 12:56 AM, Hulk said: My record is 58 skips - no more, too many injuries and don't have much snap left, haha That's really impressive! Not so many years ago that would have been the world record. I picked up stone skimming 8 months ago, so my numbers are still low. My best throws should be around 50 meters and 30 skips. Aah! Injuries, don't tell me. I put a lot of effort on getting better joint mobility to prevent that, but it's difficult. Thank you for the suggestion! Link to comment Share on other sites More sharing options...
Rahul Posted March 19, 2022 Report Share Posted March 19, 2022 Gek, may I know ur methodology for this experiment Link to comment Share on other sites More sharing options...
Hulk Posted March 19, 2022 Report Share Posted March 19, 2022 Perhaps stone skimming (aka "lobsta cutting," "ducks and drakes" (my favorite), "slipping," "frogs" ...) events will make a comeback. Many of the high-profile events were cancelled these last two years. I hope Gek was able to find a reasonable source for skimming stones - actual rocks, that is - ready to throw. A few minutes of web searching yielded several leads, per my post above (19-APR-20). There are piles of skim candidates on a few of our beaches here on the central coast of California. Some of the sedimentary rock breaks down to wafers, which weather down to skimming size. The Pacific Ocean isn't an ideal skimming pond, most of the time... Link to comment Share on other sites More sharing options...
Pyewackette Posted March 21, 2022 Report Share Posted March 21, 2022 @Hulk OMG and I used to be happy to get 3 or 4 skips LOL! Link to comment Share on other sites More sharing options...
Hulk Posted March 21, 2022 Report Share Posted March 21, 2022 heh, don't have that fastball anymore - can barely throw at all. Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted March 21, 2022 Report Share Posted March 21, 2022 They haven’t been back in 2 years. I hope they made out okay! Link to comment Share on other sites More sharing options...
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