kpknd Posted July 1, 2014 Share Posted July 1, 2014 It seems most people use bentonite clay for thier nozzels, I have been using fireclay I get from the college ceramic department. I have used bentonite but I think it erodes more than fireclay. Link to comment Share on other sites More sharing options...
nater Posted July 2, 2014 Share Posted July 2, 2014 (edited) I use a mixture of Hawthorn Bond fireclay, graphite and wax for nozzles. Edited July 2, 2014 by nater Link to comment Share on other sites More sharing options...
dagabu Posted July 2, 2014 Share Posted July 2, 2014 I am experimenting with Precious-Cat-Dr-Elseys-Ultra for nozzles. No, I dont own a cat or even like them but there are some that swear by it. I will press a couple nozzles with it and show you what it looks like. http://c4.wag.com/images/products/p/prc/prc-006_1z.jpg Link to comment Share on other sites More sharing options...
nater Posted July 2, 2014 Share Posted July 2, 2014 I have been experimenting with that based on Ned's recommendation. It works great for me when pressed to 5k on the comp or more. Any less, or if hand rammed, and I cannot get it well consolidated. I have also noticed that the nozzle angle in my spindles from Ben Smith are more touchy to the larger grain sizes of the kitty litter than my set from Wolter and Steve K. I think large grains do not not fill the narrow space due to the steeper angle. A smaller mesh size of nozzle material mixed with the kitty litter is perfect. For the same reason, the kitty litter by itself does not work with SBR motors either. Link to comment Share on other sites More sharing options...
Maserface Posted July 2, 2014 Share Posted July 2, 2014 I prefer the finished product when using powdered bentonite. But the precious cat litter is good too, I press all my nozzles plenty hard though (over 6000) If you are worried about erosion you might need to try a slightly damp (with water or sodium silicate) refractory powder, or dietemacious earth. What fuel are you running that is burning out your nozzles ? Link to comment Share on other sites More sharing options...
ddewees Posted July 2, 2014 Share Posted July 2, 2014 Cetco 36 mesh bentonite... you'll never use anything else. Link to comment Share on other sites More sharing options...
kpknd Posted July 2, 2014 Author Share Posted July 2, 2014 I prefer the finished product when using powdered bentonite. But the precious cat litter is good too, I press all my nozzles plenty hard though (over 6000) If you are worried about erosion you might need to try a slightly damp (with water or sodium silicate) refractory powder, or dietemacious earth. What fuel are you running that is burning out your nozzles ?I an using oiled BP with less sulfer. I have been using grog in the motors over 1# but it pitts the nozzel area of the spindle a little. The use of damp clay, does'nt that have a tendancy to affect the fuel or shrink when it dries? Link to comment Share on other sites More sharing options...
dagabu Posted July 2, 2014 Share Posted July 2, 2014 Cetco 36 mesh bentonite... you'll never use anything else. I have used it and was not impressed with the nozzle erosion. I an using oiled BP with less sulfer. I have been using grog in the motors over 1# but it pitts the nozzel area of the spindle a little. The use of damp clay, does'nt that have a tendancy to affect the fuel or shrink when it dries? The Precious Cat has no 'grit', my spindles look nice for a lot longer and the rammer faces look shiny not pitted. Depending on the clay, most of them shrink when they dry out, better to keep them at room humidity when pressing IMHO. Link to comment Share on other sites More sharing options...
MrB Posted July 2, 2014 Share Posted July 2, 2014 I use ball-milled bentonite kitty litter that i put a tiny bit of motor oil in. Not enough to make it wet, just enough to make it more prone to clump together. Someone advised to use used motor oil, but for now i haven't run out of my stashed supply, so i haven't tried it. Pretty sure it's going to work just as well. Might give a visual indication to the amount of oil used.I don't use grog, or other "hard" additives, i found they cause wear on the spindle.B! Link to comment Share on other sites More sharing options...
ddewees Posted July 2, 2014 Share Posted July 2, 2014 I have used it and was not impressed with the nozzle erosion. The Precious Cat has no 'grit', my spindles look nice for a lot longer and the rammer faces look shiny not pitted. Depending on the clay, most of them shrink when they dry out, better to keep them at room humidity when pressing IMHO. Lol, it's the same exact thing as the cat litter you suggested... yet screened to a more precise mesh. Link to comment Share on other sites More sharing options...
dagabu Posted July 3, 2014 Share Posted July 3, 2014 I will try that DD, thanks for the tip, I want to make sure the clay makes it all the way down to the end of the divergence. Link to comment Share on other sites More sharing options...
kpknd Posted July 10, 2014 Author Share Posted July 10, 2014 I went to a pottery studio and picked up a pound or so of Kaolin and something called Ball Clay. Anyone tried any of those? Link to comment Share on other sites More sharing options...
modestmortal Posted July 27, 2014 Share Posted July 27, 2014 @kpknd. I have always stuck with using bentonite for nozzles. So I can't say much about kaolin or ball clays in that application. However I have some experience with them in pottery. Kaolin doesn't have much shrinkage, but can be brittle and hard to clump. Ball clays tend to clump very easily and stand up to high heat, but shrinkage rates are high. Up to 16% depending on which ball clay you have. Generally a blend of the two would be made to suit the application. Since you have both on hand, give them a try and let us know what you think. Link to comment Share on other sites More sharing options...
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