Slump bowls Posted September 4, 2019 Report Share Posted September 4, 2019 Is there an easy way to flip a heavy (50 lbs) slump mold without denting or damaging the leather hard bowl inside the slump mold? Link to comment Share on other sites More sharing options...
Min Posted September 4, 2019 Report Share Posted September 4, 2019 I think I would work out some sort of jig to fit the slump mold in so you can pivot it upside down. Closest I could find of this type idea is this Rotating Slip Casting Table. I'ld make it with a few alterations, forget all the slip casting stuff in the video for starters. Make it so the cradle is just a bit taller than your slump mold. Have the slump mold on a piece of plywood with some holes drilled around the edge then have another piece of ply (same size) across the top of the mold. Put the mold onto the rotating table sandwiched between the two pieces of ply and then secure them together with some webbing (or rope) then rotate the table upside down. Undo the webbing/rope and remove the top piece of ply and the slump mold, leaving the slumped clay bowl upside down on the bottom piece of ply. It could then be flipped right ways up again. Other option would be to get another pair of hands to help flip it over onto a board. Link to comment Share on other sites More sharing options...
Slump bowls Posted September 5, 2019 Author Report Share Posted September 5, 2019 I was thinking about something like this, but could not nail down specifics. I did not want to make a dozen prototypes. Yeah, another pair of hands would be ideal. But, where I live does not make this very doable. Thanks, the video gave some possibilities on how to approach the issue. B. Link to comment Share on other sites More sharing options...
liambesaw Posted September 5, 2019 Report Share Posted September 5, 2019 I seen a video one time of a man who makes big giant three part vessels, like hundreds of pounds, and he made a contraption to flip them over so he could join pieces. It functioned like a teeter inversion table, you sandwiched the part, removed a pin from the table and flipped it over and then put the pin back in place before removing the piece. Was real impressive, but didn't look expensive, just well engineered. Good luck to ya! Link to comment Share on other sites More sharing options...
Chilly Posted September 5, 2019 Report Share Posted September 5, 2019 And fill the cavity with something, sponges, crumpled towels, anything to help support the clay, so it doesn't try to collapse. Unless it is very dry, of course. Link to comment Share on other sites More sharing options...
Min Posted September 5, 2019 Report Share Posted September 5, 2019 11 hours ago, liambesaw said: I seen a video one time of a man who makes big giant three part vessels, like hundreds of pounds, and he made a contraption to flip them over so he could join pieces. It functioned like a teeter inversion table, you sandwiched the part, removed a pin from the table and flipped it over and then put the pin back in place before removing the piece. Was real impressive, but didn't look expensive, just well engineered. Good luck to ya! A flip top table with an accessible opening underneath should work. If you used something like a pneumatic stool underneath so when the mold was flipped over you could push the stool underneath it and raise it up to support the piece then undo the strapping and roll it out. Link to comment Share on other sites More sharing options...
Russ Posted September 5, 2019 Report Share Posted September 5, 2019 How about this: lay a piece of plastic in the bowl. Get a couple of cans of spray foam from home depot, lowes, walmart... fill the inside of the bowl and let it harden (might take overnight). Trim the excess foam flat with a bread knife. You now have a reverse slump mould. should be much easier to flip the bowl with the inside support... or outside? Whichever it is. Link to comment Share on other sites More sharing options...
Leila Posted November 30, 2019 Report Share Posted November 30, 2019 On 9/5/2019 at 11:59 PM, Russ said: How about this: lay a piece of plastic in the bowl. Get a couple of cans of spray foam from home depot, lowes, walmart... fill the inside of the bowl and let it harden (might take overnight). Trim the excess foam flat with a bread knife. You now have a reverse slump mould. should be much easier to flip the bowl with the inside support... or outside? Whichever it is. Hi, It is a surprising idea. Would this foam mould need to be isolated? Foam looks a bit rough, will the mould be sleek, or does the spray leave some lines ? I have seen that foam spray forms cavities. What would you recommend as a release agent? I am right into the "big heavy mould" problem, for bowls with diameters like 46 cm. Cannot wait give it a try with a smaller bowl tomorrow! Link to comment Share on other sites More sharing options...
Russ Posted November 30, 2019 Report Share Posted November 30, 2019 You might try the thin plastic sheeting to line the inside of the bowl ........or if its greenware and youre finished with it and ready for bisque firing you could try a non stick food spray that would burn off quite quick. there are also several types of spray foam. Some that expand alot... some for windows that expand a lot less and some that cure very dense. Experiment for us to see what works the best. Ive used spray foam to build LARGE slump moulds three feet or approx 1 meter across. They work very well. Link to comment Share on other sites More sharing options...
CactusPots Posted November 30, 2019 Report Share Posted November 30, 2019 I fellow potter I know who does large stuff has an engine stand modified as a pot flipper. From my experiments, the issue is supporting the clay and having enough tension on it so it doesn't slide when it's in the half way position. If it's leather hard or better, it's easier. I need to flip it while it's still as soft as possible, so I can work out joints on the inside. Much harder. Big pots are fun to do, but lots of extra trouble. 50 lbs would definitely require some advance logistics. Link to comment Share on other sites More sharing options...
Leila Posted December 1, 2019 Report Share Posted December 1, 2019 Thanks, I am off to the store ! Link to comment Share on other sites More sharing options...
Pres Posted December 1, 2019 Report Share Posted December 1, 2019 Two wheels on either end of a wooden frame. best, Pres Link to comment Share on other sites More sharing options...
Leila Posted December 3, 2019 Report Share Posted December 3, 2019 On 11/30/2019 at 10:47 PM, Russ said: You might try the thin plastic sheeting to line the inside of the bowl ........or if its greenware and youre finished with it and ready for bisque firing you could try a non stick food spray that would bu Hi, Unfortunately I didn't stick to your manual.. I sprayed backing spray on the glazed ceramic prototype, and it got stuck... Can the foam residues be somehow cleaned ? Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted December 3, 2019 Report Share Posted December 3, 2019 If you need to dissolve residue, you need some acetone. It’s in nail polish remover in smaller quantities, but you can get it uncut from places that sell auto body supplies. Canadian Tire has it for sure, and I think you can also get it at Home Depot in the paint section. Link to comment Share on other sites More sharing options...
liambesaw Posted December 3, 2019 Report Share Posted December 3, 2019 Spray foam bonds permanently once cured. Uncured foam can be removed with acetone but once it's hard, it's too late for solvents. Link to comment Share on other sites More sharing options...
Russ Posted December 3, 2019 Report Share Posted December 3, 2019 If your piece is glazed then perhaps a single edged razor blade could be used to remove the foam residues. Link to comment Share on other sites More sharing options...
liambesaw Posted December 3, 2019 Report Share Posted December 3, 2019 22 minutes ago, Russ said: If your piece is glazed then perhaps a single edged razor blade could be used to remove the foam residues. Or fire! Fire works! Link to comment Share on other sites More sharing options...
Leila Posted December 5, 2019 Report Share Posted December 5, 2019 On 12/3/2019 at 9:39 PM, liambesaw said: Or fire! Fire works Hi liambesaw, Fire ? That is how - with a gas burner ? Yes, the platter is glazed. I will try acetone first and, well, report..: Link to comment Share on other sites More sharing options...
Leila Posted December 5, 2019 Report Share Posted December 5, 2019 On 11/30/2019 at 10:47 PM, Russ said: Ive used spray foam to build LARGE slump moulds three feet or approx 1 meter across Hi Russ, The foam forms cavities, how do you avoid this? Do you compress the foam somehow ? Because if I do not manage to clean the foam from inside the glazed plate, I will try to make a hump mould. Link to comment Share on other sites More sharing options...
liambesaw Posted December 5, 2019 Report Share Posted December 5, 2019 53 minutes ago, Leila said: Hi liambesaw, Fire ? That is how - with a gas burner ? Yes, the platter is glazed. I will try acetone first and, well, report..: I was thinking you could scrape as much as possible off and then put it in a bisque firing Link to comment Share on other sites More sharing options...
Russ Posted December 5, 2019 Report Share Posted December 5, 2019 There is a high density foam that only forms small bubbles. Dont go for the "big gap" filler foam. The bowl you want to use for the mould should be lined with a thin plastic and then pealed off the hump mould after its set. Where it contacts the plastic it should be bubble free UNLESS you sand or rasp the surface. Once the inside is complete cover the hump mould again with plastic and make the negative mould. using the set of moulds you can easily flip the bowl either way to work on the inside or outside. Link to comment Share on other sites More sharing options...
Fred Sweet Posted December 5, 2019 Report Share Posted December 5, 2019 Russ- Don’ t forget about the thickness of the clay used. The way you are suggesting doesn’t allow for it and, if made that way, won’t allow the form to be flipped without marking or distorting the clay form. Regards, Fred Link to comment Share on other sites More sharing options...
Russ Posted December 6, 2019 Report Share Posted December 6, 2019 If i remember correctly the inside is made first. Clay at the correct thickness is slumped over the mould. Then the outside mould is made. Its been about 20yrs since ive done this... Link to comment Share on other sites More sharing options...
Leila Posted December 14, 2019 Report Share Posted December 14, 2019 God bless the inventor of the baking spay! After procrastinating quite a while, I just scratched the foam a bit, with my fingernail.. The foam gets off, I will clean the rest with acetone. Of course, no mould is produced... On 12/5/2019 at 8:58 PM, Russ said: There is a high density foam that only forms small bubbles. Russ, I will definitely try again. Big lightweight moulds would be such a relief Link to comment Share on other sites More sharing options...
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