Val Posted March 11, 2015 Report Share Posted March 11, 2015 I am struggling to get nice rims on my slump or hump molded items. Any tips ? I tried adding a coil, and it's better but not great. Link to comment Share on other sites More sharing options...
Val Posted March 11, 2015 Author Report Share Posted March 11, 2015 Just to clarify, I mean rims on the items I make from slump or hump molds, not rims on the molds themselves Link to comment Share on other sites More sharing options...
clay lover Posted March 11, 2015 Report Share Posted March 11, 2015 I often add coils, what was wrong with the coils you used? I do have to me careful not to kink them up when adding. Link to comment Share on other sites More sharing options...
Val Posted March 11, 2015 Author Report Share Posted March 11, 2015 I tried again with a coil at the top outside of the bowl shape, (with the hump form still inside, and everything upside down,) I ribbed to blend into the body of the bowl. When it firmed up a bit, I took out the hump form and turned right side up. Then I had to add a tiny coil to fill in between original rim and coil addition. A lot of work...........but it actually turned out better than when I tried to add the coil to top rather than side of the rim. Where do you add your coil and at what point in the process? Thanks I am more of a wheel person, learning backwards....... Link to comment Share on other sites More sharing options...
Marcia Selsor Posted March 11, 2015 Report Share Posted March 11, 2015 For hump molds I make wide rims to keep them from warping when I remove them from the hump. They can be shaved or cut down later. Link to comment Share on other sites More sharing options...
clay lover Posted March 11, 2015 Report Share Posted March 11, 2015 Sounds like you are trying to make the coil disappear into the wall of the piece, is it for added height? I add coils to slumped pieces and want they to stand out as a design feature. we might want different results from our coils. I add at the soft leather hard stage, any drier and the coil is too stiff to join neatly for me. the piece stays in the slump until the entire thing shrinks away from the edge and is stiff enough to stand alone.[ Link to comment Share on other sites More sharing options...
alabama Posted March 11, 2015 Report Share Posted March 11, 2015 I'd trim the rim level then fold the rim back then smooth the seam. That way, there isn't a coil added and time wasted. Although it looks like a coil, since it is only a round, thickened rim. In my humble opinion. Alabama Link to comment Share on other sites More sharing options...
PeterH Posted March 13, 2015 Report Share Posted March 13, 2015 The Romans were quite good at it. Photo is from http://pottedhistory.blogspot.co.uk/2010/04/samian-ware-workshop.htmland shows a replica Samian ware bowl, together with replica mould and stamps. Note that the mould ends in a frieze, and the pot is much taller than the mould. I've never seen a clear description of how they did it. Virtually all descriptions I've seen state that the foot and rim were "added later" and done on a wheel. A few [very vague] descriptions could be consistent with a wheel-thrown proto-pot being dropped into the mould and then expanded into it. In which case it would be easy to leave ample well- shaped clay to tidy up into a rim. Anybody know how they actually did it? Link to comment Share on other sites More sharing options...
bciskepottery Posted March 13, 2015 Report Share Posted March 13, 2015 For slab work, I use Bill Vangilder's edge tool to make round edges. I usually edge when the wares are medium leatherhard. https://www.baileypottery.com/potterytools/vanGildertools.htm Link to comment Share on other sites More sharing options...
Val Posted March 13, 2015 Author Report Share Posted March 13, 2015 Glad to know about the rounding tool. I think I will try the rolled method also. I know everyone has to kind of find their own way, but I do not like wimpy rims, which mine seem to be. Alabama,by "wide" rims are you saying you extend the rim beyond the mold them trim later? Link to comment Share on other sites More sharing options...
Jugbird Posted March 14, 2015 Report Share Posted March 14, 2015 I have added a bold rim to slump-moulded plates and dishes by attaching an extruded 'coil'. It's just a round hole die, larger than the thickness of the plate's walls. I lay a square piece of metal on the die before starting to extrude. The corner of the square blocks off 1/4 of the circle so that it looks like an old Pacman (wish I could add a drawing here). The extrusion then fits nicely onto the slipped top edge of the slab plate and forms a tidy, bold, comfortable rim. I think I'll make some of those again now! Link to comment Share on other sites More sharing options...
alabama Posted March 14, 2015 Report Share Posted March 14, 2015 Hey Val, I think your slump mold is synonymous with what I call a basal sherd, so yes I extend the rims beyond the slump mold and immediately trim them. From start to finish, a 6, 8, or 10 inch bowl is made(from coils), trimmed, and incised between 18 and 22 minutes. Globular types like water jars take at least 45 minutes because of the extra coils....Coils are like speed bumps, they are necessary but slow you down. A coil adds about 10 minutes to add and smooth the seams, almost from any sized vessel. If you're making them in your lap out in the woods, and not on a table, expect a few more minutes added to the time. Alabama Link to comment Share on other sites More sharing options...
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