JohnnyK Posted October 3, 2022 Report Share Posted October 3, 2022 Hi All...I am looking to use a textured glass light fitter as a slump mold for a bowl. What should I do to get an effective release from the glass? Quote Link to comment Share on other sites More sharing options...
Roberta12 Posted October 3, 2022 Report Share Posted October 3, 2022 I use cornstarch. Some use wd40 (I don't like the smell) and some use spray veg oil. Some people use a smooth cloth between bowl and clay. r. Quote Link to comment Share on other sites More sharing options...
Kelly in AK Posted October 3, 2022 Report Share Posted October 3, 2022 Dry cleaning plastic, it’s so thin. It’ll produce some wrinkly texture but probably allow the texture of the mold to transfer well. I’ve never tried corn starch for this sort of thing but use it regularly to keep clay from sticking to clay (lids, for example). I’m gonna play with that! Quote Link to comment Share on other sites More sharing options...
irenepots Posted October 3, 2022 Report Share Posted October 3, 2022 I like cornstarch too. I apply it to the slab then invert in on the mold. Piedmont Pottery 1 Quote Link to comment Share on other sites More sharing options...
Babs Posted October 3, 2022 Report Share Posted October 3, 2022 I use thick green dishwashing liquid.Smear liberally Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Mark C. Posted October 4, 2022 Report Share Posted October 4, 2022 I use spray veg oil-as cheap as I can find it.If its an slump mold then the clay needs to comne off very soon as to cracking if its a hump it dries away . I make lots of fish from glass this way-most are hump and i tremove them as soon as I can. Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Pres Posted October 4, 2022 Report Share Posted October 4, 2022 I have also used bakers spray for forms to separate especially if using heavy texture also in the mold. best, Pres Quote Link to comment Share on other sites More sharing options...
Mark C. Posted October 4, 2022 Report Share Posted October 4, 2022 For mos forms I use laguna/Axner Pure lube-I bought a gallon about 20 years ago and will last another 20 https://www.axner.com/pure-lube.aspx if this does not work I switch to veg-oil spray Quote Link to comment Share on other sites More sharing options...
JohnnyK Posted October 4, 2022 Author Report Share Posted October 4, 2022 And the winner is...oil spray, with the most votes...but, I think I will try each of the methods. The biggest problem that I see with the oil or soap is what to do with the trimming scraps-toss or recycle and how to go about putting a foot on the molded piece after? Would it be best in this case to flatten the bottom and go without a foot? Another option would be to throw the bowl and not worry about the texture. Here's a photo of the light fitter that I plan on using...about 15" diameter. Quote Link to comment Share on other sites More sharing options...
Min Posted October 4, 2022 Report Share Posted October 4, 2022 If you use the form as a hump mold you can put the foot on straight after making it. Just make sure to get the clay off the mold as soon as it's set up. If you are going to be making a bunch of these I would make a mold from a thickish slab inside or outside the light cover, about 3/8" then bisque fire it really low, like cone 08 and use that for the mold going forward, won't have to use any mold release if you use bisque for the mold. I would put a foot on it, that is quite a wide bowl, having a foot will help support the walls and prevent it slumping during glaze firing. Magnolia Mud Research and Callie Beller Diesel 2 Quote Link to comment Share on other sites More sharing options...
JohnnyK Posted October 4, 2022 Author Report Share Posted October 4, 2022 11 minutes ago, Min said: If you use the form as a hump mold you can put the foot on straight after making it. Just make sure to get the clay off the mold as soon as it's set up. If you are going to be making a bunch of these I would make a mold from a thickish slab inside or outside the light cover, about 3/8" then bisque fire it really low, like cone 08 and use that for the mold going forward, won't have to use any mold release if you use bisque for the mold. I would put a foot on it, that is quite a wide bowl, having a foot will help support the walls and prevent it slumping during glaze firing. Thanks for the input, Madeline...I have an order for just one bowl and the original thought was to use the glass as a slump mold to pick up the texture. The only reason for making additional versions would be to test the various release methods... Quote Link to comment Share on other sites More sharing options...
Mark C. Posted October 4, 2022 Report Share Posted October 4, 2022 Is the texture on the inside or outside? hopefully on the inside It needs a foot-thow and attach one Quote Link to comment Share on other sites More sharing options...
JohnnyK Posted October 4, 2022 Author Report Share Posted October 4, 2022 1 hour ago, Mark C. said: Is the texture on the inside or outside? hopefully on the inside It needs a foot-thow and attach one The texture is on the inside of the glass--outside of the clay. With that in mind, how do I remove the oil to install the foot? Scrape the clay where the foot would be installed? Quote Link to comment Share on other sites More sharing options...
Mark C. Posted October 4, 2022 Report Share Posted October 4, 2022 Since its an inside form and dries away from form-I would go with pure mold lube from axner-its not oil based and its easy . I use it on a curved plastic tray sushi form and add a round thrown foot. You could also use plastic wrap in lower part so oil is not ever put on that part of clay. The oil is an issue so do not use it at attcahment spot Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Babs Posted October 4, 2022 Report Share Posted October 4, 2022 When you scratch ad slip to attach the small amout of lube doesn't affect the fot attaching. Shouldn't be much trim with molded pots to worry re reclaim.sacrifice it if worried. Quote Link to comment Share on other sites More sharing options...
JohnnyK Posted October 4, 2022 Author Report Share Posted October 4, 2022 Thanks for all your suggestions! I was just thinking, too, that I could put a layer of sand topped with a layer of cardboard in the mold to give the form a wider, flat bottom. That would give me an area to install a foot without having to worry about any kind of release material... Quote Link to comment Share on other sites More sharing options...
oldlady Posted October 4, 2022 Report Share Posted October 4, 2022 johnny, i have been doing this for years. i just use some WD-40 inside the bowl and spread it around, all over with a foam brush. get it in and out of the texture. once it is inside the mold it will only affect the clay that you press down into it. no mess. smell is not awful. cannot see enough detail about the bottom. use a circle of cardboard where you want the bottom to be flat. Quote Link to comment Share on other sites More sharing options...
Min Posted October 5, 2022 Report Share Posted October 5, 2022 16 hours ago, JohnnyK said: I could put a layer of sand topped with a layer of cardboard in the mold to give the form a wider, flat bottom. Many people like a continuous curve inside a bowl going from rim to rim, aesthetic choice. Quote Link to comment Share on other sites More sharing options...
Mark C. Posted October 5, 2022 Report Share Posted October 5, 2022 What Min says is very true-I like that curve as well Not a flat bottom bowl fan myself Quote Link to comment Share on other sites More sharing options...
Rae Reich Posted October 10, 2022 Report Share Posted October 10, 2022 Instead of a foot ring, attach 3 separate leaf-like shapes for feet? Babs and JohnnyK 2 Quote Link to comment Share on other sites More sharing options...
Joy pots Posted October 11, 2022 Report Share Posted October 11, 2022 Use very thin slip let it dry & make your form. joy Quote Link to comment Share on other sites More sharing options...
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