Premo Sculpy. Mine says 30 minutes for each quarter inch of thickness. But, I mean, his little feet are thin, but his fat belly is fat. (Funny, I’m beginning to have the same problem.)
I only have limited experience working with polymer clay, but I have read that a tent made of aluminum foil and placed over the piece while it is baking can help prevent browning.
The tent technique is especially recommended if you do not have a dedicated oven of some kind for baking the clay. Use a dedicated glass dish and cover it with foil. It will help keep the clay from mixing with your food (and you should not use polymer clay to make items that will be in direct contact with food). You definitely want to avoid allowing any polymer clay items to burn. Don’t cook it above the recommended temperatures. Cook longer if you need to, not hotter. The fumes they give off when they burn are a lot nastier than you might expect.
Pets should also be kept away from the fumes.
The temperature settings on your oven or toaster may not be accurate. An oven thermometer will help you read the actual temperature and help eliminate discoloration and fumes.
This is an important point, especially if you have birds. The fumes from polymer clay can kill a bird, and they’re probably pretty nasty to other small cage animals, like rodents or reptiles.
When in doubt, is there any way to tell if a piece is “done” before you take it from the oven? You obviously can’t pinch it, or ruin the texture, and you probably can’t poke it with a toothpick.
When my SIL started me out on bead making, she gave me a book to help me learn. I’ve followed the instructions in the book and never had any problems. Bake 30 min. at 200, then an additional 30 minutes at 275.
Actually, there are no “fumes” from properly curing polymer clay - however, burning polymer clay releases (c’mon brain, dig up that chemical name…) HYDROCHLORIC! That’s it, hydrochloric gas, which is dangerous at about 300ppm. It’s my experience that long before you get to 300ppm, the ghastly smell will have you flipping windows open and running outside yelling “oh ugh!”
I was part of a research project involving polymer clay safety, and your pet bird and pocket pets are not in danger. At this very moment, I’m getting dinner on the table so can’t comment much more, but anyone is welcome to email me (it’s in my profile.) I’ve been a professional polymer clay artist for fourteen years. Otherwise, I’ll be back in a bit to read the thread more closely.
Since there seem to be quite a few Dopers who work with polymer clay, maybe someone can help me with a problem. Both of the craft stores I use have been out of the glaze I use for my beads for over a month. I recently found out about two local craft shows I would like to sell my jewelry at, but I really need to get some inventory built up - one show is in October and one is in November. Is there any substitute for the bake on glaze? Would polyurethane (I used it on my hardwood floors) work?
Okey-dokey, I’m back.
Selkie has the right of it, sending you to Polymer Clay Central for starters. There is LOADS of info there. I also like Polymer Clay Daily (polymerclaydaily.com), a site run by former National Polymer Clay Guild president Cynthia Tinapple - it’s not an instructional site, but she has tons of great links there, plus her daily entries highlight all kinds of inspirational ideas.
I generally bake in a dedicated convection oven. Convection ovens are not always easy to find, but there are decent, small ones available for around $100. Toaster ovens tend to heat unevenly, because they cycle on and off, and there is a greater risk of scorching because of the shape and location of the heating element. When I am doing volume curing, I do use my home oven. As I said, I’ve been doing this a long time and have participated in studies about polymer clay safety, so I have no worries about this, HOWEVER, if you’re at all nervous, err on the side of caution. Baking in a covered roasting pan dedicated to clay is a great way to cure pieces AND it allays any fears of contamination.
Pieces will “slump” very slightly during the curing process, and if you’re baking on a cookie sheet or other shiny surfce you will likely get shiny spots. You can line your baking sheet with paper - computer paper, index cards, cardstock, paper bags all work fine - paper won’t burn at the temps the clay cures at.
The clay can be cured multiple times (and whoever said it’s better to bake for longer times than at higher temps is correct.) So for the bird sculpture for example, I would bake the larger pieces first, then add on the smaller pieces such as the feet. Adding raw clay to cured can be done very easily with Sobo glue (which is a PVA white glue) or liquid polymer clay (you only need a very thin coat of either between pieces.) I do not generally sculpt - I’m a jewelry maker - but I do recommend any of the sculpting books by Maureen Carlson or Katherine Dewey.
I do a LOT of millefiore canework, so my own most valuable tool is my pasta machine. I recommend the Atlas Pasta Queen brand. On the Polymer Clay Central site somewhere there are directions posted by Desiree McCrorey on cleaning pasta machines - but I have been using the same one for thirteen years and have only cleaned it once, and it works just fine. When I cleaned it, I did remove the shields per Desiree’s directions, and that helps me keep clay from getting gummed up inside. You can now purchase pasta machines that have the shields already removed, from Polymer Clay Express (polymerclayexpress.com). Thye have lots of other fun tools there, too. My second most valuable tools (tied for the position) are a Kato NuBlade - a long, thin, single edged razor blade - and a Kemper Pro-Tools needle tool. Both can be purchased from Michael’s or Hobby Lobby.
I definitely recommend following the curing instructions on the packages of clay - each brand cures slightly differently. I prefer Fimo for much of my work, and it cures at a slightly higher temp than Sculpey or Sculpey III. I BELIEVE Katoclay has a higher curing temperature than Fimo, but I don’t work with that one often enough to know for sure. The different brands also all have slightly different qualities - Sculpey (the plain white or terracotta colors you buy in larger packages) is the softest and least sturdy of the polymer clays; Fimo is more brittle and less opaque than Sculpey III; Premo is noted for its flexibility when cured, etc.
There are a lot of books out there I love - Donna Kato has a pretty good one out called The Art of Polymer Clay that covers a lot of stuff from absolute beginner level through pretty advanced techniques.
I’m not here on the SDMB as often as I used to be, so I reiterate - if you have any questions I might be able to help with, just email me. Have fun!
One brand has been found to be superior: Flecto Varathane Diamond Finish. It’s about $12-15 a quart, but that quart lasts a long time. Be sure to get the waterbased kind; it says on the label. It’s available in satin, semi-gloss and glossy finishes.
:smack:
… at Home Depot, Menard’s, Lowe’s, and the like. Sorry for the imcompleteness of my first answer!
Thank you so much, LifeonWry! I see a trip to Lowes in my very near future!
Thank you for this (and all the other) information! Since my first polymer clay experiences also involved a preteen who tended to forgetfulness, we did indeed have a lot of the flipping open of windows and running outside in the early days. It’s good to know that we weren’t actually harming our pets (or ourselves) at the time.
I know, I’m coming off as a big snotty know-it-all here, but this project recommends a spray sealant which will absolutely never ever work. The propellants in spray finishes will react with polymer clay, and the finish will become gummy fairy quickly, and will honestly NEVER dry completely.
Regarding over-cooking/scorching/burning: I should have mentioned that the single best investment you can make for polymer clay is an oven thermometer. They run about $3 each, and you can get one wherever you can buy kitchen stuff. When we tested various ovens at a clay retreat some years ago, we discovered temperature variances of up to 30 degrees in some ovens! If your clay is consistently scorching even though you’re following curing instructions, your oven thermostat is the likely culprit.
I realize I’m a polymer clay addict. I learned this when I clicked on LifeOnWry’s website and did a fangirl squeal (“0000! I know her work!”)
I can’t improve on the above advice at all, but in terms of sculpting, which I do quite often, I really love clay shapers of all sizes, in both black and gray link for those who don’t know what they are. They’re indispensible for doing miniatures.
My second favorite tool, weirdly enough, is a plain ol’ stylus for a handheld.
You might want to try this site for project ideas. It’s from the HGTV website, and they often have polymer-clay projects on their shows.