Has anyone ever repared a piece of pottery that has broken while being fired? Can you use wet slip and connect the pieces back together and fire it again?
Thanks for any help.
Has anyone ever repared a piece of pottery...
Has anyone ever repared a piece of pottery that has broken while being fired? Can you use wet slip and connect the pieces back together and fire it again?
scardie, if it's been bisqued there is a commercial adhesive you can use, but I'm afraid once it's been fired slip is unlikely to work. You could fire the pieces to maturity and try to glue them together after they're fully fired, but they may shrink differently and may not fit together like they did when they were greenware.
Depending on the piece and where it's broken, if your careful enough, you can use the glaze as the "glue" to keep pieces attached to a main piece. At least I have before. Now, I don't know about anything substancial like a handle to a casserole or two halves to a pot, but flowers on a pot or a chunk broken out of a vase I've done before. Hope that helps some.
Ok, thanks! I will try both. This is a pretty important piece and I took forever to do with alot of detail. I'm thankful it came out as well as it did and didn't explode while firing. It's my first attempt at something like this so...live and learn (learn not to do THIS again:))
If you're "gluing with glaze" remember there will be some movement---that technique works great if it's a relatively flat piece.
You can use MAGIC MENDER or another commercial repair goop. YOu can also use your own slip or also clay that you wet and gently wrk over the crack or break. I Have had moderate success in repairing cracked or broken pieces.. Of course when a piece explodes in the kiln.. you can kiss magic mender bye bye!
I can't think of anything else. Is the piece a functional one? If it is where the break is will make the difference if you can use it or not.
Yes it is functional. It is a jug with sculpture surrounding the jug. The only thing that broke off was one leg and that doesn't affect the jug (holding water, etc). I have used the magic mender and it didn't work well but I think I made a mistake. Let me explain the steps I have taken and then maybe someone can help me understand what to do next...I plan of firing it AGAIN next week...
1. I made the jug on the wheel.
2. I sculpted the image around the jug
3. I fired the greenware jug at cone 04 (approx 1900 deg.) to bisque
4. I glazed the jug at cone 06 (approx 1800 deg.)
5. The leg broke off. I used magic mender - put glaze over it when it dried and refired it to cone 06 (approx. 1800 deg.)
I think this is where I made my mistake...I should have fired it at greenware cone (04 - approx 1900 deg.) to make it harder that it would get at 06 (approx 1800 deg.)
6. The leg broke off again. I repaired it again - the same way but I fired it at cone 04 (approx 1900 deg.) The leg held beautifully but the glaze was very dark - no big deal - still pretty. But there were some cracks where I had applied the greenware/magic mender to the leg. So now if I fill the cracks with magic mender and cover the magic mender with glaze (the instructions said I could do that) should I fire at cone 04 or cone 06?
UGG...what a learning experience:(
Gee, it sounds great. I hope you'll post a picture here.
I am a novice. I can not give additional advice. I remember my teacher not recommending refiring glaze more than twice. And I see that you have already notice a compromise in your glaze's color. I did not realize the leg broke off after you had glaze fired; I thought it broke off after bisque, but before glaze. That is when I use the glaze as a "glue". I had never used it as a "glue" on a second glaze firing. And I've only ever heard of people using the majic water or vinegar on greenware, so I'm no help there.
Other than an epoxy at this point, I don't know what you can do. I hope some expert comes on and can give you a great tip. I'll be all ears! Good luck.
I wouldn't fire it again. If it is a cone 06 glaze and you re-fired it at 04 that is why it got dark. It was fired at to high of a temperature.
Use a polymer clay clay like Fimo to fill in the crack. If you can find the right color use that if not get white. Bake it in your oven. Then find "porcelaine" or an different paint for porcelain. Use it to cover the white and then bake it in your oven. I get porcelaine at Micheal's.
Use a permanent marker. Either on the crack to disguise it or on the Fimo.
Just remember the crack isn't keeping you from using it. Oriental rugs are made with a mistake in them because only god/gods are perfect.
Next time this happens if the break is a clean one try gluing it on with an epoxy.
A good rule to use is use the highest temperature glaze first. If say you fire at 06 than never firer higher than that you can go to 08, 014 etc.
This message was edited Feb 21, 2009 9:20 AM
Thanks guys! I am so glad I read this today cause I was gonna give one last firing today:)
Zenpotter: I am going to try what you said ...Use a polymer clay clay like Fimo to fill in the crack. If you can find the right color use that if not get white. Bake it in your oven. Then find "porcelaine" or an different paint for porcelain. Use it to cover the white and then bake it in your oven. I get porcelaine at Micheal's.
I think I might take some pottery classes...I've only been at pottery for a year and I'm tired of making unnecessary mistakes.
Hey we all make mistakes. There is so much to learn and so many variables. It is fun to go with the flow and see what happens.
No such thing as an "unnecessary mistake"! Classes are good because you are exposed to experiences other people have had, and that will give you more creative ideas. Plus, having a solid understanding of how clay and glaze and firing all work together is very helpful. But sometimes those "mistakes" turn into great new techniques!
I call those "mistakes" HAPPY ACCIDENTS! Sometimes they turn out better then what I Had first envisioned.
I am probably the "Happiest" potter in Va.. I Have had SO MANY Happy Accidents!
Well, I'm done with the face jug...the "happy mistakes" did turn out to be happy ones....I started a new thread for it...check it out for the photo.
There is a very easy recipe for pottery glue.
Here is the recipe:1 part of each-ball clay powder
Mix ali together until it becomes a paste.
I have used it on greenware&fired pieces.I saw it
on ceramics art daily website.(great website for potters)
Thank you Oddiebaby. So let me make sure about this...you can use this recipe on greenware and then fire it ooorrr you can use it on bisque and then re-fire it??? Wow what a wonderful piece of info to have at hand.
Have you ever tired it drying out the clay body you are using and then grinding it into a powder so that it ends up being the same color?
I haven't tried that but I am willing to try anything at this point. I have 3 other face jugs in the process and I KNOW I will come up against this problem again.
a friend of mine fired a beautiful lidded pot but the bottom cracked and she was heart broken. Can this pottery glue be used to repair it??. its already been fired once.. she said she'd go a head and glaze it and just set it out for looks but if we can fix it (so to speak ) that would be great!
Im a new potter and just found this forum... looks like Ill be hangin out here now..
blkraven2: I have 2 experiences with broken bisque pieces.
First: let me tell you what I did with a piece of the wall tile "dragon"...it's the easiest story to start with. The piece was just an oval-ish type piece, flat (for the wall). I dropped it as I was carrying it to the kiln. It was already bisque. It broke in half. I was using a glaze that had crystals in it. So, I added more of this glaze to the edges of the two pieces and pushed them together so that when they touched they would bind in the firing. I also put some of the crystals on top of the crack so that they would melt right over the crack and help fill it in. The binding and filling worked great but you could still see the crack some. I could have filled in the crack with more glaze and fired it again and covered the crack but it wasn't that important to me.
I know you aren't supposed to fire more than twice but let me tell you, when you have a piece that has taken you a week to make - 6 hours a day - and you are selling it - you will do what it takes:) And that leads me to the second story...
"The Gambler". He is a chameleon face jug. I have a photo of him somewhere in all this. His legs kept breaking off!! I can't remember the sequence for sure but the second time I fired him (he was already bisque) I put that magic mender on AND put cover coat over that and re-fired him (second firing). Legs broke again (I don't think I let the mender dry long enough). This time I took my clay and recovered his whole legs - BOTH OF THEM - put the clay right on top of all the glaze, etc. and attached them to the stump he was sitting on so they would be stronger! I EVEN recovered the stump with clay!!! Brave hu!! By now I was desperate!! Let it dry for days. Put envision glaze over the legs and stump (that is like a cover coat but comes out with a shiny glaze) – re-added the crystal glaze to his legs (I don't think it was supposed to go on clay) and let her rip (re-fired a third time)!!!! Yikes...but what else could I do?
Well...he did come out darker in places but he's a chameleon...what does that matter. But his legs came out so light (compared to the other places where I used the same glaze but that glaze had now been fired 3 times (blush)...but his new legs look like "chaps" - you know - those things cowboys ware when they ride their horses. Beautiful!
Now I wouldn't recommend this to ANYONE! But it worked for me. And his legs were as strong as cement!! The colors were still brilliant - darker but still nice. And I sold him instead of throwing him away:)
ok, now where is that recipe from oddiebaby!! Got a new piece done and guess what....lol...when I blew into it (after it was bisque) I felt air coming out of the bottom!!! This is a jug!! It's supposed to hold water!! I filled it with slip and let it drip until it clogged up. Then filled the whole jug up to close any other holes. All of a sudden...slip came pouring out of the rabbit's nose holes!!!! LOL...LOL...LOL!!! I guess you had to be there. I thought about leaving the holes so that when you pour out your liquid that is where it would come out but they are too low down on the jug. So now I have to make some clay nose plugs to shove up into her nose so that when I refire her it will close those nose holes. The whole jug is glazed already with several kinds of glazes (all cone 06). So here we go again...Second firing...cone 04 or cone 06???:)
My husband has a saying..."no one is completely useless, you can always be used as a bad example". So everyone watch what I do and DON'T DO IT!!
Scardiecat Ill let her know and if ti does work out Ill pot about it..
Well, I'm glad you posted all that detail, because I took two big tiles out of bisque a couple of days ago, and they have small cracks in the edge. I was really ticked about having to scrap them, and I think I'll try repairing them before I toss them and start over. They took a lot of clay, and I hate to waste it. At this point all I'll be out is the glaze & kiln space if they don't make it, so I may as well give it a shot! If you can do all that and have your piece turn out so well, I should be able to figure something out, too!
I just talked to a potter in NC today (trying to get her to fix the Gambler for me) and she said broken pottery couldn't be fixed except by glue. I wonder...Be careful...I'd hate for someone to blow up their kiln or other pottery cause I did something I wasn't supposed to do and just got away with it cause of luck:) When I think about how much new clay I put all over all that glaze.....yikes....
I have repaired ALOT of GREENWARE pieces when they have come out of the kiln and they have cracks, stress fissures etc. ONce they are glazed fired and something happens then that's a different story. Sometimes you can try and disguise the break with a clear glue and maybe an acrylic paint. It is tricky after the piece has been glaze fired and then breaks.
I did get that right didn't I? you added raw clay to fired clay?
Have you re-fired the piece? I don't see how it would work to add clay after it has been bisque fired. The new clay will shrink and crack and possibly form air pockets.
If I repair apiece after it has been greenware fired and I Need to repair it, I usually use Magic Mender, allow it to dry thorughlly then re-apply again if necessary. Sometimes I use slip or raw clay if it is a larger crack... allow to dry thoroughlly then reaply again if necessary . After it has been dried completely then I refire it, or glaze it and see what happens.
Make sense? Or am I clear as mud?
sometimes I think I am explaining things well... I UNDERSTAND but people look at m like I just sprouted horns. Sorry if I wasn't too clear.
"I" did put fresh wet clay over the legs and stump of the gambler AFTER I had fired him to bisque (04) AND glazed him and fired him to cone 06!! I promise!! I couldn't get the legs to stop breaking - even after using the magic mender. I didn't have anything to loose by then. It either worked or it didn't. The legs and the stump had been glazed and fired at cone 06. The legs broke off again when I picked it up. So, I decided to attach the legs to the post so they would receive more support. To do this (remember the glazed legs were already off the glazed piece) I covered the legs - over the glaze - with fresh wet clay. I then attached the legs to the stump and covered them and the whole stump with fresh wet clay. When the clay dried I used envision glaze (a glaze that is not meant for green ware but the lady at the ceramic shop said you can use it on green ware but it won't come out as "dramatic" as if you use it on bisque) and I also applied the grystal glaze I had used before on the legs to the fresh clay when it dried. I then refired the piece at cone 04 so that the clay would cook to the correct temp and be strong. I didn't worry about the glaze as much as I worried about the bisque being strong. The glazed did come out darker each time I fired but it didn't take the beauty of the glaze away - just made it different.
It did work BUT I would say that it was a high risk job meaning that I think it COULD have blown up with all that fresh clay over all that glaze. But it didn't and the end result is what you see when you look at the photo of the Gambler on one of the other threads.
This is the honest truth. I felt I didn't have a choice and I put so much work into him I was going to try everything until he finally blew completely up:) Besides, I guess I'm new enough to pottery to not know enough about the "what not to do" that I didn't really think I was doing anything wrong. Lessons learned - love that.
Well, I tried it again...the bottom to one of my bisque face jugs cracked a little so I put a whole new bottom on it. During firing the bottom popped off!! Luckily the jug didn't get hurt. The nose plugs did work though. Small cracks around the edges but the glaze will fill those.
I did remember though that when I recovered the stump to the gambler and refired it the top clay did crack (from the shrinkage) but I filled it with the glaze and it looked like a textured stump. There were some small cracks in his legs too but the glaze I used on the legs had crystals and that really filled the cracks.
I've been reading a pottery book and they talked about putting colored slip on bisque. I was thinking maybe that is one way to fill a crack or some mistake in a piece of bisque.
My goal is to never have to try to mend bisque again.
Your luck with putting bisque ware together with wet clay fascinates me.