Glaze Tips & Tricks

[Patricia Bridges]

Everyone has experienced this - Not all of our glazed pots are pleasing .....We unload our glazed pots from a warm kiln with the excitement of a 5 year old- waiting to get down to that shelf which holds the one piece we really want to see......and Yeck - there it is. Not what we planned, perhaps even ugly. Sometimes it's just a flaw that makes it unusable/ un-sellable, a tiny spot that we missed glazing or a drip that dripped too far.

I sell my work so salvaging a piece means more than just liking it- it means potential revenue lost. But regardless of the final resting place of your work - we all like to salvage our mistakes.

Reglazing is a tricky business. In the studio where I teach I try to get my students to understand that it's a risk to reglaze and that the piece may very well be even worse off. Existing glaze remelts and moves, warpage and blistering can occur, and other over fired looking effects can overcome.

I tell my students it's a waste of kiln space and glaze to refire/reglaze a piece that only your mother would like - so be sure it's a worthwhile piece to begin with. Sometimes I have found great new combinations by mistake in the process of reglazing though. That said.

The Application of new glaze - Heat the pot up - microwave- heat gun - whatever will get it hot. Then reglaze it. This makes the new wet glaze dry quickly on the surface and adhere better. If it's just a small spot you need to heal then feather the glaze in over the area. If it's a dip - then be sure to have a nice big fat clearance at the bottom so it doesn't run to the base. Sometimes I put those pieces on a biscuit, depending on how close the first glaze came to the base. 

Heat Helps- Reglazing can be a Risky Business.

[Donna Ferrara]

very true, Patricia. I have also sprayed the piece lightly with hair spray and then dipped- that has worked well for me.   But I very rarely reglaze, as you said, it's too iffy. 

[Patricia Bridges]

I have used hair spray as well - I prefer doing it without any barrier- Some people use a little gum solution painted on first.

By heating it up I find it's easier to clean it up and wipe it off from where I don't want the new glaze. 

[Cheryl Thiruvathukal]

188Hi,

I am having issues with my Georgies Ceramic and Clay PG630 Zinc-Free Clear glaze.  I am using this G-Mix, which the lady that does glazes tested on my clay with great results.  I have been having crazing mainly inside.  I have considered many things.  Maybe too thick of glazing.  I don't have good instructions for pyro. cones, but this is a brand new kiln (Skutt KM 818).  I would write more, because you seem knowledgeable, but I will start here. Nice to meet you!

[Patricia Bridges]

Hi-Nice to meet you

more details -

what cone do you Bisque

what program /Ramp to you fire for Bisque & Glaze

How thick is the glaze? Pudding, Cream, Pancake Mix, Milk, Water Like

Got any pictures?

Thanks

[Cheryl Thiruvathukal]

Hi,

I am going to give general information tomorrow and some pics.  I got some info from the store. :) I will be back though.

[Sharon Canfield]

I have several pieces of pottery that the glaze fired on is too plain to my liking.  I read that you could mix glycerine and stain and apply to a warm pottery piece.  The stain would be powdery so have to handle carefully.  I am only wanting to add some small decorating marks for interest.  Not much detail was given regarding the process.  Would you know anything about it?

When they say refire, do you have to go to Cone 6 again or do you only need to find where the current glaze becomes soft? Does the melting point of the stain give the key to firing cone temperature?

Would like to know more details on this process if anyone has tried it.

Thanks.

 

 

[Cheryl Thiruvathukal]

5

Hi there Sharon,

I am still looking into this.  I have question. Are you putting this on pieces already fired with glaze on them? It sounds to me like you are, because you said, "go to Cone 6 again."  It seems like you are using a stain mixed with glycerin, which makes it easier to brush on underglazes or stains to  (from Clayart thread I read that about glycerin and stains/or underglazes).  I would think that you would fire to cone 6, but I wonder if you put that over existing glaze, if it will not bond properly to the piece. It seems like glaze turns to glass, so stain would not be able to penetrate it properly or bond properly. That isn't necessarily correct.  I have a similar problem with not getting rich enough color. I do this:  First, I heat the piece up in the oven to 200 to 300 degrees. Second, I remove it with oven mitts. Third, using a sponge, I sponge glaze while turning the piece on a lazy Susan. Fourth, and this is if you need more than one coat, I would use a heat gun or hair dryer to warm the piece slightly.  I do this outside if a hair dryer and use a mask for protection if possible.  It helps subsequent coats go on to warm the piece.  This technique deepens the color and I have been satisfied with its results. I wonder if you could use the other stuff on the next pieces to deepen color, then applying glaze and firing the next time  around.  I hope this makes sense.  Thanks, Cheryl  P.S. I am going to ask a friend also though to be sure.  Any other questions, let me know so I can add them to this person. He is really talented.  If you don't hear more from me, what I said is likely the most I have right now on the subject. Good luck!  I am sure it will be fine.

[Sharon Canfield]

Thanks Cheryl, sorry I did not get back to you sooner when you went to all of the trouble to answer me.  I have had health issues and have not been back to Electric Cone 6 for quite a spell.  But, I did want to thank you for your response.

[Cheryl Thiruvathukal]

5

Your very welcome.  Sorry you are having health issues. I have also, so I get that.  I hope you feel better and are able to resume.  Take care and write any time.

[Robert spicer]

My problem is using amaco potters choice glazes that turn out nothing like the colors portrayed on the web site. I'm firing them to cone 6 but also fired some of them to cone 5. Any ideas?

[Norm Stuart]

Which Amaco glazes in particular?  If it's Ancient Jasper and Palladium which don't turn out like the photos, you're in the vast majority of customers who use these two products. Palladium needs to be fired hot while Ancient Jasper needs thick areas of application and thin areas of application, plus a miracle.

If it's other Amaco glazes which don't look similar, remember that their samples are fired on white rather than brown clay.  Their products also need three heavy coats of glaze, which can seem wrong given their custard consistency.

Given these guidelines, most of their other glazes should look fairly similar to the photos you see online.

Robert spicer said:

My problem is using amaco potters choice glazes that turn out nothing like the colors portrayed on the web site. I'm firing them to cone 6 but also fired some of them to cone 5. Any ideas?

[Robert spicer]

Both of those are not even close as well as iron luster and ironstone. Glad to hear I'm not alone, I thought I might be doing something wrong. Thanks for your help