Glaze is super wet, takes forever to dry

[Polydeuces]

Hey y'all~ 

Curious about this issue and what I can do to correct it. I mixed up a batch of Folk Art Guild White (Cone 6). It was settling on the bottom so I added a little epsom salt solution, sieved, measured and thinned to around 136 sp. gravity. It felt alright, but then I dipped it and it takes *forever* to dry.

I only did a small handful of test pots with it and they actually came out looking really nice (IMO). But this consistency makes these pieces difficult to work on in a timely manner. 

Any recommendations? I was thinking that maybe adding some more dry material might help in case the glaze is pretty water-logged, but I didn't think a 136 spg was super wet. The mix is below, in case that gives anyone any ideas.

 

 

[Mark C.]

Glaze drying time can be several factors

1st is glaze to thick?

glaze is over another and gets to thick?

pot is wet?before glazing

pot is Biqued to a very high temp?Hard bisque and all glazes dry slowy

Glaze to thick is my guess-many of my cone 10 glazes are specify gravity with higher numbers (more water less glaze)=faster drying

Have you scratched the glaze surface to see its thickness?

 

[Polydeuces]

Thanks for the reply, Mark! 

Perhaps I'm mistaken, but I thought a higher number indicated more dry material in the glaze. Whenever I add water, it tends to weigh less. I fire at cone 6 and the majority of my glazes function well in application & results between 135-145.

I typically wipe down my pots with a damp (but not dripping wet) sponge just to give them a once-over—doesn't prove to drastically affect the drying time on other glazes. I bisque to 05. 

I haven't scratched the surface of any of the pieces yet, but to memory, it didn't *seem* overly thick like when I've dipped into a glaze that I left unattended for a long time and dip into. 

[Bill Kielb]

In addition to your working conditions (local humidity)
You should not need bentonite in this recipe as it only acts to help suspend and you have more than enough clay already. In addition Gerstley is going to make this  dry very slowly as well. So, looking at the chemistry, the 18 Gerstley gets you about 0.2 boron of which you likely only need 0.15 for cone 6. So for a small batch you could try would be: 12 Gerstley and zero bentonite. Most dipping glazes end up to be an SPG of 140’ish so mix up 100 - 200  grams to 135 / 140 and see if this improves your drying enough to tolerate.  You should be also  able to reduce your clay (EPK) easily to 15 as well,  10-15% is usually fine to keep things suspended.

Subbing all the Gerstley for a Fritt and rebalancing this is also a possibility but then takes potentially some testing to make sure the fired result is similar enough to what you are accustomed to.

All of the above obviously requires testing to be sure it still fits your clay and it’s texture is suitable. Texture changes are easier though as for more gloss, increase silica, more matte, decrease. All within reason though, can’t do that forever. The chemistry of this glaze says when fired to maturity, some level of matte but with the current excess Gerstley it could fire relatively glossy.

A last note: folks have preferences for their dips and therefore have a preference for an SPG. We like three second dips, (1,2,3 as fast as you comfortably count) but you may have a different preference therefore your preferred SPG may not ever match mine.

[liambesaw]

Mine never settles, and I don't add bentonite. The gerstley does more than it's share to suspend it. I wonder if you just got tricked by the gerstley into adding more water, it gels and makes glazes seem thicker than they are.

I suggest letting some water evaporate off, I don't think it'll sink when there's less water.

Gorgeous glaze though!  Be patient when drying, it definitely doesn't need any epsom salts 

[Callie Beller Diesel]

Nothing with Gerstley should need either bentonite or Epsom salts. 

[Mark C.]

another factor is dip time or pouing time?

Again is it to thick when scratched??

( Perhaps I'm mistaken, but I thought a higher number indicated more dry material in the glaze. ) yes thats right-none of my glazes are this watered down. But I am not a cone 6 person and have zero experience with that temp in glazes

[Polydeuces]

Thanks for the replies everyone!

I'll try mixing up a couple test batches without bentonite. I'll leave the GB as is on one, and on another lower the GB—but do I need to need to replace it with anything? 

I might like to try in the future experimenting to bring it to a bit more of a matte texture. But I dunno, I tend to have bad luck with mattes as a whole so maybe not...

As far as the current batch I have, it's a pretty small 1 gal bucket. I'll still be using it on certain smaller things, probably. But if I've already added the epsom salts to this batch, what is the longevity of that effect? I'm just assuming that hitting it with some Darvan may not be the best idea. Mark, I'll dip test pots tomorrow and get a better idea. It didn't seem too thick when I was last glazing—just wet.

Thanks again!

[liambesaw]

Don't lower the GB, this glaze does not move at all and melts just fine the way it is!

[Bill Kielb]

1 hour ago, Polydeuces said:

but do I need to need to replace it with anything? 

 

Not likely  - often it’s just a waste of chems as evidenced by the 2% bentonite. The  general rule for bentonite is up to 2% to help keep difficult recipes suspended. Those generally are the recipes with less than 10% clay. Your recipe I believe contains nearly 18 - 20% clay so it is already beginning to be on the high side of clay content as well as excess boron for cone 6 from gerstley.

Recipes with interesting equal amounts of materials are often the result of folks adding, firing and adding other chems until they get a result they like. Do they remove previously added stuff? Probably not. For a couple hundred grams of experimenting my thought would be mix it up without, likely will have a minor effect on the fired result. The boron is excessive now and removal of some Gerstley and some clay gets this back in the region it already started anyway. Gerstley does cause issues with respect to gelling, drying, cracking while drying ........ Perfect chem matches can be done on this but what’s the point of  perfectly chem matching what appears to be an overloaded recipe?

For the one or two hundred grams, I would try the subtraction first, if nearly what you can tolerate with drying time, you can always tweak the texture and color to match.

Getting mattes (true mattes), is fairly easy actually, don’t let them scare you. Growing mattes by Downfiring  a bit more trials though. True mattes from the get go are much easier to tune in. Generally slowly decrease your silica and observe your matte.

[Bill Kielb]

42 minutes ago, liambesaw said:

Don't lower the GB, this glaze does not move at all and melts just fine the way it is!

Ideal for cone 6 would be 0.15, he is at 0.20. Not sure why he wouldn’t try for 100 grams. Has high amount of clay anyway. I would try the adjustment, both actually, why waste natural materials? Save the planet. Convert your colorants to a percentage of the glaze and adjust accordingly is likely something that will be required. Fix the drying issue, color to taste would be the suggestion.

[liambesaw]

1 minute ago, Bill Kielb said:

Ideal for cone 6 would be 0.15, he is at 0.20. Not sure why he wouldn’t try for 100 grams. Has high amount of clay anyway. I would try the adjustment, both actually, why waste natural materials? Save the planet.

Sure, try in a small batch maybe, but this is a "special effect" glaze that tends to go really ugly when the recipe is off.  I've seen it go from beautiful cream breaking red to dirty orange brown just from trying to sub out the GB for frit.

[Bill Kielb]

25 minutes ago, liambesaw said:

om trying to sub out the GB for frit.

Subbing out Fritt is a super significant change which likely changes the colorant amount needed. I think It’s worth the try as is, otherwise let’s just leave 2% bentonite in every recipe so the color amounts  won’t change. Keep in mind the tin is listed as a component and not colorant and bentonite is listed as a colorant. Hey a perfect 102% after correcting.

Like many recipes, I suspect someone added more clay, didn’t melt enough then more Gerstley and there that’s perfect. Lots of trial and error glazes this way, often consuming chems they don’t really need. I get it,  Sometimes it’s not worth all the work of the tweaking but is a colossal waste of natural resources. Bentonite, my pet peeve!

There is a good point to be made here though,  when colorants are not expressed as a percentage, it is difficult to add or subtract anything from a recipe and not have a pronounced effect on the color.

[Polydeuces]

Hah—concerning the bentonite, nearly every cone 6 recipe I come across has 2% in it (as an additive that isn't factored into the 100%). I would enjoy using it less. Stuff is a bit of a pain to work with, anyway.

[Bill Kielb]

37 minutes ago, Polydeuces said:

Hah—concerning the bentonite, nearly every cone 6 recipe I come across has 2% in it (as an additive that isn't factored into the 100%). I would enjoy using it less. Stuff is a bit of a pain to work with, anyway.

Yeah it’s not magic stuff. The rule in general is up to 2% (not over) to help keep things suspended. If you have more than 10% clay generally things are fine. 20% clay, the recipe is getting thick. Gerstley itself tends to make things gel and has drying issues. So having both would definitely mean bentonite was likely added just because............. who knows?

Liam has a fair point especially when colorant amounts don’t reflect their true apportionment in the glaze. Removing bentonite changes the recipe apportionment so you may need to change colorants slightly to return back their influence in the recipe.

when designing a glaze it’s really rare to land on a bunch of whole numbers. Not to say that rounding to the nearest gram is not doable but recipes with a pattern of similar whole numbers are  more often trial by fire stuff. It can be good, but often is wasteful.

[Min]

11 hours ago, Polydeuces said:

 I'm just assuming that hitting it with some Darvan may not be the best idea.

It will slow down the drying, I wouldn't do it.

I agree with the advice about letting some of the water evaporate off the bucket of glaze. If the glaze goes on too thick then dip for less time. If you only have a few pots to dip you can also warm them up slightly, to around 150F, and then dip them, they'll dry faster. 

If the glaze melts well with the amount of alumina it has in it, like this one does, I wouldn't lower the epk content. Having as much alumina in the glaze as it will tolerate improves the durability of the glaze, the epk is supplying a fair bit of alumina along with silica (and other oxides). Silica is on the low side as the recipe stands right now, lower the epk and it will also lower the silica content. Could easily bump it up by adding more silica but I don't see a net gain in decreasing one material if it means you have to increase another. Agreed that this recipe doesn't need bentonite.

 

[Mark C.]

(Stuff is a bit of a pain to work with, anyway.)

welcome to ceramics

In cone 6 glazes many of them can settle like rocks so 2% is a good idea -no harm really if you mix the Benonite ib hot water its an easy deal.

I would avoid Darvan as that can really mees with dry times

The best glaze flotation product is Magma.will not change glaze colors and will float bricks

[Polydeuces]

Thanks so much for the tips, everyone. For now, I'll leave the bucket lid off while I run the dehumidifier, and will do some more testing as I near in on the next glaze fire.

Much appreciation! 

[Mark C.]

10 minutes ago, Polydeuces said:

Thanks so much for the tips, everyone. For now, I'll leave the bucket lid off while I run the dehumidifier, and will do some more testing as I near in on the next glaze fire.

Much appreciation! 

Once the glaze settles just scoop some of the clear water off the top.

[Babs]

Lots of recipes for thisxglaze where frit is used and simpler to make by sounds. May alleviated pros totally . Google it

[neilestrick]

The key to using bentonite is to dry mix it really well with the other ingredients, or at least one other ingredient, before adding it to water.

[liambesaw]

38 minutes ago, neilestrick said:

The key to using bentonite is to dry mix it really well with the other ingredients, or at least one other ingredient, before adding it to water.

I find just letting it slake first works really well.  Don't add anything til it sinks

[liambesaw]

3 hours ago, Mark C. said:

Once the glaze settles just scoop some of the clear water off the top.

Don't do this, the glaze contains quite a bit of solubles like lithium, sodium and borate