Liquid quartz

[Askerbasker]

Does anyone have any experience with the product liquid quartz. It says that its a “glaze” that is food safe and makes unglazes clay waterproof.

I am interested in making primitive ceramic objects that can still be used with food even though they are unglazed. Glazes doesn’t really look good on primitive ceramics.

[JohnnyK]

It is NOT a "glaze" in the traditional sense, and it WILL burn off if you fire it!

A few years ago I tried working with liquid glaze on a couple of bisqued pots to see if it would make my Raku pieces able to hold water and got some disappointing results. After sealing the pots as per directions, letting them dry, then water testing them, I found that they DID absorb water and leak. When I contacted the manufacturer, they asked me if I had thoroughly washed the inside of the pot to remove ALL dust that may have been in the pot. I had not done that before the sealing process, so, I am assuming that's why my pots leaked. I have not gone back to do additional testing, but plan on doing so in the not-too-distant future. The stuff is VERY expensive and, unless you have some spare cash to throw away, I'd hold off on doing so until you get more input.

If there are others out there that have used it successfully, feel free to chime in...

[Min]

Previous thread discussing this product here. 

@JohnnyK, there is a new Mod Podge clay sealer that claims is okay on the top rack of the dishwasher and another for outdoor use, wonder if those would work just as well for your raku?

[JohnnyK]

8 hours ago, Min said:

Previous thread discussing this product here. 

@JohnnyK, there is a new Mod Podge clay sealer that claims is okay on the top rack of the dishwasher and another for outdoor use, wonder if those would work just as well for your raku?

With fall upon us and shorter days, I'm putting my farm to bed for the season and will be able to spend more time in the studio. Part of my agenda will be to spend some time working with the LQ.  I'll also check into the Mod Podge sealer to see how it works, too!

[maz]

I've just tried the Liquid Quartz Sealer and had excellent results as per waterproofing,  however,  on other items (partially glazed and twice fired to cone 6), it's showing a mould like surface discolouration after putting it through a dishwasher several times. I'm starting to think this is because I sanded the raw parts of the item and didn't wash and dry thoroughly enough before spraying on the LQ. So moisture is possibly trapped creating the awful grey mould appearance. I've decided to refire to remove the product and burn of the mould. 

Hopefully this will eliminate the problem and I will be wiser next time.

[Min]

@maz, thanks for sharing your experience with it. Let us know how your re-fire goes.

Welcome to the forum 

[VermontPotter]

I'm curious as well about this Liquid Quartz product. I'm specifically looking for something to fill the occasional pinhole in my wares.  I'm unsure if the inside of pinholes are porous at all. The product states the surface must be at least partially porous for it to work.  I was also thinking of just using clear epoxy?   I have a few pieces that I love that just have a couple of pinholes and I have already refired them.  There must be a compatibility issue or my bisque firing didn't entirely burn off stuff. I saw someone note that epoxy with its low viscosity just pops out of small holes so I was not sure if epoxy could work? I'm looking to fill a few tiny pinholes on bwols that I would intend to use as food serving dishes. Any thoughts folks? 

Thanks!

Marc 

Purple Barn Pottery

[Bill Kielb]

4 hours ago, VermontPotter said:

There must be a compatibility issue or my bisque firing didn't entirely burn off stuff.

Possibly true but often a function of a glazes fired viscosity and surface tension  (oddly enough) and ability to heal. Search for drop and hold firing schedule, glaze pinholes, etc…. I would agree - glaze pinholes in wares  intended for food, or even if potentially could be used for food, Certainly not a ware I would consider keeping  -ever. I usually destroy the piece always worried someone at some point in the future might unknowingly use it for food service. I actually don’t know of any experienced potters who would consider filling the pinholes in their wares for food service with a chemical fix.

Epoxy viscosity

Epoxy comes in many forms, the typical household stuff is about the viscosity of maple syrup. Not super low, like water but not super high either. Epoxy also comes in a putty form - semi solid and stays where you put it so super high viscosity I guess.  Epoxy even comes in a uv curable form so the viscosity of that - not necessarily relevant. Epoxy also comes in food grade compositions. An example: https://www.permabond.com/industries_served/food-safe-epoxy-adhesive/

Not many potters I know would risk this repair on any food surface. Instead they would bisque longer or solve the glaze issue or only use tested durable defect free glazes as a liner for their food service stuff.

Edited November 20, 2023 by Bill Kielb

[Min]

On 11/19/2023 at 7:54 PM, VermontPotter said:

I'm unsure if the inside of pinholes are porous at all.

If you do an absorption test on your clay it will tell you this. It's a good idea to test a claybody for absorption using your kiln and firing methods rather than what a clay manufacturer publishes it as. For functional ware below 1 - 1.5% is usually good. Link here on testing absorption if you need it. If the clay isn't porous for all intents and purposes and you run your pots through the dishwasher I wouldn't worry about the odd pinhole. Aesthetics are a different point, a pinhole on a pristine porcelain piece is going to stand out far more than one on a rustic piece. 

Ryan Coppage article here discussing bacteria growth on crazed glazes. Conclusion is if your clay is vitrified and the pots run through a dishwasher bacteria is not an issue. (article is behind a paywall but you can access 3 free articles a month) I haven't come across any literature proving pinholes harbour more bacteria than craze lines.

Edited November 21, 2023 by Min
added a link

[neilestrick]

Pinholes with smooth edges on a vitrified body are not an issue as long as they're cleaned well. However from an aesthetic standpoint they may not be desirable.