Liquid Quartz Ceramics Sealer
It is a food safe, permeating sealer designed for use on unglazed ceramic ware, rendering it waterproof, stain resistant, & yet completely unchanged in appearance.
Liquid Quartz can be applied to all unglazed, stable, porous surfaces; bisque ware, vitrified ceramic ware (yes it is still porous) & alternatively fired clay bodies (pit, smoke, saggar, barrel, naked raku) to create an invisible, long lasting, protective barrier against moisture, food juices, & other contaminants.
Made from SiO2 (or Silicon Dioxide/Silica), a naturally occurring oxide & one of the most abundant minerals found in the Earth’s crust, most commonly in the form of Quartz. It is used extensively in the production of glass, glazes, underglazes, clay body stains as well as terracotta, earthenware, stoneware & porcelain clays. It is highly abrasion resistant (7 on the Mohs scale) & thermal shock absorbing.
Liquid Quartz is certified food safe to the stringent EU food safety standards & rated as a non-hazardous substance. It is essentially self-cleaning, being hydrophobic & oleophobic; resisting staining from oil, grease, acids, alkalis & alcohol as effectively as any matt glaze, reducing the need for chemical cleaners & harsh detergents. Water will simply bead off, taking surface contaminants with it. (Note that just like a matt glaze, prolonged contact with some foods may still mark the sealed surface. To avoid this, plates should be rinsed clean as soon as possible, as with all your ceramic ware.) It cures completely within 24 hours without firing or further treatment, & is completely invisible once dry. It is dishwasher & microwave oven safe to 450°C (& also stable to -70°C, making it popular for outdoor sculptural work in extreme conditions). It is also antibacterial & will help prevent the formation of algae, moss, fungus, scale & efflorescence. It is UV stable, but may not completely halt the fading of all finishes, this is being tested by time now. It has been field tested on restaurant plates that are still in use today (since 2014) with daily dishwasher cycles & extremely high usage.
While Liquid Quartz is NOT for use over glazes, it has become very popular with artists who glaze only part of their work, to seal the unglazed sections & prevent staining from lips & fingers, as well as dishwashers, & to prevent water seepage under the glazed areas. It has also proven useful for sealing properly cured underglazes (fired to the manufacturer’s instructions). Liquid Quartz will not effect the glazed sections of your work, (it will simply bead & run off a non porous surface during application) nor will it change the look of your clay body or underglazes. We have also had reports of great results sealing leaky glazed wares from woodfirings, in between the cracks of crazed & crawled glazes from both electric & gas firings, & on the unglazed areas of raku fired work.
what can’t it do?
It cannot seal an unstable surface (still powdery or crumbling after firing), or a water sensitive surface, like an air dried clay body or ink/paint decorated finish, as it works by soaking in to the surface, creating a root ststem within the clay body & fusing with it, rather than creating a seperate strata like an epozy or varnish that can hold an unstable surface together (but is not food safe). It is not suitable for air drying clay.
It cannot make your underfired/toxic glaze food safe, as it cannot seal over a non porous surface like a glaze.
It cannot stop underfired clay from being suceptible to chipping & cuttlery scrapes. While it will render them waterproof & impermeable, the integrity of your clay body remains unchanged with application.
It cannot seal a dirty/greasy/dusty/contaminated/pre treated surface. As with any product, the effectivenes will only be as good as your pre-prep & application. Please download the Instructional PDF below & read how to best prepare & apply the product.
If you use a post firing chemical (like ferric chloride) or any potentially toxic ingredient in the firing of your work that will not burn out at the temperatures you fire to &/or has nano sized particles, you should test your work to ensure no leaching occurs.
Liquid Quartz is effective because the particle gap is nano sized, prohibiting the passage of larger particles like water or other liquids. This is why it is also important to seal only completely dry work, as trapped water will not be able to escape when heated.
how do I use it?
Liquid Quartz is a post firing applied product, so it requires no further firing to cure it. It is applied by brushing, spraying, or dipping (see the PDF below for more details). It works by creating a root system in the porous surface, fusing with it, then self leveling on the surface of the clay body, where the water carrier evaporates leaving only an invisible layer of silicon dioxide, fused permanently with the clay body. It is fully cured & ready for use in just 24 hours. For detailed instructions on how to apply it or prepare your work effectively for application, as well as other general product information, tips & tricks, please click on the link below or at the top of the page to download the PDF for your reference:
Please download the guidebook & read it
how long does it last?
Liquid Quatrz has been in use on plates in commercial restaurants since 2014. These plates are still in use, & continue to be waterproof & functional today. As with any plate, glazed or sealed, your treatment of the surface will effect the longevity of the finish. Harsh chemicals, abrasives, or heavy cutlery scraping can alter or degrade the surface of any dinnerware item (this is visible even on many traditionally glazed plates), but if you take good care of the surface by washing with mild detergents & avoiding abrasives, it could last longer than the plate itself.
Note that if the surface you seal is not completely solid (lowfired/low bisque) the sealer will still fuse with the surface & be waterproof, but only for as long as the surface remains intact, therefore heavy scraping of cutlery on unstable bisque fired plates is not recommended. Earthernware clay bodies fired to their most vitrified temperatures (terracotta etc.) can be sealed with much success, but will remain more suceptible to chips & damage than high fired stoneware or porcelain, as the claybody itself is not suitable for restaurant quality plates, cracking easily & requiring gentle washing to prolong the life of the piece. This is the nature of the clay body, & cannot be changed by sealing the surface only. While your work will be waterproof & stain resistant, it will remain brittle & easily scratched if low fired.
Over time the tiny particles on the surface that facilitate beading (the lotus effect) will flatten out with everyday use (from the constant wiping with cloths & sponges during cleaning & use etc.), & the surface will demonstrate less beading of water & other liquids. This is usual & in no way affects the water resistance or food safety of the surface, as the sealer has fused deeply with the clay body & will continue to form a barrier long after the surface has become worn with use & age.
how much do I need?
Average coverage is 50-75ml/m2 for very porous surfaces (vitrified ware will take less). A standard size, low-mid fired dinner plate will usually require no more than 10-15ml, even when using the dipping method, which will ensure the most thourough coverage. Even at this maximum absorption rate, the product is more cost effective than glazing when calculating materials & firing costs (not to mention the labour involved with glazing).
Below is a table demonstrating how economical the product is (broken down by the varying cost per ml depending on the size of the container ordered) so you can compare it with your glazing costs or use it as a guide to help you price your work for sale.
Note that these estimates are an approximate guide for using 15ml / piece (which reflects our findings for the most porous surfaces tested) high fired wares will require much less product to seal than shown here: