Additive to be added to a 1:4 shellac weight to alcohol volume mix. Cross links in about 20 days and forms an extremely tough final coat.

Notes updated July 2016

HARDENER FOR SHELLAC SOLUTIONS.
(Note: From early 2016 this product has been formulated to allow use in any portion desired provided the mix ratio is carefully adhered to. In other words the several components in the solution now decant and maintain proportion).
 
After shellac has been dissolved in ethanol it is possible to introduce additives that cause the shellac to cross link over a period of about 20 days. Note that this crosslinking process can be shortened within reason by 2.5 days for each 10 degree Celsius increase in temperature with lights or a heater. This additive has been mixed to be appropriate for maximum hardening. It is added after the shellac has been put into solution. The hardened shellac can be used on table tops so that condensation & heat rings do not occur. Also increases resistance to alcohol. The additive must be in intimate contact with the shellac solution for 72  hours before the hardened shellac can be used. Application gear must not be allowed to go dry otherwise brushes, rubbers & spray nozzles will go rock hard. Wash them out well with metho. For heat resistance on window frames, tables etc, every coat should be with the hardened shellac. Process of application & coating intervals of hardened shellac is identical to unhardened shellac. When using a rubber apply some oil on long strokes to prevent tearing. This additive slightly slows the drying process which reduces blooming & allows for a brush to be used on large surfaces without the "edge" drying before you have time to get back to the start point.

SHELF LIFE - Hardened shellac can be treated as non hardened shellac for the purposes of shelf life. We recommend waxy grades - orange and button - should be used within 24 months of being made up and the de-waxed blonde, ruby, garnet and white grades within 18 months.  Refrigerate both flake and made up polish. Shellac is an organic product.  Do not freeze.

MIX RATIOS - This product assumes you are starting with a polish made up to a 4:1 ratio weight of flake to liquid volume of alcohol (e.g. 1  kilogramme flake to 4 litres of alcohol or 2.2 pounds of flake to 1.05 gallons of alcohol).  For a 250ml mix put 41 grams of hardener in the container and top up with the 1:4 shellac mix
For a 500ml mix put 81 grams of hardener in the container and top up with the 1:4 shellac mix etc
Allow 72 hours for the made up hardened mix to mature before use

THINNING  - When the hardened shellac mix is made up as advised above it can then be thinned as desired for use. The use of 100% denatured absolute alcohol (DAA spirits on the Australian market) or IMS  (Industrial Methylated Spirits  - usually specified to be 95% proof) is strongly recommended. Hardware store methylated spirits may contain unacceptable amounts of water which can cause blooming in the finished work.  

CLEAN UP - Note that the common practice of leaving polishing brushes loaded with polish and uncleaned between work sessions cannot apply to hardened polish as brushes will go rock hard and not be restored for use.

TOUCH UP & RESTORATION - Hardened shellac cannot be treated as normal shellac for touch ups and re-coats. In this respect it is similar to other catalysed varnish finishes. Re-coats outside the 20 day application window will not meld with the older polish.  Scuffing the old surface to form tooth may be attempted.

TOXICITY - Given that the ethanol has off-gassed this hardener does not affect the toxicity of the shellac base which is rated as food safe and widely used as a pharmaceutical, confectionery and fruit glossing agent. It is rated as a food by the US FDA.

DOMESTIC ORDERS - Have to ship via road courier and require a physical address and delivery instructions

EXPORT ORDERS - This product is only available for domestic Australian orders.ply.

RELATED PRODUCTS

• Ondina oil for lubrication HERE.
• Brushes HERE
• Pumice HERE
• French polish & Shellac data sheet HERE