Contact
PRAVÝ SMALT
Ing. Veronika Šeďová
Hvězdová 13 Brno 60200
+420 608 081 716
veronika@pravysmalt.cz
Frequently Asked Questions
We have prepared some answers to frequently asked questions.
Repairing old enamel signs is very problematic and usually does not lead to success.
When making a new sign, the enamel well has a certain depth. After firing and sanding off the excess enamel so that the enamelled area is on the same plane as the compartment, the fine layer of metal is always sanded off and the compartment is a little shallower. Every tenth of a millimetre is crucial to the result. Repeating the whole procedure therefore runs a great risk of breaking through the enamel and the compartments and devaluing the original mark.
Another problem can arise when re-firing old enamel with new enamel, when the old enamel, new enamel or both enamels start to fall off during natural cooling. This can be caused by small impurities getting into the cracks and also by poor bonding of the new enamel to the substrate. Not all enamels work well with all materials. With tombak (copper with a small amount of zinc), the amount of zinc is also a factor that causes problems when enameling. Some metals need special enamels made to meet the exact needs of that metal’s composition.
When old enamels are restored today and lost enamel areas are replaced, they are often two-component cold enamels, thanks to which an almost identical shade can be mixed and everything is done cold. It is a synthetic substance that we do not use. We only produce genuine enamels.
We recommend that you hide the old enamel emblem with historical value in a display case and we will put it on your car.
The enamel is fired at a temperature of around 800 °C. By soldering the screw with tin, this temperature is far from being reached and the enamel remains undamaged. The only danger is if too much pressure is applied to a hard base, the enamel could crack, so it must be backed with a fabric or soft base.
Another simple option is bonding with a two-component epoxy adhesive. There is a wide range of metal adhesives that are completely reliable and, when applied correctly, there is no risk of the joint not being strong enough.
In case of interest and by appointment, we can arrange the attachment of screws or pins.
We use genuine jewellery enamel and copper. In the past, mostly tombak was used, which is copper with a low amount of zinc, usually up to 15%. For enamelling purposes, tombak with 3-5% zinc was also produced. The higher the percentage of zinc in the material, the harder it is to enamel. This material is virtually unobtainable nowadays. Brass cannot be enamelled because of the high amount of zinc.
Generally, jewellery enamel manufacturers usually list copper, gold and silver as enamellable metals.
Generally speaking, the dirt is removed by the jar and warm water. Copper oxidizes and darkens, which may be desirable to some, the product acquires a patina. To restore the brightness of the copper, we can recommend Sitol – a glass and mirror cleaner for metals, which also contains ammonia. It cleans and polishes the copper beautifully and leaves the enamel undamaged. After using Sitol, it is always necessary to wash the residue thoroughly with spring and warm water.
The price of shipping depends on the country where the package is sent. We pay for the shipping within the Czech Republic via Zásilkovna. We require payment on account before shipping. We will send a photo for approval after agreement before shipping.
Máte zájem o odběr novinek?
Nebojte se, nemáme čas posílat vám spamy. Jsme příliš zaneprázdněni výrobou originálních smaltů.