Chroming guns

The ancient technique of silvering has been updated, modified and reinvented, to allow chrome plating of all types of surfaces and objects. The spraying technique involves guns with double nozzles as well as a series of spare parts for a chrome plating system, coupled with reservoirs where the liquids are stored.
Originally the adventure process consisted of a soaking or pouring the products onto a glass plate.
It was mainly used to produce mirrors. Nowadays, modern chrome plating systems consist of spraying silver plating products with guns.

The silver mirror is obtained by the meeting between 2 chemical products to be more precise and in terms specific to chemistry. This is called reduction of silver nitrate through a reductant.

To develop the technique of spraying these liquid chemical solutions, it was necessary to find special sprayers capable of projecting liquid at the same time. This has therefore been made possible with the special 2-nozzle guns, for the “double nozzle” guns.

Why use guns with 2 separate nozzles and not just use a Y-hose that leads the 2 combined products into the spray chamber of the classic single-nozzle gun directly ?
This of course has been tried and unfortunately the results were quickly very bad. The reason for this is that the products react very quickly and very strongly with each other (nitrate A and reducer B) and this creates rapid clogging inside the gun and contamination problems after just one or two uses of the gun.

Guns for chrome plating systems

What type of equipment can be used to spray silver ? In truth, it is possible to use just about any sprayer or gun. The products, which are very dilute solutions of chemicals, have a viscosity equal to that of water, so it is possible to use very fine nozzles.
However, it has been shown that is not not recommended to atomize finely, i.e. to create a mist of sprayed products, because this does not really bring more and it creates a significant disadvantage: the products oxidize more easily in the air when they are atomized. As a result, it is not necessary, as many believe, to use spray guns to spray the silvering products onto the substrates. In truth, chemicals can even be poured onto the surface.
Spraying has the advantage of saving products and increasing precision because it will deliver the right amount of products very evenly to a specific area and avoid Tasks. Over the past thirty years, many silver plating systems have been created and double-nozzle guns have been widely used. There are many types, which are originally manufactured for spraying special polyurethane paint or even chemicals.
These guns, very often incorporated into chrome plating systems, nevertheless have an Achilles heel . Their internal composition includes too much metal : nozzles, needles, ducts are all made of metal, certainly stainless steel, but often the layer is thin and it is found in various alloys.

All these metals, and this is also the case for the stainless steel of the needles and nozzles, react with the ions of chemical products, such as tin chloride or silver nitrate.
The result is the rapid formation of layers of metal agglomerated on the internal walls of the gun but also on the needles and the nozzles which, quickly, clog or create an imprecise spray. It is then necessary to brush, rub the needles or bathe them in ultrasonic cleaning baths to strip them. The downside is that the clogging is very fast and you have to constantly clean all these metal parts that make up the guns.

Plastic sprayers

Sprayers made entirely of plastic offer a wide range of advantages over metal guns.
First of all, they are easy to use, unlike metal twin-nozzle guns, which require complex adjustments.
Plastic sprayers do not work with chemicals : they are perfectly neutral, whether for interior pipes, nozzles made of 100% plastic. As for the needles, they do not contain any.
Plastic sprayers are economical : you can count around twenty euros for a sprayer, compared to 200 or 300 euros for a metal gun. They are also extremely easy to repair, ie you can change the nozzle for 5 euros. Plastic sprayers can be adapted with different types of nozzles, with round or flat jets, with different spray angles.
The sprayers do not use pneumatics, i.e. the product projected and 100% liquid, and thus, there is less oxidation of the liquids during the journey between the gun and the surface.
The results are exactly the same as those obtained with metal guns.

Other types of guns

You can find guns with a single nozzle on the market, in which you can see different ones through which the liquids are projected. Inside the gun, the liquid does not touch, it is not in contact at any time, because there are 2 inputs for the supply of products and two outputs. However, reviews and reviews of these guns are not very positive, and the price of the gun is very high.

There are very modern and very innovative guns that combine the use of all guns at once. That is to say that we find on a gun all the functions of 4 guns usually present on a chrome plating system (the activator gun, the rinsing gun with water, the double gun for the money and the reducer).
These electric guns, equipped with diodes and buttons to select which product must be sent, have a quadruple input for the 4 products mentioned before. This is very practical. However, this type of gun is very expensive and quite complicated. When it no longer works, you have to send me for repairs or buy another one, which represents very significant expenses.

Vats for chrome plating system
Hoses for chrome plating