Where to find technical information about finishing materials

In order to get a good stain or varnish on the wooden objects you have decided to finish, whether you are an amateur or a professional, you need to make sure that you have the necessary information on the products used, that you know how to mix them, apply them, process them, so that you get the desired result. DIY enthusiasts will find information about the characteristics and how to work on the label of products bought in DIY stores. For those who work in workshops or factories, this technical information can be found in the product data sheets, safety data sheets and working technologies that you should be provided with by suppliers of finishing materials.

In these documents you will find very important data to help you choose the right products for your purpose. It is very important to study them before you start working with the materials. The product may be very good, but if it is not properly prepared you may not get the result you want. Some information about what you find in these documents might be useful.

Fact sheetis the business card of every product. It contains information on product characteristics, application instructions, drying times, whether and how to sand, etc. Regardless of the manufacturer, the data sheet has minimum information on physical properties. The properties most often present in a data sheet are solid body, viscosity and specific gravity.

Solid body is the amount of solid resin remaining after evaporation of the solvent. The higher the percentage of solids, the better the product. In the case of non-curing products such as nitrocellulose, the solid body is the amount of material remaining on the wood substrate after drying. For products with hardening, the amount of material remaining on the board is not always equal to the sum of the 2 solid bodies. Sometimes, as a result of the chemical reaction, compounds can be formed that lead to the growth of the solid body. But even then, the bigger the solid, the better the lake.

Viscosity is another very important feature. In production it is measured using a viscometric cup with a standardised nozzle. The cups can be FORD (English measuring system) or DIN (European measuring system), with a very small difference in nozzle diameters due to the different measuring systems. The cups have different numbers - 2, 4, 8 - depending on the nozzle diameter through which the product flows. The number of cups is directly proportional to the nozzle size. In the data sheet we find the initial viscosity of the product, measured, in general, at a temperature of 20°C. In the application technologies there are indications of the viscosity on application. It is measured after the material has been prepared for application (diluted and catalysed if necessary). Viscosity is temperature dependent and inversely proportional to temperature.

Specific weightis the mass of the volume unit. It can be used to calculate volume or applied mass.

In addition to the physical properties, the data sheets also contain information on the substrate to which the product can be applied, the recommended application quantity, drying time and other useful information for the production process.

The drying time is of several kinds. Dust drying time is the time during which the varnish film dries on the surface so that the falling dust is no longer embedded in the film. Impression drying timeis the time after which we can handle the finished object without the risk of leaving marks. Drying time for sanding is the time after which sanding is done lightly, resulting in a fine, white powder. Drying time when packing is the time after which packaging can be done without the risk of printing.

Another very important document is safety data sheet. In fact it is a document that you must have. In the safety data sheet you will find information on the chemical composition of the product, the impact and risks of its use on human health and the environment, how to store and transport the materials, first aid in case of accidents, contact persons in case further information is needed. It is compulsory to have safety data sheets, in Romanian, for each product used and to present them in case of an inspection by the Environment Agency.

Another "tool" you need is working technology. It can be a general technology, proposed by the manufacturer and valid in most cases, or it can be established after testing in production, with the existing machinery there and under specific environmental conditions. It is a useful document in production because it contains information on each stage of the work, from the preparation of the blank wood substrate to the final coat of varnish and packaging of the finished product.

I recommend that you ask for these documents every time because they are very helpful. In addition, in the case of safety data sheets, it is compulsory to have them, thus avoiding penalties which can be very "painful" to the pocket.