Nitrocellulose varnish: varieties, composition and characteristics
NC varnish (it is also called nitro varnish, or nitrocellulose compound) is the best choice for protecting wooden furniture. This composition is the result of compounds of nitric and acid cellulose esters.
The application of nitro varnish on wood helps to improve the aesthetics of the coating, and a colored or transparent film is obtained (this will depend on the specific type of varnish). The individual properties of the product will depend on the addition of resins and plasticizers (for example, water-resistant nitro varnish), pigmenting components of an organic type (create a color or shade of the surface) to the composition.
Nitrolac is usually used for processing benches, pedestals and cabinets.
The base of the product is high-quality nitrocellulose (polymer of artificial origin, structure which is very similar to fibers from natural cellulose). The mixture is immediately ready for use, and the varnish composition itself dries quickly, and the result remains homogeneous, even and firm. Also, the product has an increased level of adhesion, and therefore it is not necessary to prime the surface additionally before application. Depending on the type of composition, the varnish can be matte, glossy, and also semi-gloss. The protective film of wood furniture has a decorative effect, but can begin to deteriorate due to high temperatures and ultraviolet radiation.
You will need to apply varnish in several very thin layers. Please note that nitro lacquer is highly flammable, so handle and store it away from fire and sparks. In order to prevent the composition from drying out, you can add a solvent (about 5% of the total varnish volume) to it, and then mix everything thoroughly.
In addition to cotton (or wood) cellulose, the composition contains organic thinners, amino-formaldehyde and alkyd resins, rosin and vinsol. Acetic acid esters, propyl acetate, toluene, xylene and ethyl acetate can be used as solvents.
From various plasticizers (nitroparaffins) phosphates, chloroparaffin and casterol can be isolated.
The dried composition remains even, durable and hard. It has a high degree of adhesion to the base, and also perfectly lends itself to grinding. It is worth working with coatings at temperatures from +12 to +61 degrees. The properties of the varnish composition make it possible to use it only indoors, since the coating is vulnerable to moisture, temperature extremes and sunlight.
It also has an increased level of danger in terms of fires.
The production technology is rather complicated, and therefore it is performed in several stages:
But tinting of nitrocellulose varnish, the technical characteristics of which are very high, is carried out by adding pigments. Without their use, the finished product will remain transparent (that is, colorless). The amount of added pigments is calculated relative to the proportion of colloxylin in the composition. The main component is classified as explosive and flammable, therefore it is stored in a sealed container and under all conditions.
When adding colloxylin, you can increase the thickness of the product. If it is too viscous and thick, it should be thinned with a solvent. In order for the paints and varnishes to have a uniform consistency, the composition should be cleaned in a centrifuge.
Colloxylins can be low-viscosity or high-viscosity grade (PSV or BB, respectively), and are made from wood and cotton cellulose. The nitrocellulose-based base helps to create a protective film after application to the surface, and solvents can be high-boiling (ketones, dioxanes, for example, cyclohesanone or methyl isobutyl ketone), low-boiling (ethyl acetate, formal glycol, acetone or methyl ethyl ketone).
The addition of toluene and xylene makes it possible to adjust the consistency of the composition. Plasticizers can be non-gelatinous and non-gelatinous. The first category includes castor oil, casterol, chloroparaffin, sovol. For the second type, phthalates, phosphates and sebacates are added.
Colloxylin preparation (weighing and loosening) is carried out in a separate room due to the high risk of fire hazard. The component should be stored in sealed aluminum barrels. The creation of nitro varnishes with a thick consistency requires the use of mixers with a horizontal type of load and the alternate addition of components - a diluent, alcohol, resins, resin solution, plasticizers, colloxylin, an active solvent. The finished varnish is packaged in cans, barrels or even tanks.
A mixture based on nitrocellulose can be prepared even at home, and for this we suggest watching a video.
This varnish composition has a number of undeniable advantages:
To apply a layer of nitro varnish, ordinary gloves and a brush are enough, and due to the properties of the consistency, the agent is applied evenly. But the disadvantages are as follows:
- The finished coating is sensitive to moisture.
- Vulnerability to temperature extremes, ultraviolet rays.
- Increased fire hazard of the train.
Such a tool is suitable only for internal work, and it is allowed to use it as far as possible from sparks, fire and various heat sources.
The features and strength of nitrovarnishes will largely depend on the brand, and the possibility of using them for certain works should be taken into account, for example, parquet covering.
This is a colorless varnish NTs-62 for wood, which is ideal for decorating decorative products, and also improves their aesthetics. Depending on the added pigments, the varnish can also be green, red, purple, or any other color. Colored varnish is most often used instead of paints, and in addition to wooden products, such nitro varnish can be used to cover mosaic showcases, paper, glass, metal, as well as lamps for illumination.
The viscosity is from 26 to 40 s, the fractional content of the dry composition ranges from 7 to 12%, the flow rate is from 0.07 to 0.1 kg per square meter. As a result, you get a colorless or colored, glossy and transparent layer. Solvents No.
646 can be used as a thinner, and the varnish should be applied in a couple of layers, after the next one has completely dried.
The varnish is quick-drying, and is suitable for metal, as well as wooden bases. Durable dried layers makes it possible to use varnish for outdoor work, and you can also use solvents No. 645 and No. 646.
The characteristics of nitro varnish are good, because the degree of viscosity is from 28 to 60 s, the drying time is from 1/2 to 1 hour, the proportion of non-volatile components is from 13 to 17%, and as a result you will get an even glossy layer. New layers can be applied only after the previous one has dried.
This brand great for furniture and wooden window sills. Fast drying varnish (dries no more than an hour at room temperature). The quality of the result is obtained when applied to a dry and even surface.
The finished coating can last about 10 years. Antiseptic additives in the composition help to protect parts from rotting and destruction by insects. Internal processing of lockers will protect things from snags. The result will be matte. The characteristics are impressive - the degree of viscosity is from 50 to 85 s, the fractional solids content is from 30 to 34%, transparent, and the level of elasticity of the film on bending is 1.
5 cm. The agent can only be used for interior work.
This varnish composition is suitable for interior work and wood surfaces. The parameters are as follows - the degree of viscosity is no more than 125 s, resistance to moisture is not less than 6 hours, the elasticity of the finished coating is 0.5 cm, and the proportion of non-volatile substances is from 33 to 36%.
The result is a perfectly smooth film with a glossy sheen.
This is a special composition with the addition of esters and resins to protect against crackling. The result will be perfectly amenable to sanding, and there is no need to dilute the nitro varnish itself before use. You should also adhere to the temperature regime during operation from +18 to +20 degrees. For other technical characteristics, the product will be similar to the previous varnish composition.
Often such varnish is used for processing interior doors, it is easy to polish and it is also resistant to high temperatures ... The characteristics are such that the fraction of solids is 35 to 40%, the degree of viscosity of the composition is 115 s, and the optimal thickness of each layer is 50 μm. The quality will be guaranteed after one or two layers are applied, and this is due to the addition of plasticizers to the product, as well as film-forming substances.
A feature of the product will be carbide resins in the composition, which make them resistant to moisture and low temperatures. The finished coating will dry for at least 1.5 hours, and the result itself will be transparent and matting.
Adding pigments to nitrocellulose varnish makes the finished coating with a slightly yellowish and pink tint. The tool will belong to the category of fast drying matting agents.
Relevant for removing defects. The drying time of the layer is 1 hour, the proportion of dry residue is from 26 to 32%, and the degree of light stability is up to 1 hour. The finished drying base will be smooth, free of "wrinkles" and foreign inclusions on the surface.
The composition of grade 551 based on nitrocellulose is used for processing textile products (fabrics for special purposes). The fractional solids content is 9%, the viscosity is from 130 to 160 s, and the shrinkage level is only 0.
6%. The very same surface, for a start, needs to be cleaned of old paint and varnish material, sanded irregularities and remove dust. The varnish must be applied in four layers, and the first will dry for about a couple of hours, and to speed up the process, it is allowed to use a construction hair dryer. Each layer should be left on for 6 to 8 hours to dry perfectly, and before applying the first coat, the surface should be treated with a water-based stain.
If you need to cover small parts with nitro varnish, for example, wood handles, it will be easiest to lower every detail into the container in which the composition is, for a couple of seconds, and then get it out and let the excess varnish just drain into the jar.
If the covered item cannot be placed on a surface, it can be hung to dry. An alternative way to apply varnish is to spray from a can or spray bottle.In all other cases, you will need to use an additional tool, accuracy and a little time.
The application process consists of the following steps:
- Surface treatment with an alcohol (water) based stain or by adding an organic solvent. This helps maintain texture and woody appearance.
- Application of the first coat of varnish, which should be allowed to dry completely (not less than 45 to 120 minutes). You can speed up the process with a construction hair dryer.
- The second layer of the product should dry for at least 6-8 hours.
- The surface should be sanded.
- Each subsequent layer should be applied in a mandatory perpendicular direction to the past.
Application features will also apply to the use of high-quality brushes, which makes it possible to obtain a uniform protective film on the surface
Posted By: Work Style |04, Nov 2020
Posted By: Work Style |04, Nov 2020
Posted By: Work Style |04, Nov 2020
Posted By: Work Style |01, Nov 2020
Posted By: Work Style |02, Nov 2020