Mastic is a universal waterproofing material used in construction. It is a product of bitumen remelting, but does not have the characteristic disadvantages: excessive fluidity at high temperatures and brittleness at low temperatures.

This material is quite viscous, which allows it to be applied to vertical surfaces. The layer can be very thin; over time it does not tend to melt.

Let's figure it out how to prepare mastic correctly. The mastic contains pure bitumen, plasticizer and filler.

For ten kilograms of the finished mixture you will need:

• 8.5 kg of pure bitumen;
• 1 kg of filler;
• 0.5 kg plasticizer.

Mastic is cooked in special thick-walled cauldrons under a lid. The thickness of the walls of the dishes should not be less than 0.3 cm. This ensures uniform heat distribution and, therefore, the bitumen will not burn.

Before cooking begins, large pieces of bitumen are crumbled and cleaned of dirt and sand. To prevent the mastic from splashing out, the boiler should be loaded only 2/3 of the total volume. Bitumen takes a long time to melt, so the mixture needs to be cooked for about 2 – 3 hours. You cannot cook mastic over a fire; the boiler must be placed away from the fire on a stand. Then filler and plasticizer are gradually added.

Fine heated and dried powder is used as a filler. You can use rubber crumbs, asbestos, mineral wool, forest moss, peat or sawdust. It is recommended to heat the mixture to 190 degrees Celsius. At higher temperatures, bitumen decomposes. Temperature changes are also unacceptable, otherwise the mastic will not be homogeneous. Excessive heating is characterized by the appearance of yellow-green bubbles, in this case it is necessary to immediately reduce the temperature. While the mixture is cooking, it is advisable to stir it, periodically removing the foam from it. It is convenient to mix the mastic with a shovel.

The plasticizer is added after the foam has subsided and the surface of the mixture becomes smooth without solid inclusions. Waste oil is used as a plasticizer. After this, everything is thoroughly mixed. The mastic is ready.

You should prepare the mastic immediately before using it, since the mixture is stored for only one day. It is worth considering that the mastic should always be hot. The optimal temperature is 120 degrees Celsius. The mixture is not recommended to be applied to bare surfaces. Therefore, you need to take care of good adhesion in advance. To do this, the surface must be cleaned of debris and coated with a primer. This will ensure high strength to the applied layer of mastic.

The composition of the primer is quite simple:

• 1 part bitumen;
• 3 parts gasoline.

The cooking technology is also not particularly complicated. Hot bitumen (70 - 80 degrees Celsius) is added to gasoline in small portions. Then it interferes until it is completely dissolved. Filtration of the primer helps remove solids. A metal mesh is good as a filter.

The primer must be applied in 2 - 3 thin layers. After applying each layer, a waiting time of 10 - 15 minutes is recommended. And only after that the surface is covered with mastic.

Making your own mastic and primer

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The primer is applied in two or three layers. Each layer should dry for 10-15 minutes. Then the surface is treated with mastic.

Technologies

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A material such as bitumen mastic is quite often used in the construction industry, because in addition to waterproofing properties, due to this component, the adhesion (adhesion) of materials of various groups can be significantly improved. It is for these reasons that bitumen mastic becomes an indispensable attribute when carrying out roofing work, for waterproofing foundations, and during the construction of road surfaces.

So can you make bitumen mastic yourself? The answer to this question will be the topic of this article.

Types of bitumen mastics

Currently, several types of bitumen mastics are actively used, but if we consider the most popular options, it is advisable to highlight the following:

Hot mastic is made by melting ordinary bitumen with the addition of a plasticizer and a binding material (a homogeneous mass should be obtained). Moreover, the list of construction operations in which this mixture can be used is very diverse. After all, hot mastic is successfully used for roofing buildings, for fixing floor coverings (wood parquet, fabric-based linoleum), and as a waterproofing layer for fencing structures.

The impeccable advantage of this material is its low cost and excellent waterproofing characteristics. While the disadvantages include low resistance to fractures (fragility) and the need to use the material only in a heated state.

Cold mastic includes petroleum bitumen and its dissolving components (turpentine, latex, etc.). This material can be used even at temperatures of 30 - 40°C.

Preparing for work

Before proceeding with the implementation of the plan, a series of preparatory works should be completed. It is no secret that when melted, bitumen is highly flammable, which is why the work site should be prepared first. Namely, to form a stable platform on which the container for preparing mastic will be located. For these purposes, it is quite justified to use refractory bricks.

Next, you should prepare a tank in which the process of cooking bitumen mastic will be carried out. Moreover, taking into account the technological features of the process (long duration), it is more justified for these purposes to use a thick-walled (3mm thick) tank with a lid. Indeed, it is in this case that the heat will be most evenly distributed throughout the entire structure of the material, and the bitumen itself will not burn to the walls of the vessel during the cooking process.

How to make hot bitumen mastic with your own hands

Before you start preparing the mastic, you should prepare the following ingredients in the given proportions:

• The main filler is petroleum bitumen – 85%;
• Plasticizer (used machine oil can be used) – 5%;
• Reinforcing additive (fillers such as asbestos, mineral wool, sawdust and even moss can be used) – 10%.

Subsequently, the process of cooking the material is implemented according to the following algorithm:

1. Crushed pieces of bitumen, cleared of debris, are placed in a tank (kettle or bucket) in such a way that their share does not exceed 60% of the volume of the container;
2. By lighting a fire, a high temperature is maintained to melt the bitumen;
3. After the bitumen has been converted into a liquid substance during the cooking process, it should be stirred periodically with a wooden spatula, thereby eliminating the formation of soot;
4. Simultaneously with stirring, the resulting foam should be removed from the liquid mixture in a timely manner;
5. After the surface of the mastic becomes smooth, filler and plasticizer can be added to the composition. Moreover, this must be done in small batches, ensuring preliminary cleaning and drying of the introduced ingredients;
6. Bitumen mastic should be cooked for three hours at a temperature of about +190 ⁰C.

If we talk about the features of applying the finished material, then this must be done at a mastic temperature within +120 ⁰C, which may require periodic heating of the entire composition.

Firstly, the preparation time for bitumen mastic should be at least 3 hours.

Secondly, to obtain a high-quality and homogeneous substance, it is very important to maintain a given temperature regime (about +190 ⁰C) and not allow significant temperature changes. One should take into account the fact that a significant increase in temperature can lead to thermal decomposition of ingredients and, as a result, cause damage to the construction product. You can find out about the overheating state of the material by an indirect (visual) method, since it is during overheating that yellow-green stains and bubbles appear on the surface of the mastic.

Thirdly, it is recommended to use the finished mastic within 24 hours after its preparation. Well, in order for the material to be easily applied to a given surface, before using it, it is advisable to pass the liquid mastic through a metal sieve.

And of course, an important factor when carrying out work is full compliance with safety regulations and careful handling of flammable materials. For greater confidence, it is advisable to equip the work site with containers with sand.

How to make a primer for bitumen mastic

Of course, to achieve the desired result, applying bitumen mastic directly to unprepared substrates is not entirely justified, since in this case the required adhesion of the materials will not be ensured. Therefore, experts recommend preliminary priming of the surfaces to be finished using special compounds. Well, preparing such a primer yourself will not take much effort.

For these purposes, it is necessary to mix bitumen heated to +70°C with gasoline in a ratio of 1 to 3. Moreover, to obtain the highest quality primer composition, it is advisable to add liquid bitumen to gasoline in small portions, ensuring its complete dissolution. Well, in order to ensure that there are no foreign inclusions (sand, debris, etc.) in the primer for bitumen mastic, it is advisable to pass the bitumen through a metal sieve before adding it.

If we talk about the technology of applying a primer, then it is advisable to carry out this procedure in several stages (2 - 3), ensuring that each subsequent layer is applied only after the previous one has dried (usually within 10 - 15 minutes).

Video review about preparing hot bitumen mastic

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When I needed to waterproof the garage roof, then I realized from my own experience that it is not only possible, but also necessary to save on materials such as bitumen, or rather bitumen mastic.

I would like to immediately correct the question, since I myself was faced with the fact that bitumen and bitumen mastic are different materials. They differ in that bitumen is essentially a natural or modified material, and bitumen mastic is a material prepared to work with certain impurities.

There is natural bitumen, this fraction is formed from oil under improper storage conditions, in fact it is oxidized oil.

Bitumen can also be obtained by vacuum distillation, but this is a complex chemical operation that can only be performed with special industrial equipment. When processing oil, namely its concentration, residual or precipitated bitumen is obtained.

So, it is not possible to produce bitumen at home; all recipes based on making bitumen from waste oil are nothing more than thickening the oil, and the final product cannot be called bitumen.

You also need to be clear that there are two professionally prepared materials in stores:

• bitumen primer
• bitumen mastic

The primer is better than mastic, it dries faster, has higher anti-corrosion properties, higher penetrating properties, can be applied to a damp surface, and adheres well. But primer is inferior to mastic in fragility.

So, you can get bitumen primer or mastic at home; you don’t need to spend money on buying already liquefied mastic. By the way, you can achieve the desired consistency, which is suitable specifically for certain jobs.

Recipe for making bitumen (or rather, ready-made material) for covering a garage roof:

You need to take 85% of the bulk of ordinary hard bitumen and crush it into small pieces.

You need to gradually pour all the bitumen into a metal container, which is heated on... for example, a fire or stove.

Next, without waiting for the bitumen to warm up, you need to add a plasticizer, the cheapest substitute is used machine oil, you only need 5% of it, no more, since the finished product can turn out liquid.

It is advisable to fill the remaining 10% with some kind of filler for more durable insulation. Personally, I added asbestos chips there, a neighbor advised me to do this, its marking A6-K-30 looks something like this:

If you need to fill the seams, then when ready, you can pour cement into the mortar, not much 1-3% of the total mass, preferably the highest quality. It will give hardness and better grip on the surface.

Now about the cooking conditions:

• The solution in the container should be no more than 60-70%, since it will have to be constantly stirred.
• It is not permissible for dirt to be present in the solution, as it may cause cracks.
• The cooking process should last a minimum of 3 hours and should not take place at high temperatures.
• Add fractions gradually as they melt and mix.
• Stir the mixture constantly and most importantly remove the foam that forms from the surface.

After the bitumen mastic is ready, it must be constantly heated, but it must be used within the next 12-18 hours.

Do not pour a lot into cracks and crevices at once; try to pour in a thin stream and over a long period of time.

Interesting recipes for homemade varnishes and the transfer of experience in working with varnishes.

To give the wood moisture resistance and a pleasant appearance, it is coated with so-called wax varnish. This varnish is made from equal parts by weight of beeswax, gum turpentine (natural) and rosin (ordinary). The composition, heated to a hot state, is applied with a brush or brush onto dry wood that is heated to a very warm (to the touch) state. After the varnish has absorbed into the wood, the coating is repeated. The part is covered until the varnish stops being absorbed. Then polished with cloth.

The covering turns out beautiful, but the processed item is only suitable for hanging on the wall, nothing more. Any impact leaves marks. Temperature, fingers,... Water generally causes whitish spots to appear on the eyes. So the durability of the coating is minimal. When removed, this coating terribly clogs the sanding paper, http://forum.woodtools.ru/index.php?topic=1252.0

Mahogany varnish:

A) Dark: in 1 kg of 96° denatured alcohol, dissolve, with frequent stirring, 500 g of shellac, 200 g of sandarac powder and 100 g of elemi resin and mastic (in tear-shaped drops). After complete dissolution, add 10 g of castor oil, stir well again and filter. At the same time, dissolve 10 g of red-brown aniline dye in a water bath in 500 g of 96° alcohol, mix both solutions while they are warm, and add 50 g of lavender oil at the end.

b) Light: the same preparation method as indicated above, only a smaller amount of red-brown aniline dye is used for coloring.

It’s not so easy to remove even from a small and flat area.

Shellac (preferably light in color) is poured into a liter jar at 1/4 height (any other cylindrical transparent container is suitable). Add ethyl alcohol (at least 96% strength) and stir with a wooden stick until the shellac is completely dissolved. Then add another teaspoon of shellac and dissolve it. Within 20-30 minutes, a precipitate forms and is removed. The resulting solution is poured into a metal jar and placed in a water bath. You can use a pan of hot water as a water bath. Do not bring the varnish to a boil, as it foams quickly and is extremely flammable. An indicator of the readiness of the varnish is its “fermentation,” during which light stripes intensively diverge from the center to the periphery on the surface of the varnish. Then the varnish is cooled slightly and filtered through 2-3 layers of gauze. After complete cooling, the varnish is ready for use. Properly welded shellac varnish has a light -brown in color and similar in thickness to fruit and berry jelly.

Bleached shellac 180 g, Manila Colac 180 g, mastic 180 g, Venetian turpentine 45 g, alcohol 3 kg, boric acid 15 g. Or also light shellac 4 kg, thick turpentine 2.5, alcohol 14.

The polish is a beautiful thing and very durable. I think its only drawback is that it is fragile and cannot be applied to elements that bend during use. Personally, I use polyurethane and acrylic varnishes. I prefer using solvents such as solvent. I tried these water-based varnishes (I took Russian ones), they are also not bad, although the shine is rather weak. Water-based varnishes work much faster; literally after 1-2 hours you can sand a layer and apply the next one, however, these varnishes foam when mixed and, due to air bubbles, the quality of the coating is not ideal. The bubbles, of course, go away, but still not the same. And those that are solvent-based are a different matter. You have to wait up to a day between layers, otherwise the surface will not be polished, but when you do it for yourself and for centuries, this is nothing. After six layers with intermediate sanding, the result is a surface indistinguishable from polishing in terms of gloss and strength (if you take “parquet” varnish).

It’s easier to take varnish like PF-157 or similar. Just two layers, or three, are enough. The coating is smooth even without intermediate sanding. And downright barbaric brilliance.

I covered the chair with one layer of Texturol and on top two layers of NTs-2139 (matte). Apply with a brush, rubbing thoroughly. I liked the result, it looks good. In operation for about six months, flight is normal. Of course, I didn’t specifically water it with water, but water got in more than once, there were no traces.
I was also advised to apply parquet varnish as a top layer; EP-2146 parquet varnish goes well on NTs-2139.

In addition to the terrible shine, PF varnishes have one bad thing - the time for complete drying (not setting) is about a month.

For polyurethane ones, it is also not recommended to put a full load on the varnish for about a week (an example from the instructions is this: if the window sill is damaged, then do not put flowers on it). In practice, I didn’t varnish the floors, but the furniture started to “slip” from the first day, and nothing bad came out, no defects. By the way, today in the store I saw a polyurethane varnish from SPECTRA-TONE and it says “polyurethane liquid plastic.” I read in the annotation that when coated, it produces a film thickness of 0.9 mm (model 285) and 1.4 mm (model 280). By the way, 1.4 mm is like ship varnish. It will be interesting to try in your spare time what kind of plastic this is.
Regarding NC: I made a high chair for my little son and coated it with nitro varnish. If the baby left puddles of water or tea on it in the evening, then in the morning white spots appeared. I didn’t try to delete them, I just noticed this nuisance to myself.

As for the secrets of Stradivarius varnish, I have my own point of view on this issue: it is impossible to improve the acoustics of wood by applying any composition to it, and the main task is not to spoil the acoustic parameters inherent in wood by nature itself with too hard or thick varnish. My varnish is not an attempt to copy the varnishes of the old masters; I set myself the task of finding an acoustic analogue. I feel the same way about all other secrets. The task is not to open and copy something incomprehensible, but to correctly pose the problem and find an individual solution. Similar to varnish, incorrectly applied primer can greatly damage the acoustics. For example, if the soil is unevenly absorbed into the wood, this will result in a very uneven sound from the instrument. It is unlikely to improve the acoustic parameters of wood using some special soil composition. I believe that both the varnish and the primer should approximately correspond in their density and elasticity to these parameters of the tree and not change their properties over time.

Lucky. Part 1

For painting work, varnishes are sold ready for use. They are solutions of various resins in organic volatile solvents. Varnishes are colorless and colored. With their help, a shiny transparent coating is obtained on the surface to be finished.

Industrially produced varnishes are divided into nitrocellulose, alkyd, bitumen and resins, depending on the type of binder.

The most available for transparent finishing at present are nitrocellulose varnishes (nitrovarnishes), in which nitrocellulose is the film-forming substance, and the solvent is a mixture of acetone with some other quickly evaporating substances. Of the various nitrocellulose varnishes available in stores, the greatest preference should be given to furniture varnishes NTs-222 and NTs-228. Their main positive quality is that they are colorless. This in itself is already very important with a transparent finish. These varnishes are easy to apply by hand, dry quickly, and can be used not only for varnishing, but also for polishing, if they are diluted to the required extent with solvent 646 or simply acetone.

Nitrocellulose varnishes for wood finishing are available in various brands. The lightest and fastest-drying varnish is NTs-218. It is the most common. In case of thickening, it is diluted with solvent 646. The varnish gives a glossy surface and is used for finishing indoor products.

Currently, NTs-223 and NTs-584 varnishes are also used, which make it possible to obtain glossy surfaces. Varnish NTs-243 is matte, it gives a silky finish without shine.

Bituminous varnish BT-577 after hardening forms a homogeneous, even black film. The drying time of the film at 20ºC is no more than 24 hours. This varnish is intended to protect the surfaces of metal structures and products. It is also used to make aluminum paint. The varnish is applied to the surface by brush or spray. Before use, the varnish should be diluted to working viscosity with white spirit, solvent, turpentine or a mixture thereof.

All bituminous varnishes are applied in one layer by brush or spray. They are diluted with turpentine or RS-2 thinner. The coating dries in 24 hours. In order to save money, in some cases bituminous paints and varnishes, due to their low cost, are used as primers for more valuable paints and varnishes.

To improve the quality of the coating, drying oil, oil paint and even paints with synthetic binders are added to bitumen varnishes. Solvents for bituminous varnishes are gasoline and turpentine.

In addition to bitumen varnish, metal surfaces are also painted black using BT-242 asphalt varnish. and asphalt-bitumen, the properties of which are identical. The industry also currently produces bitumen anti-corrosion acid-resistant varnish BT-783, pitch varnish, and varnish VT-5100.

BT-577 varnish mixed with PAP-2 powder forms a paint that, after hardening, creates an even silver film. The drying time of the paint at 20ºC is no more than 16 hours. The paint is used for painting metal products used in atmospheric conditions. Varnish and paint are toxic and fire hazardous.

Lucky. Part 2

Currently, alkyd varnishes (pentaphthalic and hyphthalic) are in demand. They are produced in a wide range. The most common varnish is PF-283 (formerly 4C). It is used for finishing wood, metal, and also for protecting surfaces used indoors that are painted with oil or alkyd paints. The varnish is applied by spraying or brushing. Solvents for it are white spirit, xylene, turpentine or a mixture of one of these solvents with white spirit in a 1:1 ratio. Drying mode at 20º C - 36 hours.

Varnish PF-231 is used for coating parquet and painted floors, finishing other wooden surfaces, as well as for coating oil paints of various tones. After coating with this varnish, the surface becomes smooth, smooth, and glossy. This varnish is waterproof and wear-resistant. It is applied in three to four layers by spraying or brushing onto a scraped surface. Solvents - white spirit, turpentine or thinner No. 1, No. 2 for artistic paints. Drying mode: at 18-20ºС - 16-24 hours for the previous layers, three days - for the last layer.

Varnish GF-166 is used for coating oil paints, wood and metal surfaces, and is not exposed to atmospheric influences. The coating is also resistant to water with temperatures up to 20ºС. The varnish is available in dark brown color. It is applied in two layers by pneumatic spraying or brush. As a solvent, you can use white spirit, xylene, solvent, turpentine or a mixture of one of them with white spirit in a 1:1 ratio. Drying time at 20ºС - 48 hours.

Among the most weather-resistant varnishes intended for outdoor use are varnishes based on polyacrylates, for example AK-156. It can be applied to metal, glass, plaster, concrete and primed wood. This varnish is commercially produced both colorless and colored. If necessary, it is diluted with solvent 646. Work is performed with a brush or spray paint in one or two layers. The first layer is dried for 24 hours.

For the restoration of old furniture, as well as for homemade furniture, alcohol, nitrocellulose, oil and other varnishes are used.

The most suitable in terms of properties and ease of working by hand are alcohol shellac varnish and alcohol shellac polish, which have been known for a long time. The foaming agent in them is shellac, a resin secreted by special insects, and the solvent is ethyl alcohol. Polish differs from varnish only in the concentration of the solution. Varnish contains 30% resin, and polish usually contains no more than 10%. This allows polish to be applied in thinner, smoother layers than varnish. Unfortunately, alcohol shellac varnish and polish are not currently available for sale. But it doesn’t hurt to know about these materials.

To clog pores during varnishing and polishing, you can use various pore fillers. But they are rarely used at home. A good filler for transparent finishes is the varnish itself.

If you are interested artistic wood tinting, then you can study the material

Thank you for your attention!