Diy artificial stone countertop

Recommendation points

• A few simple rules
• Form making
• Sealing and preparation of formwork
• Chemistry, resins, mixtures
• Filling the countertop
• Grinding and polishing

Usually countertops with artificial imitation of stone are made by hand either for the sake of interest and increased skill, or in order to master mass production. In any case, it is very important to know the technology, and we want to tell you about the manufacture of “stone” countertops from chipboard with a polyester coating.

A few simple rules

You will need a properly prepared indoor space. In fact, this is a so-called 3×4 meter clean room, the walls and ceiling of which are covered with plastic wrap, and the floor is cleanly swept, washed and does not form dust. The room must have good ventilation, while the temperature is maintained at least 25 ° C.

Pay attention to quality control and safety. Work is carried out only in closed clothes with long sleeves. Since the polymerization process is accompanied by an abundant release of styrene, it is possible to work only in cellulose-carbon respirators and goggles, this gas is extremely toxic. All actions are performed only with rag gloves, there should be no greasy marks and prints.

For work, you will need a strong and stable table 2×2.5 meters and a height of at least 80 cm.Its tabletop is a 16 mm thick chipboard sheet, from the bottom of which a crate of 15×60 mm wooden slats is screwed on, placed on the edge and forming a lattice with a pitch of 35×35 cm. the surface should not have joints and traces of fastening, therefore the tabletop is leveled with acrylic putty and finely sanded. The table should be stable, you will have to walk on it, sit on the edge – the tabletop should not bend.

Form making

First, a drawing of the countertop in a 1: 1 scale is applied to the table surface with a simple pencil. The places of installation of the sink, niches for tapping, front edges and radius elements are marked.

On the straight edges of the sink, laminated chipboard strips with a height of 55–60 mm are installed. All corners and edges are strictly straight, so the sawing must be done with professional equipment. The planks are fixed strictly along the marking lines with hot glue and wooden cubes from the outside. This forms the external formwork, for the formation of the radius elements of which flexible plastic plates are used..

After the formation of the outer contour, the formwork of the cutouts for the sink or hob is added to it. If the sink is planned to be cast, it is necessary to acquire an acrylic matrix. It is glued exactly according to the marking with hot melt glue, then pressed to the table by its own weight. Any excess glue that comes out must be cut off with a boot knife..

Sealing and preparation of formwork

The inner surface and the edges of the matrix completely determine the shape of the future product, so there should be no flaws on the vertical and horizontal surfaces. The gaps between the planks and planks are sealed with garden pitch, the excess of which is cut off or pressed with a spatula. Vary the same cut edges of the chipboard and all kinds of surface disturbances are sealed, as a result, the form should take on ideal geometry and a smooth surface without flaws. Additionally, on top of the sink matrix, a washer from a garden varnish is installed, which forms a depression of the drain hole.

To form a milling on the front edge, as well as for edging cutouts and washing, you need to use a special steel plate, the corner of which is cut in a negative shape in the manner of a figured spatula. The task is not difficult: the corner of the form is filled with garden varnish, then the figured transition is smoothed with a plate. It is important not to tilt the tool and press its edges firmly against the formwork table.

When the mold is completely ready, a layer of separating wax is applied to it, and after 20 minutes it is polished with a soft cloth and blown with compressed air. Next, the entire surface is covered with polyvinyl alcohol from a hand sprayer and left to dry completely. The form is ready to be filled.

Chemistry, resins, mixtures

For the preparation of a quality mixture, precise proportioning is very critical. Ingredients are dosed by weight, they need to be weighed using digital scales.

First, the base of the stone is prepared: 30% of the gelcoat is mixed with 70% of the free-flowing filler. You need to mix it by hand with a wooden stick, you cannot whip this mixture. After stirring, about a kilogram of base is selected and corked in a plastic container as a repair kit. The amount of finished gelcoat – 3.5-4 kg for each m² surfaces.

The second mixture is polyester primer. This is a common polyester resin that is tinted with a dye paste as close to the main color as possible. Up to 40% calcite can be added to the resin to harden the soil and reduce shrinkage. Soil will be required from 4 to 6 kg for each m² countertops, about the same is consumed for an average cast sink.

These mixtures can be stored without oxygen access for decades, for their hardening it is necessary to add about 1–2.5% of a hardener (catalyst). If the room temperature is lower than the recommended one, a small amount of cobalt is added to the mixture after stirring the catalyst. Chemistry for liquid stone is sold in sets and is accompanied by comprehensive information on the mixing technique, proportions and characteristics of the mixture, it is these recommendations that should be followed.

Filling the countertop

First, a gelcoat with a filler is sprayed onto the prepared matrix; at each stage, about 1 kg of the base is mixed with the catalyst. The average pot life after catalyst injection is 15 to 30 minutes. Application is carried out in the thinnest possible layers to avoid the formation of micropores.

First, vertical surfaces are sprayed, while it is necessary to ensure that the composition does not creep, periodically allowing the surface to dry out. Next, the gelcoat is applied with the maximum covering layer on horizontal areas. Congratulations on your first application. After the surface has polymerized so that a fingerprint remains on it, but the resin loses its stickiness, you can proceed to the second. In total, 3-4 applications are required, at the end an additional gelcoat coating of the vertical face edges is performed.

After 40-50 minutes, the worktop can be poured. Slightly more than a third of the primer is mixed with the hardener, poured into a mold and carefully leveled with a spatula. Then a pre-cut fiberglass cloth is laid on the ground, pressed and smoothed with a spatula so that the impregnation is maximum. Now you need to leave half of the soil, and the rest is evenly distributed over the fiberglass.

The sink is also coated with soil at this stage, but thicker fiberglass is used to strengthen it..

After gluing the first layer, when the reinforcing fabric is well smoothed and all air bubbles are squeezed out, a chipboard insert is placed in the mold. It is cut to size, 5 mm smaller than the shape and each of its elements, for ease of movement, you can screw several door handles.

Part made of chipboard does not have to be solid, but gaps of more than 5–6 mm are unacceptable. In the insert, you need to make 8-10 holes per square meter with a diameter of 6 mm in order to release excess soil. On top of the chipboard for 10-15 minutes, a bending of about 40 kg / m is established², you can also spread the liner from the ceiling with thin wooden planks

While the oppression is installed, all cracks and gaps are filled with soil. When the load is removed, half of the remaining soil is poured into the mold, the protruding edges of the fiberglass are folded and another canvas is laid. The rest of the soil is poured over it, they are leveled with a spatula and the tabletop remains to dry and harden for about 14-16 hours.

Grinding and polishing

The next day after pouring, you need to knock down the formwork with a hammer and undermine the countertop by driving a flat spatula under it and pressing it with a pry bar. After that, the sink matrix is ​​removed and the entire tabletop is installed on soft foam blocks. From the seamy side, the contours are carefully cut and the back side is sanded with P80 and P120 sands.

After that, the table top is turned over and carefully sanded with an alternate increase in grain size from P80 to P420, the best quality of the front surface is achieved by using carborundum as an abrasive. For processing relief areas and washing under the sandpaper, a foam pad is installed.

Grinding should be done with a disc machine, in the last two stages, the movements are exclusively circular. LBM and tape machines are poorly suited for these purposes. If the worktop is glossy in the project, the final stage will be polishing the stone with a foam rubber wheel with an abrasive paste.