Hardcast is a range of silicate bonded materials. It is used in place of concrete where very low permeability is necessary, for acid resistance. It is also very quick setting, and can be used in thin applications where concrete would be sucked dry before it can set, for example repairs of factory floors. It can be used to repair acid damaged floors: Hardcast Acid Resistant Floor Screed.

Hardcast light is acid resistant insulation. Chloresist is the high temperature version, used in incinerators where chloride attack is the main problem.

Hardcast Fine Acid Resistant Mortar is used as a glue where air setting is not possible, for example when bonding impervious sintered ceramic tubes. The data sheets are all very similar, just read one and you know all the tricks. Once you have started using Hardcast, you will seldom use concrete again for small jobs.

Chloresist ​

Description; A refractory material for resistance to chlorides.
It has low permeability and actively scavenges chlorine to form sodium chloride.

Applications; Incinerators burning PVC. Vessels in which metal chlorides are reacted. Protection from chlorine or HCl vapours.

Installation;
Add +17% Hardcast Binder to Chloresist powder and vibration cast, or Add +30% Hardcast Binder to Chloresist powder and pour it.
Use gloves, the material is highly alkaline.

Density;
Wet vibrated density; 2,3g/cm³
Wet poured density;  2,1g/cm³

Packaging; 22kg polythene bags of powder plus 6,5kg polythene bottles of Hardcast binder.

Hardcast Acid Resistant Floor Screed​

Hardcast is a product range based on a complex silicate bonding system.   It is totally inorganic, quick setting, strong, acid resistant and refractory.   Hardcast is also made in plaster and casting grades.   Hardcast is also available as a lightweight insulation material.   The lightest is the injectable insulation, with a density of 0,3g/cm³.   Normally the density is around 2,2 to 2,4g/cm³.

Hardcast sets within 2 hours, and is fully serviceable within 24 hours.   It can be applied to any structurally sound surfaces.   Damp floors or dirty floors should first be painted with Hardcast binder. Hardcast is fully resistant to Sulphuric acid, Hydrochloric acid, Nitric acid, Phosphoric acid and organic acids.   It is not resistant to Hydrofluoric acid or alkalis.Hardcast Floor Screed is supplied in two parts; 20Kg bags of beige powder and 33.3Kg drums of the liquid Hardcast Binder (or 7 kg bottles).   Add +50% binder to the powder.   (Two parts powder to one part binder by weight)    

Shelf life is virtually indefinite in unpunctured bags. ​Hardcast Floor Screed has a viscous consistency and spreads easily, but is difficult to get flat and smooth.     It should preferably be placed within 20 minutes of mixing, and should not be left exposed for more than 10 minutes, as it forms a thin air-set skin which will not bond.   Cover the surface with geotextile or cloth as soon as it develops a dry skin.   (About 5 minutes, depending on humidity.)   Cover with plastic if you want to bond more material on top.  If you do not cover the surface, it pulls tight and tears open. After mixing powder and liquid the colour is light orange.   It can easily be coloured by adding hardware store oxides.All Hardcast materials form a thin air dry skin on the surface.   This surface is not chemically set, and must be washed off after installation.   Washing is complete once the soapy feel has been replaced by a sandy feel. Hardcast Floor Screed can be used as a backing layer for acid resistant tiles.  Hardcast is not porous and will not absorb liquids. Hardcast sets rapidly on hot surfaces.

​Moulding: Hardcast is useful for moulding.   The smooth impervious surface takes up very fine detail.   The fairly low opacity allows easy colouring.   It releases very easily from all smooth surfaces, but bonds well to rough and porous surfaces.     After it has set, about 2 hours after mixing, it has a very slight shrinkage and releases a liquid alkaline liquid which loosens the casting.   It is easily released after 2 hours, but not so easily after 12 hours or more, as crystals form in the release liquid which stick to rigid surfaces.   It releases from most surfaces but sticks to glass.​

Development no. 130100

Hardcast Fine Acid Resistant Mortar​

Hardcast is a product range based on a complex silicate bonding system. It is totally inorganic, quick setting, strong, acid resistant and refractory. Hardcast is also made in plaster and casting grades. Hardcast is also available as a lightweight insulation material. The lightest is the injectable insulation, with a density of 0,3g/cm³. Normally the density is around 2,2 to 2,4g/cm³.

Hardcast sets within 2 hours, and is fully serviceable within 24 hours. It can be applied to any structurally sound surfaces. Damp floors or dirty floors should first be painted with Hardcast binder. Hardcast is fully resistant to Sulphuric acid, Hydrochloric acid, Nitric acid, Phosphoric acid and organic acids. It is not resistant to Hydrofluoric acid or alkalis.

Hardcast fine is supplied in two parts; 20Kg bags of bright white powder and 33.3Kg drums of the liquid Hardcast Binder. Add +50% binder to the powder. (Two parts powder to one part binder by weight) Shelf life is virtually indefinite in unpunctured bags.

Hardcast fine has a thick viscous consistency, and is very easy to work with. It should preferably be placed within 20 minutes of mixing, and should not be left exposed for more than 10 minutes, as it forms a thin air-set skin which will not bond. The surface texture is very smooth. It is not suitable as a traffic surface. It can be made non-slip by sprinkling clean sand onto the fresh surface immediately after trowelling.

Hardcast fine can easily be coloured. The natural colour is light beige. Other colours which have been made are; concrete colour, red, blue, white, green, black. Most other colours can be made at a slightly increased cost. Grindings from cutting of acid brick may be added to Hardcast fine and smeared over the joints to make the joints less visible when used with red acid brick.

Hardcast fine costs R81/kg. Installed cost is therefore around R145 per square metre at a thickness of 5mm. Ordering; If one tonne is ordered, you will receive 10 x 33,3Kg drums of liquid binder and 33 x 20Kg bags of powder. Binder charged at R24/kg.

Applications; Mostly used as a mortar for acid resistant brick and tiles. It has very good adhesion, and less chance of failing at the contact surface. However, a continuous backing layer must always be trowelled on first as a backup seal.

Moulding; Hardcast fine takes up very fine detail. After about an hour, it can be stripped from a mould, at which point it has formed a thin liquid layer which acts as a mould release against impervious surfaces. Hardcast will not bond to plastic at all. It bonds well to glass.

When used as a surface finish, The airset skin may shrink and tear, especially in dry weather. To prevent this, cover with plastic immediately after the skin has formed. Otherwise paint the skin with oil. This skin is not chemically set, and is water soluble. It is however only a fraction of a millimetre thick.

All Hardcast products set very rapidly on a hot surface.

Hardcast is not porous, and will not absorb liquids.

Hardcast Floors around Furnaces​

Hardcast is a product range based on a complex silicate bonding system. It is totally inorganic, quick setting, strong, acid resistant and refractory. The chemical composition is typically more than 95% silica. Hardcast sets in about one hour at ambient temperature and very rapidly at high temperature. Hardcast dehydrates completely, and will therefore not explode if molten metal or slag is poured over it. Hardcast is ideal for repair of casting floors and ferrochrome furnace charging floors. A patch on a charging floor at around 60 to 100ºC is fully serviceable for charging car traffic in 15 minutes. Repairs can therefore be effected without disrupting production. Hardcast has a compressive strength of around 60 MPa.: twice the strength of good structural concrete. For light service floor repairs 15mm has proved adequate, but for most purposes 50mm is recommended. On new installations, a 50mm capping of Hardcast on ordinary concrete is recommended. Hardcast is supplied in 25Kg thick, clear polyethylene bags, with 33.3Kg drums of liquid Hardcast Binder. Plus 14% binder is mixed into the powder and vibrated into place.

The standard casting grade is very coarse. Plaster and fine grades are also available. The density is around 2,3g/cm³. Surfaces to be repaired are usually dirty, dusty and sometimes friable. A coat of Hardcast Binder painted on is often recommended. The casting grade costs R20 338 + VAT /ton. Installed cost would be around R42/m² + VAT per mm thick, i.e. R515/m² + VAT at 1 inch thick. Hardcast for repair of pavements and factory floors(3) Hardcast is a product range based on a complex silicate bonding system. It is totally inorganic, quick setting, strong, acid resistant and refractory. Hardcast is available in several grades for differenr applications. Hardcast sets within 2 hours, and is fully serviceable within 24 hours. It can be applied to any structurally sound surfaces. Damp floors or dirty floors should first be painted with Hardcast binder.

Hardcast is fully resistant to Sulphuric acid, Hydrochloric acid, Nitric acid, Phosphoric acid and organic acids. It is not resistant to Hydrofluoric acid or alkalis. The biggest advantage of Hardcast over concrete and cementitious materials is that it can be successfully placed in thin sections. There is no need to dig a vertical hole before repair. The repair can be tapered to 2mm thick. Hardcast is not porous, and will not absorb liquids. The density is around 2,2g/cm³ The maximum particle size is about 4mm. The standard colour is a light grey similar to concrete. The colour is easily modified by addition of oxides. Hardcast is supplied in two parts; 25Kg bags of powder and 33,5Kg drums of the liquid Hardcast Binder. Add about +16% binder to the powder. Shelf life is virtually indefinite in unpunctured bags.

Strength: For hand placed material about 30MPa, for drier, mechanically compacted material, about 60MPa.

Mixing: Hardcast can be mixed by hand or in a concrete mixer or pan mixer. Hardcast has a viscous semi-fluid consistency, and is very easy to work with. It should preferably be placed within 20 minutes of mixing, and mixing equipment should not be left with material in for more than half an hour.

Surface preparation: Brush the surface clean and remove oil, grease, paint etc. Do not use water. Paint the surface with Hardcast Binder, until all dust is absorbed in the liquid and the whole surface is wetted.

Curing: Cover with plastic for the first hour. (In dry weather it will develop surface cracks if exposed.) Keep water off it for the first two hours. Keep traffic off it for the first four hours. All Hardcast products set very rapidly on a hot surface. Around a furnace, for example, in fifteen minutes, sufficient strength was achieved to drive a forklift over a 40mm repair.

Applications: Factory floors where rapid repair is needed. Factory floors where the damage tapers to a shallow depth. Roads which cannot be closed for long. Kerbs etc. where the volume of repair is too small for concrete to set properly.

Price: Hardcast costs R20 338/ton.

Ordering: Powder and binder are both charged at R16 078/ton on combined weight. If one ton is ordered, one ton of combined net weight of powder and binder will be supplied, rounded off to the nearest packaging unit.​

Hardcast For Acid Resistance​

Hardcast is a product range based on a complex silicate bonding system. It is totally inorganic, quick setting, strong, acid resistant and refractory. Hardcast sets within 2 hours, and is fully serviceable within 24 hours. It can be applied to any structurally sound surfaces. Damp floors or dirty floors should first be painted with Hardcast binder. This treatment will also neutralise acids on the surface. Hardcast is fully resistant to Sulphuric acid, Hydrochloric acid, Nitric acid, Phosphoric acid and organic acids. It is not resistant to Hydrofluoric acid. Hardcast has a compressive strength of around 60MPa. i.e. twice the strength of a good structural concrete. Hardcast can be made to suit any requirements:

Particle size; Coarse castable, mortar or coating.

Surface texture; Smooth, sandy or rough.

Colour; Light beige, concrete colour, red, blue, white, green, black and most other colours at a slightly increased cost.

Hardcast typically costs around R8 400/tonne. Installed cost is typically R25 per mm thick per square metre. Therefore R672 per square metre at 1 inch thick. Hardcast is also available as a lightweight insulation material. The lightest is the injectable insulation, with a density of 0,3g/cm³. Normally the density is around 2,2 to 2,4g/cm³.

Hardcast has a thick viscous consistency, and requires experience with installation. The first installation should be done by an experienced operator. Hardcast is supplied in two parts; 25Kg bags of powder and 33.3Kg drums of the liquid Hardcast binder. Add +14% binder to the powder. Hardcast is also made in plaster and fine grades. Shelf life is virtually indefinite in unpunctured bags.

Hardcast light

​Hardcast is a range of silica based acid resistant materials. Hardcast Light is the cellular insulation version. 

Description; Hardcast Light is virtually impervious. It consists of Hollofill; small ceramic hollow spheres, in a dense impervious acid resistant silica matrix. It is prepared by mixing powder and a liquid binder, to a pourable consistency. It sets in roughly an hour.

 Chemistry; Hardcast Light is essentially silica, 78% pure. Totally inorganic. 

Texture; The particles are all fine; the largest particle size being 350micron.The particles cannot easily be discerned with the naked eye. 

Density; The density is very low, 1,l to 1,2g/cm3 after drying at 4000°C. 

Porosity; The apparent porosity is 15%. The pores are all very fine, resulting in very low permeability. The true porosity is high, in the region of 50%, giving about 35% volume of totally closed pores.

 Insulation; Hardcast Light is a very efficient thermal insulator, due to its low density, impermeability and ultra-fine closed porosity. 

Permeability; It is almost impervious. This can easily be demonstrated by the tongue test. It does not adhere to the tongue at all. It has the feel of glass when tested by the tongue. 

Refractoriness; Hardcast Light starts deforming by melting at around 1100°C.

Acid resistance; The only acid which rapidly attacks Hardcast is hydrofluoric acid. Hardcast is dissolved by alkaline solutions.

Gas resistance; The very low permeability of Hardcast Light ensures that gases barely penetrate it. Deposition of solids in the material cannot exceed 15% by volume.

Strength; As the name implies, Hardcast is a hard, strong material. It may slump under pressure before it is dry.

Setting ;The set is an irreversible chemical reaction, and is not easily disturbed by contamination. Set is considerably accelerated by high ambient temperatures. The surface will rapidly set and form a skin by air-drying. This skin is not chemically set and is not acid resistant. The skin should be scraped off if it forms while still placing the material. The skin may shrink and tear under conditions of low relative humidity. To prevent this, place plastic sheet on top of the skin immediately after it has formed.

Installation; Powder and binder are mixed to a pourable consistency, and poured into place. The shuttering must be well sealed, as the material is fine and fluid. No vibration is required.

Structure; The material can develop no major structural defects when installed by pouring into sound shuttering.

Mixing; Mixing by hand is possible. Mixing by shovel on the floor is not possible as the mix is too fluid. Pan mixers should have a door seal in good condition. The ratio of powder to liquid binder is 100 parts to 70 parts. 

Pumping; Hardcast Light is ideal for pumping.

Curing; For applications under heat, drying out should proceed slowly to 400°C. The low permeability should be borne in mind to prevent steam explosions. Drying may start immediately. Fluffy white efflorescence may grow from the surface. It is not a problem, and can be washed off.

Colour;  Light grey. 

Handling; Silica is known to be a respiratory hazard. Hands should be washed at frequent intervals while installing Hardcast, as it sets rapidly due to the warmth and evaporation. After use, apply skin cream several times. Prolonged exposure will cause hands to feel rough and dry, the same as with portland cement. Binder will burn if it enters a cut or the eyes. Wash eyes thoroughly with water. Binder is not harmful if swallowed, but has an unpleasant soapy taste. 

Packaging; Hardcast Light powder is supplied in 15kg plastic bags, wire tied. Hardcast Binder is supplied in 33,3 kg plastic drums. 

Shelf life; Unlimited. 

Volume required; The wet density is 1,36tons per cubic meter, and orders should be placed for the total mass. Powder and binder will be correctly proportioned by the supplier. 

Applications; Thermal insulation where acids are present. Gas tight sealing in any application up to 1000°C.  Protection of steelwork against corrosive gases, hot of cold.