Textured Paints and Coatings
Textured paints and coatings containing perlite have the advantage of being very lightweight coatings with a consistent appearance and also have excellent insulation properties. Perlite can be added to both oil and water-based coatings, adhesives and filling and texturing agents.
Advantages
Standard concretes and screed have densities between 2000 and 2200 kg/m3. The density of perlite concretes and screed is from 600 to 1050 kg/m3 which improves the thermal efficiency and also reduces the weight of the final structure. It should be noted, however, that lightweight concretes and screeds are susceptible to wear and should therefore be protected with an adequate toppping to prevent indentation and dusting.
Advantages
- Bulk filling at low cost..
- Low oil absorption.
- Snow-white colour minimises pigmentation costs.
- Special grading for texture control and low dust content..
- Lightweight and conveniently packed in 100L plastic sacks.
On the wall:
- Ultra lightweight nature reduces the tendency to sag and run.
- Special grading process ensures absence of oversize particles which could mar the appearance.
- Inert in an industrial atmosphere (chemically like a foam glass) so it is not a contributor to yellowing.
- Forms an excellent insulator in its own right and increases those of the coating to that of wood at the same thickness.
Grades
Perlite is available in seven different particle sizes and up to four different densities for the most widely used grade
Name | Grade | Size | Finished Texture |
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Ultrafine | 05 | 0.01 - 1.0mm | Very fine or none |
Superfine | 10 | 0.15 - 2.0mm | Normal |
Medium | 15 | 0.15 - 3.0mm | Normal |
Special | 25 | 1.00 - 3.0mm | Normal |
Through Grade | 321 | 0.15 - 6mm | Normal |
Standard | 35 | 1.00 - 5.0mm | Very bold |
Supercoarse | 45 | 1.00 - 6.0mm | Very bold |
Note: the above ranges are only indicative and subject to a tolerance of up to 10% above and below the range specified |
Mixing Machinery
Petlite is an expanded mineral aggregate and the coarser grades will not permit high rates of shear to be used in the mixing process. A slow speed mixer with broad paddles is reqcommended as follows:
Motor | 1 hp per 100 litre batch i.e. 10 hp ofr 1000 litres batch size. |
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Gearing | Variable speed reducing the final drive to 50 - 200 rpm. |
Paddles | Broad paddles at two levels to sweep 15 to 20% of batch volume. |
Mixing Vats | Allow 40% for bulking whilst Silvalite is added to the mix. Covers are an advantage. |
Note: Formulations requiring a high level of shear prior to the addition of Perlite should first be mixed with appropriate high-speed equipment. |
Mix Applications
Oil-based textured coatings suitable for spray application.
Use 0.9 - 1.0 litres of loose Perlite per litre of finished coating (approx. 8% by weight) as follows
Bold Texture | Use Perlite Standard 35 and Medium Grade 15 in the ratio of 2.5 or 2:1 |
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Medium texture | Use Perlite Special Grade 25 and Superfine 10 in the ratio 2:1 |
Fine Texture | Use Perlite Superfine Grade 10 or Ultrafine Grade 5. |
Oil-based textured coatings suitable for roller (or spray) application.
Use 0.6 - 0.7 litres of loose Perlite Superfine Grade 10 per litre of finished coating (approx. 5% by weight.
Use 0.5 - 0.65 litres of loose Perlite per litre of finished coating (approx. 4 to 5.5% by weight) in the proportions indicated above
Applications
Generally heavy-duty spray equipment such as the Graco 9:1 ratio "President" pump is recommended but large volume pressure vessel and "hopper" gun equipment can work satisfactorily.
In all cases the following tip sizes are recommended:
- Bold Textures 3/8" to 1/2" (8 - 12mm)
- Medium Textures 3/16" to 1/4" (5 - 6.5mm)
- Fine Textures 1/8" to 3/16" (3 - 5mm)
Packaging
Perlite is supplied in heat sealed plastic sacks holding on average 100 litres (3.5 ft3) and weighing 8 - 14 kg according to the grade. A full load comprises 750 bags on a 40ft. curtain-sided trailer whilst the smallest economic delivery is a pallet of 25 bags. Quotations can be provided on an ex-works or delivered basis