POLYBOND Polybond Limited, Unit 6 William Street, Northam, Southampton, Hants. S014 5QH Tel: 023 80 223266 Fax: 08700 527587 |
Test 1 - Resistance To Artificial Weathering
Introduction
The resistant to artificial weathering has been determined on a "Polybond Q19" coating applied to aluminium panels.
Preparation of Test Coating
Two 13cm x 8cm (5" x 3") aluminium panels were coated on one face with the sample of Polybond Q19 mixed according to the leaflet supplied* with the sample. The first coat was allowed to dry before applying a second coats. Both coats were brush applied. The coated panels were then held in the normal laboratory atmosphere for 14 days to allow the coating to fully cure.
Test Procedure
One of the panels was exposed to artificial weathering for 2000 hours according to the method laid down in BS3900 (Part F3) 1966 "Resistance to Artificial Weathering (enclosed carbon arc)". After the 2000 hour test, the coating was compared with the unexposed control panel for any evidence of deterioration or change.
Results
Some yellowing and loss of sheen was observed. No chalking, cracking, crazing, softening or other changes were observed.
Remarks
The sample of Polybond Q19 has exhibited a good resistance to artificial weathering over the 2000 hour test period.
Test 2 - Liquid Water Permeability
Introduction
The liquid water permeability of "Polybond Q19" applied to mortar rendering has been determined.
Preparation of Test Coating
Three blocks of mortar rendering 6" x 6" x 1" thick were prepared and cured. The mortar mix was the normal 1:1:6 by volume Portland cement/hydrated lime/sand mix. When cured and dry, one surface of each block was coated with the sample of Polybond Q19 mixed and applied in accordance with the leaflet supplied*. The coating was allowed to cure for 14 days in the laboratory atmosphere prior to testing.
Test Procedure
A watertight cap was applied to the surface of the coating and a hydrostatic pressure of 20cm of water was applied. After 24 hours the rate of passage of water through the coating was measured. The procedure was essentially that described in BS473 - Concrete Roofing Tiles.
Results
| Specimen | Water Permeability (ml/cm²/sec x 10-8) |
| A | 12.0 |
| B | 16.7 |
| C | 18.2 |
| Mean Result : 16 |
Remarks
Good quality concrete and concrete roofing tiles are expected to possess permeability under this test of less than 3 x 10.6 ml/cm²/sec. The Polybond Q19 coating tested has a permeability of only about one twentieth of this figure and may therefore be regarded as impermeable to liquid water.
Test 3 - Water Vapour Permeability
Introduction
The permeability of "Polybond Q19" towards water vapour has been determined on a coating of the material applied to a mortar rendering.
Preparation of Test Coating
Three blocks of mortar rendering 6" x 6" x 1" thick were prepared and cured. The mortar mix was the normal 1:1:6 by volume Portland cement/hydrated lime/sand mix. When cured and dry, one surface of each block was coated with the sample of Polybond Q19 mixed and applied in accordance with the leaflet supplied*. The coating was allowed to cure for 14 days in the laboratory atmosphere prior to testing.
Test Procedure
The specimens were tested for water vapour permeability by a modified procedure of the method described in BS2972 1961 (Section 12).
Results
| Specimen | Water Vapur Permeability (75% Relative Humidity and 25°C) (g/m²/day) |
| A | 8.3 |
| B | 10.4 |
| C | 8.7 |
| Mean Result : 9.1 |
Remarks
Materials with a water vapour permeability of less than approx 13g/m²/day are regarded as water vapour barriers under normal conditions. The coating of Polybond Q19 tested therefore behaves as a water vapour barrier.
Test 4 - Adhesion Before and After Accelerated Weathering
Introduction
The adhesion of "PolybondQ19" to asbestos/cement has been determined on specimens before and after a period of accelerated weathering.
Preparation of Specimens
Four 12cm x 8cm (5" x 3") panels of asbestos cement were coated on one face with the sample of Polybond Q19 mixed and applied in accordance with the leaflet supplied*. The first coat was allowed to dry before applying the second coat. Both coats were brush applied. The coated panels were then held in the normal laboratory atmosphere, two of them for 14 days to allow the coating to fully cure before subjecting them to an accelerated weathering procedure and two of them until completion of the accelerated weathering when all four were tested for adhesion.
Accelerated Weathering Procedure
The panels were subjected to the artificial weathering procedure described in BS3900 (Part F3) 1966 for 2000 hours.
Adhesion Test Procedure
Circular aluminium discs of 2" diameter were fixed to the painted surface of the test panels with an epoxy adhesive and when cured (air temperature curing) the direct tensile strength of the assembly was determined. The nature and position of the failure plane was noted in each case.
Results
| Test Panel | Failing Load (lbf/in²) | Nature of Failing |
| Control specimens not subjected to accelerated weathering | (i) 111 (ii) 132 | All four specimens failed entirely |
| Specimens after 2000 hours artificial weathering | (i) 119 (ii) 124 | Within the body of the asbestos cement |
Remarks
The adhesion of Polybond Q19 to asbestos/cement is excellent exceeding the cohesive strength of the asbestos/cement itself. The adhesion remains better than the cohesive strength of asbestos/cement after 2000 hours of accelerated weathering.
Test 5 - Adhesion to Damp Surfaces
Introduction
The adhesion of "Polybond Q19" to a damp surface has been determined by a direct pull-off method.
Preparation of Test Panels
Three approx 18cm x 18cm (8" x 8") asbestos cement panels were coated with a paraffin wax on their rear faces and edges. The panels were then immersed in water overnight. After 16 hours immersion, the panels were surface dried to remove any liquid water and immediately coated with Polybond Q19 according to the leaflet supplied*. The coating was allowed to dry for 4 hours before applying a second coat. Both coats were brush applied. The behaviour of the paint during the drying stage was noted. The coated panels were then held in the normal laboratory atmosphere for 14 days to allow the coating to fully cure.
Test Procedure
Two 2" diameter threaded aluminium discs were glued to each of the coated faces of the three panels using an "Araldite" adhesive. The discs were then pulled off in an E-Tyre Tensomer. The load at failure was recorded and the nature of the failure was noted.
Results
| Specimen # | Load At Failure (lbf/in²) | Type Of Failing |
| 1 | 98 | 100% failure in panel |
| 2 | 65 | 100% failure in panel |
| 3 | 53 | Panel failed by fracture |
| 4 | 85 | 100% failure in panel |
| 5 | 52 | 100% failure in panel |
| 6 | 66 | 100% failure in panel |
Remarks
None of the coated areas tested failed at the coating/substrate interface. In our opinion, the sample of Polybond Q19 tested shows excellent adhesion to a damp asbestos cement background.
Test 6 - Resistance to Alkalis from the Background
Introduction
The resistance to alkalies from the background has been determined on a "Polybond Q19" coating applied to clayware vessels containing a solution of alkali.
Preparation of Test Coating
Three unglazed clayware containers were coated on their exterior surface with Polybond Q19 mixed according to leaflet supplied*. The coating was allowed to dry for 4 hours before applying a second coat. Both coats were brush applied. The coated containers were then held for 14 days to allow the coating to fully cure. Approximately one half of the coated area was then painted with an alkali sensitive distemper and allowed to dry overnight.
Test Procedure
Two of the containers were filled with 5% solution of sodium hydroxide covered with a clock glass and held for three weeks. The coatings were examined periodically for any evidence of alkali penetration through the coating as indicated by a colour change of the alkali-sensitive distemper. After the three week test, the coatings were also examined for any loss of adhesion or evidence of change compared with the control coating.
Results
No colour change of the alkali sensitive distemper was observed during the three week test. The coating remained firmly adherent and no other changes were observed compared with the control coating.
Remarks
The sample of Polybond Q19 possesses excellent resistance to alkalies from the background under the conditions of test and in our opinion would remain adherent to freshly constructed concrete or rendered walls where dampness might bring alkalies out of the cement into contact with the coating.
Test 7 - Resistance to Permanent Staining by Rust
Introduction
The resistance to permanent staining by rust has been determined by assessing the effectiveness of various cleaning agents in removing rust stains from the surface of a "Polybond Q19" coating.
Preparation of Test Coating
Four 13cm x 8cm (5" x 3") aluminium panels were coated with the sample of Polybond Q19 mixed according to the leaflet supplied*. The coating was allowed to dry before applying a second coat. Both coats were brush applied. The coated panels were then held for 14 days to allow the coating to fully cure. Drops of a laboratory prepared suspension of iron rust were then induced to fall onto the panels and allowed to dry.
Test Procedure
The ease of removal of the rust stains was assessed by rubbing and then scrubbing the stained coating with the following cleaning agents in the order shown.
Results
Ease of removal of rust stains :
| Cleaning Agent | Stain Completely Removed By | |
| Rubbing | Scrubbing | |
| Water | No | No |
| Detergent | No | No |
| Soap | Yes | Yes |
| Cleaning Powder | Yes | Yes |
Remarks
Water and detergent solution both failed to effectively remove the rust stains from the coating even by vigorous scrubbing. Rubbing separately with soap and an industrial cleaning powder was however, effective. The results suggest that, although the sample of Polybond Q19 can be stained by the particular form of rust produced in the laboratory, such staining with probably other forms of rust can be completely removed from the coating by rubbing with soap and water or by use of an abrasive cleaning powder. It was noted that the cleaning powder did not appear to have any visible effect on the coating itself.
Test 8 - Resistance to Impact
Introduction
A coating of "Polybond Q19" applied to dense concrete has been tested for its behaviour under impact.
Preparation of Test Coating
A slab of dense concrete approx 12" x 12" x 2" thick was cast and cured. The concrete mix employed was a normal 1:2:4 Portland cement/sharp sand/gravel aggregate mix which would have possessed a strength of 5,500lbf/sq. at the time of the tests. When the slab had dried out the Polybond Q19 was mixed and applied to one surface as per the leaflet supplied*. The coating was allowed to cure for 14 days in the laboratory atmosphere prior to testing.
Test Procedure
Various steel balls of differing diameter were dropped freely onto the coated surface of the slab which was positioned horizontally. The balls were permitted to drop from increasing heights, a different position being arranged for each impact. After the impact, the coating was examined for evidence of damage, loss of adhesion etc.
Results
The first sign of damage from impact by a steel ball was obtained from a 2" diameter ball (weight 534g) dropped from a height of 6"l. Under this impact the coating showed incipient disbonding from the concrete surface.
Remarks
The test, although somewhat empirical, readily reveals inherent brittleness or defective adhesion of a coating. The results on Polybond Q19 indicate that the coating applied to normal dense concrete is extremely resistant to damage by impact.
Test 9 - Colour Fastness To Light
Introduction
The colour fastness to light of "Polybond Q19" has been determined by the method laid down in BS2782 (Part 5) Method 507B.
Preparation of Test Panel
One 4.5cm x 2cm (1.75" x .75") aluminium panel was coated with the sample of Polybond Q19 mixed according to the leaflet supplied*. The coating was allowed to dry for 4 hours before applying a second coat. Both coats were brush applied. The coated panel was then held for 14 days to allow the coating to fully cure.
Test Procedure
The panel was placed alongside a series of wool fabric samples containing dyes of graded light stability. Half of the test panel and half each of the fabric specimens were masked before testing the exposed areas in a Xenotest machine according to Method 507B in Part 5 of BS2782. Following the test, the exposed portion of the test panel was compared with the masked portion and the degree of change matched against that of the closest wool standard.
Results
BS Fastness No 6-7 or better.
Remarks
The sample of Polybond Q19 possesses excellent colour fastness to light.
Test 10 - Resistance to Spread of Flame
Introduction
The resistance to spread of flame has been determined on a "Polybond Q19" coating applied to asbestos cement panels.
Preparation of Test Coating
Six 91cm x 23cm (36" x 9") asbestos cement panels were coated on one face with the sample of Polybond Q19 mixed according to the leaflet supplied*. The first coat was allowed to dry before applying a second coat. Both coats were brush applied. The coated panels were then held in the normal laboratory atmosphere for 14 days to allow the coating to fully cure.
Test Procedure
The coating was tested and classified for surface spread of flame in accordance with BS476 (Part 7) Section 2.
Results
All six specimens behaved consistently. There was no contribution to the pilot flame and no flaming occurred on any of the specimens.
Remarks
In accordance with the flame spread classification given in the Standard, results show that the sample of Polybond Q19 coating tested has a Class 1 surface. For a full description of Polybond Q19 please refer to our General Leaflet. *Leaflet supplied - "Instructions for the application of Polybond Q19
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Polybond Ltd Unit 6, William Street, Northam, Southampton, Hampshire, SO14 5QH
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The claims made in this document are made in good faith and are based on exhaustive tests carried out over a long period.
Polybond Ltd. , their agents and their distributors cannot accept any liability for the behaviour of their materials in individual cases.
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