9. Topcoat
General information
(also see Mixing Resin, Topcoat and Catalyst)
- Premium Topcoat is supplied in 5kg and 20kg containers.
- Premium Topcoat is supplied as Dark Grey RAL 7011 or Light Grey BS 00 A 05. Other BS colours are available as special order. Contact Matrix for range, prices and delivery.
- Topcoat will require catalyst to convert it to a cured coating. Do not forget to add catalyst.
- Topcoat provides a durable cosmetic finish and works as a UV barrier preventing UV degradation of the laminate. It is essential to apply Topcoat.
- Given similar conditions resin and topcoat require similar quantities of catalyst (see Catalyst Addition Chart)
- Check the laminate before applying the topcoat and carry out any remedial work that is necessary (rectify poor consolidation, air entrapment, untidy laminating).
- Topcoat is better applied the same day and as soon as the laminate reaches the initial cure stage (defined as being able to withstand foot traffic without strand displacement).
- If this is not possible (due to m2, weather or time constraints) apply the topcoat within 24hrs.
- Within 24hrs there is no need to sand other than to remove nibs and improve the finish.
- After 24hrs the laminate must be thoroughly abraded with 40-60 grit aluminium oxide before applying topcoat or bonding may be impaired.
- Wipe the bare trims with acetone on a cloth before applying topcoat (to prevent ‘fish-eyeing’ on the topcoat finish).
Applying the Topcoat to details and trims
- Catalyse a small quantity of topcoat (1-2kgs) and apply to details (use brush or small soft roller)
- Then use a small soft roller to apply catalysed topcoat to the trims and perimeter edge. Do not splash topcoat onto walls.
- Apply topcoat to the vertical trim face. Then hold the roller at an angle to the bottom of the trim to cover half of the radius return on the front of the trim. To protect the fascia from topcoat, hold a piece of flashing trim behind the trim as you apply topcoat to the trim radius.
Applying the Topcoat to the main laminate
- Calculate how much topcoat you will need to use to cover the main body of the roof (see Estimating).
- Knock it down into equal small batches in buckets (no greater than 5kg and much less on smaller roofs).
- Catalyse the batches sequentially as required and apply to the deck with a short pile 6” or 9” roller.
- The fibre pattern should be just visible. Do not coat the roof too thickly or the topcoat will crack
- Do not apply Premium Topcoat to a deck hotter than 30 deg C
- Do not apply Premium Topcoat to a deck cooler than 15 deg C
- Use Premium Zero Resin and Topcoat in cold weather (contact Matrix for advice)