Megagloss HG

Product description

A high gloss two-component linear polyester-polyurethane topcoat with outstanding abrasion resistance, excellent gloss and colour retention and very good flexibility, specially formulated for top-class yachts.

Recommended use

As a topcoat over an epoxy coating system where a durable high gloss finish is required in aggressive atmospheric exposure. Megagloss HG is only suitable for spray application.

Film thickness and spreading rate

                                                                             Minimum                    Maximum                    Typical

Film thickness, dry (µm)                                     15                                 40                                20

Film thickness, wet (µm)                                    30                                 80                                40

Theoretical spreading rate (m²/l)                      34                                13                                 26

Comments

Per wet-on-wet coat. Three wet-on-wet coats at 20 µm DFT each is recommended.

WFT values are for unthinned Megagloss HG. After thinning, to achieve specified DFT it is necessary to increase the WFT with 20-25%.

Physical properties

Colour According to colour card and Multicolor tinting system (MCI)

Solids (vol %)* 52 ± 2

Flash point 14ºC ± 2

VOC 403 lbs/gal (3,39 gms/ltr) USA-EPA Method 24

Gloss Glossy

Gloss retention Excellent

Water resistance Very good

Abrasion resistance Excellent

Solvent resistance Very good

Flexibility Very good

*Measured according to ISO 3233:1998 (E)

VOC figures: For whites. Other colours may have different VOC contents.

Surface preparation

All surfaces should be clean, dry and free from contamination. The surface should be assessed and treated in accordance with ISO 8504.

Coated surfaces

Clean, dry and undamaged compatible primer. Please contact your local Jotun office for more information.

Other surfaces

The coating may be used on other substrates. Please contact your local Jotun office for more information.

Condition during application

The temperature of the substrate should be minimum 10°C and minimum 3°C above the dew point of the air. The temperature and the relative humidity should be measured in the vicinity of the substrate. Good ventilation is usually required in confined areas to ensure proper drying. With forced ventilation, avoid heated air at first as this may cause surface drying and solvent entrapment. The coating should not be exposed to oil, chemicals or mechanical stress until fully cured.

Application methods

Spray Air-fed pressure pot/"air-mix" or traditional air-fed pot gun. Airless spraying is not recommended.

Application data

Mixing ratio (volume) 1:1

Mixing 1 part Comp. A (base) to be mixed thoroughly with 1 part Megagloss 1:1 Comp. B (curing agent).

Pot life (23°C) 8 hours (Reduced at higher temp.)

Thinner/Cleaner Jotun Thinner No. 18/19

Reduce the viscosity by thinning the product with Jotun Thinner No. 18 at

temperatures between 18ºC to 35 ºC, or Jotun Thinner No. 19 at temperatures between 10ºC to 18ºC. In very high temperatures above 35ºC, use a blend of Thinner No. 18 and Thinner No. 12.

Spray Tip Orifice 1.0 - 1.1 mm tip size for pressure pot and 1.1 - 1.3 tip size for gravity gun.

Guiding data conventional spray

Pressure at nozzle 3.5 bar when trigger is depressed.

Note The ideal viscosity of Megagloss HG is 14-16 seconds when measured with Ford Cup #4 (13-15 seconds with DIN Cup #4). This may require thinning by approximately 20-25%, depending on temperature and the solvent used.

Megagloss HG Base 3 can be used as a clear varnish. Reduce the amount of Megagloss 1:1 Comp B with 10%.

Drying time

Drying times are generally related to air circulation, temperature, film thickness and number of coats, and will be affected correspondingly. The figures given in the table are typical with:

• Good ventilation (Outdoor exposure or free circulation of air)

• Typical film thickness

• One coat on top of inert substrate

   

  Substrate temperature	10°C	23°C	40°C
  Surface dry	16 h	8 h	2 h
  Through dry	24 h	12 h	3 h
  Cured	10 d	7 d	3 d
  Dry to recoat, minimum Dry to recoat, maximum 1	16 h 72h	8h 72h	4h 48h

  1. Wet-on-wet application. Three coats should be applied in one session. Apply each coat when the preceding coat is tack dry, as soon as the coat may be touched without leaving paint on the finger. After the third coat is applied, wait until the following day before additional coats (if needed) are applied.

  The given data must be considered as guidelines only. The actual drying time/times before recoating may be shorter or longer, depending on film thickness, ventilation, humidity, underlying paint system, requirement for early handling and mechanical strength etc. A complete system can be described on a system sheet, where all parameters and special conditions could be included.

  Typical paint system

  Faired above-water exterior of yacht (steel, aluminium or GRP):

   

  Megacote Aluminium Red Toned 1 x 125 µm (Dry Film Thickness) Megafiller or Megafair 8000 µm(Dry Film Thickness)

  Megafiller Smooth	500 µm	(Dry Film Thickness)
  Megaprimer Grey	1 x 125 µm	(Dry Film Thickness)
  Megaprimer White	1 x 125 µm	(Dry Film Thickness)
  Megaspeed Undercoat	1 x 50 µm	(Dry Film Thickness)
  Megagloss HG	3 x 20 µm*	(Dry Film Thickness)

   

• Three coats applied wet-on-wet

Other systems may be specified, depending on area of use

Storage

The product must be stored in accordance with national regulations. Storage conditions are to keep the containers in a dry, cool, well ventilated space and away from source of heat and ignition. Containers must be kept tightly closed.

Handling

Handle with care.

Packing size

4.5 litre unit: 2.25 litres Megagloss HG Comp. A in a 2.8 litre container and 2.25 litres Megagloss 1:1, Comp. B in a 2.8 litre container.

Health and safety

Please observe the precautionary notices displayed on the container. Use under well ventilated conditions. Do not breathe or inhale mist. Avoid skin contact. Spillage on the skin should immediately be removed with suitable cleanser, soap and water. Eyes should be well flushed with water and medical attention sought immediately.