Application

Once thoroughly mixed, Seaguard by Zinga can be applied by using a normal paintbrush, a short-fiber roller (not for the first coat) or a conventional or airless spray-gun. When applying Seaguard by Zinga it must only be thinned with seaguardsolv, which is available from your nearest distributor.

Seaguard by Zinga can be applied in a wide variety of weather conditions. The application surface temperature range is from -15°C to +60°C where conditions allow with a maximum humidity of 95% so long as the steel temperature is 3°C above dew point. Like all coatings the substrate surface should be free from all types of contamination.

The broad range of allowable application conditions that Seaguard by Zinga affords means that very few days are lost during projects due to poor weather i.e. the maintenance window is extended. This, combined with Seaguard by Zinga's unlimited shelf life, ensures minimal wastage of either time or materials during a project.

Surface preparation is the key to a good performance of any coating. Any form of contamination on the surface will create areas where the Seaguard by Zinga is not in direct contact with the steel, disrupting its electrochemical connection, the electron flow and hence the cathodic protection.

Therefore, the surface should be cleaned to be free from:

  • Dirt
  • Oils and greases
  • Salts
  • Mill scale

 

There are three ways to remove the contaminations from the surface:

  • Solvent cleaning
  • Detergent cleaning
  • Steam cleaning

Solvent cleaning is only recommended for small, non-critical applications, SeaguardSolv by Zinga can be used.

Detergent cleaning is preferred over solvent cleaning; but steam cleaning at 80°C is most preferred to create a clean surface for Seaguard by Zinga application.

Correct steel cleanliness for Seaguard by Zinga application

The second most important step in surface preparation is the creation of a surface profile. This ensures adhesion of the coating to the substrate. Seaguard by Zinga will only adhere adequately on a rough surface!

A surface profile consists of profile depth and profile roughness. For good Seaguard by Zinga adhesion, Seaguard Film Galvanizing System advises a profile depth between Rz 50 and 70 µm and a profile roughness Ra 12.5.

To create this roughness, the substrate should be grit blasted or slurry blasted to SA 2.5 (cleanliness) – or by using a steel brush for small, non-critical applications. If the surface already has adequate roughness (due to weathering or previous blasting), the surface can also be cleaned to SA 2.5 by using UHP washing.

Always keep in mind: the performance of Seaguard by Zinga depends highly on the quality of the surface preparation!

Once thoroughly mixed, Seaguard by Zinga can be applied by using a normal  paintbrush,a short-fiber roller(not for the first coat) or a conventional or airless spray-gun.

Seaguard by Zinga must be thoroughly mechanically stirred to achieve a homogeneous liquid before application. After a maximum of 20 minutes, re-mixing is necessary.

Seaguard by Zinga application by brush or roller:

Seaguard by Zinga can be applied using a normal paintbrush (natural hairs) or a short-fiber roller for smaller applications or to perform a stripe-coat.

In order to fill the profile of the substrate better, it is advised to dilute Seaguard by Zinga 3-5% (mass on mass – see below dilution table). This will give a smoother finish.

It is always recommended to treat corners, sharp edges, bolts and nuts with a stripe coat (by brush) before applying a uniform coat by spray.

For more technical data, see Technical Data Sheet of Seaguard by Zinga.

Seaguard by Zinga application by conventional spray:

Seaguard by Zinga can be applied using a conventional spray gun. In order to ensure good circulation of the Seaguard by Zinga, it should be diluted 10 to 20% (mass on mass – see below dilution table) depending on pressure at the nozzle and nozzle opening. More dilution for the same nozzle will give a smoother surface finish (less porous).

For more technical data, see Technical Data Sheet of Seaguard by Zinga [link].<

Seaguard by Zinga application by airless spray

Seaguard by Zinga can be applied using a conventional spray gun. In order to ensure good circulation of the Seaguard by Zinga, it should be diluted 5 to 7% (mass on mass – see below dilution table) depending on pressure at the nozzle and nozzle opening. More dilution for the same nozzle will give a smoother surface finish (less porous).

For more technical data, see Technical Data Sheet of Seaguard by Zinga.

Dilution table

 

Brush or roller

3-5%

Conventional spray

10-20%

Airless spray

5-7%

1 kg

0.03-0.05 kg /

0.034-0.057 L MULTI METAL SOLVENT

0.10-0.20 kg /

0.114-0.228 L MULTI METAL SOLVENT

0.05-0.07 kg /

0.057-0.080 L MULTI METAL SOLVENT

2 kg

0.06-0.10 kg /

0.068-0.114 L MULTI METAL SOLVENT

0.20-0.40 kg /

0.228-0.457 L MULTI METAL SOLVENT

0.10-0.14 kg /

0.114-0.160 L MULTI METAL SOLVENT

5 kg

0.15-0.25 kg /

0.171-0.285 L MULTI METAL SOLVENT

0.50-1.00 kg /

0.571-1.142 L MULTI METAL SOLVENT

0.25-0.35 kg /

0.285-0.400 L MULTI METAL SOLVENT

10 kg

0.30-0.50 kg /

0.342-0.571 L MULTI METAL SOLVENT

1.00-2.00 kg /

1.142-2.283 L MULTI METAL SOLVENT

0.50-0.70 kg /

0.571-0.800 L MULTI METAL SOLVENT

25 kg

0.75-1.25 kg /

0.856-1.427 L MULTI METAL SOLVENT

2.50-5.00 kg /

2.854-5.708 L MULTI METAL SOLVENT

1.25-1.75 kg /

1.427-1.998 L MULTI METAL SOLVENT

When applying Seaguard by Zinga on a Zinc surface,Seaguard by Zinga has to come in contact with pure metallic Zinc to ensure a good electrochemical connection and hence a cathodic protection of the substrate.

If a Zinc rich substrate is subjected to the environment, it will form Zinc salts (zinc oxides, zinc carbonates and others) which form a barrier.

This zinc salt barrier has to be removed before applying Seaguard by Zinga.

For more information, please contact the Seaguard Film Galvanizing System Technical Team.

Seaguard by Zinga reloading:

The surface should first be cleaned to remove dirt, oils or greases by steam cleaning at 140 bar at 80°C (preferably) or solvent cleaning (SeaguardSolv by Zinga).

Old weathered Seaguard by Zinga has a layer of Zinc salts which form a passive barrier on Seaguard by Zinga. This zinc salt barrier has to be removed before applying Seaguard by Zinga.

To test if all Zinc salts are removed: rub a clean test area with a clean, white, lint free cloth dipped in SeaguardSolv by Zinga. If the white cloth shows a dark grey colour, the surface is ready to coat. If the cloth remains white or light grey, the surface must be given more preparation by the chosen option.

For more information, please contact the Seaguard Film Galvanizing System Technical Team.

Seaguard by Zinga can be overcoated with a topcoat to give a coloured finish to the structures.

Like all porous Zinc rich coatings, care should be taken to ensure compatibility of the topcoat with Seaguard by Zinga.

In practical conditions, we advise the use of a sealer to avoid any problems with the compatibility of the topcoat.

It is not possible to give an extensive list of products which are or are not compatible with Seaguard by Zinga. Every topcoat has its specific characteristics which make compatibility on Seaguard by Zinga more or less likely.

We can only give general guidelines to detect whether or not it is likely that a topcoat is suitable for use on Seaguard by Zinga or not.

General guidelines:

Listed characteristics below can give a good indication on the compatibility for Seaguard by Zinga.

1. Paint type.

Never apply alkyd paints on Seaguard by Zinga. The alkyd will react with the Zinc and make it saponify.

Water based products can cause formation of Zinc salts underneath the topcoat, resulting in bad adhesion. Water based coatings should not be used on top of Seaguard by Zinga.

2. Drying time.

In general,fast drying paints perform a lot better on Seaguard by Zinga. Fast drying paints allow less time for the solvent of the topcoat to penetrate the Seaguard by Zinga layer and consequently damage its cathodic capacities. Ideally, the paint should not have a touch dry time (20°C) of more than 1 hour, with 2-3 hours maximum.

3. Acid formation.

If the topcoat forms acid products upon curing, this can affect the Seaguard by Zinga coating. Information on the product formation upon curing can be found in MSDS sheets.

4. Time for complete cure / polymerization.

If a paint is fully cured, it can no longer affect the Seaguard by Zinga layer. If this cure time is short, the impact on Seaguard by Zinga is also reduced, insuring better compatibility.

5. Sulphates in binder and/or solvent.

Seaguard by Zinga is sensitive to sulphates. Therefore topcoats containing sulphates should be avoided.

Testing compatibility:

If a topcoat is used directly onto Seaguard by Zinga, it is advised to always perform a small test application on a test plate. This prevents problems on a big structure and also gives the applicator the chance to get to know the product.

For more information, please contact the Seaguard Film Galvanizing System Technical Team.

Mist/Full Coat Technique:

To avoid bubbling of a topcoat or sealer overSeaguard by Zinga, we advise to apply the paints using a mist/full coat technique.

A thin coat of sealer or topcoat is applied over the surface of Seaguard by Zinga before a full pass of the coating at the normal film thickness. This thin film penetrates only the surface layers of the Seaguard by Zinga and seals its surface. Also relatively porous, the mist coat presents little obstacle to the passage of air from these upper layers.

Mist coat

Application at least 6 hours after Seaguard by Zinga is touch-dry.

25 to 30 μm DFT >continuous layer.

Normal dilution according to the technical data sheet.

Full coat

Application at least 2 hours after the mist coat is touch-dry.

Specified layer thickness minus 25 to 30 μm DFT (of mist coat).

Normal dilution according to the technical data sheet.

First, a thin continuous layer is applied which gives air bubbles easy passage through the film. The first mist coat also provides a barrier for aggressive solvents in the topcoat.