Promain was approached by Bexley Council for advice and guidance on an anti-corrosive painting system for street furniture, in particular railings. The council required a hardwearing coating that was anti-corrosive as well as easy to apply, preferably via brush application. Our technical team set to task on compiling a specification.
Promain’s first step was to ascertain the type of steel the railings where constructed from and also to assess the condition. The technical team conducted a site visit and liaised with our client from Bexley Council on site.
Our conclusions were that the construction of the railings in question was mild steel with areas of light rust. Whilst on site was also able to observe a large number of cyclists using the railing to chain their bicycles too. This meant what we specified had to be durable enough to withstand the impact and abrasion caused by the locks and chains used for securing bicycles. On return to our Hitchin office we set about putting together a specification based on what we had observed on site.
As with all painting projects and specifications, we began by advising the surface preparation. The first step in surface preparation we advised was to abrade the surface. This would ensure the removal of any loose or flaking areas of rust. In addition, this abrasion would produce a key on the surface aiding in adhesion of the priming coat.
The second step in the surface preparation was to fully clean and degrease the surface. This was to ensure the complete removal of any dirt, loose particles and contamination. Promain specified PPG Prep 88 for cleaning and degreasing. PPG Prep 88 (Formerly Sigmarite 88) is a clear water-based cleaner specifically designed for removing oils and other contaminations from a variety of different substrates. PPG Sigmarite 88 dramatically improves recoatability to aged substrates by removing dirt and bacteria build up without leaving behind any residue.
The next section of specification covered the priming coat. The priming coat had to anti-corrosive and provide a good foundation for the top coat to adhere too. Based on these requirements, we specified PPG SigmaRite 2136. PPG SigmaRite 2136 is a micaceous iron oxide coating or M.I.O coating. These type of coatings contain hard, dense pigment of iron oxide. This provides barrier protection by impeding the path of water and other corrosive agents. You can use it as a protective coating to increase resistance to blistering, delamination, and corrosion.
You can find MIO’s widely in highways approval specifications for the protection of street furniture. Also being a single pack paint it would not require any specialist preparation. You can also apply it by brush. We advised that one coat should be applied at rate of 7.1m2 per litre, achieving a DFT (dry film thickness) of 75 microns. This DFT was in accordance with the manufacturer’s recommendation to provide optimum protection of the steel.
The third and final part of our specification was to advise a suitable topcoat. We had already ascertained from our site visit that the top coat had to be hard wearing as well as easy to apply. Based on these requirements, our choice for the topcoat was Centrecoat Fast Dry Gloss.
Centrecoat Fast Dry Gloss is a single pack lead free, hard wearing industrial rust-inhibitive, corrosion resistant urethane modified alkyd offering excellent performance to weathering even in costal atmospheres. It is also mould and algae resistant with a high gloss finish that is fast drying even at low temperatures. Promain specified a two coat topcoat system at coverage rate of 10.5l per m2 per coat. Applying the paint at this coverage rate would achieve a DFT of 100 microns. We were confident this paint system would provide the durability, protection and ease of application required.
Our specification was submitted to the team at Bexley Council. They now apply the system to other items of street furniture as it went so well. This system stands the test time too. It continues to be on the specification by Bexley Council.
If you require a specification or paint system for a similar project, do hesitate to contact our technical team on 01462 421 333. Our manufacturer trained team can tailor a specification and advise a paint system based on your project requirements.