3M Rail Coatings Replacements By PPG Selemix

Underground

Since the closure of 3M’s paint and coatings factory in Northallerton in the final quarter of 2017, all the stock that was produced has now been diminished. The paint industry has now been left with a gaping hole in the market. This has mainly effected the rail industry, London Underground and also steel coatings industries.

Promain have worked closely with PPG and TfL to find replacement systems for contractors.

The Closure Of 3M Paints & Coatings

The 3M side of their products were formulated by E Wood, Thortex and Copon. Prior to 3M buying out these original companies, they were UK brands that formulated fantastic paint coatings that were unsurpassed. 3M being a global success brought these companies in the early 80’s and 90’s. As a result, this opened up the specialist coatings market to the brand.

However, 3M saw their paints and coatings sector proving to be not as successful as they hoped. The UK factory was an expensive asset. 3M’s heads in America therefore chose to abandon all paints except a few international pipeline products.

The Repercussions of 3M’s Market Exit

Since the closure, 3M’s paint specifications are still found across the rail and infrastructure sector. Unfortunately, due to minimal notice given to the market, specifiers had just 3 months to arrange alternatives. To find suitable substitutes expensive testing, certification and worrying time frames were needed to be allowed for.

BogiesThis entailed fabrication companies within the rail industry without suitable specified coatings for inside or outside trains, or underneath trains such as bogies. These companies are now calling Promain’s technical team looking to purchase 3M EA9WB, 3M EA5WB, or for example Copon Hycote. Contractors still need paints for rail rejuvenation.  Metal plates on trains, products for fuel tanks or water containers on the underside of trains need protection. Specified applicators still believe these products are available. Unfortunately, now they are all gone, and we need to find replacements.

The Future of APR London Underground Paints

Working closely with PPG Selemix, TfL (Transport for London) and London Underground Limited, Promain have now come up with some solutions to the lack of 3M coatings. These are in the form of PPG Selemix Aqua, Selemix Direct. Both of these systems are primer and topcoat systems in one. They have very good adhesion properties to various types of surfaces.

Introducing Selemix Direct & Selemix Aqua

Selemix DirectSelemix system has been fire tested to reach the rigorous standards required for the UK rail system. Selemix Direct now certified for BS 6853. This covers BS476 Part 6 and 7: The Surface Spread of Flame and Propagation of Fire.

However, Selemix Direct cannot currently be used on London Underground. This is as it doesn’t have the smoke inhalation or toxicity of smoke testing certified as yet.

Selemix Aqua system does however have these tests under it’s belt as it is a waterborne product. Waterborne is different to water based as some solvents are still used. The testing on Selemix Aqua has been extensive for this reason. All the old 3M products such as EA9WB, EA9WB Primer, and EA5WB were all water based and used on London Underground.

Selemix Replacements for 3M EA9WB

The Selemix Aqua system consists of 8-110 and 8-111; with finishes gloss and matt respectively. Originally, 3M’s EA9WB Primer was always produced in a matt finish. 8-111 relates to the replacement of 3M’s primer. EA9WB Coating was produced as a semi gloss or high gloss finish so Selemix Aqua 8-110 is an ideal replacement.

However, Selemix Aqua does not require a primer. So, if a specification requires a matt finish, you can use Selemix Aqua 8-110 Matt. A major benefit of this system is the lack of a primer. This saves contractors time, cost and keeping restricted access times to a minimum.

Selemix Aqua is a polyurethane coating that is a two pack – meaning it has a base and a hardener. Selemix Aqua requires users to buy the base and hardener separately. This is unlike other epoxy systems you may have used before. The hardener for both 8-110 and 8-111 is Selemix Aqua 9-110 Direct Hardener.

You can apply Selemix Aqua to various coatings and substrates such as:

  • Correctly prepared mild steel
  • Galvanized steel
  • Aluminium
  • GRP

This also includes various rolling stock components such as vinyl. Adhesion tests are recommended to be performed prior to application to ensure suitability. Selemix Aqua has the fire certification for EN45545, the railway standard on fire safety on rolling stock across Europe.

On the London Underground Approved Product Register (APR), this system can be found under specification number 5075.

Alternatives To Other 3M Rail Coatings

Below are the 3M products within the rail sector that no longer exist that need replacements specified:

  • EA9WB Primer and Coating
  • EA5WB
  • WB Urethane Dicol 170 – A polyurethane finish used over EA9WB primer to give a very hard wearing topcoat.
  • PU WB AG 180 – An anti graffiti coating used internally on trains.  Replaced by Selemix Direct / Aqua depending if station or train will be below ground or not. Selemix Direct is in use on the overground within Network Rail currently.
  • EA9 HB – A high build specified coating for long term corrosion protection to ferrous substrates.
  • Hydraseal 190
  • 3M Thortex coatings

The replacement for all the above products is Selemix Aqua two pack. We can tint the base to an almost limitless range of RAL and BS shades. The system requires you to use a 2.5:1 ratio mix base to activator.

Mixing Ratios For Selemix Aqua / Direct Bases & Hardeners

Promain have made Selemix Aqua more accessible to rail contractors to purchase. You can now purchase the base in 2.5 litre tins with hardeners in 1 litres. This will ensure that the ratio of the mix is met. The 2.5 litre base (8-110 or 8-111) can be provided in a 5 litre tin for ease of use. You can fill the void easily with the hardener and thoroughly mixed. There is no confusing measures of thinners required. You can thin Selemix Aqua with water as per the product data sheets.

Selemix Direct has a 4:1 ratio between the base and activator. It is available in 4 Litres base and 1 Litre activator. As with the Selemix Aqua, the Direct base is sold in a 5 litre tin to allow the incorporation of the hardener prior to to the mix. Selemix Direct however does require incorporation of a percentage of thinners – the quantity depends on the application and coating system.

Where To Buy Replacement 3M Paints For Rail

Promain are the main supplier of industrial paints and coatings to London Underground and Network Rail. As the main distributors of PPG Selemix, you can find all of their products available on our website here.

Alternatively, you can see our full range of RT98 Railtrack specified paints and coatings on the London Underground Approved Product Register here.

PPG Nexa Autocolor Paints Specification

Nexa AutocolorMoving on from the Selemix Aqua and Direct, are the Nexa Autocolor products. Nexa Autocolor is another subsidiary to PPG. They have had fire testing certifications produced and are in specifications ready for use on train bogies. Nexa Autocolor is only suitable for Network Rail trains and not London Underground currently.

This system is a little bit more involved than the Selemix products. You do on the other hand need a 3 part primer and topcoat.

Nexa Primer

Nexa Top Coat

This Nexa system is a bit more involved. Subsequently, it would be best to discuss your requirements with the technical team first.

Finally, contact our technical team if you require any clarification or further details with London Underground paints. Contact our technical team on 01462 421333.

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