Its age meant the paintwork on the Newcastle High Level Bridge had started to show areas of significant breakdown. So the time had come for the bridge to be refreshed and totally repainted - it was no longer feasible to paint over what was there. This was part of a major refurbishment.
In comparison to the existing paintwork, which is regarded as 'low tech' by modern standards, a slightly modified version of the Nework Rail Protective Treatment M20 was provided by Leighs Paints - a five-coat paint system heavily geared towards corrosion protection.
After fully blast-cleaning the bridge to remove the existing paintwork, a second blast-clean to Sa2.5 ensured an excellent surface profile to which the paint system could fully adhere.
The bridge then received the first of the five coat system, which was Leighs Metagard L674 Epoxy Blast Primer at 50 microns dft. This was to prevent corrosion before the full paint scheme was applied.
The second coat, Leighs Epigrip C402V2 Zinc Phosphate Primer Buildcoat, includes an anticorrosive pigment and a barrier pigment to prevent water from passing through the paint film and causing the iron to corrode.
A rigorous 35-day inspection and repair procedure followed the first blast-cleaning operation and during this a significant number of small holes were discovered in the cast-iron substrate. These areas were treated with a pencil grinder to open up the holes to ensure they were properly painted. Meanwhile the larger surface imperfections were filled with a lightweight filler, Leighs Epigrip F122. This product, which is based on a epoxy resin system, gives excellent intercoat adhesion and the residual flexibility built into the product enables it to withstand the levels of movement within the bridge structure.
This was followed by a second coat of Epigrip C402V2 after which the vital full and stripe coats of Epigrip C401, an epoxy MIO, completed the protection system for the Newcastle High Level Bridge.
Finally a coat of Reistex C137V2, a high gloss acrylic urethane finish was applied, giving an aesthetically pleasing result that matched the original colour standard.
To account for the colder months of the year, Leighs Paints supplied a low temerature curing epoxy primer and undercoat. Epigrip M902 and Epigrip M901 replaced Epigrip C402V2 and Epigrip C401 respectively. This enabled work to continue through the winter period without delays as these low temperature curing products continue to cure down to 0°C.
Towards the end of the project, the manufacturer was also asked to supply a paint system for carbon fibre plates that were being bonded onto the bridge. Tests carried out in the company's research and development laboratories proved that the same system being used on the ironwork also had excellent adhesion to the supplied samples of carbon fibre.
