High Performance Highway Structures - RIBAProductSelector.com

Type IV - Galvanised Parapets
Metal Coating:
Hot Dip Galvanising
Coating System:
1st Coat: Item 155, Interprime 160, ‘T’ Wash
2nd Coat: Item 110, Intergard 307, Zinc Phosphate Epoxy Blast Primer (2 Pack)
3rd Coat: Item 111, Intercure 324, Zinc Phosphate HB/QD Epoxy Blast Primer (2 Pack)
4th Coat: Item 168, Interthane 870, Polyurethane (2 Pack) Finish to 50 μm mdft
Minimum Total Dry Film Thickness of the Paint System: 175 microns
For the maintenance of steel highway bridges the Type I system would be applied to structures where all of
the existing coatings are to be removed by combined wet/dry abrasive blast cleaning to Sa2½ standard.
Under circumstances where total removal of the existing paint system is not seen as necessary or where
blast cleaning is not practical the use of surface tolerant epoxy primers and barrier coats is recommended
and a typical system utilising these coatings would be:-
Surface Preparation:
Prepare all areas of corrosion by abrasive blast cleaning or power tool cleaning to clean steel, removing all
loose coatings to a firm edge. Clean down overall and present a clean, dry surface for painting.
Coating System:
Patch Prime: Item 115, Interplus 256, HB Epoxy Aluminium Primer (2 Pack) to 100 μm mdft
1st Overall Coat: Item 116, Interseal 670 HS*, HB Epoxy Undercoat (2 Pack) to 75 μm mdft
2nd Overall Coat: Item 116, Interseal 670 HS*, HB Epoxy Undercoat (2 Pack) to
75 μm mdft
3rd Overall Coat: Item 168, Interthane 870, Polyurethane (2 Pack) Finish to
50 μm mdft
Minimum Total Dry Film Thickness: 300 microns
*For overcoating existing chlorinated rubber or acrylated rubber paints the use of Item 116, Interplus 770, is preferred.
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