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Polyester Fiberglass Repair Instructions (Non Mould)

  • 2 min read

APPLICATIONS: Norski Polyester Fibreglass product sand accessories are for small repair jobs on boats, caravans,cars, fibreglass sheeting on roof areas, guttering and other places, where patching of metals or timber is required to prevent moisture/water ingress. Fibreglass is used as roofing products such as ‘Laser light’, car parts, horse floats, water tanks,boats, planes and almost everywhere you look today. It is an extremely versatile substance.

PREPARATION: Important:To obtain maximum adhesion,the surfaces must be thoroughly cleaned to remove all rust, loose paint, busted fiberglass (if the product is already made of this)and any other contamination that may be present. Use of Norski Cleaning Fluid or strong detergent and warm water is usually necessary(if there’s rust or dust) before sanding of the surface takes place. Allow to dry thoroughly before sanding. You may also have to wash or clean your job after sanding as well.

APPLICATION: Normally, fibreglass repairs (and most others) are carried out on the inside, or back of the laminate, to bridge and reinforce the problem area, prior to restoring the outer face.

1. Clean and sand down the surface to a minimum of 75mm (3") surrounding the damaged area. Tape over any holes on the outer surface.

2. Cut up the fibreglass mat with scissors or knife to the size of the sanded area. Multiple layers will be necessary for strength,and the number will depend on the thickness of thelaminate and rigidity required.

3. To determine the amount of resin required for the job on hand,refer to the coverage statement below. Stir the resin and catalyst mix thoroughly before use. Next lay out the fibreglass patch onto a piece of cardboard or plastic and wet thoroughly with resin using the enclosed brush in the kit. Coat the sanded area with resin and immediately lay on the saturated fibreglass patch. Work on to the surface to remove any air bubbles or wrinkles and allow to set. Repeat the process for additional layers.

4. Remove the tape on the outer face before curing takes place and fill any deep cavities with additional resin and fibreglass mat to leave an under-filled surface of approximately the thickness of one of the enclosed mixing sticks(2mm)and allow to cure. 

5. Sand the under-filled area to provide a good bond with the filling and/or finishing coats.

(a) Where a painted finish is required, fill with polyester filler, allow to cure. Sand smoothand apply the finish coats.

(b) Fora fibreglass gelcoat finish, apply Norski Gelcoat (also supplied in a kit from Norski) to slightly overfill the repaired area and allow to cure. When cured, sand smooth with wet and dry sandpaper (P600-P800), finishing with a very fine grit paper(P1000) and polishing.

RESIN COVERAGE STATEMENT: To wet out quarter of a square meter of 300gsm chopped strand fibreglass mat, use 500mls Resin and 150 drops of catalyst. The formula for the above statement is 30 drops of catalyst per 100mls of polyester resin