by rob h » Sat Jan 27, 2018 5:50 pm
If it's small holes Isopon p40 is a mix of fibreglass and filler, sand with fine glass paper 1200 around the hole about 2 cm. Back to metal at the edges. Put a smear across hole, use masking tape at back if necessary. Let it go fully hard, sand back, use some fine stopper filler over the top sand back til almost transparent. Use a decent undercoat and it should be fine. Get a piece of metal, drill a hole and practise first if your worried.