I have an inter grated washing machine but the fixing on the inside of the machine for screws to fasten to have fell out of place so they now have nothing to fix to and will not hold the hinge for my door ( bottom hinge only ) would a self tapping screw make a strong enough fixing or would I need something like a plaster board fixing to anchor at the other side of the thin appliance metal to get a tight hold ? Please help any suggestions would be great