what is the difference between polyglass and fiberglass,which one dries harder and more rigid?Can fiberglass be combined with epoxys to make it more rigid?What resin is the hardest and light weight and wont crack under extreme vibrations?
Fibreglass is a matt or cloth formed of very fine strands of glass. It is mostly combined with a thermoset resin of some type, initially polyester resin groups were used but have proven in some cases to be woefully inadequate in a marine environment. Today the industry standard is epoxy resin groups with 'E' glass cloth (coated specifically to encourage bonding between the glass and the epoxy) and various modifiers such as carbon, graphite, kevlar, aramid etc. This type of structure done right it so far in advance of polyester GRP (Glass reinforced Plastic) it is not funny. Think of a mast built in carbon fibre - several times stronger and two or three times lighter than the finest of aluminium spar - GRP cannot even be considered for that application as it is too brittle and too heavy. Polyglass is a waterproofing membrane - based on polyurethanes with glass fibre added to give great strength. Some water and waste tanks are sold under that title, as well as industrial surface coatings.
put Dawn directly on the stain
I wouldn't use soap. It might lock in the stain. Try Oxyclean or OxyBright. Goes by many other names all with 'oxy'. Works great! Good luck!
