ORTHOTHALIC POLYESTER RESIN: LBI-301
- A majority of fiberglass parts are constructed of polyester resin.
- Good general purpose resin.
- Excellent for most repairs.
- Provides a repair that has similar strength & flexural characteristics to the original part.
- Tolerant of temperature and catalyst variations during lay-up.
- Wets out fabrics quickly and easily.
- Isothalic polyester resin is more water & heat resistant than orthothalic polyester resin.
ISOTHALIC POLYESTER RESIN: LBI-302
- Exhibits higher strength characteristics than orthothalic resin.
- About 90% repairs on a fiberglass boat can be made with this resin.
- May be used for molds because of its better abrasion resistance and heat tolerance.
- Has better UV and water resistance.
- More corrosion resistant than orthothalic polyester resins.
- Has greater impact resistance due to its increased strength and flexibility.
- May be used for underwater repairs.
VINYLESTER RESIN: LBI-901 & LBI-902
- Stronger and more durable than polyester resin.
- Most professional repairs are done in vinylester.
- Makes strong stiff laminates.
- Excellent bond strength to sanded laminate and core materials.
- Will bond to epoxy resin.
- Higher resistance to chemical, water and UV than polyester resin.
- Higher resistance to vibration and shock loads.
- Due to its higher strengths it has better tensile and flexural characteristics
- Highly resistant to water absorption that causes osmotic blistering that can occur with polyester resins.
EPOXY RESIN: LBI-1101
- Has higher ultimate strength than polyester or vinylester resins.
- Adheres well to wood, aluminum & steel.
- Excellent for covering wood with fiberglass.
- Can be thickened with additives to make a wood glue or a structural putty to replace rotted wood.
- Has electrical insulation properties.
- Has the strongest bond with carbon and kevlar reinforcements.
- Has better flexibility than polyester or vinylester.
- Can withstand substantial impact without cracking.
- Higher resistance to to environmental and thermal degradation than polyester.
- Has lower shrinkage than polyester or vinylester resins.
- Epoxy laminate generally requires much less labor to fair.
All three resins have their own unique roles to play in fabrication and repairs.
- How do they compare in cost?
- Epoxy is the most expensive, Polyester is least expensive & Vinylester is in the middle of the two.
- What materials work with these resins?
- Epoxy adheres to carbon fiber and kevlar better than vinylester or polyester.
- Epoxy is also the best choice for laminating over wood.
- Over 95% of all boats, truck & car bodies are made of E-Glass(orthothalic polyester resin and isothalic gelcoat)
- Polyester or vinylester are much better to use than epoxy for polyester fiberglass repairs.
- Generally on the scale of strength, water resistance and bond strength, Epoxy and Vinylester are the best, Isothalic Polyester is in the middle and Orthothalic Polyester is the weakest.
- Vinylester may also be used over polyester resin to help prevent osmotic blistering.