Use this procedure to perform minor repairs on cars, boats, or other fiberglass items. This method is particularly suitable for objects in contact with water. The guide covers basic repairs, not the more delicate ones, and does not include instructions on how to apply the gel coat.
Steps
Step 1. Measure the damaged area
If it's longer than a quarter of the entire object, use an epoxy. Otherwise, use polyester-based resin. The slower hardening compounds are the most resistant, unless you dry them with UV rays.
Step 2. Note:
resins dry better above 18 ° and with moderate humidity.
Step 3. Note:
polyester-based resins are porous, so they are not suitable for areas that often remain underwater.
Step 4. Reinforce the repair with fiberglass
If the damage is extensive or structurally, you will need to use fiberglass to reinforce the repair. If the size is small you can use a fiberglass paste, otherwise use the fiber cloth.
Step 5. Remove the broken pieces and clean the area to be repaired with acetone
Step 6. Mark the area with paper tape
Step 7. Mix the resin and catalyst in the proportions indicated on the package, for a total volume double the area to be repaired
Use a cup and an object to mix.
Step 8. Attention:
avoid contact with the skin, use protective goggles and a mask.
Step 9. If you are using fiberglass paste, add it to the mixture until you get a consistency similar to that of peanut butter
Step 10. If using the fiberglass cloth, cut a piece of it to completely cover the damaged area and apply the resin to both sides of the material until saturated
Step 11. If you are using resin without fiberglass reinforcement, apply the compound until the entire area is filled
Step 12. If you are using a woven cloth, apply the material until the entire interior of the damaged area is covered
If there are any holes, you will later fill them with more resin, or with resin and fiberglass, as explained in the previous steps.
Step 13. Note:
if the catalyst works quickly you will have to work quickly to apply the compound before it hardens.
Step 14. Allow the repair to dry according to the times indicated on the package
Step 15. Attention:
the resin produces heat when it dries. Do not touch!
Step 16. Once dry, remove the tape and sand the damaged area
You can use a coarser sandpaper (40-60) to get more or less to the desired level, then switch to a finer paper (100-200) to smooth the surface, finally a super fine paper (300+) for the final touch. You can use even finer papers or polishing compounds to achieve the desired effect.
Step 17. Attention:
wear appropriate protective clothing when sanding fiberglass. Even though they have no smell, the resins used for repairs are toxic.
Advice
Don't buy more resin than necessary. These products do not keep very long once opened. You will find disposable kits for sale in hardware stores
Warnings
- Do not touch the resin before it is dry. These compounds produce heat when they dry.
- Warning: epoxy resins, polyester based resins and catalysts are toxic substances.
- If the resin comes into contact with your skin, don't try to peel it off. Use a waterless hand cleaner to remove it.
- Wear gloves, goggles and a mask.
