Abrasions - Minor
Minor abrasions are marked by the scraping off of gel-coat or paint in a small, localized area. Scuffing of the underlying fiberglass layers is also not serious, as long as major damage hasn't been done.
This is often seen around the keel or bottom-centerline of boats, and is caused by beaching or "poor technique" when loading and unloading the boat from its trailer.
Other times, abrasion damage is seen on the sides of boats that have been "rafted" with others or have contacted pilings at the dock.
In order to repair abrasion damage, you must determine how deep it goes. If there is no discoloration, but only a rough texture, the damage has probably not gone past the gel-coat layer, and is not serious. The
pages on finishing will cover how to address this.
If you can see another color, this means that the gel-coat has been compromised, and you will need to sand down to determine the depth of the damage. Don't forget to wipe down the area with acetone first.
Mask off the area around the repair site with low-tack masking tape and newspaper.
You will probably find that the gel-coat has worn through, but little damage has ocurred to the fiberglass underneath.
If there is minimal damage to the fiberglass, mix up some slow-cure epoxy resin and brush over the area to seal it. Let this cure overnight.
Next, wipe down the area with acetone again and sand with 120 grit paper. (Wipe it down with acetone again) and proceed to the finishing steps.
Abrasions - Major
Damage is considered major when a large area has been affected and when the damage to the fiberglass layer is more than superficial. If the hull's core is exposed, the damage is definitely major!
Repairs on such damage often require the addition of fiberglass cloth to provide strength to the repair. Fairing compounds and other fillers may also be required to provide the correct shape for the hull.
The first step is to acetone wash and sand away the damaged area to provide a clean, undamaged surface to begin with.
For large areas, only work on one side of the boat at a time. This gives you the other side to use as a template for reshaping, if required.
Next determine what work must be done to ensure that the repair has the correct shape. You do not want to have to build up a 8" deep repair with cloth and resin - use a filler. I'll discuss this step in a later article. For now, don't hesitate to contact me with any questions you have. Next, sand out the repair area to a minimum 12 to 1 slope using 80 grit paper.
Cut out pieces of biaxial weave fiberglass cloth to fit the repair area. Plan on 3 to 5 layers. The first piece will be the smallest with the following pieces getting progressively larger.
Wipe the repair area down with acetone.
Mix resin and slow-hardener in a disposable cup, and brush onto the entire repair area.
Place the smallest cloth piece on the repair and wet it through with additional resin mix.
Use a fiberglass roller to remove air bubbles from under the cloth.
Wait a minute and then repeat for the next larger piece of cloth.
Repeat for all remaining pieces of cloth.
Let the repair cure overnight.
After the repair is cured, wipe it down with acetone and sand with 120 grit paper.
You are now ready to go to the finishing stages. BACK to Structural Repairs from Abrasions
