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As a boat owner, always ensure no leaks in your boat. This means ensuring all boat fiberglass repairs are attended to with haste.
You don’t need to be a Harvard or Cambridge Scholar to know how to repair boat fiberglass. Almost anyone can perform a fiberglass boat restoration with the right tools and materials.
So, say goodbye to spending thousands of dollars at a repair shop. With just a few hundred dollars, you can achieve the same results and learn a thing or two.
Allow WindyHq to show you how to patch fiberglass boats. You’ll surely have no regrets.
Required tools
Here is a list of all the tools you’ll need to get that fiberglass from its current damaged state to a fixed state.
- Heat gun
- Rotary tool
- Safety goggles
- Sanding block
- Mixing cups
- Boat wax
- Gelcoat
- Gel coat reducer
- Rubbing compound
- Stir sticks
- Latex gloves
- Countersink bits
- Masking tape
- Wet/dry sandpaper
- Polyester resin
- Dust mask
- Acetone
- Disposable spray gun
Expected cost
As we said earlier, a DIY fiberglass boat repair will cost you far less. The cost is further reduced if you already have many of the required tools and materials; you’ll need to only spend $150 on the buffer. There’s nothing to worry about; many of the essential materials you’ll need cost $250.
This is much cheaper than the repair shop price, which averages $2000-$2500 in states like Texas. In some other states, be ready to spend as much as $4000.
Necessary Precautions to Remember
Here are some necessary precautions to remember. Adhering to them will ensure that you enjoy a hitch-free boat fiberglass repair process.
When working with fiberglass, it is important that you know that the resins and hardeners you’ll be using during the repair process are toxic.
So, it’s crucial that you wear adequate protective clothing, gloves, safety goggles, and respirator masks to not inhale these dangerous fumes. The same applies to polyester resin; it has an awful smell.
Get a lotion to coat your hands and palms as an extra layer of protection. It will protect them from resin if the resin slips past the gloves. Once the resin touches your skin, do not hesitate to wash your skin with water.
Step-by-step process to repair a Fiberglass boat
Finally, we’ve gotten to the section you’ve been waiting for. It’s time to show you how to fix a fiberglass boat.
Step 1: Remove designs and graphics
The first thing you want to do is ensure that pinstripes, transom names and license numbers are taken off. This is because after the repair is complete, you’ll need to get new ones. For vinyl decals, choose a heat gun, while for painted graphics, a 1200 grit sandpaper will do.
The heat gun would make the design or graphics soft and pliable, then all that is left to do is use a scraper to lift the vinyl off.
Acetone will also come in handy when removing any adhesive. Alternatively, you could opt for an adhesive remover.
N.B: To prevent the destruction of the Gelcoat, be careful and avoid overheating the surface when removing graphics and designs with a heat gun.
Step 2: Cut away the damage
Now that the graphics and design are off, you need to cut away any damaged area and affected area. This is the better option, as trying to save the damaged fiberglass won’t just cut it; it’s merely a waste of time and effort.
Inspect the extent of the damage using a screwdriver with a plastic handle. Tap the affected area with the plastic end of the screwdriver. If the affected area is still solidly laminated, it will still sound sharp, whereas if it is delaminated, you’ll notice a dull sound.
Once you are done determining the extent of the damage, go inside the boat. At the same point where the fiberglass is damaged outside, ensure there is nothing in the way. Once you do this, create a circular cut at the damaged section.
Once cut, check to ensure there is no other delaminated point. If there is any, enlarge the hole.
Step 3: Remove the wax
The next stage is the wax removal process, also known as dewaxing. The dewaxing solvent is applied before grinding to ensure that the area outside the hole is free of traces of mold release.
Applying this solvent also keeps the inner surface free of wax surfactants. Doing this will ensure that the bond around these regions does not weaken.
Step 4: Start grinding
With old wax gone, it’s now time to begin the grinding process. First, ensure that you are well protected. Wear safety glasses, gloves, dust masks and long sleeve clothing.
Once you are adequately protected, load the disc sander with the properly sized disc and grind the area surrounding the hole, ensuring that the bevel around this perimeter is at a 12 to 1 level.
At the inner surface, grind a rectangular area beyond the bevel to serve as a base for the finishing layer of cloth.
Step 5: Apply a heavy paste of wax around the hole
This step, also known as the mask and mold step, will require you to get and cut smooth plastic laminate (Formica) or thin and clear acrylic (Plexiglas) to a size that is about one foot larger than the hole. The Formica or Plexiglas will serve as the backing on which wax will be applied.
With the wax on the backing, the next thing you want to do is spray the backer with polyvinyl alcohol (PVA) mold release. Once done, screw the backer to the exterior of the hole.
You’ll find out that once screwed to the hull’s surface, the backer will assume the proper shape if the hull is curving in one direction only. However, if it is curving in two directions, you’ll need to use your heat gun on the acrylic screw to get the backer in the proper direction.
Step 6: Cut sufficient fiberglass fabric
The right quantity of fabric to start with will be double layers of 1 ½ ounce mat, after which you should alternate this with 6 ounces of cloth. After examining the thickness of the hull, you should be able to determine the number of laminates you’ll need to get the hole fixed.
The first layer of the mat should fit the inside diameter of the hole, while subsequent layers should be about an inch smaller.
By doing it this way, the area of the secondary bond will be a lot tougher, and the bond between the new cloth and old laminate will attain its highest possible bond strength.
Step 7: Using Polyester or Vinylester resin
Polyester or Vinylester resin is the ideal choice if the damaged section is above water, however for underwater, trust epoxy resin to do the job perfectly. However, this is not to say that epoxy won’t work well for above-water repairs. If you need a strong bond, trust epoxy.
If you choose polyester or Vinylester resin, getting a laminating resin will become crucial to the project’s success.
Laminating resin creates the chemical bond you need between the different laminates, and although it doesn’t cure immediately, you can get it to cure by sealing it from the air with plastic. Polyvinyl alcohol (PVA) mold release is another great choice.
N.B: When carrying out repairs, do not use epoxy resin on Gelcoat; they are chemically incompatible, and the laminates will not adhere properly.
Step 8: Use proper amount of catalyst
Don’t worry; you’re almost done. To ensure that you do not spend the rest of your life waiting for the laminates to dry, you’ll need a catalyst/hardener.
Opt for a Methyl Ethyl Ketone Peroxide hardener for polyester and vinyl ester resin. Also, ensure that you mix the correct quantity of catalyst and resin before applying. The general rule is that four drops of hardener catalyze 1 ounce of resin at one percent.
Many times, temperature, weather conditions, the volume of the catalyst applied, and thickness of the laminate can affect the cure time.
Hardening of the catalyst won’t begin after 30 minutes, and it will continue for two hours. However, we recommend a cure time of 8 hours before moving to the next step.
N.B: Before applying catalyst or hardener to the laminate, ensure you stir it properly to prevent undercutting the laminates or weakened layup situations.
Step 9: Final finishing with sanding and waxing
Finally, we’ve gotten to the end, and all that’s left to do now is apply the final finish, sand and wax.
The final finish will occur after the curing of the laminates is complete. Only then should you apply a pre-cut piece of mat and a large cloth over the patched area and smoothen. Next, seal It up with PVA and allow it to cure for 8hrs.
Once you do this, get the backer out of the outer section, apply Gelcoat paste with a brush and give it time to cure.
In another 8hrs all imperfections should be filled. Then finally, you can decide to hand sand the patched area with fine-grit wet or dry sandpaper. Once sanding is complete, use a wet cloth to clean the surface of the repaired boat.
Also, applying rubbing compound and buffing compound as directed by the manufacturer will help you polish the repaired area. You might also choose to use wax as the final finish, but ensure you apply any new graphics and design before waxing.
N.B: When laying up Gelcoat, it’s crucial you remember not to apply more than four plies at a time to prevent a situation where the heat generated through the layup process overcooks the resin causing it to weaken.
Conclusion
It’s crucial that you follow these steps religiously to grasp the boat fiberglass repair process. You’ll also find that we’ve included several materials that will ensure that the process goes smoothly. So trust the process, and you’ll find out that with little to no previous experience, you also can learn how to repair fiberglass.
