26
Sep
Another video from our GRP Quicktips Series - How to brush apply gelcoat. The trick will be accomplished by a power sander bringing the blistered region back to the fiberglass.
The first coat will still be tacky.
How to apply gel coat to fiberglass. To apply the gelcoat with a brush dip the brush in the gelcoat so theres a liberal amount of gelcoat on it. Brush the gelcoat onto the fiberglass using short vertical strokes. First thing you want to do is look at the surface you want to apply gelcoat to.
If the surface is already covered with gelcoat or if the surface is a fiberglass or polyester resin then applying gelcoat will be a snap. If the surface is paint then the paint would have. Step 2 - Apply the Gelcoat.
Step 3 - Sand Down the Gelcoat. Step 4 - Allow the Layer to Dry. Will fiberglass stick to gelcoat.
Its sanded and more gel coat is applied. Also when doing a repair or re-gel coating its not real a chemical bond because the gel coat or glassresin that your applying on is already cured so it will be a mechanical. Once you have washed the fiberglass give the area where you will be pouring your gelcoat a good buffing with some sandpaper.
This will give your surface a slightly raised edge which will help the gelcoat cling to the fiberglass. Mix thoroughly to ensure that all gel coat is properly catalyzed. Apply gel coat to your part.
Spraying gel coat is recommended for more accurate and consistent coverage. Apply gel coat in 4-5 layers at approximately 5 mils each allowing 15-20 minutes between layers for a total thickness of 20-25 mils. Another video from our GRP Quicktips Series - How to brush apply gelcoat.
All materials seen are available for purchase at wwwecfibreglasssuppliescoukPlea. Grind the gelcoat away from the fiberglass using a grinder and 36-grit griding discs on a soft grinding pad. Scrub the entire area with detergent and then rinse with clean water.
Smooth the area with a Scotchbrite pad once the surface is dry. Starting with 40 or 80 grit and finishing with 100 or 200 grit use low-grade sandpaper and scale it up. That should remove debris and rough up the surface sufficiently to bind with a fresh gelcoat.
The trick will be accomplished by a power sander bringing the blistered region back to the fiberglass. Applying Gelcoat by Brush or Roller Use a Brushable Gelcoat. When applying gelcoat by brush or roller we recommend the Ultra Plus Brushable Gelcoat.
Other Gelcoats are best applied by Spray The Ultra Plus Brushable Gelcoat is designed to self-leveling and is much easier application. It allows for a much smoother finish and less time finishing the gelcoat. Complete the first gelcoat then wait four hours before applying another.
The first coat will still be tacky. Press on the coat with your finger. It shouldnt leave an impression with your fingernail.
Apply a second coat and allow to harden for another four hours minimum. This coat will be tacky but hard enough to resist leaving a fingernail impression. Step 2 - Apply the Gelcoat.
Making sure that your gelcoat is applied evenly on the paintbrush go over the base of the boat beginning on one side and working your way over. Make sure that you give your boat a thick layer as a thin layer may not. This video from FibreGlassDirect provides a brief guide on how to apply a Brush Polyester GelcoatBefore starting any project please ensure you familiarise.
The gel coat will start to gel before you can pull all the tape off this will mess up the tape lines you will also drop the tape andor the masking paper on the wet gel coat requiring more work later to fix it. The compressor will malfunction mid spray job then stop working completely and you wont have a. Usually RTM moulders pre-treat their moulds with a low shrink gel coat in order to ensure a high level of smoothness hardness and colour.
The gel coat has to be left to thicken before processing can continue this stage is not always necessary using veils which means the moulding process does not take as long to complete. In this episode I finally gel coat the engine compartment and seat boxes. I also demystify using Duratec high gloss additive for a backside air cure with.
For applying your gelcoat you can either roll the gelcoat on like paint or you can spray it on. We also sell a Brushable Gelcoat that can be applied with a brush. If you decide to roll on the gelcoat be sure to use a solvent-resistant 18 or ΒΌ nap.