6 Steps to Proper Surface Prep for Gelcoat

gelcoat-sandingApplying gelcoat is a process that requires a bit of skill, a lot of know-how and the right tools and materials. So, before you spray or brush the gelcoat on, you want to make sure you prepare the surface you are recoating for the best results.

Step #1 – You will want to start off by cleaning the surface with Lacquer Thinner to remove any wax and oil. The next part of step 1 is sanding the surface with 80 grit sandpaper, like our OEM brand. This will knock all the oxidation and wax from the surface. You do not have to sand it down to raw fiberglass. Make sure you use proper safety equipment, like dust masks.

If you DO have raw fiberglass spots, you are just going to lightly hit those spots to clean them up. These areas will usually require a second coat of gelcoat.

Step #2 – Clean with Acetone or MEK Solvent and let the solvent dry. As soon as it’s dry, you can get started, but don’t wait more than 20 minutes before starting your process.

Step #3 – If you are doing multiple coats of gelcoat, the first coat should not have wax or Sanding Aid in it. If you purchased Interior Gelcoat, it already has wax in it, meaning, if you are applying multiple coats, you will want to wait until the gelcoat is cured and wipe it down with Lacquer Thinner and then sand the gelcoat before applying your second coat.

Step #4 – Mix in your catalyst and apply your gelcoat by either spraying it or brushing it, using our brushable gelcoat. After applying, let it sit for 12 hours before doing anything to it.

Step #5 – Lightly sand the gelcoat with 1200 grit sandpaper or use a compound that is equal to 1200 grit, like our Aqua Buff 2000. Larger blemishes will require a lower grit sandpaper to knock down any high spots.

Step #6 – Apply a wax to give it that factory shine. We sell Farecla, Presta, Flitz and 3M brands that work great.

8 Solvents for Cleaning Up your next Job

solventA major part of our business here at FGCI is dedicated to solvents. Solvents are used for many things, but especially for cleanup. When you finish a project, you want to be able to clean up your mess, right? Everything from cleaning spray guns and brushes to wiping down the project afterwards, solvents are an important part of your project process. When you start a project, you want to make sure you pick up something to clean up, but which one works best? Let’s look!

Acetone

Acetone is a necessity for cleaning up polyester resins and gelcoats. Acetone is also a very important step in treating your part before spraying gelcoat, as it helps get any and all oils off the part to avoid blemishes. This is probably the best overall cleaner.

Lacquer Thinner

Lacquer Thinner is a must for removing oils. You will see a lot of mechanics use this for parts cleaning and washing as it is great for removing a lot of the grease left by engines. You will also see this product offered in different degrees of purity, from the wash-grade to the medium to the high-grade.

Isopropyl Alcohol

Our Isopropyl Alcohol is 99% water free. This product is great for cleaning epoxy, especially for wiping down a new epoxy bar-top.

Mineral Spirits

Mineral Spirits are a tried and true paint cleaner you will see used by anyone painting a polyurethane or enamel paint as it breaks down the paint very quickly.

Styrene

Styrene is a common solution found in resins and gelcoats, sometimes called ‘wax.’ Styrene is commonly used to thin down resin to allow it to seep into wood easier. We don’t recommend using it to thin gelcoat, however.

Toluene

Toluene is a great multi-use product as it’s great for cleaning epoxy, but it also works for cleaning paint as well. Toluene is mainly used for cleaning up silicone and it does a great job on 5200.

T-12

T-12 is a very volatile solvent used mainly for cleaning epoxies. This solvent dries extremely quickly, but you will see it used frequently for cleaning brushes between uses.

Xylene

Xylene is used mainly as a thinner for enamels. It can also be used for cleanup for paints as well.

The most important thing to remember with all of these solvents is that they all require proper protection. Gloves and some sort of clothing protection would be the least you can do. You may also consider respirators and eye protection as well. You also want to remember that all of this material is flammable, so be cautious and store it properly.

5 Tips on Various Fiberglass Coatings Solvents

1. Acetone is good for cleaning polyesters, but not epoxies.

129132

2. Lacquer Thinner tends to be a good solvent for cleaning surfaces to remove wax and oils.

129173

3. Isopropyl Alcohol 99% (water free) is a mild solvent that is recommended when using Epoxy Table Top Resin and cleaning new epoxy surfaces.

129155

4. Mineral Spirits works well with paint and polyurethane enamel.

129187

5. Styrene reduces polyester, iso and vinyl ester resins for better wood penetration.

129208

5 Tips for Using Gelcoat

Gelcoat Photo1. When spraying gelcoat, we recommend using spray guns with 2.0 nozzles or bigger.
2. We recommend chilling the gelcoat down to 70°F to prolong the working time.
3. Before using gelcoat, it must be stirred/agitated. The use of a mechanical agitator is preferred. Do not whip air into the gelcoat.
4. Gelcoat is suited for a broad range of high quality, open-mold, lay-up applications including boats/yachts, swimming pools, sanitary ware, sinks, recreational vehicles, commercial/mass transit vehicles and industrial components.
5. Apply in smooth brush strokes yielding a wet film thickness of 18-20 mils. Gelcoat can be brushed, poured, rolled or sprayed .