In this article we will look at the process of manufacturing the fiberglass part.
This article assumes that you have a mold for your fiberglass part. These forms can be made of metal, plaster or plastic.
First make sure that your mold for your fiberglass does not have oil and dirt by washing it in clean, warm water. Let it dry completely.
Release Agent
To prevent the fiberglass part from sticking to the mold, you need to apply a removal agent. For best results, we recommend using paste wax followed by an agent for the separation of PVA.
Start by applying two pasta coatings to the mold. This may be in the form of a cystic or aerosol product. We prefer an aerosol product for quick and smooth application. It is imperative that the means for unlocking be as smooth as possible, since this can affect the surface of the finished casting.
After the initial two layers of pasty wax have dried for at least 30 minutes, you can start applying the agent to release the PVA. We use a soft sponge for applying this coating, as we want the surface to remain without stripes. We find that the brush tends to leave streaks that may appear on the surface of the finished fiberglass part.
Make sure you cover the entire shape area with a release agent. Keep track of any runs in the release agent and smooth them out with a sponge as soon as you notice them.
Now allow the baking powder to dry completely. If necessary, you can speed up the drying process with a hair dryer.
Gelcoat
The gelcoat is the first first layer of resin that will absolutely become the visible surface of the part you are creating. This resin coating does not contain any reinforcement, such as fiberglass matting, to make it as smooth as possible. Reinforcement of detail will flow into subsequent coatings on the back of this initial gelcoat.
1) The first step is to find out how much gelcoat you need for the part. You can do it like this by evaluating the surface area. 1 square meter of mold surface usually requires about 500 ml of gelcoat.
Once you have an estimate, pour the right amount of gelcoat resin into the mixing container. Mixing containers can be as simple as a waxed glass for paper or for more resin, you can use an ice cream container.
Gelkot are different types, but for this article we will use the most economical, which is white. This can be changed by adding pigments to create the desired color of the finished part.
2) Now we need to figure out how much catalyst we need to set for the gelcoat. A necessary catalyst for polyester resin gelcoat is a dangerous chemical challenge MEKP and should be used with great care.
Avoid touching the catalyst and it is strongly recommended to use rubber gloves in a ventilated room. The required amount of catalyst is quite small and varies on hot and cold days. On a hot day, we recommend using a 1.5% catalyst for your mix, where we use 2% on a cold day.
So, for example, if you want to mix 500 ml of gelcoat on a cold day, you need to develop 2% of your resin (a simple calculation is 0.02 x 500 ml = 10 ml). We need 10 ml of MEKP catalyst when mixing 500 ml of resin on a cold day,
3) Now we need to mix the catalyst and the resin together in a mixing bath. Mix well using a flat wand, for example, a wand with a hood.
Gelcoat application
Using a clean brush, apply the first layer of resin to the mold. Ensure that the coating is thick and even. Work as quickly as possible, as the gelcoat tends to start the installation in just 10 minutes. Aim for a coating thickness of 0.5 mm.
As soon as you apply the first coat, you need to wash the brush thoroughly so that it can be reused. It is recommended to wash it in acetone.
Allow the first layer to dry before starting to apply a fiberglass coating. For drying, depending on weather conditions, it usually takes from 2 to 6 hours.
Prepare fiberglass matt
In this article we make a small part, and we will use two layers of 225 um of chopped mat for reinforcement. For most small jobs, only two layers of fiberglass are required.
We can prepare our matting, tearing and cutting it into parts of suitable size for ease of use. It is better to rip the mat to avoid hard edges on your pieces. The torn edges will allow the matting to stick together with each other and create a much stronger part.
Preparation of resin for fiberglass
We now apply unique resin layers with fiberglass to the part. These are the layers that make the part strong.
First we need to figure out how much resin we need for each layer. On average, you will need about 500 ml of resin per square meter of 225 g of glass fiber mat. This amount will increase if you use heavier mats.
The use of fiberglass for partial
- Mix the laminating resin and MEKP in a mixing bowl and mix well.
- Now apply a thick resin coating on a layer of dry gel coat.
- While this coating is still wet, apply the matting pieces that you previously ripped into pieces, making sure that you overlap every detail.
- Apply another layer of resin over the top of the matting, using an ejector motion using a brush to avoid moving the mat parts out of position. Ensure all parts are resin coated.
- Let the resin sit for a few minutes to allow the resin to absorb the matting, and then use a special metal rolling tool over the matting to squeeze air bubbles.
- Then you can immediately apply any outstanding layers of fiberglass matting in the same process, until you reinforce the part as you wish. Let the pieces cure all night.
- Remove the fully cured part from the mold using a wooden wedge to pull the part free from the mold. Work around the part until it is free.
Completing part
The edge of your part will be rather rough and sharp. With care you can clear this edge using a hacksaw. It can be further cleaned with a file and both, making the edge smooth and safe to touch.
Rinse the part under water to remove all disintegrating agents and dust.
Additional Information
This process gives you a strong role with a smooth surface on one side with a rough substrate. If you need a part with a smooth front and back surface, you can apply a finishing coat of polymer paint on the rough side.
