Making a Fibreglass Part From Oil And Dirt

First ensure that the mould you have for your fiberglass part is free from oil and dirt by washing it in clean warm water. Allow it to dry out completely.

Release Agent

To ensure the fiberglass part doesn't stick to the mould you need to apply a release agent. For best results we recommend the use of a paste wax followed by a PVA release agent. Start by applying two coats of the paste wax to the mould. This can take the form of a brush-on or aerosol product. We prefer the aerosol product for speed and smooth application. It is vital to keep the release agents as smooth as possible as this can affect the surface of the finished casting.

After allowing the initial two coats of paste wax to dry for at least 30 minutes you can start applying the PVA release agent. We use a soft sponge to apply this coating as we want the surface to remain streak-free. We find a brush tends to leave streaks which can show up in the surface of the finished fiberglass part. Make sure that you cover the entire area of the mould with the release agent. Keep checking for any runs in the release agent and smoothen them out with the sponge as soon as you notice them.

Now allow the PVA release agent to thoroughly dry. You can speed up the drying process with a hair dryer if necessary.

The Gelcoat

A gelcoat is the initial first coat of resin which will ultimately become the visible surface of the part you are creating. This coating of resin does not contain any reinforcement such as fiberglass matting so that it can be as smooth as possible. Reinforcement of the part will come in subsequent coatings to the back of this initial gelcoat.

1) The first step is to work out how much gelcoat you need for the part. You can work this out roughly by estimating the surface area. 1 square meter of mould surface usually requires about 500ml of gelcoat .

Once you have your estimate pour the right amount of gelcoat resin into a mixing container. Mixing containers can be as simple as a waxed paper drinking cup or for larger amounts of resin you can use an ice cream container.

2) Now we need to work out how much catalyst we need to set the gelcoat resin. The catalyst we need for gelcoat polyester resin is a dangerous chemical call MEKP and should be used with great care.

So for example if you are wanting to mix 500ml of gelcoat on a cold day you need to work out 2% of your resin (simple calculation 0.02 x 500ml = 10ml) We need 10ml of MEKP catalyst when mixing 500ml of resin on a cold day.

3) Now we need to mix the catalyst and resin together in the mixing tub. Stir well using a flat stick such as a paddle pop stick. Using a clean brush apply the first coat of resin to the mould. Make sure the coating is thick and even.
For more information about Fiberglass Needled Mat,3d Spacer Fabric Factory,Fiber Glass Roving and Parabeam 3D Fiberglass please visit my website.

Fibre Glass Yacht Construction

What's fibreglass made out of?

For the purposes of this article it is beneficial to understand a few basic facts concerning how fibreglass boats are constructed, their typical strengths and weaknesses and most importantly what are the visible signs that manifest themselves to the owner, such as stress cracks, de-lamination, osmosis and so forth.

Basic Construction

Fibreglass boat hulls are generally composed of several laminations (or layers) of glass fibre cloths, impregnated with polyester, vinylester or epoxy resin. This is usually done by building a "female" mould and creating the fibreglass hull within by a series of subsequent stages:

The hull is then usually re-inforced with more layers of glass and resin onto areas that are under stress and the whole hull sealed with a final layer of clear resin. The rest of the internal fittings such as roof, decks, bulkheads and keel are added when the finished hull is released from the mould. (This does not always apply! Different builders vary this).

Wooden components

Often in fibreglass hulls, wooden components have been used to reinforce areas, such as galleys and so on. Often, the wood is subject to water exposure and swells, eventually causing rot and decomposition.

LAMINATED CORES

Many modern boats have been constructed using internal cores together with resins. These can be polyurethane foam, end grain balsa cores and many lightweight racing hulls are using various lightweight "honeycomb pattern" materials.

These materials decrease the weight of the hull, often with very little strength loss. Also, the use of "closed cell" foam cores combined with epoxy resins has safe guarded many of these "composite constructions" from early failures but all must be subject to high quality and standards, especially where deck installations and fittings are concerned, due to repeated high loading.

UNDERWATER

Just because the hull is underwater does not necessarily mean it will degrade any faster but in the case of poor maintenance, hidden factors may be at work. Lack of anti-fouling procedures allows marine growths to proliferate. Barnacles are a sure-fire gel coat killer if they are allowed to remain undisturbed at work!

Naturally, a weed covered hull will hide the dreaded "osmosis blisters and underwater metal fittings will be subject to damage by galvanic electrical corrosion if the right conditions exist. Rudders and props, shafts too, are often overlooked when a hurried slipping takes place, usually for a quick anti-foul.

For more information about Fiber Glass Roving ,3d Spacer Fabric Factory,3d Fabric and Fiberglass Needled Mat please visit my website.