Mold-making: Prepping the plug surface

Table of contents

Teams that do this

Baja, CEV, CU Solar Boat, Hyperloop

Chemicals involved & MSDS for each (should also be included in confluence SDS) 

Safety Gear

• Nitrile gloves
• Gray (VOC) masks/respirator

Step by step

(Baja - Partall Paste Wax)

1. Before the gel coat is sprayed, the plug must be waxed and buffed seven times to ensure the mold will not stick to the plug and will be able to be pried off. Waxing should occur only a few minutes before gelcoat is sprayed because hardened wax does not have the lubricant qualities we want in order to pop off the mold later.
2. Use cut up T-shirts/rags to swipe up a small amount of wax from the thin and then wipe it over the plug. 

(FSAE - Seal & Release chemicals - Frekote FMS & 700-NC)

Applying Frekote FMS (“Seal”)

1. The mold surface must be clean and free of any release agent or other contaminants. Remove any contaminants with a suitable cleaning solvent & high grit sandpaper.
2. Wipe on a smooth, thin, continuous, wet film of Frekote FMS (Low lint paper towel or microfiber is a good application method). Avoid wiping over the same area that was just coated until the solvent has evaporated (Making sure not to miss any areas during the application). It is suggested that small areas be coated working progressively from one side of the mold to the other. Only work in a few square feet at one time until you are comfortable working with this product. Within seconds of applying the FREKOTE FMS, the solvents will evaporate and the applied area should be wiped clean with a lint free microfiber cloth. 
3. Wait 15-20 minutes for the coating to cure at room temperature.
4. Repeat the application two more times so there are 3 coats total.

Applying Frekote 700-NC (“Release”) 

1. Once the seal (Frekote FMS) is done curing on it’s final layer, the release (Frekote 700-NC) can be applied.
2. Frekote 700-NC can be applied to mold surfaces at room temperature up to 135°C by spraying, brushing or wiping with a clean lint-free, cloth. When spraying ensure a dry air source is used or use an airless spray system. Always use in a well ventilated area. 
3. Wipe or spray on a smooth, thin, continuous, wet film. Avoid wiping or spraying over the same area that was just coated until the solvent has evaporated. If spraying, hold nozzle 20 to 30cm from mold surface. It is suggested that small areas be coated, working progressively from one side of the mold to the other. 
4. Initially, apply 2 to 3 base coats allowing 5 to 10 minutes between coats for solvent evaporation . 
5. Allow the final coat to cure for 15 to 20 minutes at 22°C.