Methods for creating a spattercoat finish
STEP ONE: SURFACE PREPARATION
Sanding the fiberglass laminate is not required with grinding discs. NCS SPATTERCOAT 42 PA bonds extremely well to GRP laminates compared to emulsion based stone chip.
However some may want to use a P36 grit paper by hand simply to remove “spikey” glass fibre which could be like needles. You save electricity, grinding discs and time in operation. You will also have less dust.
It also bonds well to steel substrates compared to emulsion based stone chip and is much more durable. Note that though NCS SATTERCOAT 42 PA bonds better than the emulsion based stone chips we would recommend the use of ATPRIME 2 as a primer in critical applications for steel.
STEP TWO: BRUSHING BACKGROUND
Spray the mist grey NCS SPATTERCOAT 42 P918 PA with Spatter gun and then simply brush over the surface. Allow it to stand for 5-10 minutes before proceeding to step 3. It will still be sticky at this point but would have thickened up due to polymerization process. Usage is between 400-700gm2 if brushed and 50-100g if spattered per m2.
STEP THREE: SPRAYING
Start spraying the 42P200 PA black-pigmented Spatter coat. By regulating the distance of gun from mould and trigger pressure spatter finish can easily by controlled. Usage in this step is about 50-100g/m2
The finish can be varied very easily. For larger spatters, simply reduce the trigger pressure and decrease the gun distance from the surface.
For a finer spatter increase trigger pressure and increase gun distance.
Because of the nature of a polyester based spatter coat and the “stickiness” this product is less prone to create elongated splatter even when sprayed at an angle to the surface
STEP FOUR: CLEANING GUN
WARNING! The process mentioned for cleaning could result in injury if not done correctly. If you have doubt that your operator is not suitably qualified or experienced then we would advise manual cleaning. This can be done by removing the clear silicone hose and disposing. The gun can then be cleaned with a brush in acetone. If operator is skilled you could follow this process:
Remove the clear plastic hose tip from the bucket containing the NCS SPATTERCOAT 42 P200 PA. Continue spraying the FRP surface until no more Spatter coat exits the nozzle.
Insert the tip of the clear silicone hose in to a bucket containing acetone and pull the trigger gently with the nozzle up against the side of the bucket as pictured. BE CAREFUL of not pulling the trigger hard as this could result in acetone splashing in to the face of operator. If doubtful follow the manual process.
You will find that this cleans the gun within 30-45 seconds affectively. The picture depicts a clear hose that just had black spatter coat. The clarity of the hose is an indication of when the process is complete.
We suggest at the end of the working day the step gets repeated with pure acetone and the surface of the gun and trigger simply wiped
STEP FIVE: INSPECT CLEAN HOSE)
This picture depicts the hose and gun after cleaning. The whole process took less than 1 minute using “dirty acetone”.
The gun had black spatter coat and shows how effective and quick the cleaning process is. We recommend one use a clear silicone pick-up hose as pictured. The operator will be able to see when the hose is clean. Using the colour of acetone is not effective and will result in wastage of acetone and time. The remainder of the acetone is pictured in the bucket and can be re-used. The acetone pictured had already been used 4 times to get the result pictured. Amount of acetone used required is estimated at 300ml-500ml and this can be reused approximately 3-5 times
In the interest of conserving acetone we would suggest that one sprays as many parts in one go as what is allowable by gel time and place a lid on the acetone container after cleaning to prevent evaporation.
STEP SIX: REPEAT THE PROCESS WITH WHITE SPATTERCOAT
This step is optional. If you are satisfied with just the black, you may omit this step. If you wish to have the white repeat step three to six with the white.
The FRP surface will be tack free within an hour.