Need some advice on how to seam two 4 x 8 pieces of melamine to create a 15 foot piece. Tried bondo and it shows with the GFRC, Any advice on how to make a clean seam that will not show in the facecoat? Thanks as always. Tommy B
Bond does work. Bevel the edges of the melamine and join them together with reinforcement from underneath. Then spread the bondo. Don't overfill or you will have more sanding to do. Use a putty knife to spread the bondo. Repeat this step until flat. Spatter spray some black spray paint on the bondo areas and them sand until the black spatter coat is sanded off. This will tell you if the bondo is perfactly flat. If it is not there will be black left in a dip or imperfection and need to be filled again.
Here is the key to pouring the concrete. Prime it. You can get away with a spray can primer if you pour a stiff mix design or plan to grind it. If you are using a loose mix design them you should use a catalized (2 part) primer. Some water-based paints will also work. Then sand it smooth with 400 grit and higher sandpaper. The water-based paints don't sand very well but then you could afford to coat the entire board.
You will have at least some polishing of your concrete afterwards, pretty much like always.
Putting a sacrificial strip of tape either side of the beveled seam before you fill lets a ridge of bondo sit just high of the seam. Remove tape and sand flush. Tape keeps bondo out of the melimine texture as well. Graeme is right about not limiting your forming options. For a cement paste finish I would use a roll of plastic film like the material Preitech supplies.
Damn, poor guys probably already on the plane to Hawaii.
James Z said:
Found in a lumber supply store in honolulu. the guy said it was really old and sold it for $15.00 a sheet just wanted to get rid of it cause it had some bad edges. last we looked they didn't have any more of the 15'.