1994 Suzuki Swift Sedan Coast Down (Phase II)

[Bicycle Bob]

Another way to get a fold in Coroplast is to run a bead of hot glue along the line. A straightedge can help guide the gun. The glue softens the Coroplast to let it bend, and then holds the angle, after some relaxation.
You can also get smooth curves, with the grain or somewhat obliquely, by slitting the inside skin in the area of the bend. I usually blunt the tip of a disposable blade for fast, easy slitting. Use it at an angle, so the cut edges will ride over each other. Stiffness can be restored by framing, or much increased by a second layer, glued on with beads of silicon seal.

[wyatt]

Originally Posted by Bicycle Bob

Another way to get a fold in Coroplast is to run a bead of hot glue along the line. A straightedge can help guide the gun. The glue softens the Coroplast to let it bend, and then holds the angle, after some relaxation.
You can also get smooth curves, with the grain or somewhat obliquely, by slitting the inside skin in the area of the bend. I usually blunt the tip of a disposable blade for fast, easy slitting. Use it at an angle, so the cut edges will ride over each other. Stiffness can be restored by framing, or much increased by a second layer, glued on with beads of silicon seal.

How long of a bend can you do that way? I imagine that the coroplast and hot glue will cool rather quickly, so I doubt a full 4' bend could be made, maybe I am wrong. I know that Basjoos has used a heat gun to warm the inside of the bend, and seems happy with the results. I think OrangeBoy has used a method of crushing the coroplast in a line to make bends. I am with you, I score the inside (cut through the innermost layer) and make the bends. The coroplast does lose strength, but the bend adds it back.

[Bicycle Bob]

4' would be a fairly long crease with hot glue, even with two hot guns to start with. For a crease across the grain, I don't cut all the way through - I just use a blunt tool with maybe a 1/8" end diameter (3mm) to make a crease that the material will follow easily. Such a groove makes a good guide for the tip of a glue gun or a small, just-lit torch flame. Hot glue or silicon can be added after the initial folding, too. The creases don't need to be straight, either.