Up late last night working on the coroplast dam.
The frame is mostly aluminium: 1/8" x 2" flat bar and 1/8 x 1/2 x 1/2 angle and tube. The flat bar is nice and easy to bend. I started by bending the bar to the same profile as the bumper. I wanted the slope to match the curve of the Previa as it comes down the windshield.
As you can see from the pictures, there is a huge parachute under the bumper forcing the air under and around the front. Bad pressure, bad. I decided to make the grille block and dam one piece for structural and visual continuity.
There is another strut that goes from the lower attachment, under the van to triangulate the support for the bar.
This is the rough coroplast shape clamped temporarily for marking cut lines.
Here it's just held on with the spring clamps prior to tapping and drilling the #8-32 pan head screws. Will drill pilot holes then use a spiral point tap from Acklands-Grainger in my hand drill which will make the process very fast.
I'm still going to put another aluminium strip on the bottom edge to sandwich the coroplast and another near the top of the bumper where there is an existing detail line. That should break up the vast expanse of Vader helmetness whilst hiding my shameful beer lubricated, dull knife, coroplast calamity cutting. No wait, those are turbulators, yeah, that's it.
I was worried that it would look too huge but I think with the coming trim additions, it should be a pleasing proportion.
Future plans include lexan or plexi headlight covers.