One or two piece wheel skirt.
 

I wonder if i should make the wheel skirts for my truck out of fender trim plus a curved sheet or as single bent/molded/carved piece.

I want the wheel skirts to go down to the bottom of the rim. I want them to look nice.

The front skirt will be articulating so it has to be quite rigid yet also line up without gaps.

What angle or radius should the edges be to be aerodynamic? Should it be gentler than standard trim?

The rear tires have trim, its missing off of the front, however i would need deeper than stock trim to give 1" of clearance to the front tire for highways turning. The rear trim doesnt stick out far enough for the bottom 6" where the vehicle curves under but is otherwise good. Its grey with a chrome stripe.

Do a mock up in paint or something similar. Just take several pictures from a few angles and just get creative. Tahrs what I did to design my front air dam.

The question is if commercial fender flares would make it easier to construct the wheel skirts or not?

How sharp can the rear and top edges be to not have a huge effect on aerodynamics?

The fender flares wouldn't stick out far enough at the bottom so they wouldnt help me there. I could make the skirt somewhat smaller without them by having most of the curve in the large gap around the wheel, inside and not outside the arch.

I've never heat bent plastic, done sheet metal work besides banging dents out or done any fiberglass work but i'd learn whater i had too to build it. The way i see it i think it would have to be made from plastic plus a frame, thick sheet metal or fiberglass.

Because they articulate the front skirts have to be strong and line up good with the body. I plan on extending it all they down to cover the whole rim, maybe it will extend lower than the side skirt im going to be adding. I decided to either have side skirts or moon caps but the gap around the tire is pretty big so I thiink i should go with the former.

sheet metal is not hard to work with. Do you have a pair of vice grips? They are a great tool for bending edges.

I do and i also have a harbor freight set of body hammers/dollys. The Dents i hammered out of the chrome steel bumper though arent etirely smooth. Flat but a bit ripply. I dont have the tools for smoothing it.The edge curves so it wuldnt be a straight bend but a compound bend all the way around. I belive that means shrinking/stretching. Also I couldnt use the really thin gauge because i need some strength. I know any shape can be formed in sheet metal with the right hand tools and alot of skill. Im not sure i could easily learn the skills to make it look good.

How strong do you need it? I used thin sheet metal for my rear wheel skirts (I think it is 18 or 22 gauge) and it has a lot of strength.

Well the wheel wells are larger on my truck and they will be attached only to 4 hinge points. I suppose i could use a frame with sheet metal too for strength. Its just the smooth compound curves thing.

Also bending a 'U'-shaped lip along the bottom of the skirt would help strengthen up the portion that is not going to be attached to anything...

Compound curves can be difficult. For strength bend over a half inch on the edges. I did this on mine and it helps a lot (I learned this while working at a sheet metal shop). The curves will also add strength. Each bend actually adds rigidity to the piece.

Until I see what you are trying to do I will have a hard time coming up with ideas on how to do it. Any one understand it and have photo shop skills?

Hmmm I only need the 1" of clearance at the front and back edges of the tires because that the part that would hit the skirt first when the tire turns. The top doesnt need to be built out much. The skirt could go down relatively vertical than gently curve in an inch between the middle and the bottom. The body curves inward going down and much more near the bottom so i would need the real curves at the front and back edges getting much deeper near the bottom.

The front edge is the bumper so i would want the curve in the gap and not on top of the bumper. Since the bottom goes in so much the bottom rear edge might have to be brought back close to the edge of the door, depends on aero angles.