Bulk plastic material for DIY splash guards/air guides?

Hey it's-a me, my Magnum is running like an alliterative animal in my 67 Coronet station wagon and I'm finally paying a little attention to the body.

Up front, any factory gap fillers or flappy bits that aren't metal are long gone. I have a lot of gaps between my core support, bumper, subframe, and inner fenders. My fan is shrouded, but its air pathway from the front has 3 huge gaps to choose from on its way to the radiator.

Out back, my impossible-to-find-in-the-future rear quarters are just flappin in the breeze fully open along their bottom edge going way up into the underbody. I'm having trouble finding something thinner than bulk mudflap material but thick enough to do some light heat forming (with an iron or hot metal forms, not a torch) without. I keep ending up at vendors catering to tarp-like needs of industrial applications.

Do I want Kydex? A generic type of plastic? What is it that I want?

I've seen some homemade aero made using coroplast like you find in election lawn signs. If nothing else, it's free - just provoke an election in your area and then reap the benefits from your more opinionated neighbours in the middle of the night.

http://ecomodder.com/forum/showthread.php/where-get-election-coroplast-signs-how-make-coroplast-23944.html

I don't think it's very good at being heat formed though. Maybe if you heated steel pipe with a torch, waited for it to cool a bit and then gently bent the coroplast over it to make a radius?

Kydex could produce some really good results. It isn't cheap and you're going to need to practice making some generic "stuff" to get a feel for it, but it is tough and abrassion resistant and can be heat shaped into darn near anything.

I've been experimenting with thermoforming ABS plastic the last few days. Apparently my wife has decided that I've taken up cosplay as a hobby so I'm currently making a sword for her. I've also made a... gun/sword/weapon/thing out of coroplast and I don't know that I would want to do that a second time. Because of the corrugation, your ability to shape and size the material is somewhat limited if you want a nice finish, plus when you cut it against the grain as it were, it's hard to form anything that isn't a straight line because you're cutting with heavy resistance then light then heavy then light, etc. It does have a slight ability to bend and conform without heat, but I never tried to apply heat.

With this sword hilt that I'm building right now, I'm using a sheet of ABS that I got from Amazon, but you could get the same thing from a local plastic supply house or from McMaster. I think what I'm working with is 1/16" ABS and it will cut with a utility knife and form with a rotary tool. I've tried different methods of putting heat in to it to form it and so far I've had the best luck with a torch and a light touch. The trick is finding something to form against that the torch won't light on fire -- fortunately, I have an empty paint can that is the exact radius of the guard so I've been using that. Using the torch to heat the paint can and then giving the plastic just a little bit of a warm-up before pressing it against the metal seems to provide the best results.

ABS sheeting works better than coroplast for this sort of thing, due to the aforementioned corrugation problems.

I can see that wae's wife is cosplaying as a Final Fantasy character...time to bring back the "is your wife hot" thread?

I made a 3D molded dash for the caprice out of ABS and a heat gun. It worked really well and was surprisingly easy to do. Just don't get it too hot. I bought the plastic from a local plastic supply place - 4'x8' black textured sheet for $50 or so if memory serves. Might have been a little more.

I second the ABS sheeting, but couldn't get any easily where I live so I bought the biggest container I could find at Walmart - pretty cheap, I think it was $5-10. I've made some aerodynamic additions to 2 of my cars by cutting and lightly forming with a torch.

I have used coroplast for a long time, it has its ups and downs but i cant get over the free part of it. Any parts showing get painted with truck bed coating.

Polycarb and a acylic sheets do well with thermal forming, but can get pricey. I have made head lamp covers before and a heavy face shield. Its easy to introduce bubbles in the surface without good temperature control. Abs has some advantages there and with price.

http://www.speedwaymotors.com/Colored-Plastic-Rolls-25-Ft,31414.html

I've done a lot with one of those rolls of plastic

^ those Speedway rolls may be the ticket for my wheel well areas that need to be more resilient to road debris. Corrugated plastic is going to get chipped up pretty quick around here.

I'm not looking to do any crazy thermal forming, just getting various straight angles I want to take a set. ABS might be a good idea for my front aero/air guide stuff - if I get like a 24 x 48 piece it'd be really easy to trace and zip out with a Dremel and a blade or something. I'll grab a sheet from a craft store or Lowes and see what I can do.

Corro plast is really tough stuff, not going to chip or crack. Especially the thicker and doubled up signs. I have some in a wheel well and have made an undertray and airdam from it. (Does well with the heat too)

The airdam was an attempt at increasing mpg on some road trips. It was scraping under the car for thousands of miles and took some heavy hits going over curbed sized speed bumps. It lasted the trip and i just left it on for a few months afterwards. It finally came off after the sheet metal screws holding it to a length of angle pulled out. Dont underestimate the stuff for strength.

Unless you need flatish sections it does get hard to imposssible to work with.

5 gallon buckets cut up make excellent material to start with.