Aluminum Body - pros, cons. query

[rstackjd]

Now don't flame - it's an inquiry is all. Car is an '88 Adams Aero.

On "winter projects" list is serious body work on my car. We are looking at several options, including purchasing replacement body parts from Adams, replacing with a body from a different vendor, or fabrication. Among the reasons for this being an issue is that due to all the mods done to the car by prior owners, and various body repairs, there is a fair amoung of excess weight in the body from bondo (no really) and other "reinforcement. I'm pretty sure I've got places where the body is 3/8 to 1/2 " thick for crying out loud. Second reason is that there are a number of repairs that are needed, including a new nose. Finally, due to mod and the aforementioned prior repairs, the body fits like crap.

Among the reasons for fabricating is mostly the learning process. I have no doubt that the time and energy to build a mold, or fabricate aluminum, and make the body itself will exceed the cost of purchase - at least at first. Assuming I keep this chassis for the long term, the initial investment will be captured over time. But I got into FV becasue I want to learn to do things, not just "buy my way" A second reason is that I'd like for my son and I to be able to start part-time, probably never profitable but you never know, racing related business, The learning is part of that.

So, with that out of the way, son, son-in-law, and I were talking about this yesterday. When they learned that aluminum was allowed under the rules, they both got real hot on the idea of fabricating an aluminum body. Since I'm not personally aware of any Vee's or First's running aluminum bodies, I figure there must be a reason.

So, I specifically interested in thougts, opinions, pros and cons of an aluminum body.

As for the foolishness of trying to frabricate our own (outof whatever material) - I understand that part already.

Thanks

Bob

[smsazzy]

There are several cars I have seen with aluminum bodies. I would recommend reaching out to Brian Harding (you know the monster mannies guy) as he has a LOT of experience with aluminum bodies. He has built several of his own cars and has always had an aluminum body I believe.

I have also seen a Vixen vintage car with an aluminum body.

I am a composite kind of guy myself, but aluminum is not a bad idea, just a pain to make it the shape you want compared to composite materials.

[rstackjd]

There are several cars I have seen with aluminum bodies. I would recommend reaching out to Brian Harding (you know the monster mannies guy) as he has a LOT of experience with aluminum bodies. He has built several of his own cars and has always had an aluminum body I believe.

I have also seen a Vixen vintage car with an aluminum body.

I am a composite kind of guy myself, but aluminum is not a bad idea, just a pain to make it the shape you want compared to composite materials.

Thanks - we'll definately talk to Brian. Have to see if I can find some pics of their cars too.

As for the actual fabrication - one the reasons son-in-law is excited about doing aluminum is that he hasan english wheel and has done a fair amount of cycle fabrication (tanks, fenders etc.) so from his standpoint this is a no brainer. From mine however, will take all the brains I have and then some! lol

[FV80]

Bob,
Having built several aluminum bodies over the years, I can add a bit of personal experience to this thread.
Aluminum is light, but it generally takes SEVERAL pieces to cover the frame adequately. I built as much as possible in flat (more or less) sheets that could STAY on the frame for the most part. The nose was relatively simple (though complex) since I could design a nose using flat pieces. The rear section, however, was the killer. Trying to make that piece into the compound shapes it really needs to work correctly, was pretty much impossible for me. Your SIL, with his english wheel, MIGHT be able to come up with the answer on that - but it won't be easy.

Another drawback to AL is that it doesn't handle the vibration very well and tends to crack unless tied down really well. You'll end up with pieces that are heavier than the equivalent fiber glass pieces and the fiber glass handles the vibration MUCH better. You can also repair fiber glass at the track pretty easily, while AL must be hammered out (I've done it a LOT of times <g>), or replaced.

On the other hand, it could take considerably less time to build than going through the process of creating a mold and drawing out your first piece of fiber glass. Depending on where you can source AL, it might also be cheaper. A LONG long time ago, I ended up with a car that was AL from the nose to the roll bar and had a fiber glass rear cover. It did pretty well at the Runoffs.

GO FOR IT
Steve

[rstackjd]

Thanks Steve and everyone else - it's nice to hear that it's not hare-brained idea after.

As I said, we're looking at the options right now and trying to learn as much as possible about the pros and cons of each. No matter which way we go I know there will be a huge learning curve, but hey, what else is there to do in Wisconsin in the wintertime any hey?

[vreihen]

How about having your SIL punch out the aluminum bits, and then use them to pull a mold for some composite panels?

Since you are interested in learning and Wisconsin winter is coming, might I suggest a good book for you? "Competition Car Composites" by Simon McBeath. He covers composite work from making a fiberglass plate all the way up to using pre-preg carbon fiber and an autoclave, mostly from the perspective of a backyard race car fabricator.

There is a quick & dirty composite construction method that doesn't require fabricating plugs and molds. It's called "cut & fold." You basically lay out a composite sandwich panel on a flat surface, cut slots in one side wherever you need to make a bend, and then use a heat gun and some muscle to fold the flat sheet into a compound shape. Here's a picture of Lehigh University building an FSAE monocoque chassis using this technique, using carbon-fiber skins on top of a styrofoam-type core:

[ external image ]

I don't know if bodywork constructed like this is legal under GCR (the monocoque certainly isn't legal in FV!), but I'm thinking that you could punch out some ultra-light bodywork using 1/8" foam core sandwiched in Kevlar. I've seen the technique used with aluminum skins over aluminum honeycomb in a book about building British hillclimb cars, and believe that Lotus used this technique to make their early composite chassis for F1. Unfortunately, McBeath's book above doesn't mention this technique, although it does cover sandwich core construction.

Before you think that I'm preaching composites, let me add that my Solo Vee currently has bodywork that I punched out of some 6062 aluminum sheet metal. I'm not a metalworker and don't have the tools, so I won't post a picture of my results. Despite the copious use of sheet metal screws and rivets, it still sounds like you're sitting inside a rattly tin box whenever the engine is running. If I knew about composites and "cut & fold" when I punched out the aluminum bodywork, I would have had a body that looked much better and took less time to build.....

[CitationFV21]

You can also find fiberglass sheets in roofing material stores:

for example:

http://ddfiberglass.com/flat-fiberglass ... rolls.html

You can get this in solid white, (or maybe other colors?)

I have a 4 x 8 roll which I have used for various products. I have to look at the "cut and fold" technique and see if it will work with this panel.

You can always go back and add thickness to it for strength.

ChrisZ