Where to draw the line between bodywork and weight reduction?!

So, while I have my windshield out and have to re-do my hood I decided I might as well tackle the rust spots on the car and give it a paint (the interior is stripped). This is especially convenient because there was this little spot right under the bottom of the windscreen, completely rusted and impossible to get to. Until now.

So, here I am, cutting squares out where there is rust to weld in new sheet (I'm new to this but I think that's how its done), and I'm thinking... "why"?! Why am I doing all this work to add weight to the car? I know its hardly anything... but it just seems counterproductive. In some of the parts, you won't even see it! For example, under the bottom part of the windshield. Yes, its structural, but its basically an enclosed beam, so a relatively small rectangle cut out of one side isn't going to do anything wrong, and the trim for the bottom of the windshield covers it, so it's impossible to see. But then again, I don't want to be ghetto either.

There are some parts that definately need a little extra metal to look good, but I'm leaning on not filling these discrete areas.. what do you guys think?

honestly, I doubt the body itself adds that much weight. With the engine, transmission, interior, and electrical out of my fiat spider.. I can almost pick up the front of the car. I know when I moved it last, I discovered that it had a locked wheel.. because I was pushing the car by hand and it was dragging that wheel.

I would do it right so you do not have to worry about it later. If you can find a place to safely remove sheet metal, by all means, do it, but nothing structural

mad_machine wrote: I would do it right so you do not have to worry about it later. If you can find a place to safely remove sheet metal, by all means, do it, but nothing structural

Agreed. Now is the perfect time to do this type of work.

having a hole isnt going to give a place for water to sneak somewhere into your cars frame causing additional rust is it?

I can pick up the front of a Miata that's been stripped of everything but suspension - but that doesn't mean there isn't significant weight present. I don't think it's possible to get a streetable Miata below 1850 lbs and even then you're going to be making some sacrifices. Meanwhile, my Locost - with the same drivetrain - comes in at 1300 lbs. What's the difference? The body.

Where to draw the line? Well, weatherproofing would be a good test to use. Do you care? If not, then there's a bunch of metal that can be disappeared.

Your talking about rust spots and holes. What is small today will be big tomorrow and will be falling off by next week. Rust that a piece of trim will cover today won't cover it for long. Also think about what caused the rust to begin with. Mostly rust is caused by moisture sitting or being traped somewhere. Cutting out a rust area, welding in a patch then blending it (doing it right)doesn't add nearly the weight as just slapping some bondo over the hole (doing it wrong).

Like GlennS said, if you leave one spot open where will the water go and what else will it effect? It sounds like your doing it right now by welding in new metal. Keep it up and your car will last much, much longer and you won't be doing the same fix next year.

nickel_dime wrote: Your talking about rust spots and holes. What is small today will be big tomorrow and will be falling off by next week.

SWEET! Active weight reduction! Why haven't the japanese thought of this? Well, except for Honda .