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Why is the tub aluminum so soft? :(

3K views 15 replies 9 participants last post by  Sunnie 
#1 ·
Installed a racing seat and rails. I was quite careful during installation when maneuvering the seat into position. If the rail or seat contacted something, I made sure to stop and try to find a new approach position instead of forcing it in. Nonetheless, I still discovered a nick on the side of my tub next to the seat. I know it's really no big deal, that this stuff happens, and the car is going to end up with some wear, but I can feel the nick with my finger and my OCD is going crazy at this. It's really my OCD that's the cause of this, but I'm really surprised how soft the tub aluminum is. There was barely any contact; just a rail resting on the aluminum before being lifted off, but yet that still left a nick.
 
#2 ·
There is a technique for working on aluminum structures...aviation technicians go to school (or OJT) for several years to learn them. You're just venting your frustrations for not knowing those techniques...

BTW...the pan in our cars is made from recycled aluminum...that is even softer than the side sills.
 
#3 ·
Did you reuse the stock bolts to reinstall the rails/seats? If so, consider just how soft the material is that's holding the seats (and you!) to the car :/

Sector's system using the reinforcement plates, or something similar, is a very very good idea.
 
#6 ·
6061T6 is a terrible material to fold up like the Lotus chassis. It would crack at all the sharp bends. It is probably a 5000 series alloy like 5052 or 5054. 5052 and 5054 alloys are designed to be bent. They age hardens to achieve their final strength. Monocoque (sp?) tubs in this country are made from these alloys.

John
 
#7 · (Edited)
Yeah I am just venting with this thread. I knew aluminum is quite soft (done a lot of work with it), which is why I was being quite careful to make sure no heavy contact ensued. It's actually a little baffling that I left a nick since I also had a towel draped over the sill. However, it's happened now and there's nothing I can do about it. Honestly the nick is quite small and I think for a lot of people, it isn't a big deal. But like I said, it just bothers me because I'm OCD.

As for the Lotus chassis, I don't think it's ever folded. The parts are extruded and then bonded together. 6061T6 is a common extrusion material.
 
#10 ·
I feel your pain with every little scratch I notice.

The first one was a scratch on the passenger side sill. I accused my wife of having done it (by accident) with either her shoe or her purse. She was annoyed that I accused her.

Now I have a look at my passenger's shoes before they get in the car. If there are any metal bits I ask them to be careful.

I'd like to think that I'm not OCD but I guess I just proved that I am.:facepalm
 
#15 ·
Yeah I blamed my wife for a scratch as well. She claimed her 3 inch heels had nothing to do with it....

Good to know about the Scotch Brite. We use this at work on super duplex.
 
#16 ·
I had a local metallurgist run a sample of the floor sheet material for me a few years ago. Dwight Laboratories....ex/retired Boing employee's started there own company. I purchased an Elise with a gash in the floor board. Sample came back as 5052. And while the car was there off the record I asked about the extrusions. There best guess was 7075 without running a sample.

And after that it sorta took the magic out of it for me....
 
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