Looked Inside My Frame yesterday...
11-06-2014, 11:56 AM
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St. Jude Donor '13
Looked Inside My Frame yesterday...
Our 2009 now has 77k miles and gets driven in rain, well, whenever it happens to be raining. We take it through the snow and salt once per year to Florida some time during the winter and come back after the salt is gone. Usually, I cover the shipping slots with duct tape for the trip down but forgot one year. Upon arrival in the Sunshine State, I wash the heck out of everything including underneath, then remove the tape. Then try to find a big rainstorm and drive around in that for an hour.
The plastic parts are doing just fine, the aluminum has some whiteish "pickling" that looks the same as any Corvette driven in the rain. A few small steel nuts & bolts are rusting, I try to paint or replace them when I see it happening.
The exterior of the frame is rust-free except for a few small chips in the paint, which I touch up every year. And the rear cross-piece, back by the bumper, where the paint is so thin it's started to rust even though the paint is undamaged.
Thinking about the rust on that rear piece from too-thin paint, I wondered what was happening inside the frame. I was able to borrow a cheap borescope and look in through all four shipping slots, both directions. I couldn't get enough bend in the scope to look at the bottom of the insides, bur was able to see the sides and top pretty well.
I saw a moderate amount of grit/sand/dust clinging to the inside top and sides, might even be salt but I doubt it. The black paint looks intact and I could find no evidence of rust.
Good news for those who don't live in the desert but want to keep their C6 for a long time.
BTW, we drove our C5 through five Chicago winters as a DD, using the now-discontinued Goodyear winter runflats, real knobbies for snow. I never looked inside the frame, but everything else top and undersides, looked about like any other Corvette when we traded the car at 66k miles.
The plastic parts are doing just fine, the aluminum has some whiteish "pickling" that looks the same as any Corvette driven in the rain. A few small steel nuts & bolts are rusting, I try to paint or replace them when I see it happening.
The exterior of the frame is rust-free except for a few small chips in the paint, which I touch up every year. And the rear cross-piece, back by the bumper, where the paint is so thin it's started to rust even though the paint is undamaged.
Thinking about the rust on that rear piece from too-thin paint, I wondered what was happening inside the frame. I was able to borrow a cheap borescope and look in through all four shipping slots, both directions. I couldn't get enough bend in the scope to look at the bottom of the insides, bur was able to see the sides and top pretty well.
I saw a moderate amount of grit/sand/dust clinging to the inside top and sides, might even be salt but I doubt it. The black paint looks intact and I could find no evidence of rust.
Good news for those who don't live in the desert but want to keep their C6 for a long time.
BTW, we drove our C5 through five Chicago winters as a DD, using the now-discontinued Goodyear winter runflats, real knobbies for snow. I never looked inside the frame, but everything else top and undersides, looked about like any other Corvette when we traded the car at 66k miles.
11-06-2014, 12:47 PM
#2
Melting Slicks
My Red is a 2007 DD with just over 83K miles. I drive it year around -- I'll be putting on the winter wheels & tires (Pirelli Sottozeros) this weekend. Here in StLouis we normally don't get quite as much snow as you do in Chicago, but last year we got 27 inches which was PLENTY. I'm very pleased with how corrosion free everything is both on top and underneath. I've never had a car last this long without any significant rust on the steel parts at all. Love it.
11-06-2014, 01:56 PM
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As long as sand and dirt aren't caked inside the frame everything should be fine. It is difficult for air to dry the inside once the wet weather has stopped and if dirt is piled/caked inside the frame it can remain wet for months. If a little salt is mixed in you have a perfect recipe for rust. The frame on my C3 rotted out and when I cut the end open I found wet sand several inches thick at the rear of the frame right where the rust was occurring.
Bill
Bill
03-30-2016, 06:10 PM
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St. Jude Donor '13
(My apology for reviving an old thread, but here's an update)
Recently I bought a cheap Amazon "endoscopic" camera with LED light that plugs into a USB port on my laptop. Only one port will work with the old-tech camera, but it works well once I got someone to load the software and explain it.
The camera is about the diameter of a cigarette and 2"-3" long, so it easily fit into the shipping slots in my frame. The wire is very flexible, so I straightened a coat hanger and taped the camera to it. That allowed me to get about 32" fore and aft of each shipping slot. Depth of field is rather limited and orientation is rather difficult to control; but I'm just looking for rust or damage and not trying to read the fine print.
I was able to fully inspect the frame interior between the shipping slots, and go fore/aft enough to see part way through the upward frame curves.
Results:
It looks like GM did a very good job of rust-proofing the frame interior with their "dunk tank" method. I found one very small spot of rust inside the driver side rear, like the paint had flaked off a small section of weld. No other rust or damage visible.
The upper surface of the interior is lightly speckled with something light-colored, the sides somewhat more so, and the bottom is 25%-50% covered with a thin layer of the same. I stuck an air nozzle up in there and tried blowing, the "dust" did not move. It could be salt from the past but the car has been driven frequently in rain for the last year/15k miles, I think any salt would have been washed away by now. And it would mean GM used some really amazing paint to keep the actual steel protected and uncorroded after 7 years/90k miles. Even around the reinforcement joints hidden "inside" the shipping slots, there is no evidence of paint coming loose or rust.
Summary:
It looks like frame rust will not be a factor in how long I keep this car, the frame will probably last longer than I will. Good news for those who like their C6.
Recently I bought a cheap Amazon "endoscopic" camera with LED light that plugs into a USB port on my laptop. Only one port will work with the old-tech camera, but it works well once I got someone to load the software and explain it.
The camera is about the diameter of a cigarette and 2"-3" long, so it easily fit into the shipping slots in my frame. The wire is very flexible, so I straightened a coat hanger and taped the camera to it. That allowed me to get about 32" fore and aft of each shipping slot. Depth of field is rather limited and orientation is rather difficult to control; but I'm just looking for rust or damage and not trying to read the fine print.
I was able to fully inspect the frame interior between the shipping slots, and go fore/aft enough to see part way through the upward frame curves.
Results:
It looks like GM did a very good job of rust-proofing the frame interior with their "dunk tank" method. I found one very small spot of rust inside the driver side rear, like the paint had flaked off a small section of weld. No other rust or damage visible.
The upper surface of the interior is lightly speckled with something light-colored, the sides somewhat more so, and the bottom is 25%-50% covered with a thin layer of the same. I stuck an air nozzle up in there and tried blowing, the "dust" did not move. It could be salt from the past but the car has been driven frequently in rain for the last year/15k miles, I think any salt would have been washed away by now. And it would mean GM used some really amazing paint to keep the actual steel protected and uncorroded after 7 years/90k miles. Even around the reinforcement joints hidden "inside" the shipping slots, there is no evidence of paint coming loose or rust.
Summary:
It looks like frame rust will not be a factor in how long I keep this car, the frame will probably last longer than I will. Good news for those who like their C6.
Last edited by Gearhead Jim; 03-30-2016 at 06:18 PM.
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03-30-2016, 08:27 PM
#7
