Rust inside the steel frame
Discussion
Last time the car was on the lifting ramp, we noticed something tearing at the back of the steel frame.
Turned out the drops came from the inside, and the tubes at the very back are corroded heavily...
Looks like some odd fluid was catched in there.
I have no idea how it came in,
and how it can eat up the steel in less than 3 years...
I have no idea if the segments and tubes of the frame are closed and if it's just the back that's affected.
I will check the rest of the chassis in december with a probe etc.
Anyone had a similar problem before?
Or do you have an explanation?
Unfortunately I missed to take some photos while it was on the ramp,
but here are some shots to give you an idea:
Left side:
More problematic right side:
Turned out the drops came from the inside, and the tubes at the very back are corroded heavily...
Looks like some odd fluid was catched in there.
I have no idea how it came in,
and how it can eat up the steel in less than 3 years...
I have no idea if the segments and tubes of the frame are closed and if it's just the back that's affected.
I will check the rest of the chassis in december with a probe etc.
Anyone had a similar problem before?
Or do you have an explanation?
Unfortunately I missed to take some photos while it was on the ramp,
but here are some shots to give you an idea:
Left side:
More problematic right side:
Did you build the car? If so, did you waxoyl the chassis tubes after you'd drilled for rivets? If not, water can get in and with nowhere to go, can corrode the tubes (it's steel after all).
The rear chassis tubes are closed at the ends, so once the water is in - it's in. That said, bizarrely the corrosion seems to have taken place in an area of chassis that's not drilled for rivets - unless it's run back there from the front rails (lots of holes in the mid section) and got stuck?
This looks like it's the rearmost lower rail member, so it's integrity is important (as is that of the entire chassis of course!) to the rear clip. Definitely a good idea to checek the rest of the chassis out in this regard.
The rear chassis tubes are closed at the ends, so once the water is in - it's in. That said, bizarrely the corrosion seems to have taken place in an area of chassis that's not drilled for rivets - unless it's run back there from the front rails (lots of holes in the mid section) and got stuck?
This looks like it's the rearmost lower rail member, so it's integrity is important (as is that of the entire chassis of course!) to the rear clip. Definitely a good idea to checek the rest of the chassis out in this regard.
Edited by Stig on Tuesday 13th November 14:46
GTRCLIVE said:
I wounder if that part of the chassis got scratched badly at some point and you didn't realize. That left uncovered might have roted though maybe....
it is possible that the steel had condensation build up inside the tubes at time of manufacture which rotted from the inside out... it certainly looks to have rotted fom the inside out and not the other way to me..just be thankful its not a mercedes or there wouldnt be anything left...
GTRCLIVE said:
I wounder if that part of the chassis got scratched badly at some point and you didn't realize. That left uncovered might have roted though maybe....
No, the outside was just fine, until we took a screwdriver and knocked of some bits to increase the hole...That's the thing I don't understand.
On the first look I don't see any way for water to get into that tube.
Especially if the tubes are closed.
And why on the back of the car. It's not the lowest point of the chassis.
The fluid that was leaking reminded us of accumulator acid.
I didn't build the car myself. No idea about the rivets, but there are no rivets at that end of the car.
I will take a closer look tomorrow. Maybe I can spot some holes, bracktes or mounts that could let some water in.
That is some serious rusting in just 3 years, Iv been doing some repainting in the same area on my car which is a 2006 model,only stone chips and a bit of surface rusting where the metal was exposed. It would surely take more than 3 years to rust through like that even if water was trapped in there?
Hope you find the cause of this and are able to remedy without too much trouble
Karl.
Hope you find the cause of this and are able to remedy without too much trouble
Karl.
Mr.Snood said:
No, the outside was just fine, until we took a screwdriver and knocked of some bits to increase the hole...
That's the thing I don't understand.
On the first look I don't see any way for water to get into that tube.
Especially if the tubes are closed.
And why on the back of the car. It's not the lowest point of the chassis.
The fluid that was leaking reminded us of accumulator acid.
I didn't build the car myself. No idea about the rivets, but there are no rivets at that end of the car.
I will take a closer look tomorrow. Maybe I can spot some holes, bracktes or mounts that could let some water in.
That is totally unacceptable and very scary. Perhaps too late but trying to get some of the inside gunk/liquid/corrosion on a swab and getting that analysed in a laboratory could give you some explanation and insight to what is causing the corrosion. Certainly a ring to the Factory to explain this "disaster" is in order (if they are not already reading his thread...)That's the thing I don't understand.
On the first look I don't see any way for water to get into that tube.
Especially if the tubes are closed.
And why on the back of the car. It's not the lowest point of the chassis.
The fluid that was leaking reminded us of accumulator acid.
I didn't build the car myself. No idea about the rivets, but there are no rivets at that end of the car.
I will take a closer look tomorrow. Maybe I can spot some holes, bracktes or mounts that could let some water in.
Talked to two different persons today and both gave me the same answer.
Looks like water came into the tube,
and it mixed with the exhaust fumes resulting in acid sulphur.
No idea what that hole is meant for, but that's one way for the water to come in:
Not sure about the transmission mount too:
So far it looks like four pipes are affected.
I will take the car to the mechanic today, and let him fix these 4 pipes.
Looks like water came into the tube,
and it mixed with the exhaust fumes resulting in acid sulphur.
No idea what that hole is meant for, but that's one way for the water to come in:
Not sure about the transmission mount too:
So far it looks like four pipes are affected.
I will take the car to the mechanic today, and let him fix these 4 pipes.
That's a strange gear box mount. It's not the same as my factory supplied mount. Shouldn't there be a rubber bush either between 'box and bracket, or bracket and chassis? Did you remove the nuts securing the bracket? If those bolts are not welded to the chassis, water could easily enter the tube below, especially if those nuts are missing!
(My Scamp kit car has a galvanized chassis which will last forever. I did ask Ted if he had ever considered this, but he thought it would probably cause the chassis to distort, and for you power to weight ratio fanatics, would probably add half a second to your 0-60 time!)
(My Scamp kit car has a galvanized chassis which will last forever. I did ask Ted if he had ever considered this, but he thought it would probably cause the chassis to distort, and for you power to weight ratio fanatics, would probably add half a second to your 0-60 time!)
Edited by GTRMikie on Wednesday 14th November 16:05
Edited by GTRMikie on Wednesday 14th November 16:09
GTRMikie said:
That's a strange gear box mount. It's not the same as my factory supplied mount. Shouldn't there be a rubber bush either between 'box and bracket, or bracket and chassis? Did you remove the nuts securing the bracket? If those bolts are not welded to the chassis, water could easily enter the tube below, especially if those nuts are missing!
The gearbox must be sitting a lot higher than in a normal build (assuming G50 of some description). Interesting!I doubt this is the cause of water ingress though. More likely the hole that was identified above.
andygtt said:
Looks like the tube has been filled with water... You need to find out why or it will happen again... If there is an underside panel make sure there are holes in it so water can drain away otherwise this maybe catching water and allowing the tube to fill.
Scary stuff though for sure.
It's still odd - you would think it would drain to the front as previously mentioned. Maybe it was damaged in that area?Scary stuff though for sure.
I don't have my car nearby, but isn't the rearmost crossmember (the one with the small hole and the screws for the gearbox mount) sealed from the tube that is rusty? If so, it would seem unlikely that water would seep into the other tubes from those holes.
Maybe the tubes were already rusty or had some unfinished welds that allowed cleaning fluid in before the powder-coating? That is assuming the chassis are cleaned before coating. A steam cleaner can find the smallest of cracks. Then the water would be held in by the powder-coating.
Also the tubes may have been already rusty inside, but I can't imagine that they would rust much more once sealed in with the welding.
When I cut my two upper rear crossmembers out (2 years ago), the tubes weren't rusty at all, and my car has been sitting around (admittedly in the dry) since 1999.
Whatever the reason, it's important that we find out, for all our sakes.
Maybe the factory should offer free ultrasonic chassis thickness testing?
Maybe the tubes were already rusty or had some unfinished welds that allowed cleaning fluid in before the powder-coating? That is assuming the chassis are cleaned before coating. A steam cleaner can find the smallest of cracks. Then the water would be held in by the powder-coating.
Also the tubes may have been already rusty inside, but I can't imagine that they would rust much more once sealed in with the welding.
When I cut my two upper rear crossmembers out (2 years ago), the tubes weren't rusty at all, and my car has been sitting around (admittedly in the dry) since 1999.
Whatever the reason, it's important that we find out, for all our sakes.
Maybe the factory should offer free ultrasonic chassis thickness testing?
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