Chassis tube wall thickness

[eng622]

What is the tube gauge SWG or in mil for the outrigger and sill tubes? I guess it would be useful to know the others as well.

[Uncle Fester]

Is there any way to measure metal wall thickness and condition?

I don't mean the traditional hammer test. X-ray would require equipment most people can't get hold of.

We really need some kind of scanner or meter based test. What is there that we could use? Even if it's something to hire, or a facility we could take a car to.

[adyw]

The eqipment you need is something called Ultrasonics.
Where I work we use a number of technics to test metal joints post welding. X Ray, Phases array and ultrasonics. What the untrasonics also does is to measure the thickness of the material the probe is on. It works by using sound waves from a probe through the metal. However I don't think it will work on circular tube. There maybe someone out there who knows more than me, but it's not the sort of kit you can hire.

[clive f]

chassis tube thickness`s are about 1mm, so if it looks badly pitted then it should be replaced, if you want the thickness measured you can look in the phone book for a local Non Destructive Testing laboratory, they could test it using ultra sonic testing, but for what that would cost ie, £75hr, you`d be better off judging for yourself!!

[AntonyJ]

clive f said:

chassis tube thickness`s are about 1mm, so if it looks badly pitted then it should be replaced, if you want the thickness measured you can look in the phone book for a local Non Destructive Testing laboratory, they could test it using ultra sonic testing, but for what that would cost ie, £75hr, you`d be better off judging for yourself!!

Just measured my old tubes (still in the boot of the Mondeo,cant decide whether to skip em or not! )
It measures about 1.8mm on the wall.

Ant

[eng622]

I was hoping they would be 1.6 mm or more. 16 SWG is 1.6 mm and 14 SWG is 2 mm. If they are 2mm when new that is quite thick and a 1.8 mm measurement (providing there were no burrs when measured)suggests the wall might be 2 mm thick. The reason I'm asking is I have de-rusted the outriggers and the most vunerable areas have rusted quite a lot. I've knocked off around 1.5 mm of rust but remembering that the volume of rust is 7 times the steel it replaces the corrosion is not that bad. There is some deep pitting but provided there is no rusting on the inside then there should be plenty of wall left.

[AntonyJ]

eng622 said:

I was hoping they would be 1.6 mm or more. 16 SWG is 1.6 mm and 14 SWG is 2 mm. If they are 2mm when new that is quite thick and a 1.8 mm measurement (providing there were no burrs when measured)suggests the wall might be 2 mm thick. The reason I'm asking is I have de-rusted the outriggers and the most vunerable areas have rusted quite a lot. I've knocked off around 1.5 mm of rust but remembering that the volume of rust is 7 times the steel it replaces the corrosion is not that bad. There is some deep pitting but provided there is no rusting on the inside then there should be plenty of wall left.

Sounds like the chassis is quite bad Eng, any pics?

[Carquake]

If TVR used the same wall thickness on the Griff as on the Taimar, they will be 1.6mm/16swg. Got to know my Taimar chassis very well, hope I never have the same experience with the Griff.

[eng622]

That's semi-bad news if they are 16 SWG (1.6 mm) but that does not surprise me as I bet only the rectangular main rails are 2 mm. I'm guessing I've lost 0.3 mm and more in the deeper pits. I don't have any pictures but what can you tell from them anyway, you can only guess from an estimate of the thickness of rust removed. There are some recent ones in another post and mine are similar in he worst areas shown but probably extend a bit further along the tubes.