what's a hairline crack? and do I have one!?

jim m

Devout Dirtbag
Hi there,

I'm stripping an Ellsworth Joker, and once I'd got to the bare aluminium of the rear triangle, I have found a very tiny line about 3-4mm long, running along the inside edge of a weld. It doesn't look very deep and it isn't a rip, it's just a short line, less than a hair's breadth, in the slight discolouration caused by the welding process.

I'll try to post a photo, but it's hard to see unless you're v close and the light's good.

Obviously I'd be gutted if this was structural damage. It's on the inside of the dropout area, and I would have thought that the top edge would be where any crack caused by hard riding would occur.

Am I clutching at straws, or is it possible to have a minor (and it is v. minor) issue like this occurring naturally through the welding process?

If it is a structural issue, is there anything I can do about it?

cheers, Jim
 
Very difficult to say without pictures,apply some pressure to it and see if it alters in appearance.
 
spudgun":3h91egq6 said:
Very difficult to say without pictures,apply some pressure to it and see if it alters in appearance.
As above. And mark the ends of it with a permenant pen, reide a bit more and see if it crows at all. Any luck its some sort of scratch. . . :?
 
Cracks can occur from the welding process but that doesnt mean there ok / or aceptable :(

A weld is a naturel stress raiser due to the change in crossection and the change of material properities in and around the heat zone - most cracks in a fabricated component will propogate from a weld bead :( Some stressed components that have gussets will have the weld extended farther than the gusset so the end of the weld is remote from the gusset in an atempt to move the stress concentration to another area.

Having said that post some pictures up so we can be sure - or take your frame to a local 'aero' welder and ask them for there opinion or to dye check it or similar.

Dont panic yet - what is the intended use for the frame ? It might have a lot of life left in it yet :D

WD :D
 
With the terms 'Ellsworth' and 'potential hairline crack' in the same post, all in the form of a question...I'd say the answer is yes. You should have the crack checked by somebody truly qualified to evaluate it...I'd consider sending the swingarm to Ellsworth.
 
Get a good scope/magnifier and a flashlight and see if you can see any separation or depth to it. If not, it might just be some overlap.

I would also contact Ellsworth for thier take on the situation.

Good Luck,
Terry
 
Have a look on the Rocol web site under products - go to flaw finder. The three tins contain a cleaner, a penetrant and a developer easy to use and will show if you have a crack or not. Available from welding suppliers and not expensive. Eliminates the guess work. ;)
 
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