Seeing the light through a rim joint weld.
 

I was curious to anyones thoughts on this, whether its something to be concerned about (I'm guessing this will be a concern and I shouldn't be riding this rim, but maybe its not totally unheard of). Anyways, in a nutshell I've always used shimano stuff but recently I decided to do a whole gruppo conversion and will be running Campagnolo everything here on, which means unlacing a bunch of wheels and searching for Campagnolo hubs, so I'm going through my inventory of 700c hoops, got a 24 hole clincher campy omega rim which I received in a trade some time back from someone here, and would make a great front rim, only thing is where the rim is welded/joined I can spot a slight gap of separation, something like this would be quite hard to photograph so I'm not really able to provide photos, but im sure there has gotta be at least a few people here that has come across something like this at some point in history. Am I ******** for considering lacing this rim up and using it thinking it will hold up just fine, or am I asking for trouble in form of a rim failure at 60km/h?

I don't think the rims are welded at the joints. I think that there's just a metal insert that fits at the ends of the rim extrusion ends that is crimped on the inner side of the rim to retain it to bridge the seam.

Chombi

If in fact the rim was welded, I would not use it, however many rims were pinned at the joint and I have seen thin gaps at the joint of those rims. If the rim was welded you should see internal evidence of welding.
Cheers

I doubt Campy ever welded any of their rims. Gap big enough for a business card to slide in?
If not, I'd use it. Once you lace it up and apply proper tension it should be fine. IMO YMMV.

Pinned and not welded yes, wasn't clear on that. the gap is small, I wouldn't be able to slide a business card through it, basically on part of the brake surface on one side of the rim, and then an even slighter one at the very center at the very aero point of the rim. If i were to try snapping the rim with my hands I don't think I would be successful, I really don't want to try though and risk bending the rim a bit If it is infact good to use, as building the wheel with proper tension will be a headache!

I suspect, though I don't know, that a reason they are not welded is due to the adverse effect of welding (due to temperature) on the material properties.

I've got a set of Omega rims built up with what sounds like the exact same thing gap. I've ridden them with absolutely no problems.

Yes exactly. Many aluminum things(rims, aircraft, etc) are/were not welded because the aluminum has to be re heat treated following the weld process or else the stresses can be unfavorable. Newer industrial advancements have allowed bike companies to be able to do such processes, therefore current rims are welded.

No. Those Campy rims are pinned, not welded. Once the wheels are built, the pin is superfluous as it is the spokes that keep the wheel intact.