On 1/14/2012 8:12 PM, DougC wrote:

The tanks I can weld with aluminum filler rod.

The (aluminum) cores are dip-brazed together already, so I doubt that
corrosion is an issue with that.

I've been through four of these in about eight years, all different
brands, and they all failed the same way. The broad sides of the bigger
tank bulge out a bit, and then the seal leaks where the bulges are, and
there's no way to fix it. And it always leaks worst in the extreme cold:
15F~10F. Vehicle overheats & shuts down,,, cylinder heads warp....

So this is why I say, no more plastic. I want metal only. THICK metal.

One article online describes them building aluminum radiator tanks using
.080" aluminum and bending the sheet to avoid having to weld the two
longer seams. **** that, I will use .125" and weld all the seams. It
ain't that hard.

.....

I originally thought of cutting off the crimp tabs, and then making
screw-clamps that would go all the way around both sides of the core to
hold the plastic tanks on better. But after seeing how the leaks are
happening, I don't think this is worth trying. I would bet that the edge
of the plastic tanks would just break off if they were held harder to
the core seal. You'd have to keep those broad sides from bulging out
somehow, and the only ways I can see to maybe do that are more difficult
than just welding up some aluminum tanks.

I haven't decided if the aluminum tanks will clamp-on or if I will just
braze them on. I kinda like the idea of a replaceable core, but don't
know how standardized they are. Judging from the one I've cut apart and
the one still in the vehicle, the cores appear to be pretty close to
identical.

So what's the problem with plastic radiators?

Mine is 11-12 years old - 150+K miles.
Only been replaced twice...