I am designing a radiator for a model engine.
Keep in mind that looks are more important than function.

The entire radiator (fins, tubes, manifold) will be made
from Stainless steel. The radiator will be about 5 inchs
square and 1/2 inch thick. There will be 4-5 tubes running
from top to bottom. I will press the 1/4 inch tubes through
60 pieces of .036 SS fins spaced about 40 thou apart.
I figure I will press the fins onto the tubes one at a time.

My problem is connecting the tubes to a manifold. Silver solder
might work but I'm not particularly good at it and I am very concerned
that the heat will tarnish the SS and I will not be able to polish
it after its assemebled. I am also concerned that 1250 degrees
will distort things and maybe cause problems.

I am wondering if I can use O rings to seal the tubes where they
enter the manifold. The manifold will be a square block of SS
drilled from the end for coolant passage and drilled from the side
for the tubes. The difficult part is cutting O-ring groves
for the 1/4 inch tubes.

First; Will this work? ie NOT leak. The cooling system will not
be pressurized but there will be some pressure from the circulating
pump.

Second; How do I cut internal O ring grooves so that it will
seal when a 1/4 inch SS tube is pushed though it.

I have a wide varity of metal working tools available. I can
cut the o ring grooves with a boring head on the mill or by
mounting the manifold on the lathe faceplate.

chuck