If you are using thick wall tube just put the O ring groves in the tube.
You could even swage an O ring grove in the tubes and not cut. You would
still need a sholder for the tubes to butt against in the manifold and
something to tie the upper manifold to the lower manifold on both sides.
Glenn
"Charles A. Sherwood" wrote in message
...

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