Valved internal reflux cooling problem

[SideJob]

In theory a friend has an internal valved reflux still exactly as planned from homedistillation.com. It works great other than it does not have enough cooling ability. It has about 10' of 1/4" copper tubbing. Is there an easy way to bend 10' of 3/8 and put some 1/4" in the void in the center? In the spaces copper mouse guard could be placed. Has anyone has a similar problem? Any suggestions would be appriciated.

[SIXFOOTER]

I ran into the same thing when I built mine. I ended up making 2 coils, one inside the other and connected them together paralell with a piece of 3/8" in the midle as a Manifold and cold finger. It knocks down everything no problem

[ipee7ABV]

if i understand correctly you can add copper scrubbers betwen the coils for more knock down power

[SideJob]

Ended up makig a coil of 1/4 ID 15' then inside that 17' of 1/4 OD. Will fill the center with copper mouse guard. Have not done a test run.

[Vapour trails]

cold finger down the middle of the coil works well