I simply bought more pump kits at the start, they're cheap enough and not easily cleaned. As yet I've not tried to replace the draw tubes mine came with.

(I did the same as you, starting with fast hardener for cooler conditions then transitioning to slow once things warmed up. But I had enough pumps to assign one to each bottle, no shifting required.)

It's entirely possible most local hardware stores carry polyethylene tubing with an ID that'd fit the pumps... but I need to measure (my guess is it's 3/16") then verify this before suggesting those reading this take my word for it.

Anyone planning this is strongly encouraged to label their pump heads appropriate to the component they've been used with. Confusing one for the other would be a disaster once they'd been reconfigured & repurposed! Do ONE pump at a time!

If there'd be an <edit> button I'd be editing my prior post right now... maybe contemplating an image-posting test or two as well... sigh....

MY 'spare' tube measures a nominal 5/16" OD at 0.316" on the end that came out of the pump's hub. Further down it's 0.322" so that hub compresses the tube a bit, which makes for a good seal.

0.0625" = 1/16" so what you want to look for is polyethylene tubing (be cloudy, stiffer than the more common clear PVC stuff) with an Outside Diameter of 5/16".

Chances are it'll come coiled in a box. It's pliable enough to be straightened but has a memory that'll retain said bend unless you subject it to a water bath at a temp near boiling for a few minutes, then let it cool while being held straight by some means.

Be careful not to pinch it when warm or it'll retain the distortion once cooled. For our purpose we want ends that are as round as possible and at the original specification's outside diameter.

My tubes came with the suction end cut to a bevel, which keeps a vacuum from forming if it's touching the bottom of the bottle. I'd cut replacements the same way: square at the pump end, beveled at the other.

Hope this helps you! If you can't find suitable tubing in a (real) hardware store you can buy it on-line (25' there for $0.21/ft) or just order more pumps I suppose. 

Thanks for this effort. I ended up purchasing additional pumps from CLC. Otherwise, I would have ended up with an extraordinary amount of tubing.

My pleasure. Sometimes the easy route's not as speedy a path.

We sell that tubing by the foot where I work (hardware store) so for myself a foot or two's the easy way.