Battery Holder From Dilated PVC Hose? Answered
I'm trying to widen about 1 foot of PVC hose. Ie. I want to dilate the interior diameter so 4 AA batteries will fit inside end to end. I'm trying to make a battery holder for my helmet light. The PVC hose is like siphon tube and I want to use it as a battery holder but it's a little too narrow.
I tried heating the hose up with steam and jamming a lubricated metal pipe inside. This worked for a few inches but then there was too much friction. I also tried a smaller metal pipe along with a chopstick but I ended up puncturing the hose.
So the question is:
What is a good way of getting this segment of siphon hose a little bit wider?
Or what else would be a nice waterproof and discreet battery holder for a helmet?