One of the carbon fiber struts on my North Face Patrol has broken and North Face is being stinky about fixing it. I'd like to try my hand at forming two new struts out of t6061 aluminium bar stock. Does anyone have any suggestions, including alternative materials? I have a well-equipped shop and a good assortment of tools with which to work. I also have a master welder who can help if needed.
What are the dimensions of the carbon fiber you are replacing? or... are they fiberglass? I think I created a spreadsheet one time for someone looking to match the stiffness between different materials for backpack struts.
6061 tube would be good. I would think bar stock would either be too bendy or too heavy. You could get some carbon fiber tubes:
Loc: Eastern MA, USA
Have you considered trying to repair the broken struts. I ask because hubby successfully repaired my carbon fiver hiking pole. I have serious difficulty finding the broken spot, even telling which pole was broken. It totally snapped and splintered when I fell on it as it was held above a downed tree and large rock. My opposite leg was skinned up pretty well, but it was the ruined pole that had me close to tears. We were able to find a broken carbon fiber arrow shaft that was a close fit to the pole's inner diameter, inserted a section then used a form of 5 minute epoxy as a filler/glue, smoothing as the repair was accomplished. Send me a PM if you want to get into more detail via phone.
Loc: Kitsap Peninsula, WA
I am considering wood dowel. Just an experiment, but they would be lighter. If they broke they could be repaired with duct tape. Contour isn't too important to me; my back seems not to mind much of anything. I went for a walk in the woods yesterday with no stays and 23 lbs. and the pack felt fine to me.