A quick wee post that might be of some use to you……………
Ben’s extending salmon net was stuck fast, no amount of pulling would free it so I volunteered to try and fix it for him. I was confident I could do it as I have done the same before with my own nets over the years.

I took the net home and used clamps to move the collar up to the end of the shank. The expansion bolt was unscrewed and kept safe before forcing the frame off the shank. As suspected, the soft insert in the collar had deformed and was in need of re-profiling with a fine file. The temptation is always to take off too much so care is required and some restraint with the file. just smooth off any ridges and try to get back to the square shape. Offer up the frame to the shank again – it should just go on but still be tight. Now for the magic.

Apply a very light coating of olive oil to the shank.I never use any other oil release agents like WD-40. And don’t try to put on too much oil, it will only cover anything it comes in contact with and attarct dirt.

Put it all back together and you are done. To maintain smooth operation simply apply a fine coat of olive oil once or twice a year or when there is the first sign of sticking.