Re: Spinlock rigid vang and am having difficulty with the lock/release switch.
I've had the same issues with mine.. have had it apart several times and there's no apparent reason why it should be so difficult.
The literature says to make sure the internal tackle is tensioned before trying to release/engage the switch, but that doesn't always work for me either.
Once the main is up it's not usually a problem to release the vang before you sheet the main in. I try to put it in the 'half way' position - it releases the ratchet support, frees it to 'vang' function but is easier to put back into 'latch/support' position later.
When all else fails, when we drop the main my wife holds the boom up until the first third of the sail drops, then she drops the boom until the vang itself forces the switch back to the latch position, then push the boom up and it 'clicks' into place. This may call for pushing the boom outside the dodger to get sufficient 'drop'. Do this gently, btw.. the switch is just a plastic bit, we've had to replace ours after breaking it once.
There's already a powerful internal tackle, we have a 2:1 on the outside of the vang as well - seems adequate.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)