1st Garboard Attempt: A Complete Cluster

This was the biggest cluster I have engaged in since rudders.  First off, I trimmed and sanded the 3rd plank, so far so good. Picture below.

But when I went to put on the garboard (with wet glue, by the way) after pushing very hard, I ran out of garboard at the chine (aft end). Basically where I thought I would have garboard over-hanging the chine to trim later. I had hull frame not covered by the garboard plank. I did test fit this and it was fine. That said, when I test fit it I allowed the garboard to spring away from the boat over the bow plank (because there is no obvious way to clamp this down). When I tried it for score I had this area screwed down and there was no way to pull the garboard back to cover the frame properly.  I briefly put on a  piece of scrap over the open space, but this seemed like a poor solution. Also I still had a pretty big gap at the transition joint. I could see right through the joint to the inside of the boat. I think this was because I was pulling back on the plank to try to get it to cover the hull frame.  So I pulled everything off and tried to clean up as much of the epoxy mess as I could to save sanding work later.

So after thinking about this for awhile, I figure that I need to cut the relief on the garboard plank for the bow plank much deeper. The problem is that I'm not sure how to tell how deep it needs to be cut (I'm going to sleep on that one, perhaps I can math my way out of it).  The other thing that needs to be addressed is the excessive amount of force I'm using to intimidate this poor piece of plywood into submission. I'm thinking I might try cutting slits lengthwise in the garboard plank to relieve some of shear stresses that the bend is inducing in the material. My suspicion is that the plywood will gladly bend, but is very resistant to shear loads of the kind I'm inducing with this twist. I will start the slits with the Fein tool, but complete them with the jig saw since the jigsaw blade is thinner. And it is easier to control the jigsaw freehand than the Fein.

This is getting detailed. I'll see if I can come up with a succinct way to convey as I go.  I am disappointed that I cannot report a successful garboard installation. But I am learning a lot about how to do this in a very hands on way, which is gratifying enough to keep me coming back for more.