Good god, what can I say - I'm finalising this post more than a year after I worked on the stringers part of the boat build. In hindsight, I can say this was the most nerve-racking stage for me as an amateur boat builder. I worked on stringers between August and October 2021.
This is the part of the boat build where you really need to take your time and not rush it. Once the stringers are epoxied on the frames, that's it - you have your boat shape, and you want it to be true to the plans and symmetrical.
I made a mistake with the first set of stringers I installed because I did not notch them into the frames enough. Thankfully a few experienced boatbuilders highlighted the problem for me and I was able to correct it early.
I recommend using a laser level if you can—even if you buy a cheap one online. A laser level on a tripod really helped me ensure that all the frames remained correctly aligned on the centreline while I was fitting the stringers.
Installing the stringers can be quite frustrating at times as nothing fits quite right naturally and your job is to make it fit. You may need to cut into the frames to, use wood rasps and other power tools to shave off timber at an angle that will make the stringers closely hug the frames and create a boat shape. The tools I used were: multitool with a variety of blades, hand saw, wood rasp... lots of swearing... some kind of magic or brute force.
You will need clamps, lots of clamps... there's never too many clamps. You will also need rope, quite a bit of it. The rope is very handy for this part as you can tie around the matching port and starboard stringers and, with a bit of cleverness, use the rope in a pulley system to bring the stringers in a very symmetrical fashion. This approach helped me keep the frames in alignment. If you're only trying to fit stringers on one side of the boat, you will find out that the forces of bending tend to shift frames out of alignment.
I started with the thin 30x22 stringers, as they are easiest to bend, followed by 50x22 strings on the chine line. With the bottom stringers, it was quite tricky to get them to sit nicely on the floor beams; you have to cut them down to a point where they join the bow knee. Lastly, I installed the 70x22 shearstrake (toerail) stringers.
