Welding on light steel sheeting can result in warping and buckling if the sheet is not pulled snugly into place before a weld is made.
Some tools will need making before installing the steel sheeting on the boat. You will need to cut 25 or more 4" to 6" long steel wedges from the stringer material. There will be some already cut, from when you spliced the stringers. However, you will find you can't have too many wedges.
Next, you will need to cut several dozen yokes from angle iron. The angle iron size is determined by two times the stringer width, minus 3/8 to 1/2 inch. (See "Sheeting Tools") Cut strips 5/8" wide and bend the ends to within a 1 1/4" to a 1" of each other. These yokes will fit over the stringer and tack weld to the sheeting. The wedge is driven through the eye of the yoke to pull the sheet tight to the stringer. Snug down the complete sheet before tack welding it in place. Sheeting Tools
When fitting the sheets to the hull, you will want to use the natural curve of the sheet whenever possible. If you plan to cut patterns first, or cut and fit the sheets directly in place. Lay out the pattern, or hang the sheet in place, so the curve of the sheet fits to the curve of the hull. The sheet's curve can be determined by standing or hanging the sheet on or from its side.
When sheeting the hull, work from side to side, keeping the hull and hull stresses in balance. As you get 2 or 3 sheets tack welded on each side of the boat's bottom, you can begin to do some finish welding. However, weld from the center line of the boat outward, staying 1/3 of the distance in from the sides until the side sheeting is tack welded in place. The inside of the hull will require a lot of welding, with accumulated weld shrinkage. The more hull sheeting you have tacked in place, the less movement there will be during finish welding. Sheet the full length of the bottom before moving to the sides of the boat.
After the bottom is sheeted, you will want to recheck the rib alignment before installing the stringers on the next section. If all is well and the alignment looks good, you're ready to install the stringers and sheet the sides. If not, now is the time to fix it. It's almost impossible to do any realignment after the sheeting is in place.
By now, your welding and fabrication skills have improved to the point where you are able to get along on your own just fine. Follow your plans and think ahead. I hope this has been helpful in providing you with an understanding of the boat-hull building process.
The building of Trinity has been a fun and challenging adventure, even though there have been some setbacks over the years.
A goal not attempted is a goal never realized.