Tuesday, June 19, 2007

More Hull Preparations for Sheathing

Although I turned the hull over for the first time last week, I forgot that I had to go back and make and install the reinforcing doubler plates that go on the inside of the upper topsides in the places where the crossbeams land and the shrouds attach. Since I'm laminating parts like this with temporary screws, it wouldn't do to glass the outside of the hull first, so this weekend I turned it back upright and installed these panels. Thanks to the fact that the hull is now suspended in rope slings, turning it to any angle in a 360 degree circle is easy to do singlehanded. I can't imagine building this boat without suspending it this way, but I had never seen this idea mentioned in boatbuilding books or articles until I saw it on Thomas Nielsen's Tiki 26 blog. Although the old jib sheets I'm using for slings are plenty strong, flat webbing is better so I ordered some 1" heavy duty straps with cam buckles from NRS and they just arrived yesterday, so when I get back to the shed later in the week I will swap out the slings.

I've spent much of the past week making lists of the supplies and materials I will need to finish this project, and shopping online for sources, organizing the time frames for when I'll need certain items, and spending some of the money I got from the sale of the Tiki 21. Keeping everything organized and staying stocked with materials and consumables on a project this size is a project in itself. I'm also researching options like making my own sails from Sailrite kits and looking at gear that will be needed later in the outfitting of the finished boat.

These are the shroud doubler plates that reinforce the hull panel where the shrouds attach to cleats on the outside of the sheer stringer. One minor departure from the plans here that I will take is to through bolt stainless steel chainplates to the topsides here rather than loop the shroud lanyards under a wooden cleat. I used this method on my Tiki 21 and it is also standard in the plans for the Tiki 30. The shrouds remain the same, but the lanyards pass through a shackle attached to the upper end of the chainplate, rather than under the cleat. This is a more secure system when raising and lowering the mast, since the lanyards can slip off the wooden cleat.

These doubler plates are in the mast crossbeam location. The middle one is the butt block used to join the topside panels together. The other two were added when I realized that the plans show a 12-inch block here to reinforce the hull in this area. It could have been made as one block, but once this is all faired and coated you won't be able to tell that it is actually three.

Here the hull is rotated to one side to make it easier to fill the many screw holes made in the assembly and the installation of things like the diagonal stiffeners. These holes must first be filled with unthickened epoxy, then faired with a thicker, filleting mix. It's a fairly slow process, but at least it's started.

Two things I needed to prep the outside of the hull for fiberglass sheathing: a set of sturdy, low sawhorses so I can reach the bottom of the keel when it's upside down, and a larger random orbital sander than the 5-inch one that is so handy inside the hulls. I built these horses out of 2x6s and made them only 14" high, which is just right for upside down work since I don't yet have my cabin bulkheads attached. The sander is a Rigid 6-inch unit from Home Depot. I was looking for a Porter Cable but found this one and thought I would give it a try since it is variable speed and has good reviews. I'll report back on it soon after I start fairing the hull.

I also ordered plenty of sand paper: 600 discs in 5 and 6-inch sizes, and in 60, 80 and 120 grit. Klingspor http://www.klingspor.com/ is a one stop shopping place for all kinds of sandpaper and other abrasive products.

1 comment:

tsunamichaser said...

Scott one thing you might try when it comes time to glass the hulls is to is to lay the hull on its side. roll out the glass over the whole area and then hang spring clamps from the cloth all around. This keeps the cloth smooth and in place. With the hull on its side you can just pour on the resin and then start squeegeeing it out.