Re: Interior stringers

From: Al Emondi emondia@spawar.navy.mil
Date: 6/6/01
Time: 7:42:15 AM
Remote Name: 198.253.34.163

Comments

I started this “wonderful” job a few days ago with my shark #173. The previous owner basically used the boat as a rain water bucket for about 10 years rather than a sailing vessel. In return, I got a great sail boat with rotten stringers. I noticed the severity when I unbolted the keel and removed the U channel inside the cabin. The stringer straps attached to the U channel hide only the beginning of what I found to be very rotted stringers behind them. The stringers are about 12-13” high so set the guide of my circular saw to 6” and deep enough to cut through the stringer but not into the ribs behind the stringer and ran it along the fore starboard stringer. After the cut, I removed the bottom section. The rot continued the whole length behind the fiberglass matting used to secure the stringer to the hull. In hindsight, I would probably set my guide to 7-8” next time to remove less material, since the rot really does seem (in my case) to be contained in the lower 4 inches or so of the stringer (you can always remove more if you have to). Unfortunately, after doing that I have also found, to a lesser extent, rotted ribs under the quarter births. So I am currently in the process of removing the quarter birth cover to replace the ribs as well. This isn’t a job I would prefer toe repeat. Since you are cutting fiberglass, a face mask and skin protection are a good idea ( I didn’t pay much attention to the later and spent all last night itching!). West epoxy sells tyvek arm sleeves which I am going to pick up today at my local chandlery, I think that will go a long way to protecting the skin. As far as cutting the fiberglass matted joints, I have used the new Rotozip tool. It seems to work well, especially with the cutting wheel attachment. I tried a simple carpet knife, but the matt was too thick and hard for it really to do justice (plus I could use another excuse for a power tool). The main idea is to replace the bad wood with good wood, by ripping the stringer and removing the lower half, you can replace the bad piece with a new piece of marine grade ply. You can transpose the curve of the hull by taping construction paper to the length of the upper part of the stringer and using a small stick and pecil, keep the stick vertical in the channel where the old stringer was, and move it for and aft. Rest the pencil ontop of the stick. This will trace out the curve that you will use for the bottom half of your new stringer insert. This is brief, feel free to inquire further.

Re: Interior stringers

From: james.posluns@utoronto.ca
Date: 10/14/2001
Time: 5:28:31 PM
Remote Name: 142.150.113.83

Comments

I have now removed, constructed and replaced the interior stringers on my boat and I must say, although time consuming, this was an easier job than I thought it was going to be. I removed the trim cap first and measured from the original joint forward of the companionway to just forward of the main bulkhead into the v-berth. I also measured every two inches along the stringer down to the hull to assess the depth and curvature of the hull. ( In hindsight, I also would have first marked a definitive line to measure from along the hull as this may have imporved the accuracy.) I then removed the nuts from the keelbolts and then the 3 cast U channels that secure the keel. Next, using a 7 dollar coarse cutting disk on my drill, a chisel, hammer and a bit of a jigsaw, I removed both stringers. Lots of dust, but by the second one, it came out in two big pieces. I cleaned up a bit and smoothed all rough edges. The boat was looking better already. Now it was off to Noah's in Toronto, where Rick is an amazing help. I bought a 4x8 sheet of 3/4 " light marine ply to make up the pieces. ( I have enough left over to build a cabinet for the kids mitts to boot!) and some fiberglass "tape" to redo the seam along with east system epoxy resin. I cut the pieces according to my measurements and faired the edge with a small hand plane starting approximately at the head of the quarterberth. I tried them in and after some fiddling they fit beautifully! I joined either end using 2" wide aluminum strapping from Metal Supermarkets ($7.00) and stainless steel bolts and washers. I epoxied the seams in place and have sealed all inside surfaces and edges with epoxy. I now have to grind and clean up the u channels, replace the keel bolts and trim caps, paint the bilge (Hinterholler Grey) and varnish the exposed surface of the stringer. I am also planning to replace the plywood floorboard with teak and holy. Nice! It may not make the boat any faster, but at least she looks good! Total cost of the project - Less than $400.00. Significant Improvement! If you see Lone Shark (709) at any regatts next year and are curious, please feel free to come on board to have a look.