ONE METHOD FOR REMOVING AND REPLACING A KEELSON/FLOOR CARRIAGE BOLT

[bob mitchell]

The floors (horizontal frame member on top of the keelson) in a Newporter 40, as in any wooden boat, may from time to time need to be removed. Removal could be to actually replace the floor, or removal of the floor could be to gain saw cutting clearance to scarf in a lower frame member. Regardless of the reason, the carriage bolts, having been placed upwards through the keelson and then through the floors, will have to be dealt with. I can think of three outcomes. 1) The nut and washer on top of the floor are successfully removed, and then, as long as the bolt shaft is not frozen by rust into the floor, or totally deteriated, you can refasten the floor using that bolt, unless 2) you spun the carriage bolt head in position down in the keelson, at which point you might consider replacing the carriage bolt and the weak plywood around it. But first you have to get the floor off, so you slip a saw saw or side grinder in between the floor and the keelson, and cut the bolt, which leaves you with the head and 3 1/2" of shaft in the keelson. 3) You can't get the nut off so you pry the floor and the whole carrige bolt comes out, head and all. (see photo below)

So in case 2 you need a way to extract the bolt. Since the hull sheathing was applied after the bolt, if you punch it downwards ( asssuming you are out of the water) then you will punch it through the hull plywood and fiberglass. So if you are really serious about punching the bolt out of the bottom then you need to remove the plywood sheathing that covers the keelson, and while you are at it, consider that you need to cut where refastening new plywood will be strong and straightforward. Once you get the old bolt out you might find that the wood around the bolt has deteriated and you need to revamp by drilling out a, say, 1 3/4", plug and epoxying in new plywood.
An alternative method is to drill down from the top of the keelson and extract a 1 3/4" plug of plywood, about 3 1/2" long, with the bolt in the center. Of course your boat should be out of the water for this because if you screw up your boat is going to sink. Captain Clyde Phillips (see "Clyde" pages on site if your interested in his history and association with Newporters) has made this point many times. When you are working below the waterline have the boat "on the hard". To determine the depth of plug cut is a huge responsibilty, because if you screw up you will go through your fiberglass sheathing - so you better know about Newporter keelsons and carriage bolts if you want to figure the depth out. I'm not taking on that responsibility.
So everything is hunky except that I could not find a hole saw with enough depth. Maybe you can. So what I did was find a piece of pipe the same diameter and basically the same wall thickness as the ACE hole saw and welded the inserted extension. I used an ACE hole saw because its features lended themselves to my modification. I cut the saw part away from the drill neck (on a lath - but you can improvise with what tools you have, or get your local machine shop to do it for minimum charge. A lathe cut is desirable because it allows you to cut an "alignment" shoulder. If you used a saw or cut off you could align the pieces on angle iron) and then inserted an extra 2", and welded it back together. (photo)

After "pulling the plug" (hahahaaaaa.......gallows humor) you can feel the keelson to check its condition, then heat gun it dry (which will also make the epoxy penetrate better into the surrounding keelson), and then replug with the epoxy saturated plywood doughnuts and new carriage bolt (see photo). The carriage bolt with the square hole plug goes in first, then successive plywood "doughnuts". I used the same holesaw to cut the plugs (usually I move up a holesaw size to get a better fit) because I was going to use some filler with the epoxy and I wanted some wiggle room to align the bolts with the holes through the floor. The square holed doughnut matches the carriage bolt shoulder and was done with a 1/2" mortise bit (cheap at Harbor Frieght). (might could get away with only round ones if you crushed the cariiage bolt into the first doughnut ahead of time) Be sure not to fill a plug hole with epoxy all at once or the exothemic reaction might cause a volcano! I would have the new floor, or old one, ready to slip over the new bolts before they dried to make sure the bolts set in the right location. This process is meant to improve the condition of the keelson as well as provide a new solid anchor between frame system and keelson.

Since the bolt that you are trying to remove is in the center of the plug you are cutting you cannot use the hole saw pilot drill bit. However you can use the pilot drill bit to cut a template that you fasten to the keelson, centered on the bolt - to hold the hole saw steady and keep it from running off. After the plug is cut you may have to chisel or pull on the bolt to get it out, and dress up the hole, but if things aren't obvious at this point you may be in trouble. .

EPILOGUE:

Well, it should be clear that I had a plan and the intent. However, when I, with great care, eased my screw driver into the hole to get a depth of cut the depth came out to be 5 1/4 inches, which is the 6 layers of 3/4" in keelson plywood, plus the 3/4" sheathing. The VERY slight tapping I did gave a very crisp, sharp, fiberglass tone. What I am saying is that as I cleaned and vacuumed the hole the plywood sheathing under the keelson was like butter and came right out. SO THAT ENDS MY ATTEMPT AT "MINOR" REPAIRS. Also, when I tested the hole saw (which worked great) for just a couple of inches, there were clear layers of sound versus unsound keelson plywood. So "Wilson" comes out of the water in July to replace selected parts of the keelson and replace most of the keelson/floor bolts (by knocking them out the bottom, since that sheathing will be cut away and replaced), along with any ribs that need repair. I would have pulled "Wilson" out in the first place, but there are no boatyards in this area that will let you work on your own boat. The good news is that I have a friend who will let me have a spot in a field near the river for free. The bad news is I have to rent a crane and trailer to get it there. Incidently, where the plywood sheathing emerges from under the keelson appears very sound. I am not sure if the sheathing damage under the keelson is extensive and a result of not being able to breath, or if it is localized and associated with the deteriation of the galvanized bolt.