by jdoorly » Mon Aug 08, 2011 10:20 pm
Hi Paul,
I assume the "nut" your describing is the knurled thumbscrew that holds or allows the fairlead block to move along the track (the nut is strangly enough the female side of the equation). Since the screw shaft is frozen it wouldn't hurt to try some Liquid Wrench and/or heat to start with, but don't melt the boat.
If there is enough of the thumbscrew's shaft still showing I would try to get a tight hold of it with a vice-grip pliers and unscrew it. If there is not enough shaft exposed to grab it I would then try to make a slot in the shaft, using a dremel tool and a friction disk, and then unscrew it with a straight blade screwdriver. If the shaft is recessed in the hole you might use a drill and a small drill bit, smaller than the threads, and run it in reverse- it might catch, with enough pressure, and unscrew the remains of the screw. There is a tool called a screw extractor that will definately catch, it has a tapered reverse thread, you drill a small hole in the end of the shaft and then use the extractor (in reverse) to unscrew the screw, but you need the correct size for the screw- I believe it is a #10-32. However, I've never come across an extractor set that still had the small extractors still intact!
If that fails you can drill the screw out using the next larger screw size pilot hole drill (i.e. #7 drill for a 1/4-20), retap the hole at 1/4-20 and get a suitable replacement thumbscrew at a hardware store. However, the 'T-nut' on the car might be too small to allow this. Last option is replace the car and block. D&R Marine probably has it or try Duckworks if your on a budget.
My tracks have a combination of wood screws and machine screws with nuts so I am unable to move them to the top of the coaming as I want and will need to cut access holes in the coamings near the tracks in the future to get to those nuts, my DS2 is vintage 1972.
Good luck!
DS2 #6408 "Desperado"