Tapped

The cold has brought all epoxy work on the boat to a halt, but there's still a ton of work to do. Friday, I drove down to see my friend Peter at Buzzards Bay Yacht Services to see what he has been up to and to drop off my old rudder shaft with his machinist to fabricate a new one. He has a bunch of projects in the works and will be really busy over the winter. When I showed up, he and his crew were working on pulling the old teak decks off a Baltic 42 in preparation for new ones. The removal of my teak cockpit sole was still painfully fresh in my mind (which was only about 10 square feet) and I can't imagine doing this job where almost every horizontal surface is covered in teak that needs to be ripped off. Uggh. Anyway, I left fabrication instructions for the new rudder shaft off at the machinist and hope to hear back this upcoming week so I feel like I'm moving forward a bit on that front.

The rest of the weekend went by in a whirlwind of family activities as usual, but I did carve out a few hours on Sunday to start dry mounting the lifeline stanchions. By dry mounting, I mean that I tapped and fitted them but didn't fasten them permanently with butyl tape (the sealant I'll be using for most deck fittings) because I want to get some paint on the underside of the decks before I permanently mount them.  I had recently ordered $100 worth of 2-1/2" Silicon Bronze screws, washers, and nuts and wanted to see them installed.

Bevel with countersink bit

All in all is was pretty straight forward but you have to make sure your tap is going straight down or it will be difficult to mount the backing plate. The first one I lined up the stanchion on the backing plate and pre-tapped the backing plate holes. Unfortunately, when I tapped the holes in the deck, I must have been slightly skewed and the screws didn't match up with the backing plate.

A little trimming here and there allowed me to seat it, but for the rest of the stanchions my procedure went as follows:

1. Place the stanchion on deck at desired locations.
2. Tap all 4 holes in deck using stanchion as guide (5/16" bit). 
3. Chamfer the edge of each hole by overdrilling with a countersink bit to allow for a slight bevel (see bevel photo). This serves to reduce stress related fractures in deck when stanchion is put under load and allows a ring for butyl tape to bed nicely into. 
4. Tap one hole in backing plate and mount tight on underside of deck, making sure that it is positioned properly. 
5. Tap remaining 3 holes in backing plate from the deck, using the mounted stanchion as a guide.
6. Fit bolts in stanchion and add washer and nut.

I still have to paint and remove the old fasteners before I permanently mount the stanchions.