Rebedding winches and stanchions

I'm rebedding the coach top winches and the stanchion bases. I have a couple of questions and would like some thoughts. I'm planning on doing the whole overdrill/epoxy/redrill/backingplate thing.

1. The coach top winches (Barlow 16s) had a thin rubber gasket between the winch base and the deck. The gaskets are pretty brittle and probably not re-usable. I purchased some gasket material from the hardware store that is approx. the same thickness and is gasoline/oil/grease/water resitent, etc. What are the thougts on using this? Should I use some 4200 between the deck and the gasket? Not use the gasket and just use the 4200?

2. I'm considering making gaskets to go between the stancion bases and the deck and then use 4200 between the deck and the gasket. Thoughts on this?

3. How big of an overdrill is recommended? The bolts are 1/4 inch.

Thanks.

1. No gasket, just use the 4200

2. Butyl rubber is the best for this application. RV suppliers sell it. Has better elasticity than the 3M products.

3. Do not overdrill, just chamfer the tops a little with a countersink bit to allow the formation of a plug around the bolt.

As long as your are rebedding, you should be overdrilling and potting all the holes with thickened epoxy. Then redrill to the correct dimension through the epoxy. This will prevent water from ever getting into the core.