What bit for drilling new garboard holes?

[USA_boater]

The previous owner never removed the plug so the plug was essentially welded in the flange and I finally had to just remove the entire flange and get a new one. The problem is, the flange that came out was 2.25in and all I could find as a replacement was a 2" so I have no choice (unless someone can find me the 2.25in) but to drill new holes. The new flange is a stainless with standard sized garboard screws (3/16???). I am going to fill the old holes with 4200 because that is what I have on hand and then use the 4200 to seal up the wood inside the hole and to seal the new garboard flange & new screws.

Any help, but especially on what drill bit to use is appreciated.

 

[Scott Danforth]

Diameter of screw shank ( not threads )

https://www.boltdepot.com/fastener-information/wood-screws/Wood-Screw-Pilot-Hole-Size.aspx

 

[Lowlysubaruguy]

You friends with any machinists. A guy with a lathe could make you a brass one the exact size of your old one. You could mail me your old one and I’d make a duplicate if it came down to it. The piece of brass that diameter and long enough to work would be my only hang up a machine shop might actually have one laying around I would have to buy one.

 

[USA_boater]

You friends with any machinists. A guy with a lathe could make you a brass one the exact size of your old one. You could mail me your old one and I’d make a duplicate if it came down to it. The piece of brass that diameter and long enough to work would be my only hang up a machine shop might actually have one laying around I would have to buy one.

Very generous; of course I'd pay what the job requires but seems like a lot of trouble. Here is what I need to know, I read that people often drill new holes anyway and rotate their garboard drain if they take it off or install a new one. If I install the 2" smaller over all diameter flange, can I just fill the old holes with 4200 or would I need to put some screws in those holes with 4200 to seal them properly?

The one thing that makes me lean towards using your idea instead is if I could just re-use the old holes and not have to drill.

SO what would you (and everyone else do)?

- get the right size (and maybe re-use holes)
- or install new smaller flange and drill new holes and seal the old ones (in some fashion)

Thanks

 

[Lowlysubaruguy]

For a fact Ill spend more time locating the piece of brass than making it. Brass cuts like butter. So if you find yourself there the offer is good any time.

Another option if you can get to the inside of the boat in this area? Which is important. You could take a piece of 1/8” aluminum use a hole saw make a disk that’s just a little larger than the flange with a hole saw then drill the center hole out a little larger than the hole in your existing flange mate the two together and then drill the mounting screw holes to match them and then use machine screws with lock nuts on them. I’d use a marine silicone that’s pretty permanent and then use the ring you made as a reinforcement on the inside. Wear gloves its a messy event and will take two people. Just keep in mind if you use marine silicone its going to be hard to remove later on so make it right.