Replacing the deck drain

Thread starter #1
I completely removed the original deck drain from my ‘79 Sunfish because it was corroded beyond repair on the inside of the hull. I have since made some minor repairs to the opening and filled the original pin holes (one was compromised during the removal) with Flexpoxy. I have sanded and prepped the opening, and dry fitted the new plug. The new plug from www.sunfisfpartsdirect.com came with two pins, but it has 3 holes on the flange instead of two as shown in the picture from their website (below). I’m assuming the third hole is just an extra/optional hole in case placement is an issue, but I’m curious to hear what y’all think? Also, do y’all have any advice on what size drill bit to use? Thanks.
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L&VW

Well-Known Member
#3
I completely removed the original deck drain from my ‘79 Sunfish because it was corroded beyond repair on the inside of the hull. I have since made some minor repairs to the opening and filled the original pin holes (one was compromised during the removal) with Flexpoxy. I have sanded and prepped the opening, and dry fitted the new plug. The new plug from www.sunfisfpartsdirect.com came with two pins, but it has 3 holes on the flange instead of two as shown in the picture from their website (below). I’m assuming the third hole is just an extra/optional hole in case placement is an issue, but I’m curious to hear what y’all think? Also, do y’all have any advice on what size drill bit to use? Thanks.

I'd find a pin to go into that third hole, 'cause every onlooker is going to question why there's nothing in it! ;)

(I've taken to wrapping the old plug with plumber's white Teflon tape).

As to size of drill bit, this could be a very good question! Most of us haven't seen a new deck drain. :confused: It could very well have been made in China, and made to metric sizes. :oops:

If you have access to an index of machinist's bits, you can "test-fit" sizes and come very close; otherwise, start with (squinting)
-inch and work on down. :cool:
 

L&VW

Well-Known Member
#4
Below is the drill bit "index" I discussed. Buying one isn't expensive, and the increments are so small, you can drill close to "outlier" sizes—like metric. They're not expensive because it's mostly real machinists that buy them, and so few real machinists. Just one of things where limited demand results in "low" prices.

Sometimes, you need a drill bit that is a little bit smaller than the hole you'd normally want to drill. This drill index fills the bill.


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#5
I managed to get my deck drain open with repeated application of WD-40. I hear water sloshing when I move the boat but I can't seem to manage to tip the boat in a way that causes anything to come out of the hole. Is the water trapped somehow? Is this common? Any suggestions on what to do?
 

Wavedancer

Upside down?
Staff member
#6
Carefully rest the boat on its side, drain down, and slant it so that the drain becomes the low point. Water should come dribbling out, but it's obviously impossible to get the last drop.
I do like the port on my relatively new boat so that I don't have to use that routine.
 

L&VW

Well-Known Member
#7
I managed to get my deck drain open with repeated application of WD-40. I hear water sloshing when I move the boat but I can't seem to manage to tip the boat in a way that causes anything to come out of the hole. Is the water trapped somehow? Is this common? Any suggestions on what to do?
Presently, I'm feeling your pain. :(

Through my inspection port, I can see ⅜" of water sitting in the bilge. So I remove the transom plug and lift the bow of the Sunfish eighteen inches higher—and nothing comes out! :confused: I do have a steeper ramp nearby, so all is not lost.

I've ordered a $18 battery-powered bilge pump, but in your case, lean your Sunfish with the drain down, and thread a line back into the drain. Let it sit overnight to act like a wick. See if it's wet during the day—which is likely. With even more luck, there might be a puddle. :)

When there's enough water to hear it sloshing—and nothing comes out—something else is at play here. :oops: Member Ghost Rider will say our Sunfish have spent some of their lives too close to the Bermuda Triangle! :eek:

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Thread starter #8
Sounds like the transom plug may be clogged, possibly foam bits? I have been told on this forum that transom plugs don’t work particularly well in Sunfish due to the foam filling the rear of the hull. I installed a new/replacement plug in the factory location this weekend.
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