Transom Drain... what next???

[zipper]

You are going to need to get a sealant, better than washers, 3m 4200 will work well for this. 5200 fast cure if you want it there permantly.

 

[tdonoughue]

Personally, I would recommend the 4200. Yes, @zipper has the magic stuff to remove 5200 (which is why now I do, too). But be aware that 'permanent' means like concrete permanent. For me, if the flap ever breaks or the thing corrodes or something, I will want to replace it. Therefore, 4200 is on my scupper.

And, while @zipper is also undoubtedly correct on the point about using sealant, I do believe that mine came with a rubber washer...