pelagic2530":29ny5zzb said:
... want to upgrade the scuppers ... to a bigger size, hopefully 6" by 18". has anyone done this?
Need to? Probably not. Want to? Yes I do. But 6" x 18" :?: , man that is
HUGE :shock: !
Now ... why? Here's my reasonings.
Reason #1 - My vessel is a '92 vintage and I have seen more than one brass scupper on a transom fail in my life, even when they look good. I even went so far when I had access to a machine shop (GE trained machinst) to make up one of those install tools that's flares over the scupper on the 'non-flared' end as you buy them in marine stores.
Reason #2 - I agree with you ... a 1" scupper is just too darn small! Heck, in my youth I could piss more water than those can drain!
However, you need to keep in mind the design of your existing scuppers first!
See that well :?: about 5-6" wide from Megabyte's 2520? Are you going to cut just that area out or cut above it?
I realy think you need to do some thinking first, and if it were me, I would NOT cut into any surrounding area
other than the transom itself ... just my $0.02.
What I am looking at are 2 options.
Option (A) will be to start at the same level of the 'bottom' where the current scupper is now and drill a 3"+ hole, so the bottom of both holes start from the same level. Into this I will epoxy a 3" diameter fiberglass tube from McMaster-Carr. But first, the hole will be heated to warm the raw wood and then thinned epoxy or CPES will be repeatedly soaked into the wood core using a syringe. This gets messy trying to epoxy the top portion of the hole, so have everything well taped off with pastic wrap. I will probably soak the wood about a dozen times or more, until it cannot absorb any more epoxy.
Once it starts to 'kick', I'll add a standard coat (regular viscosity) of Raka epoxy (
www.raka.com). Once that cures I'll sand it to fit the frp tube, then will solvent wash off any amine blush and will then glue in the 3" frp tube using a thickened epoxy. I'll most probably use a somewhat easy-to-sand structural/adhering filler, like micro balloons, and not kitty hair or cabosil (not really for strength).
To prevent water from coming in when backing, waves, or a following sea, I will attach Rabud Sea Scuppers (see below) that can handle a 3" outlet to the transom. Make darn SURE you have room for these or other scupper flap with your swim platform or other ... !
See
this link, then go to "Sea Scuppers".
Option (B) will be to use a different shaped and LARGER form of fiberglass shape from McMaster-Carr ... but I am not sure of what size. FWIW I have not found a foolproof and reliable scupper flap design thingy that I like except for the ping-pong ball scuppers sold by Rabud and T-H Marine.
They are 100% reliable! I like the T-H model even better as the base stays attached to the transom while the cap can be spun off (loosen a set screw) to clean it. Cleaning the Rabuds means you break the seal of Life-Caulk or whatever goop of choice you attached it with.
All deck hardware and screws holes in my boat are wetted out with epoxy when I refurbished the hull, so I am not too concerned about removing it and resealing it. Besides, on my 2520, the scuppers are a good 5"+ above the normal waterline. Replacing these scuppers will be the 2nd to the last piece of non-glass hardware that hasn't been wetted out with epoxy and rebedded since I bought my empty & abandoned hull. The OB bracket is next, but that's another chapter in my 'to do' list.
Run through this ... see if it helps you ... and come back and ask away. Either way, both of us should document this process with photos for posting to the CP archives.
Cheers
!