Knife valves for scuppers?

[Brian.Dixon]

The Bay Weld boat that I looked at was, if I recall, 26 ft long and it had one 3" or so scupper in each aft corner, and this was in 2004 or 2005.  Could be that they use more scuppers now, or on a 26 ft boat, they just don't (didn't?) put 4 of them in?  And yes, they're very nice boats ... but expensive and expensive to operate.

[Todd j]

Dimensions are from the chine flat at the transom. 
  You can see where the inlet to my scuppers are in the second photo, along with the foam plugs with a strip of gorilla tape on the front side.
My disappointment with my design resulted from four fat guys all on the cockpit deck bottom fishing.  While idling back into swell the deck would flood through the scuppers.  Perhaps I could try this again with only the aft most inlets plugged and have entirely different results as my deck is sloped aft. 

[Dan Boccia]

So Todd it looks like your scuppers are close-ish to the centerline of the boat, rather than the far outsides (port & SB) of the deck? I wonder how they would be if they were to the far outsides... I always find that the boat is either slightly or fairly listing one side or the other, and the water is always on one side or the other of the back deck, so I'm betting that makes a difference, just unsure how much. I've never seen them installed close to the CL like that - always to the far outsides or close to it. Anyway, interesting details this is bringing up.

Brian, yeah, they have changed their designs quite a lot since early 2000s.....they have grown tremendously and now do all their own very advanced engineering/marine architecture in-house. Also, their 26-ft boats might have smaller scuppers - their boats go up in volume a LOT from 26 to 29.

[Todd j]

Interesting observation.  The way I built the boat didn?t allow them to be any further outward.  Seems like they might be less likely to flood due to lopsided loads or changes in weight on the deck like people moving around.   I need to do a better test of their performance. 

[Grady300]

As a reference, Bay Weld Boats only puts in two 3" scuppers in boats that are of similar size to the GA and operate in the same waters.  I like Chuck's rectangular scuppers for more flow (but hard to close).  Chuck's epic 1800-mile open-ocean trip from San Diego to Puerto Vallarta in Mexico proved the point well when he went through some extremely rough conditions on the way ... water going OVER the top of his Kodiak...

YES THEY SAVED MY BACON. I used the typical round ones on my Tolman Widebody. my experience with those caused me to go with 1 1/2" x 6" on my Kodiak. What a good decision they work flawless getting a ton of water over the top on every wave we burred the bow. BTW I raised my cockpit 3" from standard with 1 1/2' slop from cabin BH to the transom.

[Brian.Dixon]

Chuck ... expand on how you made those awesome scupper tubes like that.  What did you use as a form, and how'd you get the tubes back off once the epoxy cured?  Thx...

[Grady300]

Chuck ... expand on how you made those awesome scupper tubes like that.  What did you use as a form, and how'd you get the tubes back off once the epoxy cured?  Thx...

Check out page 7 on my blog. Pretty much has all the info. Super easy!!!  https://www.glacierboats.net/forum/index.php?topic=834.90

[Brian.Dixon]

Check out page 7 on my blog. Pretty much has all the info. Super easy!!!  https://www.glacierboats.net/forum/index.php?topic=834.90

Thanks ... that post was a while ago!  I missed the part where you saw cut just barely through the glass to help release the tubes from the molds.  I wonder if a good whack with a heavy enough 'persuader' might get the molds out without cutting?  You had 4 wraps of plastic on them, which is seemingly plenty.  A saw cut that gets glassed over like you did is very simple too, so either way ...... they turned out great!

[Grady300]

Oh I tried that, I think it was just to much friction. Once I made the cut it came out with ease. Glassing over later was as you say simple.
I have used this method a few other times, like a FG sleeve through the lower transom. Between the wood and the Brass tube the main drain plug goes through on a Devlin Broadbill Duck hunting boat I built yeas ago. Never have to worry about dry-rot in your drain that way. I did not install a lower drain on my Kodiak, it's moored 24/17

[json]

I did the same sort of thing that Grady did here but instead of using MDF for a mold I think I used some purple insulating foam that I got from home depot and wrapped it in some wax paper. I think I was able to get it out pretty easy, even without cracking and breaking it out (some of the wax paper might still be in the tubes actually). I love these fiberglass tubes as drains though, like Grady says, you never have to worry about them rotting or becoming compromised. Pretty slick idea.

[Rbob]

I have a question about the scupper tube angle, how much?   I am thinking about installing these on my boat, deck is raised 4 " I was thinking I could put the exit a little below the water line, my thinking is that a fairly steep incline of the scupper tube would help water backflow.

thoughts?

[json]

Rbob - I put these flaps on my scupper holes and have not had any problems with water coming in. I didn't put much of a down angle on my tubes. However, I do have a current issue I am working on correcting with bow down trim, so not sure how much these are actually blocking water from coming in due to them just sitting high up or out of the water.

https://www.seaworthyinnovations.com/shop/sw1023?utm_medium=email&utm_source=customer_notification

[Brian.Dixon]

Rbob - I put these flaps on my scupper holes and have not had any problems with water coming in. I didn't put much of a down angle on my tubes. However, I do have a current issue I am working on correcting with bow down trim, so not sure how much these are actually blocking water from coming in due to them just sitting high up or out of the water.

https://www.seaworthyinnovations.com/shop/sw1023?utm_medium=email&utm_source=customer_notification

Nice to see rectangular scuppers ...

On your bow-down issue, you had a lot of fuel in a large/long forward tank, right? What's your corrective action plan?

[json]

Brian, I am going to move the convo around my trim over to my build thread so I don't derail the convo here. I am really happy with how my scuppers with the tubes and these flaps worked out though, they are far better than the hodge podge idea and implementation I had for them previously.

[Grady300]

I have a question about the scupper tube angle, how much?   I am thinking about installing these on my boat, deck is raised 4 " I was thinking I could put the exit a little below the water line, my thinking is that a fairly steep incline of the scupper tube would help water backflow.

thoughts?

I SLANTED MINE ABOUT 3/4 INCH IN 2 FEET