There's a hole in my boat, now what.

[Mike Banks]

I am with Blinkerfluid. Then if sanity returns you can replace the Cape Horn and find a pair of swing-out davits that will well clear the Cape Horn, and be SO MUCH safer in a storm because you can turn the dinghy on its side once secured therein.

I think the Cape horn is an essential if one is going to do any serious passage making.

.

[stormalong]

Originally Posted by blinkerfluid

Yes, it does. It may not reduce the structural strength to the point that the transom would fail, but removing material from the transom (or any bulkhead) will definitely reduce it's strength.

Also, installing a pipe or similar through a hole will increase the strength of the area the pipe/etc is going through, provided the inserted piece is bonded/attached in such away so that it cannot move independently of the bulkhead/etc it is going through. This is why they weld in bulkhead penetrations on ships where a hole is cut in a bulkhead for a pipe/etc. The bulkhead penetration (essentially a short pipe itself) isn't there to support whatever is going through it, it's there to add strength back to the bulkhead.

I'd also say that a hole that is designed to be in the boat is a lot different than one that's been added later. I would not be surprised if a lot of the exhaust/vent holes you mentioned have structural reinforcement on the inside of the transom that you simply can't see from the outside.

OK, believe what you are going to believe. Waste your time and money on unnecessary structural repairs.

[blinkerfluid]

I don't think i'd want a dinghy on transom mounted davits for ocean sailing, I'd be too worried about it filling with water. Our davits are going to be on our arch, which should let me look underneath the dinghy when it's all the way up.

I can't/won't argue about the merits of a windvane, though I think if I put one back on, I'd go with a hydrovane. Then I wouldn't need the hole anyway

[blinkerfluid]

Originally Posted by stormalong

OK, believe what you are going to believe. Waste your time and money on unnecessary structural repairs.

So... just duct tape it then? I mean, it's not structural.. In college we used to duct tape over the sailing dinghy drain holes when we ran out of drain plugs, so I know it can keep water out. The key is to put it on a dry hull, once it's wet it doesn't stick as well.

It's not what I "believe", it's engineering. Removing material out of a bulkhead reduces it's strength. I already agreed with you that, in this case, it wouldn't reduce the strength enough to cause a failure. If I'm already going to be grinding on the boat to do the repair, I might as well do it right and not halfass it.

I'm curious what you would call structure, since you apparently don't think repairs of the hull below the waterline count as structure either.

[geoleo]

Get your holesaw --- cut a FG piece 3"dia from somewhere negligible on boat to fit snug and glue that in with white epoxy Marine tex ----mask all for neatness.

[stormalong]

Originally Posted by blinkerfluid

So... just duct tape it then? I mean, it's not structural.. In college we used to duct tape over the sailing dinghy drain holes when we ran out of drain plugs, so I know it can keep water out. The key is to put it on a dry hull, once it's wet it doesn't stick as well.

It's not what I "believe", it's engineering. Removing material out of a bulkhead reduces it's strength. I already agreed with you that, in this case, it wouldn't reduce the strength enough to cause a failure. If I'm already going to be grinding on the boat to do the repair, I might as well do it right and not halfass it.

I'm curious what you would call structure, since you apparently don't think repairs of the hull below the waterline count as structure either.

There is structure and there is structural weakness. structural weakness means the hull will fracture under stress. As I have said: I have filled in through hull holes in my boat decades ago with my method. None have ever shown any signs of failure. So my method has proved itself over many years and tens of thousands of sea miles.

And yes, duct tape would keep the water out and as an emergency repair it would do it but I would replace it ASAP.

"I might as well do it right and not halfass it" OK, do it your way but know that your way is overkill. Overkill certainly gets the job done.

[mlydon]

The Cape Horn is a very nice windvane....someone put out $4-5k to put it in....personally, I’d keep it. Dinghy can ride AFT of the mast, under the mainsail boom, as many do....

You can also have davits, use them at anchor with the vane stowed (very convenient), then when travelling far, dinghy on deck, davits stowed, windvane in use.

You can have your cake and eat it, too!

Matt

[jharding]

I love my cape horn and would never consider giving it up for a hydrovane or any others that are just added on. the cape horn is more trouble to install but worth it, all lines are inside not hooked up to the wheel going across the cockpit. A hydrovane is another rudder hung on the back end and has a lot of forces going through its mounting. My cape horn is installed along with dingy davits on the back end, it can be done, no big deal, I also would not go offshore with dingy in any davits, needs to be on deck. I have sailed some Island Packets with the Hoyt boom and didn't care for it, hard to get sail flattened out. If you are off shore sailing you won't tack very often and the small staysail is easy to tach anyway. Don't get rid of the cape horn, it is one fine piece of equipment.

[Reefmagnet]

That hole won't weaken the transom in any significant way, shape or form. Perhaps if it was a raggedly cut mess with notched stress concentration areas then that would be different.

There's an engineering reason this is so, but it is simpler to consider real world situations where beams are lightened without incurring significant structural strength losses...


It's possibility of water entering the hole that is the important thing to consider and even then it doesn't need to be particularly super strong in order to resist the force of any wave likely to strike the back of the vessel.

[Cheechako]

A couple good exhaust fittings and it's easy peasy. SS, Bronze, plastic. $20-$70 or with built in flappers.:
https://www.amazon.com/EXHAUST-THRU-.../dp/B006C5OUEY
https://www.marinepartssource.com/ma...itting-1200287
https://www.marinepartssource.com/ma...u-hull-1200298

[blinkerfluid]

That first one in your list is the one I was looking at if I go that route. I like that it's pretty close to flush mount and won't stick out into the swim platform area at all.

[Cheechako]

Originally Posted by blinkerfluid

That first one in your list is the one I was looking at if I go that route. I like that it's pretty close to flush mount and won't stick out into the swim platform area at all.

On my 31 footer, the biggest issue was how much rise from the stern outlet to the cockpit wall scupper. 3" hose can be quite rigid! IIRC I used PVC fittings with hose connecting each end.
Another option is to get a stern fitting that is threaded not barbed, then reduce down to a reasonable size like 1.5-2" for the cockpit end. Or just send a bilge pump out that stern fitting once you reduce it down.

[Cadence]

Originally Posted by Jono as 2234

I did this for a similar hole in my glass cruiser hull, although a bit smaller.
The boys in the Marina call it "making a f... up into a feature"

That about sums it up.

[blinkerfluid]

If I go the cockpit drain route, I think I'll install 2 new 1.5" drains in the cockpit floor, then run them to a 1.5" to 3" Y and connect that to the exhaust fitting. I think the biggest issue is going to be making sure we have enough slope to drain the cockpit.. I'll have to get under it and see what kind of room I have for hoses.

[flyingnut40]

P.M me if you are looking/ willing to sell the Cape Horn.
Best Regards Dennis