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glhotka · 03-01-2016, 09:24

I have a Formosa sailboat that has 2 Dorado boxes with solid bronze cowl vents. They appear to me as if they should unscrew from the bronze base on the top of the dorado box, but I can not seem to break the cowl vent loose from the base. I assume they are threaded so the cowl vent could be removed and a bronze plate or plug screwed into it in instead.

My question is does anyone know how these come out. I have removed the 4 screws that hold the base to the top of the dorado box and have the cowl vent and base together off of the boat. I have tried PB Blaster, WD 40 and even soaking it in kerosene for a few hours to see if that would break it loose.

There does appear to be a recessed set screw in the front of the cowl vent right near the base that I assume would be used to tighten and keep the cowl vent facing a certain direction, but either mine is missing or corroded down in the recessed hole. I have not drilled that out yet waiting to see if someone knows how these are normally put together or can share what you may have done or how yours work if you also have the solid bronze cowl vent and base.

Please feel free to reply with any information or even a close up photo of video of how yours work. Right now I don't want to break anything or destroy it so will continue with PB Blaster to see if that will help. IF not, I may have to just install them back on the way they are and not have the ability to rotate them.

Looking forward to a response. Below is a picture and small video showing the type I have.

Terra Nova · 03-01-2016, 11:06

The setscrew prevents the cowl vent from turning.

Dorade vents are named after the yacht Dorade, on which they first appeared.

Nicholson58 · 03-01-2016, 12:05

The 'snorkel' vent top should unscrew from the base. Yours appear like ours. We also found removing the box was the only way to re-finish. Use a scotch-bright wheel to polish the brass. Also, there is a rubbery block I bought at Home Depot; 3-pack. These have different grits cast in and easily hand polish SS or brass. Use the 'fine' only. We have no rotation prevention but your post explains the hole I found.

glhotka · 03-01-2016, 20:29

Do your cents unscrew from the base (in other words they are threaded onto it) or do the twist a portion of the way and lift straight up?

Celestialsailor · 03-01-2016, 22:14

If there are no set screws holding them, I would recommend a propane torch on the base only and quenching with WD40 and reheating a few times. As a Machinist, I've done this a few times with great success.

Oceandeep · 04-01-2016, 09:34

I have a Hudson Force 50 with similar bronze vents. The vent screws into the base and there is a set screw that can be adjusted to keep it from turning.
If you can loosen the set screws and apply some penetrating oil hopefully you can unscrew the base. I've attached some pictures for your reference.
Good luck

glhotka · 04-01-2016, 10:45

Thanks. This is helpful. I will try the heat method and drill out the set screw if needed to see if I can remove it

reed1v · 04-01-2016, 16:23

My cheoy lees' vents screwed off their base, which itself was screwed into the dorado boxes.

glhotka · 05-01-2016, 05:22

Thank you very much Reed1v

Orion Jim · 06-01-2016, 19:09

Quote:

Originally Posted by Terra Nova

Dorade vents are named after the yacht Dorade, on which they first appeared.

Apparently this needs repeating

Alan Mighty · 06-01-2016, 22:30

Quote:

Originally Posted by Terra Nova

Dorade vents are named after the yacht Dorade, on which they first appeared.

Quote:

Originally Posted by Orion Jim

Apparently this needs repeating

And that Olin Stephens (1908 - 2008) was the designer (and launched Dorade in 1929).

And perhaps even that Stephens named his boat after a fish, the common name of which meant 'the gilded or golden one' from Latin deaurare, to make golden, from Latin aurum, gold.

reed1v · 07-01-2016, 05:10

Now that we are getting supercilious, The cowl is not the dorado. Its the dorado box the cowl fits in. Cowls normally vent directly to the outside and do let water inside if facing the wind and rain. Forward cowls normally face aft to help suck air out.
Despite Wikipedia's claim, air boxes were in use long before Olin was a baby. What was unique is the cutsy vents he employed on his yacht designs to make them, well, cute for the well heeled set. Cowls normally were big ugly things. he made them small and sparkly polished bronze or polished ss.

Fwiw, if you got a dorado box, make sure the drain hole is free to drain. Otherwise water can build up. Given their size on most pleasure boats, a vent fan inside, fitted to the opening, makes them really useful. Otherwise they really do not move a lot of air unless you got lots of them. My old 36' luders had 7 of them(4 for main cabin, 1 for anchor locker, 2 for stern) The bow and stern ones did not have dorado boxes.

Dorado boxes do significantly cut down on air flows.

zeehag · 07-01-2016, 05:16

DORADO is a freeking FISH. the box is a DORADE. the vent is a COWL.
please put your fishies back into the ocean and work on your doradE boxes.
thankyou.
mine have a set screw. it is obvious how to remove em from the boxes.
the set screw is on the cowl .
the removal screws are screwed into the wood of the doradE box.
the beautiful wooden boat named doradE was named because she was golden. made of gold. dorade. NOT dorado.
dorade boxes were designed to prevent water from flowing into boat with the ventilation.