NateHanson
Sustaining Member
The mushrooms are more of a drag, so the hardcore racers will probably have trouble sleeping at night if one of those is on the bottom of their boat. But I think you're right that there's a lot more work involved in installing a new flush through-hull. The hull should really be built up on the inside, before the countersink is drilled out.
jreddington
Member III
Unless you have a particular need to keep drag way down such as racing, stick with the mushroom. The countersink on a flush through hull seems like an unecessary weak point (and opportunity to mess up the installation).
Time to churn up the Archives
http://www.ericsonyachts.org/infoexchange/showthread.php?t=569&referrerid=28
This is one of *many* relevant threads about this topic. Having a "flush" exterior presence might gain you a nano-knot of speed, but also might be more psychological than measurable. :nerd:
The other caveats regarding the bronze mushroom type are the threat of electrolysis and the weight added to the boat compared to composite material thruhulls.
(As to the later issue, that extra 6-pack of beer carried for the sail back to the dock after the race will out-weigh all the weight savings in your thruhulls!)
Do a search on Bronze thruhulls, Marelon thruhulls, and Forespar.
Lots and lots of cogent discussion. Using "thread tools" you can organize any thread for easy saving or printing, as well.
I installed all bronze ball valves on our prior boat;
and all Forspar "OEM style" valves on the present boat -- and our threaded part of the fitting was ground off flush on the outside, after the epoxy set.
They are not so much "installed" as they are now an "integral part of the hull structure"...
Several "right" answers to this -- so do what lets you sleep well.
Loren in PDX
http://www.ericsonyachts.org/infoexchange/showthread.php?t=569&referrerid=28
This is one of *many* relevant threads about this topic. Having a "flush" exterior presence might gain you a nano-knot of speed, but also might be more psychological than measurable. :nerd:
The other caveats regarding the bronze mushroom type are the threat of electrolysis and the weight added to the boat compared to composite material thruhulls.
(As to the later issue, that extra 6-pack of beer carried for the sail back to the dock after the race will out-weigh all the weight savings in your thruhulls!)
Do a search on Bronze thruhulls, Marelon thruhulls, and Forespar.
Lots and lots of cogent discussion. Using "thread tools" you can organize any thread for easy saving or printing, as well.
I installed all bronze ball valves on our prior boat;
and all Forspar "OEM style" valves on the present boat -- and our threaded part of the fitting was ground off flush on the outside, after the epoxy set.
They are not so much "installed" as they are now an "integral part of the hull structure"...
Several "right" answers to this -- so do what lets you sleep well.
Loren in PDX
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