Thru-hull sizes

[tjelle1946]

Probably metric for millimeters--jorgen

 

[chris20636]

Rob,

I don't have the thru-hulls with me (still firmly lodged in hull), but I do have the gate valves here. The valves are all labeled Ametal AHA-60. The only other markings are a number that differs. I have:
engine cooling 10
seawater intake for sink 10
toilet intake 15
toilet output 32
sink output ?? (still installed on boat)

From taking some measurements and comparing to the dimensions given at
http://www.forespar.com/catalog/plumbing/thruhull251.htm
I'm guessing that the toilet intake (15) is a 1/2" thread size. This guess was somewhat confirmed when I found
http://www.conbraco.com/products/marine/indexmar.html
Notice that they list the 1/2" thread size as 15 mm and the 1 1/4" thread size as 32, which matches the dimension of the toilet output valve.

Both of these size thru-hulls seem easy to find. However, the only 1/2" seacock I found was at forespar. The problem is now the two valves marked "10". What size are they? And are they available?
As for size, notice that the inches to metric measure is not an exact conversion, i.e 2.54 cm = 1". Continuing the search, I finally found this chart,
http://www.pennusa.com/pennpage/directory/spec/metcons.htm
This seems to indicate that the "10" fittings are the same as 3/8" fittings.

Availability? I finally found some 3/8" thru-hulls at
www.perko.com

All excited, I switched over from their thru-hull page the their seacock page and, Doh!, no 3/8" seacocks. Mutter...mutter... what good is selling a 3/8" thru-hull if you don't sell anything to go on it. After looking at lots and lots of google search pages, I'm beginning to think you're right in that the small ones are not available. (please someone prove me wrong!!)

However, it might not be a bad idea to go up in size, at least for the engine cooling. I noticed on the Beta Engine install notes, that were on the VAGB CDROM, that the new engine requires a 3/4" raw water cooling system. I might consider doing that for future expansion possibilities. As for the seawater sink intake, going from 3/8" to 1/2" doesn't seem that traumatic, unless some sort of adapter can be found to fit a 1/2" seacock onto a 3/8" thru-hull.

Ack, enough rambling on. Hope some of this has been helpful.
Chris

 

[bbach1949]

Hello: For what it's worth, I used Conbraco "Apollo" flanged seacocks and
Perko through hull fittings when I replaced all gate valves on V-1071. 1 1/4
inch for head discharge which fits 1 1/2 inch hose; 1 inch for sink
discharge, 3/4 inch for head intake, and 3/4 inch for engine intake (from
which I tapped off for seawater intake to galley sink using a check valve to
prevent engine from pulling back from sink side). I eliminated the old
engine thruhull and moved it to the previous location of the sink intake on
the port side. Newer Vegas are no doubt different.

These seacocks work great, as they are smaller bodied than Perko and thus fit
in the tight spaces of a Vega. They are also reasonably priced through
Defender and others. I used plywood backing blocks saturated with epoxy and
a layer of cloth over. I suppose you could try to capture the bolts holding
the flanges, but I think it worked fine to use flat head bronze bolts
countersunk on the outside of the hull and covered over with 5200. More
flexibility when installing, and you can try the handle position before
committing to a bolt layout. Again, there is not a lot of room! Just snug
the bolts since bronze will stretch and ultimately break. The thru hull
should be holding things together mostly anyhow.

I thought of using Marelon, but they are also somewhat bigger bodied than the
Conbracos. No other fears, however.

I sleep better knowing how stout the through hulls are now.

I jacked the old thruhulls out with a bolt through a block with a hole big
enough to let the outside flange slide into it as it broke loose. Casey
describes this method in his "This Old Boat" book. No grinding, no pounding,
no hull stress.

Just my humble opinions, Bill Bach