seacock during reynolds ownership

S

slowtrot

New member
I took the seacock out and found a Perko bronze strainer on the bottom. The Perkp has straight threads until the last 1/2 or so and then they taper. The compression nut has straight. threads. The valve is a regular 3/4 type with tapered threads. The seacock was sealed top and bottom. The core was dry and untouched, just raw wood. No sign of water ever being there.

The question is how much to dig back to fill the core. Should I remove about an inch back, fill with epoxy, and then rebore the hole and install a seacock or is there some other step. I have read all the posts about potting. I dont have lots of experience with general boat epoxy but I have great faith in JB Weld. Would JB Weld work as a filler?
 
The second link that ferret30 provided is great. Use a dremel tool (or similar and a small grinding tip to remove the core inside the glass layers. You can also use an allen wrench in a drill - the balsa core is soft and easily removed. You don't need to go back too far, a 1/4" is plenty. The goal is simply to have a reasonable layer of epoxy sealing the balsa core in the event that the sealant around the penetration leaks (perhaps I should say eventuality as it will leak someday if not redone periodically). It's not a strength issue, just a sealing issue.

Definitely don't use JB Weld, use thickened epoxy. JB Weld is too brittle. You should be able to use painters tape (or similar) to tape off the bottom and fill from the top. The epoxy is relatively easy to use. By the West System stuff a few mixing cups, some cabosil thickener and some popsicle sticks.

As for the seacock install, a compression nut with straight threads going onto something with tapered threads just ain't right. You might want to post a few pictures of the parts so we can advise you. If you're going to do this, you want to do it right so while the epoxy is curing, you might wind up making a trip to the local marine store to pick up a few new parts for a proper seacock installation. Ideally, the seacock will have a nice flange that mates up to the hull bottom to distribute any torque on the valve over a larger area. I don't know what you have but not all are installed with a flange and we've seen some with brass (instead of bronze) fittings.
 
You mention a strainer on the through-hull: just curious, but what is this supplying? I ask because my preference is usually not to have an outside strainer (if I knew what the supply was for I could elaborate).

I'm not sure I completely understand what you found there (photos would really help us to help you), but in a nutshell, the through hull will be NPS (straight threads). The part of the seacock that engages the through-hull should also be NPS, but oftentimes I see NPT (tapered) thread valves "forced" onto NPS through hulls. This results in only minimal thread engagement which can be dangerous.

Presuming this is below the waterline (the strainer makes me think it is), and it is in a cored part of the hull, here is what I would like to see:

1) Parts
- Good quality bronze or Marelon (type of plastic) through hull (I like US-made bronze)
- Good quality bronze or Marelon seacock
- Backing block inside boat (I like to use fiberglass for this) (may not be necessary depending on how you close out core)
- Suitable hose (wet-exhaust hose is usually a good bet for below-the-waterline hose)
- Good clamp (e.g. AWAB). Single clamp only is fine or even best - double clamps often land in such a way as to put excess pressure on the hose at the too-short end of the barb, which makes them worse than (good) single clamps (ABYC only recommends double clamps for fuel fills and exhaust systems).

2) Installation/routing
- No "stack" of components or fittings inside boat that provide leverage for damage due to impact
- Nothing that makes it too hard to get to the valve to close or exercise it
- Seacock flange secured to boat (there are various ways)
- No external strainer unless really necessary (can be hard to clear when underway; you may not need a strainer or you may be able to use a strainer inside the boat that you can get to while underway)
- Core closed out if in cored area of hull (via one of below methods):

a) An "excellent" way is to remove core in a ~6" diameter circle from the inside of the hull where the seacock will go, and then close it out with a new layer of fiberglass (thus through-hull only goes through fiberglass).

b) A "very good" way (which is likely good enough and which is much better than just a "lick and a promise" of sealant alone) is to cut the core back past the fitting and any fasteners and backfill the area with thickened epoxy, then to re-drill the hole to the proper size. In other words, in this way you are still drilling through skin/filler/skin, but the "filler" is thickened epoxy and not balsa wood.
 
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