#1
IP: 108.202.198.134
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Thru-Hulls
An added bonus to removing the A4 from the boat was the chance to take the cockpit drains apart and see what was up in there. I don't know if it is true of all Bristol 27's but what I found was unacceptable and dangerous. The cockpit 1 1/2" OD male end (molded FRP) was connected to a 1" ball valve via a 1 1/2" hose, a plain steel close nipple and a plain steel connector. (This resulted in a 1 1/2" OD to fit the hose). As an added attraction the ball valve was frozen. Open.
No need to mess with hose clamps - just shook the hose and the nipple sheared at the valve. Please don't tell me the factory did this. Below is my solution. The 1 1/2" ID hose slides over the1 1/4" OD hose perfectly. McMaster-Carr 1" NPT to 1 1/4" barb. Don't waste your time looking for a 1" NPT to 1 1/2" barb. And the hose is cheaper. Howard
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S/V Swimmer Bristol 27 |
#2
IP: 71.200.119.246
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Raw water thru hull
Here is my solution for the raw water intake:
I found as many people adverse to an external strainer as I did in favor of one, so I found one that can be removed for cleaning. It had a bevel I did not believe I could easily make in the hull, so I blended fiberglass fibers from mat like that pictured with resin to make a base plate for the thru hull itself. the strainer opening is held in place by a circlip and can be taken out. The backing plate pictured was made with multiple layers of mat and resin, Its about 3/8 of an inch thick. Next I have to get a 3/4 NPT nipple like the one you have pictured, to route hose to my strainer. James |
#3
IP: 199.168.148.136
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When you get the new plumbing installed open and close the ball valves every so often. It will keep them from "freezing" in the open or closed position.
TRUE GRIT |
#4
IP: 108.202.198.134
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Maintenance
John, I just got the boat last Fall. Haven't had her in the water yet but I will hopefully be more conscientious than the PO. There I go again, taking things personally.
Thanks, Howard
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S/V Swimmer Bristol 27 |
#5
IP: 100.0.123.247
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Howard - It is not a good idea to mix threads on a thru hull installation. The ball valve will be NPT tapered but the thru hull will be NPT straight.
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#6
IP: 108.202.198.134
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Threads
Thanks, Hanley
I'll check it out soon as I get the winter cover off the boat. Howard
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S/V Swimmer Bristol 27 |
#7
IP: 184.0.105.143
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Quote:
As Hanley pointed out the threads should be matched for the thru hull and valve. Here's a good "How To" article to read through... http://www.pbase.com/mainecruising/replacing_thruhulls
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-Jerry 'Lone Ranger' 1978 RANGER 30 |
#8
IP: 173.53.22.120
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Quote:
But I think there's a possibility that the flanged through-hull seacocks are straight threads, meant to go on the through-hull fitting. It looks to me like that's what you've got? Just double-check the threads to make sure.
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#9
IP: 173.50.76.170
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That barbed fitting is brass, and I'm assuming the red handled valve is brass as well?
From your location, I'm assuming you are sailing in fresh water, but. . .you can still get dezincification. Just an FYI. . . Groco makes a flanged adapter base for use with ball valves. I've done 3 of the 6 thru-hulls in boat my with these. They are very nice. Groco thru-hulls also have a composite threaded end and will allow you to use an NPT valve on the end safely. I did 2 of my thru-hulls like this. . .mostly to cap off 2 unused holes in the boat. It was cheaper and easier than glassing over them Just tossing my 2 cents in here |
#10
IP: 71.178.84.65
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hcrisp, the first year I had my boat I learned all this...that pbase site of maine cruising's that Jerry posted is an authoritative source on the subject in my opinion.
I personally have been really happy with Marelon. My boat had pipe nipples glassed into the hull as thru-hulls, and I won't bother to tell you what was screwed onto them. I cut/beat/hacked them out, put in marelon thru-hulls, and then marelon seacocks. Where necessary, I cut backing plates out of PVC board of the necessary thickness (epoxied/5200'd to the hull) so the seacock would not bottom out on the threads. Then the seacock was screwed to the backing plate. As Hanley eluded to, the issue is usually mismatched threads. Straight thread thru-hull fittings with straight thread seacocks + a thread sealer = good. Don't forget to double clamp anything below the waterline.
__________________
-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#11
IP: 108.202.198.134
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NPTism
Yeah, I hear you. I shouldn't be using brass below the waterline. Zinc is a loser but freshwater is more forgiving. It beats plain steel.
The ball valve pic in #1 is tapped NPT so it fits the hose connector shown. Now I wonder about the through hull. Did someone force the NPT ball valve on the thru-hull? First thing I'll check when the cover is off. Howard
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S/V Swimmer Bristol 27 |
#12
IP: 71.178.82.166
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Howard...maybe...lots of times people force NPT onto straight threads and they 'get tight' so they assume they are OK, when they are really binding, but not sealing.
As I am sure you know, this is a much easier problem to deal with while the boat is dry than when it is floating..
__________________
-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#13
IP: 68.204.101.73
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Howard - While it is possible to force the ball valve down onto the straight thread thru hull, it is something you will always have to worry about. Hymodyne has the correct solution: a straight threaded thru hull with a ball valve seacock. The installation as you found it is not good. The only way to make it safe is to run a tap thru the ball valve housing to create, in effect, a straight internal thread but I don't recommend the procedure. The tap will cost more than the thru hull.
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#14
IP: 173.50.76.170
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Um, maybe they don't do that anymore? I bought my sets from JTD a couple years ago and the combo thread was part of the description and a selling point for me. . .I don't see them listed like that anywhere now. . .so, I dunno
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#15
IP: 174.94.20.181
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Thru hulls - thru hull fittings - and hoses are no place to try and save money.
The Maine Cruising Forum has the best explanation of how-to install a thru hull and fittings anywhere. I replaced 3 thru hulls - fittings - and associated hoses on my Corvette this year using the Maine Cruising forum as my blueprint - I have 3 more to go. It was a lot of hard work, sweat and money but worth it in the long run IMO. Remember a thru hull and it's associated parts are the only thing preventing your vessel from going to the bottom. Last edited by 67c&ccorv; 05-14-2013 at 10:48 PM. |
#16
IP: 24.224.152.244
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Thru Hulls
Guys,
I've watched guys breaking themselves up trying to get into small spaces and to remove thru hulls. Just a quick note: I used a dremel tool with a diamond cut blade on it. Shove the end into the thru hull from the outside about 1/2 inch to 3/4 inch depending on fiberglass thickness... and zip a cut all around. One smack of a hammer will put one piece on the ground and the other inside the boat. When I was overhauling the boat in 2007 I was fighting like a animal and pulled muscles in my ribs to get one off and had to figure out a way to cut it. I asked myself...what can I get in there to cut that SOB off. Have since shown or done it for others. Less than 5 minutes that hole is open! It is a good idea as well to mix some epoxy with glass fiber and rub it around the exposed fiberglass in the hole with your finger as well...just to permanently seal the fiberglass. Let that dry before installing new thru hull. That will save allot of sweat and swearing.
__________________
Mo "Odyssey" 1976 C&C 30 MKI The pessimist complains about the wind. The optimist expects it to change. The realist adjusts the sails. ...Sir William Arthur Ward. Last edited by Mo; 05-23-2013 at 10:08 AM. |
#17
IP: 24.188.38.160
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I had pipe glassed into my Tartan 27 and gate valves threaded on. Yup, original factory. Everything else on her was nicely done. Go figure. I replaced the head intake and discharge with bronze. Heavy and expensive. I have subsequently replaced everything else with Marelon and I'm happy so far.
Marelon appears to resist sticking better. |
#18
IP: 70.91.159.33
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Nice install 67
+1 on the Marelon, Also it was the only 1/2" NPS seacock I was able to find.
Had I known better at the time. I would have taken out the 1/2" and up sized to 3/4' but it's performing well at present as it is.
__________________
Mike, Slower-Lower Eastern shore, MD 1973 Pearson 33 1967 Bristol 27 |
#19
IP: 99.141.136.198
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my C30 had glassed in pipe nipples. I used a hole saw just large enough to get on the outside of them. Drilled from the underside of the boat - easy peasy
I then cut the inside "volcano of resin" square to the new thru hull leaving enough to make a nice landing for the big washer. bedded the flanges on the outside in 5200 |
#20
IP: 173.50.76.170
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I replaced the last of the 38 year old glassed bronze nipples with bonafide seacocks this spring. With all the stories I've heard and warnings presented to me. . .they were all in perfect condition with no signs of pink under the blue/green layer. No leaks, no deterioration, and they PO had even put new ball valves on them.
Of course, I never would have been able to tell how well they were with out getting them out. . .which I guess is part of the point of replacing them |
#21
IP: 166.147.88.47
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plugging thru hull
Took motor and shaft out of the boat...would like to plug the thru hull - temporarily.....thinking of epoxy in a wooden plug.....can be drilled out when is time to install shaft again......?????...better ideas??
Last edited by 2dogsnight; 05-22-2013 at 12:38 AM. |
#22
IP: 68.56.139.11
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That is plywood? I usually cut a piece to fill the hole, then back it with a larger piece inside, against the hull. Use screws and glue (epoxy).
If you want to re-drill it, no biggie. |
#23
IP: 98.248.12.160
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Mo, I am having trouble visualizing how you used a dremel tool to remove the old thru hull. Can you explain in more detail what kind of diamond cutter you used? What did you remove to get the tool inside the hole? A picture or diagram would really help.
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#24
IP: 74.101.158.133
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In my opinion hacking out through-hulls is the perfect job for a Sawzall, and is punching above the weight class for a Dremel.
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#25
IP: 206.125.176.5
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tenders, I went straight to an 8# mini sledge and beat mine out..
__________________
-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
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