knot meter

[shrevemr]

Due to the overwhelming response on the stern mount ladder for gas can storage, I thought I might get some response for yet another, possibly dumber question.

The bottom paint around the thru-hull fitting for my knot meter is flaking and some of the caulking (sealant) seems to be exposed. (viewed from under the boat).

While the temptation to ignore this is strong, I would hate to start shipping water in the middle of a trip somewhere. So my question:

What is the best procedure for fixing this and is it something a layman should attempt.

Thanks in advance for any help.

[mgoller]

It could be just fine, or not.  You'll need to determine how it is installed.  I have heard sailors with thru hull anything lay awake at night contemplating what "could happen".  The only cure is make sure it was installed right.  And possibly install a bilge pump that is float activated.
Where is installed, is it accessible from where? 
Seems like if you could get at it you could start digging it out, clean it and rebed it.
I guess you'll need to describe things more and why you suspect a problem.
I remember the question about the gas can mounted on the transom.  My thought was don't do it, so I figured you wouldn't want to hear that.  It is probably the safest place for extra fuel though.

[shrevemr]

Thanks for the response. The rack for the gas can turns out to be a small "swim platform"  with a fold-down ladder. A small gas can can sit there with the ladder up, tied in, and the can is out of the cockpit and out from under foot without having to be stored down below.

The knot meter doesn't currently leak and the boat stays on the trailer most of time. In the process of redoing the bunk boards and other refurbishing on the trailer, I couldn't help fiddling with the knot meter, and that's when I noticed the flaking and and a little of the caulking missing.

I will pull the sensing unit this weekend and try to determine what might be involved with re-bedding the housing. I want to be proactive so I hopefull won't have to add this to my other nighttime worries.

1. Is the anchor holding?
2. Did the anchor light burn out?
3. Did I leave anything turned on that's discharging the batteries?
4. Am I in water shallow enough that something big can't run over me?
5. Am I in water deep enough that I won't be aground when the tide changes?
6. Do I think they noticed that I wasn't at work this afternoon

Thanks again for the response. I'll let you know how it goes.

Mike Shreve, CP16  "La Atrevida"
#855

[TroyVB]

Just realized that you had your question answered by Marcus.  I should have read further.

I do knot have a thru hull on my CP16 but had one on a previous boat.  The housing was threaded with a large nut on the inside of the hull.  As Marcus said you will have to determine the installation but the removal of the thru hull requires very little in terms of special tools.  If you're concerned I would rebed and not worry.  Life is too short.

Here is the procedure that I used:
1) Remove any hardware holding the thru hull
2) Place a long hex head bolt with a washer through a scrap of 2x4 about a foot long.  From the outside place the bolt through the thru hull with the threads inside. Place a small block on the bolt on the inside then a washer then the nut.
3) On the outside place to shorter blocks between the 2x4 and the hull
4) Send a helper inside with a wrench that fits the nut to keep it from spinning
5) Tighten.  As you do the thruhull will be pulled out.  keep an eye on the hull as you tighten.

Clean up the housing or get a new knotmeter and reinstall.  You will sleep better knowing that you did the job and it was done right.  Maybe way more info the you needed or wanted, but I hope it helps.

[spaul]

I couldn't help myself after reading Mike's worry "did they notice I wasn't at work today" ? I noticed early in my career that being on the golf course was the only valid excuse for being absent, even dying was a scheduled request. With that in mind I gave serious thought to naming our cp27 "Golf". SInce it was always ok to be "golfing" and never ok to be "sailing". I thought if I said I was going "golfing" (which would have meant sailing) that little white lie would be ok and all would be happy.

So I took the package offer two years ago and now I go sailing whenever I want since I hate golf, and that's because I'm so bad at it. Just cold evening thoughts before dinner. Stop worrying and go sailing ! That's my advice and I'm sticking to it.

Steve Paul
cp27/2  "IM PAUL SIVE"

[shrevemr]

I wanted to take this opportunity to say "Thanks" to Troy VB for the step by step  on the removal of the knot meter. I will remove and re-bed the unit for sure; takes a couple hours and will alleviate a lot of anxiety, leaving me free to worry about the other things on my list.

As for a sailboat named "Golf", perhaps an alternate spelling would be "Gulf", depending on your latitude. "Gone gulfing" sounds pretty business-like to me. Thanks for your advice; I intend to follow it.

[Craig Weis]

Well my 2~2 inch drilled holes through the hull were sealed with the threaded insturments just gooped to the max with 3-M 5200 [slow set, say about three days] then after setting I simply cut the excess away with a razor blade in a 1/8 to 1/4 wide swath around the circumferance of each Rayathon Bi-Data 40 insturments. The 3-M 5200 sticks tight. We use the same material at Palmer Johnson when we build our 150 ft and 120 ft Sport Yachts.

No flappers. I don't want anything hanging down under the boat's hull that should not be there slowing my boat down. Skip. Not a drop of a leak yet and it's been five years...and NEVER paint over the 'goopy' stuff. Why? It'll never stick.

[Rick Klages]

I prefer to have no below the waterline through hull fittings and use GPS for speed measurement.

ick

[Glenn Basore]

Rick , sounds good to me, why would any one drill a hole when you can use a GPS system ?

And how important is a depth meter any way ?

I read some place, the depth meter will only give accurate readings if the boat is truly vertical, if heeled over there use less, is this true ?

[fiddlerami]

Before "compacting" down from a 30 foot sloop to the CP-16, I used to do some fishing in Lake Huron.  I wanted to be like the stinkboat guys who would always talk about how they "marked" fish while they were out.  I bought a Hummingbird fish finder (with depth readout) at Wal-Mart for not a lot of money.  I mounted the transducer to a piece of PVC with a SS hose clamp.  The PVC snapped onto the vertical tubing of the swim ladder via some open-ended PVC clips.  I also adapted it to the inflatable dinghy I used when cruising the North Channel.  I kept the fish finder and setup when I sold the boat and installed the clips on the motor mount of the CP-16.  It works slicker than frog hair.  The heeling of the boat makes little difference in accuracy - the irregularities of the bottom are greater than the fluctuation caused by heeling in reality.

[multimedia_smith]

I really like the idea of your removable unit... anytime you can avoid drilling holes in the boat, you've taken a step toward retaining its value... not to mention avoiding potential problems.  I too use a GPS for a speed indicator... for depth... when you only draw 18"... when I can see the crabgrass or feel the rudder touch... I know to go deeper.  I use the swim ladder for a gas can mount, and I managed to mount my bimini without drilling any new holes.
Right ON!
Dale