Silly questions - Winter boredom setting in.

[smoothmove]

Dear Forum

Think there's no such thing as a silly question? These may require you to re-think that position. To make it as painless as possible, I'll ask 'em all at once. These are a mongrel assortment of things that have sort of bothered me for a long time, but I always thought someday I'd figure out. Well maybe the day has come to ask for help.

1. Why makes a Flush Deck a Flush deck? People call my 1968 38' DCMY a flush deck but it clearly has a 1 foot rise from the front deck to the back deck. I've seen half a dozen differrent styles of boats called flush decks and I can't really see the common element.

2. Why do I always see boats with fresh bottom paint where they have not painted the boat leveler hydraulic cylinders. I have a VC-17 bottom and the only place not painted is the hydraulic cylinder bay. This area became "Mussel Beach" this year but the rest of the bottom is clean. Wouldn't it be OK to paint these?

3. In that same vein, why isn't VC17 a more popular bottom paint? I just squirt it off at the end of the season and slap on a fresh coat in the Spring. Not trying to sell the product - I'm just curious.

4. I hear all these horror stories about failing bilge pump switches. Why couldn't people take a page from computer designs and use a RAID or RAI(S) - redundant array of inexpensive switches. I can't see a problem wiring a couple of switches in parallel. It seems pretty unlikely that both or all the switches would fail at exactly the same time.

5. On my boat at the helm, there is are 2 pull switches that operate forward and aft bilge pumps. These switches must be OUT for the pump to operate. It would be easy to accidentally turn off the power. Does this seem right? For that matter, why would you want to turn the bilge pump off anyway? There has to be a good answer to this, since Hatteras did it that way. Their position is always the thing I think about as I'm leaving the boat and I have to go back to double check.

6. In smaller boats, it always seemed obvious when you transitioned to "planing" That "transition" is not really apparent on my Hatt. Is it when the wake parts as it passes the stern? I don't really detect an overcenter kind of speed that that I can back down the throttles and maintain with less power.

Anyone care to enlighten? I'll say thanks in advance.

Eric

 

[Paul45c]

5. On my boat at the helm, there is are 2 pull switches that operate forward and aft bilge pumps. These switches must be OUT for the pump to operate. It would be easy to accidentally turn off the power. Does this seem right? For that matter, why would you want to turn the bilge pump off anyway? There has to be a good answer to this, since Hatteras did it that way. Their position is always the thing I think about as I'm leaving the boat and I have to go back to double check.

I'll take a stab at a couple, if you like. On this one, I'd start with a question. Are you sure your automatic float switches are not wired so as to always have power to them? On most boats, they're always potentially hot, otherwise how would the automatic work? On mine, I've got a rocker switch that has three positions: off, auto, and on, with that last being a spring-loaded momentary position (in other words, it's only in that position when you're holding it there). For some reason, it has the "off" presumably to kill power even in auto mode, though I've never held it in the "off" position. I agree with you that a push-pull is not ideal for a bilge pump; I have one on my vacuflush head control in the head, and people bump it closed all the time and then tell me I have a problem down below.

6. In smaller boats, it always seemed obvious when you transitioned to "planing" That "transition" is not really apparent on my Hatt. Is it when the wake parts as it passes the stern? I don't really detect an overcenter kind of speed that that I can back down the throttles and maintain with less power.

Anyone care to enlighten? I'll say thanks in advance.

Eric

Some have described Hatts as semi-displacement hulls, on which you normally never get that really bow-high transitionary plowing aspect prior to a recognizable plane; regardless, most would consider your boat planing when you see that old rooster tail form up aft of the transom.

 

[Hows Hatt]

I have one to add. Why is a convertable called a convertable? Thanks. Howard

 

[SKYCHENEY]

I use VC17 too and I love the stuff for fresh water. I have no idea how it would work in salt water, but I bet Maynard Rupp will be able to tell us soon. With the VC, I paint everything except the shafts and props. I paint the struts, rudders, tabs, and tab cylinders. When I bought the boat the cylinders were not painted and were covered in muscles as well. I decided to scrape and paint and I haven't had a problem since.

As far as Flush Deck goes, I think it was originally used to designate any aft cabin boat that did not have a trunk cabin. I'm not completely sure, but it seems to make sense.

 

[smoothmove]

I'll take a stab at a couple, if you like. On this one, I'd start with a question. Are you sure your automatic float switches are not wired so as to always have power to them? On most boats, they're always potentially hot, otherwise how would the automatic work? On mine, I've got a rocker switch that has three positions: off, auto, and on, with that last being a spring-loaded momentary position (in other words, it's only in that position when you're holding it there). For some reason, it has the "off" presumably to kill power even in auto mode, though I've never held it in the "off" position. I agree with you that a push-pull is not ideal for a bilge pump; I have one on my vacuflush head control in the head, and people bump it closed all the time and then tell me I have a problem down below.

Some have described Hatts as semi-displacement hulls, on which you normally never get that really bow-high transitionary plowing aspect prior to a recognizable plane; regardless, most would consider your boat planing when you see that old rooster tail form up aft of the transom.

That's a possibility - that the switch is meant to overide an "off" water level switch. That's not how it's wired, but who knows how it started out. The owner's manual states
"The pumps ar powered by 12 volt from the Hatteras electrical Panel, where the master and individual switches must be on for operation. They are controlled by separate switches on the bridge control panel, and discharge overboard. (a good idea - my parens)

 

[ADaily3224]

I thought the questions were pretty good.

I had one of those 38's with the same set up for the bilge pumps. I bought new float switches for all three pumps, installed new power switches so they would operate like the newer Hatteras. I was annoyed by the pull push switches too.

VC-17 it's a super product but you don't see it that much because #1 it's considered a sail boat product. #2 it's expensive. #3. It's not compatible with any other bottom paint. Every bit of old paint has to be removed from your hull before it can be applied. After cleaning the bottom At least 5 coats of VC tar needs to be applied, and 5 coats of VC-17 to follow. I have it on my 21 Outrage and wouldn't think of having anything else. I thought about it for the Hatteras but the cost of getting every inch of old bottom paint off the Hatteras stops me cold.

My 38 DCMY had the JT671N's at 310 HP each, It's a heavy boat with lots of weight forward. Up until about 2,200 RPM the boat produced a bow wave, it was heavy in the nose. It climbed out very smoothly and ran a nicely at 14 to 15 MPH with no bow wave and a fairly flat aft wave, which may explain why there isn't the traditional hump. By the way, your boat is a DCMY not a flush deck, I think Chris Craft captioned the term Flush deck when they introduced the 41' flush deck motor yacht. From bow to stern everything on deck was at one level. I think I'm correct on this but someone else may have a different opinion.

Tony D

 

[jim rosenthal]

I thought 'flush deck' refers to the fact that the deck in a MY of that type is all on one level. If the other Eric sees this, he will probably know the answer...

I have seen boats with paralleled bilge pump switches. No reason you can't do this. Higher quality switches like the Ultra have partly solved this problem. Bilge pump switches lead a hard life, I think.

I agree about the pull out switches for the BP circuits. I don't think anyone makes a knob-type switch like that (Perko, CH etc) that is ON when pushed in and OFF when pulled out. And we're all so used to the old type, we'd probably screw it up. I would, certainly.

I DO paint my hydraulic cylinders. It helps a bit. A bit. I just get Mussel Shoals, not Mussel Beach . But there's always growth there.

 

[Boss Lady]

Because of the deep vee extending all the way back to the stearn, you do not ever really plane a Hat like you do on lighter, less dead rise hulls. We barely get above the threshold where the boat rises out of the water far enough to escape the drag. It does get out of the water far enough to reduce the drag some, but we are still pushing a lot of water out of the way. Hence the semi-displacement/semi-planing designation. We are doing both at the same time. If you could go 30 knots you might find the transition point, but in reality anything below 25 knots makes "planing" questionable. I can maintain a plane on my Fountain down to about 23 knots, any slower and it drops off step and it takes huge amounts of throttle to get it back up on the step. This is on a 38' boat with a 10' beam that only weighs 13,000 lbs. We are lying to ourselves if we ever think we are actually planing a deep vee hull that weighs 40,000+ lbs or more at 18 knots. LOL You can also see if you hit a planing speed by looking at the fuel curve while running the boat, you will hit a sweet spot where you mileage is optimum. If you best mileage is at hull speed then you are not getting up on plane. I get my best mileage in the Fountain at 50 knots (1.5 mpg) thank you Flowscan! Anyone willing to post some Flowscan numbers for rpm/speed/mpg?

 

[jim rosenthal]

Chris, I am not getting Floscans, but I am going to install pyrometers and boost gauges with my new engines. I have been told that you can also figure out the sweet spot in the rpm range using those. Does anyone know more about this and can direct me to a source of information on it? I have not had much luck on this.

 

[J's Dream]

Dear Forum

5. On my boat at the helm, there is are 2 pull switches that operate forward and aft bilge pumps. These switches must be OUT for the pump to operate. It would be easy to accidentally turn off the power. Does this seem right? For that matter, why would you want to turn the bilge pump off anyway? There has to be a good answer to this, since Hatteras did it that way. Their position is always the thing I think about as I'm leaving the boat and I have to go back to double check.

Eric

Eric,

Those switches should IMHO only operate the manual mode of the bilge pump. On my electrical panel from Hatteras I have individual breakers for each bilge pump...and the breakers send power to the pumps, allowing them to be on automatic, with the switch only operating the pump manually.

As for why you would shut off a pump??? Say you had a little oops, or a real OOPS ...and you drained gallons of oil or fuel into your bilge. Well, if you pump that out, and the right person (or wrong person) sees it happen, get out the checkbook, cause its gonna cost you.

Jason

 

[Maynard Rupp]

I surely am the VC-17 guru I guess. Yes, all the old paint needs to come off. If you care about your boat, all that crap should come off. I hired a great guy, he used 38 ngallons of stripper, then sanded the entire bottom clean. I paid him $1100 for our 36' Hat. Next I fixed the 10 or so blisters and rolled on 7 coats of interprotect 2000. The Interprotect is all rolled on in a single day, you just head for the bow when you reach the stern. In the evening I recommend 6 Advil and a very hot soak in a tub. Next morning we rolled on 2,(not 5), coats ov VC-17. Each winter we spend about 20 minutes with a scotch bright pad getting off anything the preassure washer missed, tape the waterline and roll on 1 coat of the VC-17. The big deal is: first, it is an awesome anti-fouling paint. Second, you never again will have to scrape, sand, or whatever, the boats bottom. Third, the stuff is slippery and should help move your hull through the water with less resistance. It was originally used on racing sailboats mainly because it doesn't build up. After you spend 200 hours making the racing boats bottom fair and glass smooth, the last thing you want is goopy crap paint on that jewell. In fact the real hard core sail boat racers use a white epoxy primer only . Yup, those poor fellows dive at least twice weekly to clean their bottoms. The white paint helps you see if any foreign matter has accumulated. Soundslike fun, eh?

I too wonder why they call a convertable that. What is it convertable to or from?

 

[Boss Lady]

Chris, I am not getting Floscans, but I am going to install pyrometers and boost gauges with my new engines. I have been told that you can also figure out the sweet spot in the rpm range using those. Does anyone know more about this and can direct me to a source of information on it? I have not had much luck on this.

Hi Jim,

I will have to think about this one, I just bought the Flowscans for Boss Lady at FLIBS, they came in last week. Makes a complex problem simple. I am a little rusty and have not done this since my drag racing days, Karl is the real thermodynamics guy. Karl, jump in here and save me! or else I will have to get a couple of books down off the shelf

 

[luckydave215]

A convertible is a sportfisher with a larger than normal house, and is therefore suitable for use as a cruiser as well as a sportfisher. Dual mode, just like a convertible car.

 

[Genesis]

Couple of things....

First, there IS a point where a Hatt (most anyway) planes. If you watch your stern there is a point where the wash separates from the stern - you can see all the way to the point of the "V" if you look down (and there's not a swim platform in the way), and the water flow coming off the stern is clear rather than turbulent.

That's the point where you're on plane - you are no longer pushing water, you're on top of the water. Yes, these boats don't rise up the way some do, but the principle is the same.

On my 45C that was right around 13kts with the tabs down.

As for optimum "sweet spot" running, I found that the Floscans told me something very important - there was very little difference between running at 13kts and 18kts in terms of fuel efficiency. Beyond 18kts the price of poker started to climb, but even then it wasn't THAT bad. Basically from 18kts on up you were between 0.4 and 0.6nmpg.

In terms of the engines being happy, however, there IS a point to pyros and boost gauges - really pyros more than the boost number. If you watch the pyros and have someone run the boat up in 100 RPM increments, sitting at each point for 3-5 minutes, you'll see that as RPM goes up the exhaust temperature does too - up to a point - then it DROPS a fairly significant amount (100 degrees or so.) This is where the boost has come fully on and exceeds the engine's fuel requirements. EGTs will then (if you keep increasing RPMs) start to rise AGAIN.

In general the 1100-rpm range is good (and safe) for long-range operation, and its economical too. But you'll only do 9kts or so.

The 1500-1800 rpm range is a dangerous place to play. There is no boost and EGTs can be sky high. If you have pyros and they're not showing distress, all well and good, but if they are, stay the heck out of there!

As you come up in the 1800-2000 RPM range, you'll see the "dip". That's a good place to run for "high cruise." Keep going and the EGTs will start rising again - that's where you don't want to be. 200 RPM off the top is almost always too far up the curve.

Much also depends on how the boat is propped. If overpropped you'll see horrifying high EGTs at higher power setings. Get 'em too high and you cook turbochargers and, in extreme cases, exhaust valves and even piston crowns. That gets expensive.

 

[MikeP]

Re "Convertible"

According to "The Yachts and Ships of Jack Hargrave," (which everyone on this website should buy!!!! - no, I have no connection) the word "Convertible" applied to a boat was first used by none other than Willis Slane who created the the first Hatteras. He wanted his boat (designed by Jack Hargrave) to be "convertable" - useable for serious sport fishing AND a comfortable boat to spend time on with appropriate amenities for the wife! So it was convertable from one use to the other (without any actual changes) and so described. There is a humorous comment in the book that if he had copyrighted the term "convertable", he'd have probably been separately wealthy from royalties since all boat builders started using the term.

There's a lot more history to these Hatts than one might think. Buy the book! Sams should carry it and requre everyone registered on this site to purchase it. Heck, if they do, I'll buy another one!!!

Yes, it's that good.

 

[Trojan]

I would check your pumps. Your pumps may be wired wrong. There should be 3 wires going to your pumps. One is hot from the panel breaker to the float switch, one is hot from the manual switch.
My 43 will plane at 13 MPH. I can tell when it planes by the rapid speed gain after it reaches 13 MPH. Then I back off. Also the side spray moves back from the bow and it is reduced. Also the wake will flatten out and the wave height will reduce. If you watch the horizon you can also see the bow rails drop down below it. I run with my tabs full down or it won't plane.
I use the same bottom paint that goes on every Sea-Ray. It's Pettit HYDROCOAT. Its a water base paint. I have been using it for about 7 years . It works good for me in fresh water. My bottom was stripped and any blisters redone just be for I purchased it.



BILL

 

[Bill Allen]

What i did with the bilge pumps was label them on, and added one of the little on/off/auto switchs. It was especially handy for the very aft pump as it allows me to switch it to on when I am down there and open the hatch. Bill