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wndsnd
11-08-2004, 04:58 PM
I have finished the port side restoration of the 1956 Town Class Sailboat that I have been working on. I had to replank about 80% of this side, however, the starboard side seems to be in
a little better shape. I saw some scribe marks on the bow that looked like the original waterline, however they stopped after about 3 feet, no doubt being sanded out over the years. Is there a method of determining the waterline with the boat out of water and inverted? Rather than paint along the laps, I would like to restore a proper waterline. Thanks

Dan McCosh
11-08-2004, 06:00 PM
It's possible with a laser level, assuming there are three or four points left from the old line. The idea is to establish a plane from these points, and use the laser to extend it to the hull.

Ian McColgin
11-08-2004, 06:38 PM
Must you do this up side down? It will be much harder to visualize.

As a first step, try to level the boat fore and aft as well as athwartships. To do the fore and aft at a best guess, looke the boat over for something that might be level when the boat's floating, like the top of the centerboard trunk or the seats or seat risers or even the floorboards it it's plain that the floors have been raised to flatten them.

Check that this line appears normal to a projection from the mast step through the partners.

Absent other confirmation, if you're still working upside down, nail a plumb line in the center of the step and fiddle the boat till the line passes through the dead center of the hole in the deck. If you've gained your senses and are working right side up, make a paper target with a small enough hole centered in the partners so you can tell a good center and aim the plumb bob at the step.

OK, assuming a general level, look at where your scribed marks are. I like the water hose level - clear tubing is nice. You mostly fill the tube and get one end, open up, with the waterlevel lined up with the scribe marks and bring the other end around to the transom and see. If this is like other TC's if vaguely remember from lovely summers in Maine in the mid '50's, it might be a couble of inches from where the transom and skeg meet. This establishes the ends of your water line.

It's gonna be very hard to get the water level method to work with the boat upside down. Maybe you have a laser.

Anyway, chaulk in the straight water line and now stop to think. The boat will look nicer if there's a little flair at the bow and stern. Also, it may happen that there's better or worse places to hop the waterline from plank to plank, especially at the bow. It may also be very easy to find an appealing flare at the stern that does not hop any planks.

So fiddle, please yourself, and step back lots.

Whatever, don't scribe it the first year. Makes it easier to change your mind next winter.

G'luck.

wndsnd
11-08-2004, 07:04 PM
Ian,

I do not have a laser however it seem like a good Christmas idea! ;) However I do not have to do it inverted, if I practice patience I can finish the starboard side, flip the boat, finish the interior, detail the trim, fill and final paint, and then decide. Or, I can have a beer and see what everyone thinks! smile.gif I did send an email to Ralph Johnson of Pert Lowell Co. Ralph is the son in law of Pert who built most of the Townies and is carrying on in the tradition building wood and glass Townies. I thought he might have a template or something.

Thanks

Bruce Hooke
11-08-2004, 07:08 PM
You might well be able to rent a laser level at a tool rental place...

Paul Piercey
11-08-2004, 07:17 PM
Don't rent one. They are very cheap. I bought one to do the waterline on a boat I built; it cost $9.95.

Paul

http://forums.bateau2.com/gallery/albums/userpics/10167/normal_ck17ps.jpg

mmd
11-08-2004, 11:33 PM
I prefer the Luddite method that Ian described. I add food colouring to the water in the level so it is easier to read (I like blue for some reason), and have valved hose fittings on each end to prevent leaks while moving about.

Bruce Hooke
11-09-2004, 12:30 AM
Originally posted by Paul Piercey:
Don't rent one. They are very cheap. I bought one to do the waterline on a boat I built; it cost $9.95.

PaulWow, they have clearly come down a lot in price from when I last looked at them. Either that or I was looking at much fancier models...

Dan McCosh
11-09-2004, 12:55 AM
they were on sale for about 10 bucks at Home Depot. The idea is to put in on a flat plate where you can rotate it to project a plane. The plane can be tilted if you can't level the boat. I did this with the boat up right, but not quite level.

Ian McColgin
11-09-2004, 07:11 AM
mmd uses lasers in his practice, so I'd take it that the water bit has some advantages if he likes it. Unlike myself, he's not technologically challenged.

The laser is nice for making a straight line if you can set it up exactly level with the level at the boat's waterline. And you have to do it the same way on both sides of the boat. Really, this is more work than the water level right off the bat.

But really, you'll find that a dead straight waterline appears to sag at the ends. So, given that you'll need some flare, the water level is the best way to check the symetry, side to side, of your preliminary markings.

Once you have the marks on, either get the boat up in the air or yourself seated on a rolling chair such that your eye is comfortably near the waterline. Start the tape at one end - good quality fineline tape like from an autobody shop rather than household masking tape - and get one hand well back, squinting towards the start point where the other hand is. You can get the tape to land nicely and be spoting any small bumbs or valleys in this posture. Hold the tape roll such that it comes smoothly off the roll and your hand is not near the tangent place where it peels off. You'll have the tape under slight stretch and if it's running over a thumb or something the edge will be blemished and this blemish will spoil the perfection of your line. A little extra time getting the tape right is a good thing.

If you're not putting on a boot stripe, you can get away with painting the topsides first to a nudge below the waterline, marking the waterline and taping to it, sanding the topside paint that's below the waterline to get a feather edge and allow bottom paint adhesion, and then painting.

G'luck

imported_Steven Bauer
11-09-2004, 08:49 AM
We used this self leveling laser to set the molds for the Elf. At the same time I made a couple of marks on the wall to use as a reference after planking to mark the waterline. The laser mounts on a regular camera tripod and you just crank it up or down until the laser line hits your mark.

http://www.imagestation.com/picture/sraid146/p6268c55abc65d2e382534c6c85867592/f651abf9.jpg

[ 11-09-2004, 09:00 AM: Message edited by: Steven Bauer ]

Bob Perkins
11-09-2004, 09:38 AM
Steve,

We have the same exact laser lever smile.gif

I used the laser for many things - lining up frames, water lines etc...

To do a waterline (easy upside down) .. You only need the WL point at the bow and transom. Once you know the WL at the transom - you can plot the same point on both sides, then level the boat. Once the boat is level - the laser would be in the same plane all the way around.

The self leveling laser makes this a lot easier - but it can be done with one that you need to level yourself.

Good Luck,
Bob

mmd
11-09-2004, 01:40 PM
Steps to re-establish the waterline with the hull upside-down:

Level longitudinally:
- Ensure that hull is free to move vertically
- Place one end of the water level (valves open) on the aftermost existing waterline scribe line so that the water is in line with the scribe line, and tape it in place with duct tape. (close valves)
- Move to the stem of the boat and tape the water level to the stem at a point where the existing scribe line is visible. (open valves)
- Using a jack, lift or lower the hull by the stem until the water level is inline with the stem waterline scribe line.
- Check for level on some other known level item (keel upper surface, centreboard casing top, etc.), if available.
- Adjust blocks to support hull.

Level transversally:
- Place water level on hull at gunwale near mid-ships (valves open), and line up water with gunwale edge. Tape in place (close valves).
- Measure from water level to transom along sheer.
- Measure same distance from transom on other side of hull and mark
- Place water level at mark, tape in place, and open valves.
- Shim boat on blocks to adjust to level.
- Check to ensure that leveling athwartships hasn’t disturbed longitudinal leveling by holding water level at known waterline marks on bow. Adjust if necessary.
- Harden up blocking so boat is stable.

Marking & scribing:
- Place water level at bow (valves open) so that water line is in line with existing scribe line and tape in place,
- Place other end of water level at intervals (every two feet would be fine – this goes really fast, so there is no problem doing lots) along hull and mark water line.
- Repeat above process on other side of hull.
- Using a long, thin batten, connect the marks. Sight along batten for a fair, sweet line, adjusting if necessary
- Using a race knife, scribe the new waterline into the hull planking.

Other comments:
- If a boottop stripe is applied, the waterline should be a straight line parallel with the water surface when the boat is at rest. If not, waterline should be curved upwards at ends as described for boottop upper line (below).
- The waterline should be an inch or two above the actual waterline so that slime doesn’t mar the boottop stripe or topsides.
- The upper line of the boottop stripe should curve gently upwards at the ends to make it look “springy”. A rule of thumb for how much is: rise forward = LWL x .005; rise aft = LWL x .0025 (a little more rise for small boats, a little less for large ones).The curve of this rise should be long – almost a continuous curve from bow to stern, not just a quick rise in the last few feet.
- If unsure of waterline accuracy, merely paint the waterline and boottop. Wait until your next haul-out to scribe the lines into the hull permanently.
.
.
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Edit to add:

http://www.imagestation.com/picture/sraid146/pa2e2c8fa2dcfcc0db64d858a9c4ebe0b/f650dcc0.jpg

This is my water level. Twenty-five feet of 3/4" clear tubing, two hose clamps, two garden hose shut-off valves, one bottle of food colouring. Total cost? About $12.00, all up. It doesn't need batteries nor a tripod, won't break if I drop it, doesn't need to be set back from the object being measured, works around corners and under obstacles, and is really low on the thief list of desireble tools to abscond with. But definitely not techno-cool.

[ 11-09-2004, 02:11 PM: Message edited by: mmd ]

wndsnd
11-09-2004, 06:33 PM
Holy Moly! I had no idea what I was getting into.
Thanks so much for all the feedback. It looks like
any procedure is very complicated. Maybe I will paint the whole thing white!

In any event, I will study all of your suggestions and figure out which I can best accomplish. Meanwhile I await an email answer from the builder and will see what he can offer.

rbgarr
11-09-2004, 07:21 PM
Another method (non-laser) only requires that you know where the waterline is at the stem and transom. It's also easier to use if the boat is upside down, which yours is already. There may be a Town Class website where someone coud help you find a measurement for the transom waterline measurement from the bottom of the skeg.

You'll need two long straightedges, each about twice the beam of the boat (if you've got them or have that much room in your shop) and a thin strong string at least the length of the boat.

Level the boat athwartships. Set up the straightedges perpendicular to the centerline of the boat, one across the stem and the other across the transom at the waterline marks. Tack the centers of the straightedges lightly into the two places. Level them and fix them securely so you can wrap the string around each straightedge and pull the string taut between them without moving the straightedges.

Wrap and tie the string around the straightedge at the stem. Tie the other end of the string on the transom mounted straightedge so that it barely touches the hull forward. Mark with a pencil where the string touches the hull. Slide the string on the stem straightedge out a few inches and toward the transom on the aft straightedge so string touches the hull a bit farther aft of the first mark and pencil that spot. Repeat all the way around the boat. Connect the dots with tape as suggested above, and eye for waviness. This is more difficult on lapstrake boats than smooth hulled ones.

This method can be used alone, but goes much faster (only a few minutes for the actual marking) with three people, one moving the string on each straightedge and one marking.

Painting the bottom is also easier if the hull is upside down. Personally I've waited to see how boats look in the water for a season to make adjustments such as the flare (waterline rising fore or aft) that Ian suggests, but he's probably got a better eye than I do.

Good luck.

[ 11-09-2004, 07:30 PM: Message edited by: rbgarr ]

carioca1232001
11-10-2004, 04:17 AM
Sorry to barge in on the water-line topic.....

I need to align the props struts, two in a row, for a twin engine installation, after having replanked the bottom.

Had thought of using a cheap laserlight pointer device used in presentations and demos.

Machine a circular cap to sit over the near end cutlass bearing assembly and to hold the laser light in the dead-centre position.

Machine another circular cap with a hole drilled in the dead-centre position and have it sit over the far end cutlass bearing.

Turn on the laser - and hey presto ?

Is there a simpler way ?

Bill Perkins
11-10-2004, 09:47 AM
Michael thanks for the specs on curving the waterline , I've been wondering about that .

mmd
11-10-2004, 10:57 AM
carioca1232001 :

Build a frame out of scrap wood with the height a few inches longer than the distance from the hull bottom to the prop hub centreline. Temporarily fasten the frame to the hull with the forward face of the timber in line with the vertical axis of the prop centreline (brace as necessary). Drive a screw hook into the timber at the point of the centre of the prop hub. Fit a length of fair, un-kinked wire (welding wire is fine) to a 3” turnbuckle. Hook the turnbuckle on the screw hook and thread the wire through the stern bearing/stuffing box. Pull the wire taut and fasten the free end of the wire to the centre of the engine output flange (or rig a temporary mount point at the point where the flange will be). This is the centreline of the shaft/prop assembly. Loosen the turnbuckle, unhook, thread it through the strut boss, place the strut in its approximate position and temporarily fix in place, re-attach the wire to the screw hook and tighten the turnbuckle. Adjust the strut position so that the wire is equidistant from the strut boss inner surface at both ends of the strut boss. Prepare shim stock for strut, place & fasten, check for accuracy. Repeat process for next strut.

Bob Cleek
11-10-2004, 08:56 PM
Oh crap... the easiest way to do it is just paint the topsides a fair bit down below where you expect the waterline ought to be. Launch the boat and take it to some very still water. (In the slip on a calm night works well.) Pour a can of cheap OIL BASED PAINT of a color contrasting with your topsides slowly into the water all around the sides of the hull. Don't disturb the surface when you do it. (Sort of like making a Black Russian with a Kahlua float.) The oil will float on the surface and spread with the surface tension until it reaches the side of the boat. Wait a decent period of time for the paint to dry. You will then have the EXACT waterline painted on your hull! This is REALLY the SIMPLEST method of all.

Seriously, the water level is the easiest way to go of all. For years whenever I'd need it, I'd make one up like the one pictured above. Finally I BOUGHT one at the hardware store. A BIG improvement. They cost maybe ten or twelve bucks. The store bought ones have the clear tubes with a valve that you can turn to keep it all from spilling when you move it and they screw onto standard garden hose fittings. This allows you to use as much garden hose as you need to hook up to make one as long as you want. As the hose diameter is wider than the viewing tubes, it is also super accurate. Well worth the price of admission and there are a zillion uses for it. I recently did some drainage grading in the yard and it really earned its keep. I didn't have much drop to work with, but was able to confirm that I had about six inches in maybe fifty feet.

On the other hand, I've been watching those laser levels since I first saw one. The good ones are STILL really expensive, like a few hundred bucks. The rash of cheapos on the market now are suspect to my way of thinking. Even the "good" low end ones in the fifty to sixty buck range will tell you if you read the fine print that they are accurate to 1/4" in 50 feet. If you are laying out the backbone of a 50 footer, you'd be WAY off, while the water level would be dead bang on for sure.

rbgarr
11-10-2004, 11:32 PM
ROTLMAO! Oh Bob, that 'floating paint' idea is such a funny notion. Oil based paint spreading to other boats or the shoreline... a stray wake causing a wavy waterline... explaining away the pollution to some authorities. :D ;)

carioca1232001
11-12-2004, 06:41 PM
mmd wrote:


carioca1232001 :

Build a frame out of scrap wood with the height a few inches longer than the distance from the hull bottom to the prop hub centreline. Temporarily fasten the frame to the hull with the forward face of the timber in line with the vertical axis of the prop centreline (brace as necessary). Drive a screw hook into the timber at the point of the centre of the prop hub. Fit a length of fair, un-kinked wire (welding wire is fine) to a 3” turnbuckle. Hook the turnbuckle on the screw hook and thread the wire through the stern bearing/stuffing box. Pull the wire taut and fasten the free end of the wire to the centre of the engine output flange (or rig a temporary mount point at the point where the flange will be). This is the centreline of the shaft/prop assembly. Loosen the turnbuckle, unhook, thread it through the strut boss, place the strut in its approximate position and temporarily fix in place, re-attach the wire to the screw hook and tighten the turnbuckle. Adjust the strut position so that the wire is equidistant from the strut boss inner surface at both ends of the strut boss. Prepare shim stock for strut, place & fasten, check for accuracy. Repeat process for next strut. That sounds beautifully SIMPLE ! However, there are two prop struts IN TANDEM, a large one by the prop and a smaller one at the point of shaft entry (into the hull). Of course, your method can be extended to cover this case.

Just for the record, the shipwright nomenclature for these prop struts in Brazil is "pê de galinha" and "pê de pinto" - hen´s foot and chicken´s foot, respectively.

Gary E
11-12-2004, 09:01 PM
Bob,
I wanted a simple and fast way of painting the bottom. So thought about a coffer dam in the travellift slip with one section filled with bottom paint, just dunk the boat in there, pick it up and drive a little further out and set in the water. Same idea for paint removal in the fall, for those that want it, fill the area with paint remover, dunk it in there then set the boat up on the parking lot. But, the marina didnt go for it. Wonder why not.

wndsnd
11-13-2004, 10:18 AM
Hello all,

I have been monitoring all your methods with interest and good humor! I am going to make a water level and keep it in the shop. In the mean time, Ralph Johnson of the Pert Lowell Co. has contacted me and he has gratiously offered his measurements for the waterline I am in need of. This should fit the bill. I will let you know how I make out.

:D

wndsnd
11-19-2004, 03:42 PM
i got the measurements from the builder today and laid them out on the hull. What I found was that even his measurements had a large degree of fudge in them. So, I went with what looked right and here is what I got.

I just used 3m masking tape for now.
http://www.imagestation.com/picture/sraid147/p8a6e56cf56cb885fb4b42e72ff7457df/f6359c68.jpg http://www.imagestation.com/picture/sraid147/p0c57b74cab7503559291e7b8367bc23d/f6359a7b.jpg http://www.imagestation.com/picture/sraid147/p0f4c483543e68ba38ede6a0707cf5939/f6359a6a.jpg

I guess I am looking for opinions now, since I am second guessing myself. Would it look better to just follow the second lap from the deck, or would it look better following a traditional waterline.

I have seen dinghy's done along the lap, and it seems to be popular. I suppose it is just personal opinion but I thought I would post the question.

Thanks