Any alternatives to chalkline for lofting?

[Dusty Yevsky]

I'm gearing up for a new boat project, a sea kayak, and will commence with the lofting shortly. On the last project I used a standard framer's chalkline to establish a baseline. In retrospect I think the line it produces is somewhat indistinct for precision measuring so I'm looking around for alternatives. I've heard of builders using braided fishing line in the chalk reel but I was wondering if there is any other approach to creating a precise baseline.

[Jim Ledger]

A Japanese ink line is very sharp and permanent.

[Bob Cleek]

Yes, an inkline is better than chalk. However, it is often easiest to simply measure up from the edge of the lofting table, which is in most instances a sheet of plywood. The edge of manufactured plywood can be relied upon as fair. Another method, if a plywood edge is unavailable, is to use a straightedge. This is the most reliable alternative.

[Dusty Yevsky]

Jim,
This sounds interesting, can you elaborate how it gets applied? Permanent is fine because the board with the BL will be cut off.

Dusty

[Dusty Yevsky]

Bob,
I'm going to be lofting onto 22' scarfed panels. My lofting table is likewise 22' long. I did use a string gauge to line up the MDF edge but found I introduced errors I couldn't correct because attaching the boards to the frame always introduced small errors regardless of my efforts. My workspace is somewhat primitive.

Dusty

[dmede]

Chalk line is usually not a good idea because you get too much bounce when snaping the line. You can stretch a thin line across your board where you want the base line (make it tight), and mark off along that line at intervals slightly less than your longest straight edge, then use the straight edge to conect the marks. Works for me.

[ssor]

A piece of music wire will provide a reference straight line that can be left in place during all of your drawing. A gentle tap with a hammer will make marks with the wire in the wood if you need them,

[Jim Ledger]

Jim,
This sounds interesting, can you elaborate how it gets applied? Permanent is fine because the board with the BL will be cut off.

Dusty

The ink line is a braided silk line that is drawn through a sponge saturated with ink. I would imagine that a thin braided fishing line and india ink might work in the same manner.

It would be a two man job with all the moves planned to avoid setting the inked line down in unintended places.

Why not just stretch a fishing line, make some marks and connect them with a straightedge. How accurate does it have to be?

[Dusty Yevsky]

Probably less accurate than my neurotic need for precision dictates. I like both the ink and the connect the dots scheme and will go with the latter.

Dusty

[Yeadon]

Probably less accurate than my neurotic need for precision dictates.

Truly, one of the great emotional struggles in boatbuilding.

[Jim Ledger]

Well, you've got to grab all the precision you can at the start because it's all downhill from there.

Hand me those shims, willya.;)

[Todd Bradshaw]

Another option is to stretch a string or fishing line tightly and down snugly against the surface and then walk along with a can of spray paint and spray straight down on it. Remove the string and it will leave a very straight line.

[Chan]

I think what you need is an old chalkline, one that's been stretched.
Brand new chalk lines leave a thick line. Once stretched several times they get thinner.
Don't load it up with chalk, just enough, stretch it tight and dry snap it, getting rid of most of the chalk, then put it down on the work surface and snap again, you should get a nice fine line, take your longest straight edge and pencil in the line.
Or buy a cheap laser.

[GregH]

I second Chan's advice about the chaulk line-- if you're getting an "indistinct" chaulk line, it's because you're using too much chaulk. And, after all, as Jim Ledger asked, "how accurate do it have to be?" The Egyptians built the Pyramids with plumb-bobs and strings.

Stop looking for some magic bullet, and learn how to use the tools you have.

[Robmill0605]

There is a way to make a chaulk line perfectly fair. The reason you get the deflection is that most builders simply pull on the line and snap it. Because you will get a slight deflection pulling the long line, it's not fair.
The answer is to pull the line tight. Then hold it down to loft floor in the middle and snap slighty to each side of center. Almost zero deflection this way.

[Ron Williamson]

I've used 25lb.braided fishing line for the last 20 years.
With and without chalk.
With, it leaves a fine clean line.My colour blind eyes like blue not red.
I saw a log house guy with an ink line,he got ink everywhere.
R

[Jay Greer]

A Japanese ink line is very sharp and permanent.
I have to mention that I started using Japanese ink lines about thirty years ago. I like them because they are so precise. I have three ink line tools that are known as "Sumi Subo". They are for lines that are red, black and white. I guess the main reason I use them as they are accurate as well as logical.
Jay

[Bob Cleek]

Why are you scarfing your table panels? Just butt them up against each other. Use a straight edge to check, but if you butt them tightly, you'll have a fair line at the bottom edge that's normal to the butts. Nail it down and get on with it! Stop fidgeting! LOL

The standard practice for laying out long lines is actually NOT a chalk or ink line. There are a number of limitations with these, as mentioned. The most accurate approach for long lines is a piece of fine wire (or fishing line, etc) that is tightly stretched along the board. You then take a pencil and mark a series of points along this wire, taking care not to move the wire when placing a point. A good straightedge is then used to connect the points, overlapping as you go. This will allow you to bridge over between points that might be slightly out of line.

[George Roberts]

I would expect a lofting table would have a straight edge on it. Use that. (If it is not straight, get some tools and make it straight.)

[Jay Greer]

Well now there then, I do use a combination tricks for my own lofting, most of which have already been described here by other posters. I do prefer the Japanese Ink line over the western chalk line.
The main trick is to first make sure the line is saturated with wet ink prior to snapping a line. After pulling out the line, I am very carefull to make sure to snap the line from a vertical position which will obviate creating a curved line. My main prefrence for the ink line is that it will not brush away like a chalk line mark will, it is much finer and more accuate in making it's mark, and it comes in three colors.
Jay

[Tylerdurden]

I am wondering if any one has used a laser for that purpose and how it went. I have a laser I use for hanging pipe and raceways but revert to the wire and chalkline for lofting.

[Chan]

I tried a laser but it was one of those real cheapies on a tape measure so it didn't work very well. In 30 feet the beam had diffused to about !/4" A decent laser I'm sure would work like a dream

[pipefitter]

You can also use permanent chalk and then blow the excess dust off and aerosol spray over it with clear urethane from the big box store. It will crisp the line and keep it from getting smudged throughout the project.

[few3]

Black chalk, and braided line works well. Black chalk is forever.

If you are looking for more precision than that, Challenger (http://www.challengeprecision.com/mall/Straight%20Edges/Parallel%20Straight%20Edges.htm) sells straights up to 6'

[zenda]

Hey Dusty,
You can get sumitsubo, traditional and modern designs, from this website: http://www.japanwoodworker.com/dept.asp?dept_id=12999

[Bob Cleek]

Sure seems like everybody is going to a whole lot of trouble to draw a straight line. Come on, guys! It's not that big a deal.

BTW, forget lasers unless you are willing to spring for a few hundred bucks, which again is a lot of money for a straight line. Most all of the home handyman models will tell you (in the fine print) that they are accurate only to +/- a quarter inch in fifty feet or so. That's just nowhere close enough for proper lofting, particularly when you consider that an error will likely be compounded every time you measure off of it to another point!

Just stretch a tight piece of cord or wire and mark points. Connect them with a long straight edge, which will accommodate any points that are out of fair. You won't get much more accurate than that.

[dmede]

Sure seems like everybody is going to a whole lot of trouble to draw a straight line. Come on, guys! It's not that big a deal.

BTW, forget lasers unless you are willing to spring for a few hundred bucks, which again is a lot of money for a straight line. Most all of the home handyman models will tell you (in the fine print) that they are accurate only to +/- a quarter inch in fifty feet or so. That's just nowhere close enough for proper lofting, particularly when you consider that an error will likely be compounded every time you measure off of it to another point!

Just stretch a tight piece of cord or wire and mark points. Connect them with a long straight edge, which will accommodate any points that are out of fair. You won't get much more accurate than that.

You're wasting your breath, these guys would rather shop the Lee Valley catalog for japanese marking brushes than build a boat ;) :D

[Dusty Yevsky]

Original poster here. I am going to go with the stretched-string-connect-the-dots scheme. Any slight errors will fall well within the tolerances of this boat. That said, I have to admit I am rather taken with the sumitsubo. I've been turning wood into sawdust for quite a long time now and never, ever heard of such a device. If only the practicality police weren't lurking around the corner...

Dusty

[3pepper]

try replacing the string in your chaulk box

use gorilla braid or spider wire braid fishing line in 50 lb test
it does not stretch and it pops a very fine line , better than anything else i have tried

the laser is a bad idea , the line it generates is fat and varies as much as a 1/4 inch . i can do better with a string line and a four ft level

use the braided fishing line , pull very tight and pop only once and you will be as accurate as anything needs to be

you can check for accuracy and straightness by streching a second un chaulked string over the popped line , almost always , there will be no deviation in straightness

the spider braid pops a line so fine and straight , you can go over it with a straight edge or level and strike it in with a pencil for a more enduring base line .

also try using black concrete stain , its a fine black powder , cheap and shows up better than chaulk .

i am just a house carpenter/woodworker but this method has worked for me for a long time
try it , you'll like it

best of luck
stephen 3pepper

[Oscarvan]

A work of art in itself....

http://www.daikudojo.org/Archive/gallery_misc_tools/sumitsubo/pics/2006_1118_185735.JPG

[Electra]

If you are using plywood templates to shape the hull, drill an 1/8" hole through an imaginary center line in each template. Align the holes using a construction laser (or even a laser pointer) and you are dead on. A second set of holes parallel to the center line can be used to correct for rotation of each template around the center line. Initially clamp the templates, then when alignment is achieved, screw them in place.

Alternatively you could pull piece of music wire taught through the holes but make sure it is centered in each hole.