loft one boat 3 times?

[Three P's]

I am just curious.....how many times have you lofted a boat before actually starting construction? i have never lofted before but I have the hang of it now because I have had to repaint over my building platform twice now......and I am not happy about it but I will prevail! I thought I was going to be able to start frame construction tomorrow but now I get to loft the plan view...again. all because i mis-measured my LWL by one inch. damn not working from the end of a tape measure anyways. I just had to vent, but I am curious to see how many fellow boat builders have had to redo this step and how many times.....

[Bob Cleek]

You may find it helpful to use ledger sticks instead of tape measures. These are simply sticks painted white upon which you mark your carefully measured distance and then use again and again for repeated measurements. Tape measures really aren't the best for lofting because of the inevitable inaccuracies that arise when you use the hook end of the tape. A long rule and ledger sticks are much more accurate.

[pipefitter]

I use a tape measure and I pull the hook out of habit.I set the inside of the blade on the outside of the pencil line and keep it a standard as it translates to how it's used throughout the boat. Being as we're supposed to measure twice, I'll burn the inch on the 2nd go round to see how consistent it is.I also use the same tape measure throughout as well so if it is off,it is off the same and those end up being the law unique to that draft.A bad read of numbers due to forgetting the burning of the inch is far more an error than keeping it simple.If the tape measure is going to be the tool used for the building,one better have practice when it comes time to cut the expensive parts,especially if having to order them to the exact count.Also,brake the tape hook when letting it in. Letting it slam full spring into the tape measure housing will increase that first inch. Also,if you drop it,more than not,it will have landed on the hook and bent it. Check it every time it gets dropped.

[Three P's]

all great ideas, and well taken. I made the complete ameteur mistake of forgetting to add the inch i burned on the LWL only. threw the whole thing off. but i have now redone the plan view and can continue as planned. I also redrew the keel and rabbet line and all of the other measurements were from the baseline so i think i am square. you would think after running a table saw for 3 years and also working construction for part of my life i would remember to add the inch taht was burned, the damnedest thing is that i did on ever measurment except for the LWL so it threw a lot of things out of whack. it is funny how the more you do something, the more it makes sense. Lofting was the biggest mystery to me when i first started researching boatbuilding over 2 years ago. now i am one step away from having the frames of a 12' dinghy in my garage :). i guess with enough persistence you can get through just about anything?

[dmede]

I use a aluminum 6 foot rule.. Its fairly accurate...

it's not just about the accuracy of your ruler, using the tic strips avoids adding error by making sure you only use your rule to measure each seperate dimension once. Once that distance is marked on your tic strip it can be carried over to other parts of the lofting or to the moulds without you having to go back and re-measure and possibly transpose a number or two. You make seperate tic strips for each station.

[seo]

I guess the consolation here is that your mistake could be remedied with a bit of paint and a few hours of time. Compared to having to replace wood, or ending up with an odd boat.
The other consolation is that doing the same job a second time in close succession, maybe you learned something useful about how to do it quicker or better.
I will now get off the Rebecca of Sunnybrook Farm routine.

[Nicholas Carey]

I guess the consolation here is that your mistake could be remedied with a bit of paint and a few hours of time. Compared to having to replace wood, or ending up with an odd boat.1 quart flat white paint...$12.00

BS 1088 marine ply...$100+ per sheet
Teak lumber...$15-20/board foot

Satisfaction of a job well done...priceless

Not much of comparison to me.

Still not much consolation -- it's frustrating :mad: to realize that something fundamental got bolluxed up and you need to re-work it, but that's why you loft it in the first place: Catching and fixing those sorts of errors early on is cheap and relatively easy. Not so much on the back end when its expensive and time consuming.

The frustration thing is why you've got the moaning chair in the shop...you do have a moaning chair installed in the shop, don't you? :D

[Chan]

Don't bother burning the inch. Start with 2 base lines, one is horizontal, one is verticle.Make them perfectly square using 6-8-10 or a squared +b squared = c squared.
Take a headed nail and put it at the line vertical or horizontal, hook the tape on the nail, preferably a brand new tape, because yes every time you drop it it will land in the end and bend the little end just enough. Once hooked tap the nail head you hook to so the end of the tape is exactly at zero and measure.
Tick strips are fine unless you need a 30' tick strip and if you use a 10' tick strip to measure 30' you are just compounding errors.

[dmede]

Tick strips are fine unless you need a 30' tick strip and if you use a 10' tick strip to measure 30' you are just compounding errors.

Since we're talking about a 12' dinghy, a tick strip should be just fine.

3p's, if you don't already have it, get a copy of "Lofting", sold by WB. John Brooks discusses using tick strips and other tips in his book "How to Build Glued Lapstrake Wooden Boats". And Greg Rossel has some general tips on lofting in "Building small boats".

[Tom Robb]

I find that my inevitable mistakes nevertheless make me nuts and more likely to make another one. I have to walk away from it for a time which works ok for me because I'm not making a living at this.
An erasable surface would be nice because you WILL need to correct the lines way more often than you'd hope.
And don't use more than one ruler/tape. Consistent is good.

[Nicholas Carey]

I find that my inevitable mistakes nevertheless make me nuts and more likely to make another one. I have to walk away from it for a time which works ok for me because I'm not making a living at this.My boss at my first 'puter programming job gave me that advice: when you get tired/frustrated/angry, you tend to get stupid. That's when it's time to walk away and go sit in the sun for a while -- it being cheaper and faster to do that than to have to do the inevitable rework necessary to fix the, uh, "improvements" made while tired/frustrated/angry.

[Beside, while sitting in the sun and cogitating the ol gears in the grey matter are still quietly churning behind the scenes -- when you come back, you're likely to have new/different ideas or perspectives.

Good advice for 'puter programming; good advice for wood butchery. :D

[garyspear]

all frustration aside. I will not ever build another boat without lofting. I started my caledonia yawl by thinking that the full size plans Iain sent were a sort of gospel. a canon that was totaly accurate and should not be deviated from under pain of death. wow did I get an education. no big mistakes but a lot of trial and error. from now on it is the table of offsets and beautifuly springy battens.

and the final lesson. fairness trumps all. even if every thing else is perfect you always favor fairness over exactness.

JMHO