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Re: Strip: Petrel Build
By:John Abercrombie
Date: 9/4/2012, 2:08 pm
In Response To: Strip: Petrel Build (David)

: I started building a Petrel and have a question I'm hoping I can
: get some help with.

: I lofted the froms from Nick's book (3rd edition) in ACAD
: everything seemed to look good. I printed full size forms, glued
: to plywood and cut out. After I mounted them onto the strong
: back I checked fair at the sheer line and it looks like one of
: the forms is off by about 1/8". Has anyone else had this
: problem?
: I checked the strong back and the centeline of the forms with a
: laser and it looks good. Should I just adjust to get it fair
: (make sure it's symmetrical) and not worry about it?

: Thanks,

: David
David:
Which form is "off"? Sometimes at the ends boats have a 'hollow' built in to the design.

If you can correct the problem by just moving the form a bit in the fore-aft direction, that's one strategy.
(You've checked to make sure the forms are on the correct side of the station lines, I assume.)

Sometimes paper plans can be stretched when gluing to the form material- double checking may clear that up.

1/8 is not a great deal and will certainly not affect the performance of the boat- I'd advise just adjusting the form or the form position to get things fair before you start stripping.
I always lightly staple some (a bunch) of strips on the molds to check fairness before getting into the actual stripping. This also 'locks' the forms in place if they are tending to wobble a bit.

You are right to be careful at this stage- it can save a lot of sanding and thin spots later.

Messages In This Thread

Strip: Petrel Build
David -- 9/4/2012, 12:45 pm
Re: Strip: Petrel Build
John Abercrombie -- 9/4/2012, 2:08 pm
Re: Strip: Petrel Build
Paul Davies -- 9/4/2012, 2:17 pm