The Spring Run strongback is really strong and straight as it's designed. Thats not to say an internal one wouldnt be, but just that there is nothing wrong with it as is. Probably the biggest disadvantage to going with an internal one is that it's not the way the directions call for, and it might be a little confusing down the road. If youve built a Guillemot, or other internal strongback design, and are familiar with the process then it might be a wash that way. It seems I remember a thread on this a long time ago, and the general concensus was that it didnt really matter which way you build, but that it's easier to follow the directions for the given design. The external is nice in that it can be used again for different boats. I have a walrus on mine now, but it's on hold till after the holidays.

: I am in the process of building my first strip Kayak, a Spring Run. The plans
: call for a six inch square strongback constructed with 10" risers to
: hold the section forms.

: Can the Spring Run be constructed using the internal strongback method with
: holes cut in each form and the forms slid on to a two by four instead?

: What would be the disadvantages of using the internal strongback method, if
: any?