It is now time to correct the twists and curves in our glued up sections.
My best reference for straightness is my planing form.
The heat gun is out again.
The three sections are done.
I will double check straightness a few more times throughout the remaining steps to make sure a stubborn curve does not come back.
With the forms out I re-marked my stations to check how close to desired dimensions I got. Since I planed each strip with the tip flush with the top end of the form this is an easy step.
I’ll measure every station flat to opposite flat, therefore three measurements. If station x is supposed to be at 0.200 inch for example, perfection would show three flat to flat measurements of 0.200. Well perfection is hard to achieve, but if I am within 0.001 everywhere I should be very happy. It is not unusual to see something like 0.200, 0.199 and 0.201 as an example. Two of the measurements are out by 0.002 of each other, but each is out 0.001 of the 0.200 target. While I aim to hit within 0.001 or better at each station I can live with a .002 difference here an there. We need to keep two things in mind. First the glue adds thickness and will increase the stations measurements - 0.002 is not unusual. That should be equal on all flat to flat measurements, but I can’t confirm that. The sanding will take care of most, if not all of that increase. Second, we only measure every five inch station to see if we are faithful to the designed taper. Using the above example if I were to move only half an inch above and below the 0.200 station, I may get three spot on measurements of .199 above and three of 0.201 below. In this case the 0.002 difference between two flat to flat measurements at the station is insignificant. As long as the measurements are not significantly off at all stations (.002 or more), and that I hit target at most stations, the odd 0.002 here and there does not bother me. I consider that faithful to the designed taper. Of course, we all continue to reach for perfection.