today's work

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • redboat219
    Admiral
    • Dec 2008
    • 2735

    This should be David's new avatar Click image for larger version

Name:	20230223_130636.jpg
Views:	344
Size:	35.0 KB
ID:	169873
    Make it simple, make strong, make it work!

    Comment

    • He Who Shall Not Be Named
      Moderator
      • Aug 2008
      • 12256

      Originally posted by JHapprich
      I believe he cut the marked portion on the upper hull.

      Jörg
      Finally. A reasonable question.

      The marked portions of the upper and lower hull indicate lateral mismatching of the seam created when the two hull halves are joined. The hash-marked areas indicate location and depth of Bondo build-up required to get a hull half in symmetry with its neighbor.

      Let's look at other use of Bondo automotive filler to tighten up hull seams:



      There was a slight mismatch between the hull halves of this beautiful Scott Terry 1/96 ALBACORE kit. The join is permanent with reinforcing glass tape on the inside. The area to be Bondo'ed was roughed up with #100 sandpaper and the catalyzed Bondo screeded on with a putty knife.



      Cured and sanded Bondo is porous and weak. I waterproof and strengthen it with a quick wipe of thin formula CA.




      Here I'm tightening up the radial seam at the stern. The edge and inside of the upper hull was waxed to prevent any Bondo from sticking; Bondo was slathered upon the after radial flange and the upper hull quickly secured in place, creating a conformal union between upper and lower hull radial break.








      David​
      Last edited by He Who Shall Not Be Named; 02-23-2023, 10:23 AM.
      Who is John Galt?

      Comment

      • redboat219
        Admiral
        • Dec 2008
        • 2735

        Thank you.
        Make it simple, make strong, make it work!

        Comment

        • He Who Shall Not Be Named
          Moderator
          • Aug 2008
          • 12256






































          Who is John Galt?

          Comment

          • He Who Shall Not Be Named
            Moderator
            • Aug 2008
            • 12256


















            Who is John Galt?

            Comment

            • george
              Captain
              • Dec 2010
              • 727

              Sorry, not sure of what I am looking at in the last five pictures. Multiple pushrod seals? But looks like a lot on one shaft for multiple casting????

              Comment

              • He Who Shall Not Be Named
                Moderator
                • Aug 2008
                • 12256

                Originally posted by george
                Sorry, not sure of what I am looking at in the last five pictures. Multiple pushrod seals? But looks like a lot on one shaft for multiple casting????
                Yes. And yes.

                It's easier to use one long brass rod core than a bunch of short cores. The current tool has three ten-seal castings, and two eight-seal castings. After casting each core rod is pulled and the individual pushrod seals separated on the bandsaw.

                Here's the less efficient 'old-school' pushrod seal tool and casting -- too labor intensive.






                David
                Who is John Galt?

                Comment

                • He Who Shall Not Be Named
                  Moderator
                  • Aug 2008
                  • 12256




















                  Who is John Galt?

                  Comment

                  • george
                    Captain
                    • Dec 2010
                    • 727

                    Ah, Thank You for your reply and educational lessons, Master Sir.

                    Comment

                    • He Who Shall Not Be Named
                      Moderator
                      • Aug 2008
                      • 12256





















                      Who is John Galt?

                      Comment

                      • george
                        Captain
                        • Dec 2010
                        • 727

                        The drill bit pictured in post #1688, is it the size of the O-ring? Was there any mod done to the drill bit before using it?

                        Comment

                        • He Who Shall Not Be Named
                          Moderator
                          • Aug 2008
                          • 12256

                          Originally posted by george
                          The drill bit pictured in post #1688, is it the size of the O-ring? Was there any mod done to the drill bit before using it?
                          To render a non-interference fit to the raw castings .062" bore -- created by the brass rod core during the casting operation -- it is hand reamed with a standard (non-modified) .065" bit.

                          The two encapsulated O-rings, within the seal body, have a nominal .060" inside diameter, but those surfaces (being much more elastic than the surrounding resin) scoot out of the way when reaming with the over-size bit. This leaves the resin bore enlarged enough to easily pass the pushrod, with the O-rings projecting into the bore enough to girdle and make watertight the fit between pushrod and seal body.

                          David
                          Who is John Galt?

                          Comment

                          • He Who Shall Not Be Named
                            Moderator
                            • Aug 2008
                            • 12256




























                            Who is John Galt?

                            Comment

                            • He Who Shall Not Be Named
                              Moderator
                              • Aug 2008
                              • 12256




















                              Who is John Galt?

                              Comment

                              • He Who Shall Not Be Named
                                Moderator
                                • Aug 2008
                                • 12256























                                Who is John Galt?

                                Comment

                                Working...