This beam has two webs, one forward of 13mm Duflex, one aft of 16mm Duflex. The forward web will have vertical hatches and conduits cut through. The aft web, with only the conduits cut through, sits on the aft edge of the 100mm lower flange and has the upper flange placed similarly overhead. In our case, as mentioned in the previous post, we will have an additional subtle but larger upper flange. However a web beam needs both top and bottom to go along with bulkheads and flanges. It was important that this be completed before moving the boat to its new location.
The bottom flange is easy, it is on the hulls, the chamfer panels and the bridge deck. The top was made up, shaped and fitted, at both ends over voids. In the centre we will be storing various things including gas bottles, stern anchor and chain, as well as installing cockpit overhead supports, sink and BBQ support. So we left all that crowded complexity for the future, and for the move just placed some temporary external tapes on the centre panel over the lockers. We focused on the complex panels at the ends of the beam, over the deep voids, and completed internal taping in these sections.
Below – The underside of the panel over the beam walk-through, completed with bonding angle, after struggling by hand with wet tapes. Nothing pretty in this work, just plenty of glue and a sealing coat on all exposed Duflex, mindful that this is a buoyancy void.
Below – The first semi-vertical panel,with its size chosen, to fit my reach down to the join with the walk-though panel. It then received a fillet and tape at that join and on each side. It has a H-join in the top edge and also showing is the second semi-vertical panel, held above.
Below – This shows the second semi-vertical panel fitted.
Below – The internal view showing the overlapped tapes – note for taping – each panel is only as long as my forearm.
Below – Again the external view. Some peel ply was used to create a keyed surface for the next panel’s overlapping side tapes. This was due to curing being required as the next panel, being kerfed, needed purchase on this one.
Below – The kerfed panel with a H-join on each edge – small but complex. Note this is 16mm core, the kerfs are very close together (10mm) and on the inside/lower edge, not as would seem here. This is actually the panel from the other end of the beam (starboard).
Below – A number of steps were required to make these panels and they were mirror image of each other. The first step was the H-joins while it was still solid and stiff. Then the second step shown here was the kerfs – cutting through the laminate with a 3mm bit which only has a 6mm long cutting edge.
Below – The third step was to repeat using a little cordless table saw with a 2.5mm blade to deepen the kerfs almost to the top laminate.
Below – The panel was then impregnated with glue, screwed in place with screws diagonal to avoid the inside taping surface, the H-join splines inserted, then after this photo, filleted and taped. The underside of the panel was covered with an extra glass fabric, to replace the cut laminate. All this effort, to produce a small curved surface.
Below – Judy’s most excellent bonding angle: Find a mold – engine crane legs, wrap in baking paper – the best and cheapest release agent, lay up 2 x 750gsm weft triax with peel ply before and after, then cure.
Below – We had little opportunity to take photos during these stages. We were working as fast as possible as we had set ourselves a deadline by booking the transport for the boat. The following photos show the finished curved panel and Judy’s work installing the bonding angle as preparation for her to fit the last panel and close the whole void.
Below – These angles were taped together underneath, cured, covered with glue and the top fitted.
Below – Photo, taken after the move, of the (temporarily) completed top. The duct tape was there to avoid losing the H-join splines during the move, as these have yet to be glued in.
The Scrumble Project 