Structural parts, Uni directional glass

Two more uni ropes done

Posted by Paul

Today I did the uni ropes in bulkheads 4 and 5, leaving only bulkhead 6 the large saloon door bulkhead to do, probably tomorrow. Then I can start to do the strip planking.

The capped section of the rear bulkhead has set and leaves a nice square top to glue to if needed or a nice surface to finish the top off. So the first task today once I had inspected the work earlier in the week was to place screws in the bulkhead below the trough for the rubber bands, then I prepared all of the tools for the day and mixed up the first batch of ADR resin.

I rolled out the next uni sheet and cut the corners off, this enables the uni rope to taper out in size in the last half meter and matches the taper in the depth of the trough. The reason for the taper is so the forces that flow down the uni trough taper out as it curves down into the hull sides. Then I wet it out using a squeegee. Once it is wet I roll it up into a rope. I then went back to the trough and put a 2mm layer of glue down for the uni to sit on and bed into, it acts like a cove filling the corners. Once the whole length is rolled up as tight as I can get it, I fold it over and over until I can carry it to the job. In the pic below I used spring clamps to hold the rope roll to stop it unravelling whilst I carried it to the boat but it wasn’t necessary, I carried the second one without the clamps successfully. Then I lay it gently on top of the trough starting at one end over to the other. Then starting at the middle and working out to the hulls I pushed it down into the trough and using my finger I squeezed any air bubble out and made the uni as straight at I could get it.

Once the uni is pushed down I filled any gaps with glue and capped it. In the forward bulkhead there is very little space to fill because it is only 15mm deep, in fact the cap is needed to push the rope down into the trough, without the cap the uni clears the trough by about 5mm. On BH5 the trough is 25mm deep and there is enough clearance to require me to fill the rest of the trough with glue before capping it.

The 3mm mdf bends really easily to meet the curves of the bulkhead and the rubber bands pull it down adequately into the glass top of the trough resulting in the neat top when it sets. I decided not to glue the pieces that were cut off on BH5 back on wet on wet as they are small and it will probably be easier to glue them onto the set resin top tomorrow.

I should be able to make the final uni rope tomorrow and fill the last trough. Once done I think I will finish the forebeam ready to fit it, then the hull to deck planking can begin. Before the actual planking can be done I need to re fit the temp bulkhead sections in order to shape the curved sections properly and glue the duracore planks together and rip the planks.

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