terça-feira, 18 de outubro de 2011

Fillets and reinforcements

Since the bulkheads and the hull planks are joined together, now it's time to reinforce the inside part before turnnig the hull upside down. It's done by adding fillets of epoxy and flox on the inside corners and then adding one or more layers of fiberglass strips. The strips were cut in a way to make the fibers in a 45° angle, to increase shear stress resistance.


Epoxy + flox fillets on the inside corners

Fillet in detail
Joint of a bulkhead, the bottom and the side plank. Zip ties covered by flox
Fiberglass strips cut in 45º angles

Hand Lay up of the fiber strips
Final result

domingo, 16 de outubro de 2011

Building the boat up!

With all the parts done we started to put the pieces togheter. And the hull started to take form. We used the stitch and glue technique. I found it very fast and easy to do, it's very impressive how fast the boat just "appeared" in front of our eyes. We used some plastic zip ties, because the planks in foam and fiberglass were not very heavy. Just a little bit of strengh at the pull and the pieces were in place.
It was very nice to see the hull taking the apropriate shape as we put the bulkheads in the right place. The shape was just beautiful!
And is good to see that the guy how made the project did a very good job!

Joinnig the sides and the bottom

Zip ties doing their job

Sides togheter with the stern bulkhead

Placing the other bulkheads

Getting in the shape!

A view from behind

And the hull start's to rise!

After the bulkheads, now it was the time to finish the bottom and the side pannels. Not much to say, it was basically the same. We decided to do this with the manual lamination method since it's simpler and the bags for these large parts would be too big. The divinycell pannels needed to be glued togheter with flox (flocked cotton fibers).
After the cure was complete, it was a little awkward to trimm, because of the size, weight and flexibility of the pieces, but not a big deal.
Next step building the pieces toghether!

Drawing the bottom on the divinycell

Pannel cut (glued with flox)

Bottom laminated and trimmed ready to build

Bulkheads Done!

And finally all the bulkheads are laminated! As seen in the last post, we had some problems with the infusion method, but the ones made with manual and vaccum bags were fine. Two pieces of hard wood were added to the stern bulkhead to reinforce the engine anchorage point. We also designed a very advanced post curing chamber :) with a black plastic bag
By the way, the bulkheads become harder each day. It's very impressive. The stern one, wich was made with more fiberglass, is very strong!
Now it's the turn off the bottom and side pannels. When they're done it will be time to build it up toghether!

Bulkheads prepared to go to the oven :) Note the hard wood reinforcements in the stern bulkhead

Post cure chamber working! Powered by Brasilia's sun!

Bulheads at the trimming site

Bulkheads ready and divinycell pannel waiting to be cut to make the bottom and the side parts. Next step!

Infusion Lamination

In some of the bulkheads we tried to laminate by infusion method. It seemed interesting but for sure it's more complicate than than manual and vaccum bag lamination.
We took one bulkhead as a test. If the results were good, we would try to laminate part of the hull this way. We made everything ready and started. The process is quick, no much time to correct mistakes. And it was exactelly what happened.
The resin and hardenner misture was too thick, and did'nt flow the way we expected. Not very good but we managed to save the bulkhead.
Everything was almost perfect until now. But that's OK, the difficulties would happen at some point.

Holes made in the foam to permit the resin flow
Cutting the fiberglass

Peelply

Adding some weight :)

3 layer sandwich: fiberglass, peelply and infusion mash

Plastic channels added to increase the resin flow

Bag ready to go
                         

quinta-feira, 8 de setembro de 2011

It's Green!

Finally, all the supplies arrived. We decided to start with the bulkheads and test some of the laminating methods: infusion, vacuum bag and manual one.
Manual and vacuum bag technics were the firsts. This methods are simple and our simple construciton condictions and skills matched very well. Our workshop is just an open garage, some of the tools are improvised and our building experience is near zero.

So we liked the firsts results! Pretty good for first timers!

Foam cut into the bulkhead form over the improvised table.

Result after manual laminating before trimming the excess of fiberglas

Close details

Going Lightweight

Analising the plan set we took a big and important decision: build the boat in Divinycell foam instead of the original plywood project.

The most important factor: weight! We estimated that the boat in foam would weight much less than the original one. We thought that Divinycell would also be easier to work with and a good quality naval plywood is not so easy or cheap to buy over here.

So the next step was purchase the Divinycell foam, fiberglass, resin and hardener and wait to laminate the first panel!

quarta-feira, 7 de setembro de 2011

Getting Things Started

After some months of dreaming and planning we finally decided to build our own sailboat. My friends Bruno and Marcos (both engineers with sail experience) and me (without any experience in sail, homebuilding nor anything else) chose the i550 project because its simple, easy to build and not expensive. After purchaising the plan set,  we analised and decided that it was doable. We were set to enter the game.