Thursday, May 14, 2009

Planking #7

Sunday evening I was able to tape all the stations + gunwhale mould + table with packaging tape to isolate the mould from the hull panel. I also got around to actually fitting 3 planks.

Last night I snuck down in the workshop for an hour and fitted 6 more planks. Planking a hull is actually a quite fast task. The time hog is the sanding.. Two more sessions and I guess the hull panel is planked + one session for the gunwhale. Then it is sanding and glassing before we try to match the hull panels. The big moment.. Got to remember to tape that moment. It will either be a "kodak moment" if the panels are ill fitting or assymetrical, or big grins if it is just right.

Sunday, May 10, 2009

Test beam made in glass.

First test tube is out of the mould. Last night around 2130 hours I began cutting and wetting out glass. Three layers of glass and three additional layers where the beam is to go. The evenings goal was to learn how to do this properly, and I certainly reached that goal!

1: Have a table for wetting out long enough for the whole piece of cloth you are working on. If not, the cloth will be hard to wet out properly and you will have to handle the cloth some, which it dont like.
2: This is a two person job. One mixing epoxy and one applying it. 3 persons would be even better.
2: Put all the layers of cloth in position on the table before putting them into the mould. Otherwise it is hard to align them properly.
3: The bag should not be too large, just a bit larger than the mould. If it is too large you get wrinkles!

After running the pressure up to 2 bar last night, the bag decided to start leaking. Somehow it managed to rupture close to the air-inlet. It was not a large hole, just 2 cm, but enough to create trouble. To try and save the situation I ran the compressor continously, but I did not take the chance on letting it run without rest for the whole night. The compressor managed to hold the pressure at 2 bar, but I suspect that the result would have been even better without the leak.
As it is, the tube is not perfect. At some places there are dents.. It looks like these dents are located where the bag have been twisted a bit? A smaller bag and no leaks should help. As the picture below shows, there is a dent where the bag have "folded" due to excessive materials in the bag.
Here is a pic of the bag inflated, resting on the bottom part of the mould. It is quite a bit larger than the mould, which I think is part of the problem.
Anyway, before committing carbon fibers, I will want to make another test run with glass.


The good news is that the finish of the beam is very nice and the method obviously works. Even with 6 layers of glass at one beam end the pressure made the laminate conform very well to the mould and no air-bubbles, gaps or anything. Overlap was very hard to see as well, so the pressure must have been immense. Considering -1bar is a perfect vacuum, 3 bars should be more than enough to consolidate the laminate for our beams.


Here is a pic of Omar with our beam mould. Looks quite dangerous! Considering that the mould holds 3 bar of pressure when the pic was taken, Omar was a bit skitterish :-)

Thursday, May 07, 2009

Gahh, compressor woes..

So I had to open the 400V controller for the compressor motor to adjust the working pressure. I was able to make the compressor stop at 3bar, but then it drops down to 1 bar before it turns on again. Not an optimal solution! Will have to seek advice with those in the know how in the composite business..

Compressor exploring..

We stress tested the mould last night. 3 bar of pressure inside it and all OK.
The bag developed a small leak at each end of the mould so we need to check that, but otherwise the system worked perfectly. Tonights mission is to find out how I can make the compressor turn itself on when the pressure falls to 2.5 bar and off again when it hits 3 bar..

Saturday, May 02, 2009

Gunwhale mould in position.

Tonight I routed the insets for the gunwhale mould and fitted it to the stations on the strongback. We are now ready to begin building panel #7! Hooray!!

Frode talked about coming over tomorrow, if he does we can turn the strongback over so it is possible to begin putting planks on the mould.