Saturday, May 12, 2007

More preparing

One of the most important things about building a boat that I should have learned by now, but obviously haven't, is that when you plan what to do in one day, you should divide it by two, subtract a bit and work a bit harder, Then you might not be disappointed about what was actually done that day. Well, the intention was to infuse the starboard float deck, but as time went by I decided instead to go home and spend the rest of this beautiful (but cold) Saturday evening with my wife.
When I arrived the workshop the heater was out of diesel and I had to fill it up and start cranking heat into the concrete walls, the epoxy and everything. It takes hours and several litres of diesel. I envy those whose problem is it is a bit hot to work, here it is too cold to even think about using epoxy without being in an insulated heated room 24-7 for at least 8 months a year, and the rest of the year it is maybe hot enough for a few hours half of the remaining days. I spend a lot of money on diesel....

First I lay out the fabric. In the foreground my Kevlar scissors, special model with micro serrations from Solingen, Germany. Insanely expensive. Now starting to show signs of weakness... (Kevlar is used for bullet proof wests, among other things):

Then I cut it 3 cm from the edge. Most of these 3 cm will be removed during the shaping of the deck to hull side radius. I placed the stringers according to plans. :

Then I placed pieces of 500g 0-90 carbon over the stringers and rolled out the peel ply, being careful to leave enough over the stringers to get a tight fit in the "corners":

Then I cut the peel ply, and applied release film and Resin Distribution Medium. Most of the surface is covered with two layers of RDM. This is due to an experiment on how two vs one layer of RDM affects the velocity of which the resin front moves during infusion. Temperature has a significant effect as the viscosity of the epoxy doubles from 30 to 20 deg Celsius. You can see the spiral tubing is started laying out (sold as a product to organize electrical chords at a reasonable price at Biltema.

Then I spread the vacuum film (nylon film specially made for this purpose, flexible and rough) over the deck and cut a piece (two really, I make two of everything as there are two floats) much bigger than one would believe is necessary. It is important to make the bag roomy, with lots of pleas. The bag will never be too large but it can easily be too small and make a tight corner somewhere and hence not distribute an even pressure to the part you are making:

Started attaching the bag to the table with tape made out of natural rubber with some kind of sticky additive. You can see I left a few cm of fabric not covered with RDM at the end of the deck. This is to reduce the risk of "race tracking". For those interested in infusion I really would recommend Henny's starter kit on infusion. The kit comes with a very instructive CD-manual and all you need except foam and epoxy to make a small panel. I think everyone who intend to vacuum bag flat panels should consider infusing instead. I find it easy, clean and with prime quality panels as a result. Infusing the hull is however a lot more work and is somehow reserved for those with a special interest in the building process.

No comments: