Saturday, August 25, 2007

Hand laminating port float exterior

I started with the deck, first the reinforced areas, then a layer of carbon and at last the hybrid. Wetted out and worked out air between each layer with a rubber squeegee. Finally a layer of peel ply which I stretched firmly around the deck to float side radius. It took approx 3 kg of resin.

Another view. Obviously no pictures during the process. The room and the resin was preheated to something like 22 deg C, and I made sure to keep a stable temperature during the whole process, hoping to decrease the bubble trouble factor.

The next day I laid the float on the side, peeled off the peel ply around the deck to float side radius and then laminated the float bow, then one layer of carbon and one layer of hybrid over all float side.

This took approx 5 kg of resin. I had a hard time getting the fabric really tight around the corners but it ended up quite OK. Nothing like a vacuum treat, of course, and I must say I am sorry for that.

Quite generous overlap at the keel area. I prepare to beach the boat in some otherwise unaccessible fjords/valleys in Lofoten and the boat have to withstand the rough conditions.

Aborting vacuum infusion of float exterior

So I kept on laying all the layers required for a vacuum infusion. Here is the Peel-ply:

Then the release film and the RDM. I learned from the latest float half that a double layer of my RDM halves the migration time of the epoxy, as does three layers. Here is two layers of RDM and the distribution tubing:

Then the whole float was sealed in the vacuum bag, leaving a 10 mm hole in the deck to connect the float inside with the atmospheric pressure.

Then I started the vacuum pump. I did not get an appropriate vacuum and I did not manage to find the leak. I figured that a larger amount of air through the system would reveal the leak. And it did. I connected an industrial vacuum cleaner parallel to my vacuum pump. Less than a minute later I observed that the float shape was changing into a less appreciative form. I rushed to the power chord and observed the float as it reversed to it's original shape.
The 10 mm hole was no longer able to provide the amount of air necessary to maintain balance of air pressure, hence the leak was in the float wall. I don't know where this (these) leak(s) is/are, but the float to deck join is one candidate, as is the possibility of my 6mm Raptor composite staples have penetrated the inner skin in the keel area (where the foam is sanded down in order to create the correct rounded shape). Here is a picture of the vacuum before the threatening collapse:

I had to sit back for a while, making a new strategy, until the final decision on how to proceed was made. I must say, I really do appreciate the quality the vacuum infusion method provides. On the other hand, I really do love sailing and I ended up finally following the designer's advice and I decided to lay the outer skin manually, praying that I would be more lucky than Jay regarding bubble trouble.
I started to remove layer by layer and preparing for the hand laminating method:

Wednesday, August 08, 2007

Preparing float exterior vacuum infusion part II

I have continued with the dry lay up of fabric, here the outside of the port float and my brother in law taking a picture:

Then covering it all up in peel ply. I use small pieces of tape to attach the peel ply to itself along the deck center line.

And here the whole float covered in peel ply and release film, same attachment technique

Next will be two layers of RDM and then start to get the tubing in place. There will be one spiral tube along the keel in order to deliver the epoxy, probably some small vertical pieces connected to this every meter to make sure everything wets out and that resin migration don't stop just under the side to deck radius. The outlet will be a spiral tube on deck in the centerline. I have made a hole in the deck in the middle of the hatch area that will not be a part of the bag to make sure the float inside remains at one athmosphere pressure even if the unlikely event of a small leak in the hull should be the case. Making vacuum inside the float would probably cause disasterous injury to the float...

Saturday, August 04, 2007

Preparing float exterior vacuum infusion

It has been quite busy the last weeks with work, necessary domestic tasks, getting my old pick-up truck through the European Union's biannual technical inspection etc. One of the few things I did not have problems with was to get approval of my modification of the 2,5L diesel with a turbo charger as seen on this picture:

I have also managed, with good help from my brother who is currently visiting, to rebate the areas for extra reinforcements on the port float deck and I am currently in the process of laying out fabric. I use one layer of 200g carbon fibers and one layer of 240g aramid/carbon with overlaps at keel and at deck to float side radius.

Here I am fastening the fabric at the bow with composite staples from Raptor:

Another view, inner side finished, still one layer of aramid/carbon to go on the outside (and on deck):