There are many photos and a video below covering the preparation and aftermath of the lay up, actual infusion and de-mold of the mast beam upper unidirectional flange.
I have put this task off for a long time, but now had to build it in order to complete any further decking.
Everyone and everything is in this post with the notable exception of one of our Tenterfield Terriers, Scout, who is busy looking after her two new male puppies. Good future boat dogs for someone. So the rest of us; Jem – dad of the new puppies, the kids, Judy and I, got on with the job.
I had previously completed a successful trial infusion using an off cut of the same 25mm duflex as in the beam. This gave me confidence to infuse as the humidity was between 75% and 85%. As fate would have it the humidity dropped below 50% the morning after the task.
Normally this flange is laid up by hand with the following schedule:
- 1 x 440gram 150mm wide Double Bias laid down first and then,
- 4 x 800gram 150mm wide Unidirectional, then to stop vertical separation another off axis
- 1 x 440gram 150mm wide Double Bias, and a further
- 4 x 800gram 150mm wide Unidirectional with a final layer of
- 1 x 440gram 150mm wide Double Bias
The actual schedule used here with the infusion process had the same layers but in 1000gram – 100mm tapes, due to being only available in this size, and the off axis layers were 750gram 141mm Weft Triaxial.
Glass Reinforcing Fabric Lay – Up
Below: The first layer – Weft Triax.
Below: This item is the key to laying up reinforcing fabric accurately and firmly whilst setting up the other materials.
Below: Unidirectional on the beam.
Below: Beam from forward with fabric laid up.
Consumable Materials
Below: Peel ply over all the fabric layers.
Below: Peel ply on the beam up close.
Below: Another angle on the peel ply.
Below: Making up the infusion medium with sleeves for the spiral wrap distribution “pipe”.
Below: Stapling the infusion medium sleeves.
Below: Threading the spiral wrap “pipes”.
Resin and Vacuum Distribution
Below: After laying the release film (which is pink) the infusion medium assembly was laid over the beam. It was then snipped to take the resin feed and vacuum lines.
Below: Inserting the reusable nylon distribution fittings.
Below: Distribution fitting almost in place.
Below: Jem says g’day. Note the measuring tape to ensure even layout of the fitted distribution and I wear all this including the gloves to keep my perspiration away from the fabrics and infusion medium until covered by the bag.
Below: Starting the distribution line set up.
Below: Vacuum workstation located out side boat on the ground to stop vibration and cut noise to the closest neighbour.
Below: Fitting the bag material. Note the perspiration – >35°C and >80% relative humidity.
Below: Finishing touches to the vacuum bag.
The Infusion
Below: Mixing the resin – Kinetix R118 and H120 hardener immediately prior to the infusion.
Below: The Video
The Aftermath
Below: Removing the bag, infusion medium etc. Note how easily it comes off, due to the use of release film.
Below: Completed Upper Flange with the peel ply still on.
Below: The top of the beam, close up with the peel ply still on (shiny).
Below: Another close up
Below: Rear side close up.
Previous Beam Infusion Trial
Lastly the previous trial as I naturally cannot cut up or sample core the real beam.
So how do I know that all the lay up has been wet through? I took the quantity of resin used, and subtracted the amounts in the lines, in the resin trap, and an allowance for that in the peelply and infusion medium. Then I compared this with the weight of the all the glass tapes which were weighed prior to laying up on the beam.
Below: A section cut through the small trial infusion, I have managed a better balance of layout due to use of Airtac2 to secure the fabric during setup before the vacuum is applied.
The Scrumble Project 