This is the side tank under vacuum on the side tank mould. I was quite happy with how this process worked. Using only 5 supporting frames and a 3mm sheet of melamine coated MDF as the mould surface the shape held very well, even under vacuum there was no distortion or warping.
This is a roughly trimmed side tank, this will be going on the port side and will house the spinnaker to keep the cockpit neat and tidy. The mould gave a good smooth surface which should be easy to paint straight to will minimal filling and sanding.
This is the "tension member" that I have Incorporated into the hull fit out. The idea behind it is to help triangulate or form a space frame between the mast step and stay mounts to help increase the stiffness of the hull and rig, which hopefully will help to reduce fore stay sag when sailing, which may ultimately allow for a wider range of rig tensions to be used. The member only weighted 280g so hopefully the advantage will be worth the small weight penalty.
This is a quick image of the fore stay mount attached to the top of the bowsprit receiving tube. The plate is made from two layers of 2mm thick 0/90 deg woven prep reg plate, then extra layers of 0 deg fibres to deal with the tensile load and +- 45 deg fibre to resist "shear out" of the fore stay pin
This is a photo of the rear bulkhead that supports the bowsprit receiver tube. The bulkhead is glass and foam with local carbon reinforcement to help distribute the load to the hull. The joining tape for the bulkhead to hull joint is laid on the -+ 45 deg to provide good shear strength in the joint.
The floor has finally been glued into place using Q-cells and epoxy.
The centreboard case was opened up and the polystyrene foam was dug out.
This is a photo to try and show the collapse that we found in out rudder. That surface was the upward facing surface in our mould when we used to expanding epoxy foam. It looks at this stage like it was a large air pocket or void which has collapsed for some reason after it was made. Although we are uncertain why it collapsed as the carbon skin should want to stay in its moulded shape so they must be some sort of suction or residual stress present to force it to collapse, time will tell...
Also completed but i don't have any photos at this stage, the port side tank has been fitted, starboard side tank has been laminated, rudder gantry fitted and trimmed, spinnaker opening shaped, spinnaker chute has been laminated and carbon plates for fittings have been cut.
Bring you more photos shortly.
Cheers
I have plans on using the f230 on a large production of carbon paddle blades, and after reading your blog I not to sure if this F-230 is the right product. Did you use the slow cure for the f230? The Heat could have caused the dimple effect on your part? Any more test done or other parts made after this one with F-230? Glen Carlin ( glen@carlinsup.com)
ReplyDeleteHi Glen, Sorry for the late reply. Yes i used the slow hardener for the resin system (Exotherm could possibly have occoured/had an influence). I feel that the problem occoured from two possible reasons. The first being either that there just wasn't enough foam in the mould in the first place (since this was basically a "one-shot" go at it). Or secondly that perhaps since there was only a small hole for the excess foam to leave from. That an internal pressure developed, which prevented the foam to expanding to the full volume or left large areas of air trapped in the part.
ReplyDeleteEither way there must have been some sort of void in the foam core or between the core and skin that has collapsed at some point either due to heat from the sun (perhaps softening the resin at the same time e.g. a resin with low HDT was used). It is also a possiblity that changes in atmospheric pressure or a leak into or out of the air pocket had an influence.
The F230 resin seemed like a good product, i feel that the flaw that we had was in the moulding process itself. I would sudjest getting your hands on some and giving it a go in the mould without a laminate to test how it flows, or expands in the mould and if any airpockets are formed. This will probably be the best way to see if your moulding technique or the product are suitable.
cheers