https://au.groups.yahoo.com/neo/groups/harryproa/photos/photostream/lightbox/527451759#zax/527451759

You might have to be logged in to see this pic, but i think it is the start of some pics of the process. There are more in the pictures folder.

On May 10, 2018 2:13:08 PM UTC, "StoneTool owly@ttc-cmc.net [harryproa]" <harryproa@yahoogroups.com.au> wrote:
|  Just a bit of background........
|
|     I'm not a potential builder of a Harryproa, as they don't meet my
|criteria, but rather interested in building a 30' catamaran or
|thereabouts.   One of my biggest priorities is achieving the most
|payload for the size cat I'm looking at. The two catamarans under
|consideration are wood epoxy, one entirely plywood, the other with a
|strip planked lower hull section.
|
|    Rob immediately suggested building from foam sandwich, and offered
|a lot of information on substitution of infused foam sandwich for
|plywood, including weight savings that look too good to be true, but
|seem to be borne out the further I research the subject.   Having found
|
|a "local" source for construction foam (Divinicell), at a price I can
|swallow, though much higher than the numbers Rob quotes in Australia,
|I'm in the process of examining the feasibility of building this way,
|and how I can pare costs down a bit without compromising the structure.
|
|     I joined this group at Rob's suggestion, hoping to gain a better
|understanding of the details of his intelligent infusion process, which
|
|are at best murky.... at least to me.   Watching Utube videos of
|infusions, some seem to involve an almost absurd number of layers of
|various disposable, materials, others only a few.  Some folks do it on
|male molds, others on female molds, some infuse one side of a part
|only,
|and others seem to manage to infuse an entire sandwich in one go.  Foam
|
|with cuts in opposite direction on opposite sides, foam with
|perforations and knife slices, plain foam, distribution mat, peel ply,
|and on and on. Porting the resin in, and porting the vacuum, are both
|obviously important, and the distribution of those ports would seem to
|be critical to getting the infusion right.    An entire half of a 30'
|catamaran hull would be a big failure if things didn't work out. Enough
|
|of a failure that wetting it out manually and vacuum bagging followed
|by
|the inevitable hand finishing would not seem so bad by comparison.    I
|
|personally find the idea of losing even a single piece of that size a
|bit more than I can stomach, and losing one, there is no guarantee that
|
|the next will work   ;-)
|
|
|       With that in mind, I've been going through the photos, and am
|just beginning to work my way through old posts to glean what
|information I can.   I'm a year or more off from beginning my own
|project, and plan to do some test pieces and more research and reading
|during that time.
|
|
|
|                                                    H.W.