Farrier Boat Building Technique

[BristolW]

Hi,

I was reading on the Farrier site (and the site where the F-39 builder is using infusion) about the heat molding of foam over planking to do one off hulls. I have seen some others on this site are using similar techniques. Is there anywhere I can learn more about how this works? It looks like you bend the foam and join it with microballons?

I am specifically interested in learning about:

How you vacuum bag the hulls halves? Do you lift the foam off the mold and encase the foam completely in the bag or is it done one side at a time like on the infusion sight? If this is the case, how is the foam held in shape? or does the vacuum only put pressure into the laminate not create forces to reshape the foam?

On average, how many layers of fiberglass with epoxy go into typical boats on the inside and outside of the foam? For say a beach catamaran, a dingy and an F-boat type trimaran? How much less or more carbon fiber sheets would be used to make the same boat?

How you could possibly join the two halves together successfully? You would have to get the edges to line up just right, somehow have the bulkheads be perfectly sized and get them attached to both hulls and then use glue to join them? Seems pretty tough. The guy doing the infusion process just glassed the inside of the hulls then put the hulls together and glassed them, and vacuumed them. Is this how they typically do it? In his case the hulls were so big that he could get inside them to glue them, but I wonder how you could do this on a small tri.

Sorry for all the questions, I just really want to lean more about composite boat building (for academic purposes only).

Thanks for the help,

Bristol

[Chris Ostlind]

Write to Henny (the guy building the vacuum infused F boat in Netherlands) and ask him a few questions. He has also prepared a nice DVD of his process along with a suggested materials listing so that you, too, could infuse your own multihull (or most any other boat, for that matter) The price for the DVD is extremely nominal compared to the learning experience that it represents on Henny's dime.

I think you will have all your questions answered through that process.

As a second line of thinking on foam multihull building.... take a look at the work done by Olivier Blanc in Canada as he has constructed a Kendrick designed, Scarab 22 trimaran in his garage from foam laminate panels he made himself.
http://www.voile.org/trimaran/

Suggestion... build something small, like a canoe or kayak, to get a handle on the process, the materials and the workflow, with hands on knowledge before you think about building a bigger boat. (If you are considering a bigger boat at all)

Chris Ostlind

[BristolW]

Thank you for the reply. I will contact him. But, I was wondering if everyone using these techniques are doing it like him. Or if he is doing something special for resin infusion. I am just looking to learn more about these questions. I do not plan on building a boat.

Thank you,

Bristol

[Chris Ostlind]

Farrier says it isn't necessary to bag or infuse his boats. Apparently Henny has his own reasons. I'd speculate that he wants to keep the resin away from his person, make as light, and strong, a boat as possible and to some extent... do it because it was challenging.

Chris

[tspeer]

Henny van Oortmarssen has been using infusion to build a Farrier F-39, and he has a great website that talks about the whole process. He even sells a CD that explains resin infusion for beginners.

You might also want to post your questions on the Multihull Boatbuilder Group.

[BristolW]

ahh, so they are not vacuum bagging these boats. I see the F-39 site, but I already know about infusion and his techniques. I was wondering what everyone else who does not believe in infusion for a one off boat is doing.

If you were to heat form the foam, remove it from the mold and vacuum bag it, would the vacuum deform the foam or does it just produce normal forces on the laminate?

If this does deform the shape and you choose to vacuum bag you would have to lift the foam out of the mold put plastic down, put the foam back, seal it then somehow brace it to the mold framing. Is this right?

[BristolW]

from Farrier website:

Tor is using vacuum bagging along with the resin infusion process but note that I do not recommend infusion for hulls unless you really want cleanliness, or would just like to try the process. Vacuum bagging hulls alone is also nice, and will give a superior product, but it is also not necessary and will increase building time. Vacuum bagging is only recommended for flat panels like bulkheads, where it is very easy to do, but again, not necessary.

http://www.f-boat.com/pdf/Tor.Rabe.F-22float.pdf

From Me:

I looks like he is only vacuum baging one side of the hull at a time.