Friday, 11 November 2011

Myth buster

For some reason people think it is easier to build in foam, I think they may have forgotten that building in foam on or in a mould is great but:

Building using the three methods of epoxy foam construction that a home builder could contemplate all cost more in consumables, equipment and require more space than the normal single garage set up. The beauty of the ply system is it can be done in a single garage, by one person at very low cost both in terms of materials and extra equipment.

If you go foam you have to build a jig, ( that you tie the foam down on to ) a male mould or a female mould ( where you use vaccum to create the foam epoxy consolidation ) or hire or part own a mould. All extra cost and time, as well as waiting for the mould to be available, ( if part of a group ) and hoping the mould doesn't get damaged. Which happens more often than you think. And then where do you store the mould?

You need to buy a vacuum pump (£250) you also need more consumables: tacky tape, breather, bread wrap, peel ply and vac bag plastic. You need more epoxy, you need large amounts of glass fibre cloth or carbon to create the foam sandwich. You need more rollers, brushes, gloves. You need a laying up table. You need the garage to be warm and not just the area you are working on. You need an extra layer of specific knowledge that most people don't have.

In the end it costs a lot more and is more difficult to do on your own. (laying up large sheets of glass on a mould is very hard to do on your own ). And all this for what? A boat that is 10 kg lighter.

Form my point of view, it's the Farr 3.7's simplicity that is it's beauty. The attractiveness of building one is wood is that building one is within the scope of a regular handy guy or girl. With no real extra boat building technical knowledge. With part of its joy being the ability to build up your cheap laser cut ply parts with minimum extra space, help, tools and consumables.

People say building in wood is harder than foam. This is only true if: you want a wood finish. And I would debate that fact even then with regard to the Farr.

If you treat wood like you do foam I.E as a core material needing filler and painting this isn't the case. If you make any visible bad joints they can be filled and painted over. It is also less true if you are using laser cut wood parts! You would also be using Bruce Farrs plans, meaning you have less thinking time and there is less likelyhood of getting it wrong!

But if foam is what people want then a having a set of AUTO CAD files altered to allow a foam skin over ply may be the way forward. I know at least one person I have been talking to was thinking this would be the way he wanted to build one. A sort of halfway foam / ply boat.

And to this end I am investigating having the AUTOCAD files altered to allow for the increased hull skin thickness that would be needed for a foam hull skin.

The above having been said. If a male or female foam sandwich construction is what you want to do, please don't let my views stand in your way. I will be the first to offer my help to anyone needing an extra pair of hands and then I'll be there slapping you on your back, saying well done when you finish it!

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