Time for lay-up?

[egor_1066]

Hi

Can anyone give me a rule-of-thumb guide for the time it takes to lay up a powerboat hull in a female mould? I'm actually looking at a 25 foot hull, but is ther a rule which says (even roughly) ... "it will take you x number of man-hours to lay up each square foot (or metre) of hull"!

Many thanks

[marshmat]

Hi Egor,

It's hard to give a definite answer, as it really depends on the skill of the workers, the materials you use, the complexity of the shape.... On the solar car moulds I did a few years ago, I think it worked out around 0.4-0.5 man-hours per square metre of cloth laid (ie, per layer). But that could easily vary from as little as 0.1 man-hour per square metre for experienced staff with good tools doing simple flat parts, to upwards of 2 man-hours per square metre on complex, smaller shapes or for the first few hours with new/inexperienced staff.

Some have reported significant labour time savings after switching from hand-layup to a vacuum infusion process. But this really depends on how good you are at planning and setting up an infusion. It can be a real timesaver (as well as producing a lighter, stronger part) but there are many ways in which infusion can go catastrophically bad if you don't get it quite right.

[egor_1066]

This is great info - thanks. I'm just intrigued that this question doesn't seem to get asked more often - without knowing the answers how can anyone - self-build or professional - budget for their project?

Oh! and I think I'll budget on the 2 hours........

[marshmat]

Quite simply, you can't budget/schedule a large project unless you have enough experience on smaller projects to be able to make educated guesses.

As I've pointed out, layup time per square metre can vary by more than an order of magnitude between a good crew / simple part and a new crew / complex part. Only once you've tried it and figured out the tricks, and know how your own crew behave, can you make a useful estimate.