foam cores and core materials

I didn’t go back and read Pascoe's stuff again, I read it years ago when it was fresh.

In one paper he said he didn't really understand the properties of the materials used to build boats, and he’d never been in a manufacturing plant to understand the process either.

Since he didn't know what he was looking at, he just came to conclusions that were a bit off in accuracy sometimes.

This was back when I was in these plants every week and knew the build process for most manufacturers.

There were products used in places that they weren't designed for, they were typically sort of adequate, but barely. In reality it was amazing some of the materials used held up as well as they did. The supplier/manufacturer of the product typically didn’t recomened the the products to be used in the way they were.

One of these was the sprayable cores used at the time. These were marketed for cosmetics and stiffening of non structural components. They were used in hulls and other stressed locations, and poorly at that.

Some of these hulls separated at the core, Pascoe reported this in a couple articles.

A lot of these boats were built in the frenzy of manufacturing around the 80's. Many of the designs were good, but the production methods left a lot to be desired.

People frequently discuss resin type as the cause of failure, it rarely is. You could use the best epoxy available, but with the skill and attention to detail that was available in production, they would have failed at the same rate as the cheapest polyester. The failures had nothing to do with the resin.

Whether a core should or shouldn't be used depends on the intended purpose of the final product. The exact same materials could be great, or a total failure.

 

One aspect of cored boats of the planing variety, rarely mentioned, is that stiffness actually improves the ride of the boat in many cases, the bottom stays in shape with wave impacts, and doesn't develop "dynamic hook", which can increase vertical accelerations.

 

One trapezing dinghy that I used to crew had the toestraps fixed to a bonded in pad at the aft end of the hull and it flexed a bit under load.My impression was that this aided performance a touch-getting the helmsman to sit out hard wasn't easy.......

One thing that Daniel Savitsky's seminal work on panel loading showed was the importance of stiff bottom panels near the bow of planing hulls.Which also confers an advantage when a sailboat crashes down into a wave trough and the rigging doesn't go slack.Efficient sandwich panels are invaluable when properly manufactured and conform to the negative stereotype when corners are cut.The question is why those corners get cut-is it lack of training for the guys with buckets of resin or is it the beancounters dominating the discussion?

 

I had no Idea he past away, probably wouldn't have started this had I realized.