Hans (and all other interested parties),

For some reason your attachment won't show itself on my PC. I also seem unable to grap it. If anybody can then please send a copy to me using my mail account wouterhijink(at)hotmail.com

I'm sure that the attached picture shows a scale with a mast tip layed on it. Most likely the scale is pointing to some high value and as such is intended to proof your case. I accept that much.

What I don't really understand is your question. I mean how can I explain something from just such a picture; for all I know you may have used some other mast or are using an alu top fitting to seal the mast (just as with Hobies / Prindles back in the day). In short it is impossible for me to explain something that I'm not part off or haven't investigated myself.

Having said this; the weighting of my own alu F16 mast and that of Frank was done in the presence of Frank, Pieter Saarberg (chief F16 measurer), you (class chairman) and myself. We have all seen my mast and can confirm that everything needed for sailing, including the sidestays, forestays, halyard and any thing else, were still attached. By that time I had been using that mast for three years and had just picked the boat (and franks) of the beach an hour before. Later that day I just connected the stays to the hulls and raised the mast. Spi halyard systems etc all went down and up with it.

We all know the scales showed a tipweight of 8.9 kg. Later Pieter noticed that the stayes were still attached and deducted 1 kg from that number and wrote down 7.9 kg on my measurement form. Franks mast was weighted without the side- and forestays and was (from memory) found to be lighter then my mast (7.8 kg).

Therefore I put my own mast and its certified tip measurement, performed in front of 4 witnesses, against your foto "of 10 minutes ago" (same with regard to Franks mast).


Now I would love to find out why the "old" masts are coming in so much lighter. If anything we can correct the situation to all our advantage when we know the cause. Afterall, my mast (and that of others like Frank and indeed Phill) show that a 8 kg tip weight alu F16 mast is possible and strong enough to survive regular F16 sailing.

It will be smart to try to reproduce the "old" masts.

Maybe the dies have worn out; that is a 1000 bucks fix (making a new die)

Maybe new dies have been made but the guy doing the milling made an error and set the machine to 1.8 mm wallthickness instead of 1.6 mm (that will add 1.9 kg to the bare mast section).

Maybe the company doing the extrusions has changed the extrusion speeds without notifying us, thus resulting in more expansion of the crossection then was intended when the die was made ?

There are a number of reasons why things may have gone wrong, but we know that truly lightweight F16 alu masts are possible as several of us actually have them. Either that or Pieters scales are totally undependable.

I say lets get to the bottom of this and try to sort this out.

I know we're are not on the best of terms recently, but you will find me a willing ally in this respect.

Wouter