Daggerboard - is GRP much better?

Thread starter #1
Is the GRP daggerboard much better than the older type? Assume both are brand new out of the box for this discussion.
thanks
J
 

LaLi

Active Member
#2
There probably aren't many brand new/unused Crompton foils around anymore... but the weight, stiffness and underwater shape should be similar to the GRP ones.

I changed to GRP foils because they're more resistant to scratches and easier to repair.

Talked with an LP representative a little while ago, and he told their foils are now built in Spain, China and the US, all being similar and all white. The "grey-top" foils by Simon Cooke were then a relatively short-time thing.
 
#3
Head-to-head the glass ones are orders of magnitude better than the old poly foam.

1. The foam ones are fragile. I've broken more tips than I can count. I've repaired 6 shark bites in the trailing edges. Last year, when recovering from a capsize in heavy air, I drove my knee into the top of the board when I got back into the cockpit. Broke the top of the board that left a knee cap sized bite out of the trailing edge by the handle(I have the scar to prove it), because there is none of that steel rebar in that location.
2. paints soft. They come with orange peel that should be polished out of the box.
3. I've seen a bunch of the old ones warp.
4. eventually the steel rebar starts bleeding rust.
 

LaLi

Active Member
#4
The biggest problem with the old Laser foils is/was that their quality varied considerably, and you didn't know whether they were good or bad until after several years of use. I've seen 30-year-old blades that didn't look more than one year old, despite having been (lightly) used all the time. Then there are the horror stories... I actually have a worst-case scenario (both centreboard & rudder blade) right here at home. Rust, broken edges, blisters of different sizes, and more rust... ok, I admit "scratch resistance" in my previous post was a bit of an understatement.

But there seems to be no difference in performance. Even the crappiest old foils are just as fast after you fill the edges and sand down the blisters. They make you slower only by looking ugly, and making you spend time repairing them when you could be sailing.

Stinger, do you have an actual choice of buying an unused old-style centreboard? If you can get a good price (like 50 % off), get it. But be prepared to work on it.
 
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LaLi

Active Member
#6
Looking at boats, which year did they switch to the new foils?
Rough timeline:
2006 - Australians start making GRP foils. Originally they have no gelcoat so the brownish yellow foam core shows through. Also, they say "Laser" in big blue letters.
2010 - LP starts to sell the grey-top GRP foils. Australians switch to all-white foils.
2014 - LP switches to all-white foils.

I'm sure there are others on this forum who have more detailed information.
 
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AlanD

Former ISAF Laser Measurer
#7
PSA started developing the GRP boards back in about 2000. They were all white, and were periodically available as each round of development occurred, often withdrawn from the market again including PSA replacing the boards that were out their. It wasn't until the 2006 that they managed to work out most* of the production issues.

* The clear coat ones, had there own production issues, with some being under weight. This was because of the clear coat resin actually weighed less than the white resin used in the pre-production prototypes. Additionally the clear coat ones also lost their tips extremely easily.

Part of the issue with the PSA boards was that there were no specs beyond what's actually in the class rules book, PSA actually had to test and measure the Crompton boards to determine what their specs actually were and then build the PSA boards to actually be inside the tolerance of the Crompton boards. The Crompton boards were never designed to be equivalent to the earlier timber boards (or other possibilities). I'm lead to believe that GRP boards were permitted well before PSA started playing with the idea, possibly back in the timber days, not that I've actually seen any other than those where it's been used for repairs.

LP had the advantage of having a set of specs to work worth to develop their boards.
 

LaLi

Active Member
#8
I'm lead to believe that GRP boards were permitted well before PSA started playing with the idea, possibly back in the timber days, not that I've actually seen any other than those where it's been used for repairs.
Yes - my impression is that the almost-mythical Laser Construction Manual has included GRP as a foil material from the beginning. That's why we never voted on the switch, as there was no rule to change. I've also heard that GRP foils were unsuccessfully experimented with in the early 1970s, before the Crompton construction was adopted.
 
#12
GRP is glass reinforced plastic.

The Laser blades are probably similar in construction to the typical modern Optimist blades. Epoxy resin,foam core, biaxial fiberglass. The Opti ones have to be see thru so they don't hide any carbon fibre in there.
 

LaLi

Active Member
#13
"Your new Centreboard or Rudder is made from an advanced type of epoxy reinforced glass fibre with a polyurethane foam core. For structural repair purposes you can use epoxy products and glass fibre reinforcement. For surface repair purposes you can use epoxy based gelcoat or PU paints."

That's what Simon Cooke says about my foils... he should know, he built them.
 
#14
They are resin infused. Which simply means they use the vaccuum pump to pull the resin into the mold. Many fiberglass products have been made this way since the late 1990's. Including the entire hulls of J/Boats and some of the highend customs. It was originally called the SCRIMP process. Other people have licensed, copied or improved on their techniques. It let's the builder have very accurate control of the resin/fibre ratio. Optimizing it to save weight and it makes a stronger/stiffer composite part. You can check out whole hulls being resin infused on YouTube.
 
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