Here's a Starboard 66 Quad which is a dog. Converting it to a Twin for a friend. Apparently identical to Evil twin which is a ripper.


Chopped out with "Buzz Tool" freehand.




No need to peel skin off. Lots of PVC reinforcing to bond to.Putting some in the bottom of the holes.

Ready to glue in.

PVC cut, glue "West System" Epoxy resin glue & Clamp



Measured leading and trailing edges of twins using centre fin as reference...assuming it's straight! The factory pair were 1.5mm out!

Sanded. A few small holes. Polyester car filler works best for smaller imperfections. Resin with Q-cell wont go off well in small volume. The car filler sands finer too.

I would not dream of doing it myself, but knowledge, and a practised hand make it look easy, and it LOOKS like a good fin setup.

The 'Buzz Tool' is a hot tip for cutting in - beats my hammer and blunt chisel.

To be able to (dramatically) modify board performance with what looks like a relatively simple 'fix' makes me wonder what else I have under the house that has not been living up to expectations...

The 2010 Quad was a PIG! I am sure that there are plenty of others out there waiting for some performance enhancement.

Quad to Twin, Single to Thruster, Quad to Single, Anything to asymmetric...yes, asymmetric, you remember those.

The jury is in - the retrofit is a raging success.

I sailed it yesterday in 22 - 30 knots with a pair of JP 15.5 fins (the tiny looking ones). I was sold on the first run - I now have a 74 litre Evil Twin (actual) and it's smaller 66 litre twin sibling - The RUNT.

I ride my 74 with 16.5 black project fins, and love it in that configuration. The 15.5's that I used yesterday are markedly smaller and I struggled at first, and felt like the board was turning from a point too far forward, as well as skidding out when board speed dropped.

I moved the fins 2-3 cm further back and that fixed the pivot point issue, as well as ALMOST sorting the skidding problem. After riding it for a few hours I got used to the skids and just enjoyed fish-tailing the end of gybes, except the one where I nearly took Greenie out and had to ditch it.

The board is FAST, I would say no different to a single, with the twins dead parallel with the board's centre line (no toeing). I am ompletely amazed that the turn characteristics are so different. Next sail I will drop in the 16.5's and see how it handles. My bet is EXACTLY like it's bigger brother. The bigger fins don't seem to lengthen turns - the 74 will turn on a 5c piece - but they keep it tracking out the back end of turns where yesterday I would have started to slide. That tracking means you can control the 'throw and switch' (sail and feet) as well as keep your board speed. One of the advantages with twins is that you can use fairly big fins without the board tending to ride-up on them.

STOKED! I now have another favourite board.

Thanks Relic - you are a legend!

Good to hear the boxes didn't fall out. The cheaper water based glue works

Good to hear the boxes didn't fall out. The cheaper water based glue works

Hi Relic is that chopper tool an attachment you put on a grinder or is it a complete unit. It does a lot neater job than freehand grinder.

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R1DER said..
Hi Relic is that chopper tool an attachment you put on a grinder or is it a complete unit. It does a lot neater job than freehand grinder.

Mike, the tool is a "Multitool". It is basically an orbital sander with much higher oscillation and variable speed. Some are better than others having a fine action. The cutting blades come in all sorts of shapes for wood and metal. Bunnings have a good range.

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Relic said..

R1DER said..
Hi Relic is that chopper tool an attachment you put on a grinder or is it a complete unit. It does a lot neater job than freehand grinder.

Mike, the tool is a "Multitool". It is basically an orbital sander with much higher oscillation and variable speed. Some are better than others having a fine action. The cutting blades come in all sorts of shapes for wood and metal. Bunnings have a good range.

Rider, I noticed you mark a depth line on the cutting blade. Is it visible when oscillating and is that how you control the depth of the cut?

The Bosch tool has a very high oscillation and is easy to control. I place my fingers much how you would on a billiard table and lower the blade into the job. The guide lines are visible when the machine is running. I also run a vacum cleaner to draw the dust away to maintain the visibility of the guide lines.

And it works, it ALL works - The RUNT - still wet following a Bellbuoy Blast this morning: