Force Fin Designs

[Bob Evans]

Found these images from 1968. Jim Pennington and I had purchased a 13 foot Boston Whaler from Dive N Surf. A special mount was made for the 55 HP Johnson motor, we had on our next 13 Whaler, these pitures show a less powerful engine. Our pay checks went directly to Dive N Surf... We haul asssss some times over to Catalina Island..no radio. But here is Jim on the matt and Robbie and me with my 16mm Underwater camera. Again with out the support of the Meistrell Family Force Fin might have never been....Jim at the wheel coming into Redondo Beach King harbour.

 

[Bob Evans]

Bob Meistrell back in the day 1966 and on his 80th Birthday. Bob is the friend who told me to " HEY EVANS WHY NOT MAKE A BETTER FIN.." and years later invested over $ 250.000 and made Force Fin happen... (copyright Bob Evans)

 

[Bob Evans]

A classic time. Robbie Meistrell Jr, drove up from Redondo Beach to check on progress and add his comments to the development of the Force Fin design and came with a Dive N Surf check to keep us kicking forward...(photo Dana Rosen) 1980 Anacpa Street trailer work shop.

 

[Bob Evans]

Working out the right thickness for any Force Fin was a challenge. Most times we just made another master. Here you can see how we added material right at the end of the foot area. One day Jimmy Gray said let's not make another master (took Months) So he took the grinder to the mold halfs and things moved faster after this point. I was dolling out each Force Fin plug and after this point just went for it. Learned sometimes the tooling could be used since most times a fin design never made production.

 

[Bob Evans]

I will say it took some time to un-screw the molds apart. So I thought we could clamp the Force Fin molds together using some of my underwater camera housing clamps. Force Fin molds went into so many different clamping designs. Remember Poly-Uethane is hot like motor oil, and at $8.00 per pound at the time, bleeding molds were bad news. Will share down the road clamping concepts...did we spend some money on this problem... Here you can see a out line of our internal shaping on the top side. . A scew down mold and next our wood box mold. Besides being super heavy this idea drifted pass on the next mold series. Force Fin

 

[JMBL]

Ready about Force Fins is beginning to get on my nerves, let me explain : I've got a nice pair down in my locker, but I'm compelled to stay at home. For once, I had time, money, nice weather, but I'm not allowed... Darn !

 

[Bob Evans]

One good thing about Poly-Urethane other than lasting for ever, was the SNAP. When you compress this stuff it gives back like a super ball. I have always told folks do a flip test on your fin to test for rebound. It's so important in the recovery phase. Here you can see the Force Fin in action and a Tan Delta Force Fin where you can see the internal ribbing system. Then the Force Fin master changes... Believe you me this what the game changer for a Higher Performance fin. One last point was the Wing tip design..Save that for dinner time ? Me doing a flip test with the Excell

 

[Bob Evans]

One final very important wing tip design change was this. Beside the flexing zones I was unable to get the Force Fin Wing tips twisting outwards on the down stroke kick. Jimmy made the right call and flared up the trailing edge...that was it. Here you can see the subtle up curve. Now the Force Fin opened up and flew...we were ready to go for the final Force Fin master #FORCEFINNERSUNITE

 

[Bob Evans]

" The most important Technology is an IDEA " Jacques Cousteau. When the time comes will go into the Mono-Force Fin development. But here is one big Force Fin blade. #FORCEFINNERSUNITE

 

[Bob Evans]

Our final Force Fin with all the right curves. This production mold pumped out a few dozen pairs. The size was ML. Time for Patent drawings to be prepaired.