|5th February 2013 07:14 AM|
Incredible. I made the attempt I've told about, screwing in the front nut of the fin head an headless screw, waiting to see it appear far from the hole of the board.
Surprise: the.. "headeless neck" of the screw was almost right under the hole!
After scratching my head for about five minutes, I then realized this.
The lower part of tuttle fin head is flat like the board hull and obviously at 90' from fin body.
BUT the higher part of a tuttle and deep tuttle fin is at an angle of what, about 15 degrees?
Then the two bolts-screw starts from their nuts and goes out over the top of fin head at 90 degrees BUT FROM THIS UPPER INCLINED SIDE! So they are naturally bent backward at the same angle!
So the screw heads over a flat deck like the one of the F158 willl ALWAYS be not flat and inclined backwards at about 15 degrees!!!!!!!
To avoid this and go at 90 degrees the holes over the tt and dt fin head should be INCLINED FORWARD at the same 15 degrees, but in this way the front screw would come out almost in the corner of fin head, not so good and strong.
And this with both the stock DT Drake Race 70 cm and the TT T-Zone 40/56 seaweed fin
Not having any problem with the Serenity I was wrongly thinking that the problem was in the board, but it's not, I have to say that pheraphs is a problem of the tuttle system. I'll check the serenity but I suppose that its hull is not flat, neither it's deck and so the bottom of its screw fin box (the so called drinks storage box).
I suppose that the TT system was invented in the years that almost every board has a stern width decreasing going back, and in this case it can be ok, but with a board like F158 that has parallel deck and hull.
Not to say that a one screw system like powerbox is not affected by these kind of problem, and this could be the reason that it has a wide concave in the middle.
Anyway with a somewhat flexible steel washer and a rubber spacer under it I've solved the problem, I'll use the T-Zone 40/56 that I've already bought for the Serenity but almost never used as I prefer for it the more extreme Select Delta Antiweed XXL that has an incredible 27,5 cm depth an allows me to ride on the shallowest waters (and wildest zones of my lagoon.
|4th February 2013 12:44 PM|
You can do as you suggest and drill new holes, but filling in the old holes and dressing the edges of the
new holes is not really necessary.
My suggestion to elongate the existing holes forward has worked quite well on many boards with this problem
in the past.
Since the holes are slightly larger in diameter than the 6 mm fin screws, if you use a rat tail file that's approxx.
6mm an make aa nice elongated 6 mm slot it looks quite good and works really well.
What weed fins are you planning to use on the F-158?
If you can get one, the Lessacher Formula Duo works really well on boards this wide and the tip is only 40 cm
|4th February 2013 07:20 AM|
Edit, just found the fin screw chart on 2004 website, very good.
|3rd February 2013 08:36 PM|
Thanks a lot. First of all my apologies for forgetting that I've already written in december another post with the same introduction, now I've reminded it and fonud it, it was about the inner inserts idea (abandoned until I'll try the board as it is)
Then now I realize that the long box is the way of building it in the strongest way as it is bonded to the deck as you say.
Thanks for the suggestion so now I/m thinking the bast way to move forward the holes, I think that with a lot of care I can do directly new holes, as they are really way back than the correct position, 4-5 mm.
I plan to screw on the head of the stock dt fin some long M6 screw without head, put the fin in the box and check with a caliber from the existing holes how far is the right position, then to make there the correct hole.
Therefore to add some good epoxy resin and seal the old holes and the edges of the new ones.
Two other small questions. What is the lenght, head included and/or without it, of the recommended screws for TT and DT fins with the F158? I can't find the spces , clearly after all these years they were erased, I suppose.
Second: on the pdf image the F158 drawing has two inserts for the chicken strap or central rear strap, but mine has only one, was at the end built to use the front fin screw for rear footstrap screw or something else?
|2nd February 2013 11:20 PM|
The fin box in your F-158 is bonded to the deck as well as to the bottom.
You can elongate the holes in the top of the board toward the front of the fin box until the fin screws line up with the brass barrel nuts down in the head of the fin.
Good idea to get some large dia. SS fender washers (31.75 OD with a 6-7 mm hole and some large rubber washer to go under the fender washers and seal the fin box from air being pulled down and onto the low pressure side of your fin.
You will have no leaks and will not affect the sturcture of the board at all.
The fin box is a large blocky cassette that gets bonded to the top and bottom of your boards hull and also
bonded into the foam interior on both sides and the front and back.
This is the easiest way to fix this problem.
|2nd February 2013 10:04 PM|
I've bought used at a cheap price a nice Starboard Formula Wood 158 from 2004 in very good conditions, very light and with only some small dings. I want to have the perfect partner fo my wonderful Serenity for light winds, right for the times that winds is slightly more. Therefore I can use also the seaweed fins bought for the Serenity.
But compared to the Serenity it has a imho strange and weird fin box. I mean I don't know why but the fin box is twice deep than necessary and than the head of my DT fins, and the inside head of the box it is really only few MILLIMETRES under the deck of the board!!!
Second thing, the hole were dramatically made wrong, I mean they ar not perpendicularly over the fin nuts but wrongly more set back toward the tail, so the head of fin bolts arrive at a about 5 degrees angle!
In this way for the first factor to find with the bolts the nuts in the fin head is really a matter of luck after a lot of attempts, so is not user friendly and hard to use for me especially in a rolling boat, because of the second, the mistake, screws when tighten horribly push only on the back side of the surface near of hole, with possible damages.
What is the reason of a so deep concave on the finbox head???
And If I fullfill with epoxy resin this useless space and make new and slightly more forward screw holes on the deck, would it be a solution or not?