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Embarrassing mast shim question

Created by Paducah Paducah  > 9 months ago, 21 Mar 2024
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Paducah
Paducah

2792 posts

21 Mar 2024 10:51am
I've got a new foil that has shims that are meant to go under the front screw of the tuttle head. They aren't full length like some intended for IQFoil, only long enough for a flat over the front barrel nut.

How does one dependably put the shim in place and retrieve it? Do you end up gluing it with something somewhat temporary? Seems to me that dropping it in and hoping the holes line up would be a recipe for frustration if they don't plus then I'd have to retrieve the shim at the end of the session. It seems to be the perfect size and color to be forever lost in the grass.

Signed,
Shimless in SE USA
Rolz
Rolz

QLD

174 posts

21 Mar 2024 3:01pm
I have them for my F4 foil that goes into the finbox... mine fit in and I don't really have too many issues in mounting them, but it does take some getting used to.

I do recommend a digital level as it does also take some practice in working out how to screw it in correctly to get the best angle.
Subsonic
Subsonic

WA

3384 posts

21 Mar 2024 6:04pm
Line it up with a screwdriver in the box (in the mast entry) then put the mast in/on it and it shouldn't shift? You can usually see a bit of whats going on through the hole when you flip the board to put bolts in, so you can check it hasn't gone astray.


hot tip from the man who likes to leave shims at the beach:
paint it orange or red so you'll see it as you wonder past it the next day whilst rigging.
Mark _australia
Mark _australia

WA

23526 posts

21 Mar 2024 7:16pm
I look forward to your next thread re fixing broken DT box
I would avoid mast shimming unless you realllly have to
Paducah
Paducah

2792 posts

21 Mar 2024 9:22pm
Select to expand quote
Mark _australia said..
I look forward to your next thread re fixing broken DT box
I would avoid mast shimming unless you realllly have to


Noted. Does my 63 kg give me a pass, though? What specific situations are you tending to see broken boxes? My foil maker is really big on getting rake in a certain range. Not that I spent much time worrying about it before.

Select to expand quote
Subsonic said..
hot tip from the man who likes to leave shims at the beach:
paint it orange or red so you'll see it as you wonder past it the next day whilst rigging.


So, to get them out, you are just flipping the board over and playing Where's Waldo?
segler
segler

WA

1658 posts

22 Mar 2024 6:24am
Mark _australia is referring to a pet peeve of mine: mounting DT foils with shims inside the box. The tuttle design, and good engineering, requires a tight and full-length contact of the front and back rounded tapers inside the box. Anything else introduces point loads. Point loads lead to box failure.

Shimming inside the box is a big part of that "anything else."
Subsonic
Subsonic

WA

3384 posts

22 Mar 2024 7:20am
Select to expand quote
Paducah said
Subsonic said..
hot tip from the man who likes to leave shims at the beach:
paint it orange or red so you'll see it as you wonder past it the next day whilst rigging.



So, to get them out, you are just flipping the board over and playing Where's Waldo?


I guess it drpends on what its made of./how solid it is. All the plastic style ones my mate has had have indeed ended up "mashed" to the top of the box, which he then has to wiggle loose with a screwdriver or other small implement. i've made mine out of fibreglass, so it tends to drop out.
aeroegnr
aeroegnr

1747 posts

22 Mar 2024 7:52am
Select to expand quote
Subsonic said..
Paducah said
Subsonic said..
hot tip from the man who likes to leave shims at the beach:
paint it orange or red so you'll see it as you wonder past it the next day whilst rigging.



So, to get them out, you are just flipping the board over and playing Where's Waldo?


I guess it drpends on what its made of./how solid it is. All the plastic style ones my mate has had have indeed ended up "mashed" to the top of the box, which he then has to wiggle loose with a screwdriver or other small implement. i've made mine out of fibreglass, so it tends to drop out.


Yeah the plastic full length shims I've got mash in to the tuttle box. So far, fine. I saw that other manufacturers do the partial shim though, I think Phantom does?
Maddlad
Maddlad

WA

925 posts

22 Mar 2024 10:19am
Ive been shimming my iq foil mast for a couple of years and its no issue. I needed to because my mast angle was too level and it causes catapaults on touch downs, which you dont want when travelling north of 24 knots on foils.
tonyk
tonyk

QLD

609 posts

22 Mar 2024 4:35pm
Select to expand quote
Maddlad said..
Ive been shimming my iq foil mast for a couple of years and its no issue. I needed to because my mast angle was too level and it causes catapaults on touch downs, which you dont want when travelling north of 24 knots on foils.


Plus 1
15,000km using box roof shim on JP hydrofoil, no issues with box
So if you have a JP chances are you don't need to worry
Bellerophon
Bellerophon

83 posts

22 Mar 2024 11:08pm
Select to expand quote
tonyk said..

Maddlad said..
Ive been shimming my iq foil mast for a couple of years and its no issue. I needed to because my mast angle was too level and it causes catapaults on touch downs, which you dont want when travelling north of 24 knots on foils.



Plus 1
15,000km using box roof shim on JP hydrofoil, no issues with box
So if you have a JP chances are you don't need to worry


Plus 2

Even specifically asked the manufacturer (FMX) if this would void my warranty .
Their answer : "just go ahead, the racers do it all the time."

No problems also with my second board (Phantom)
I admit : I (only) weigh 78 kg and don't use more than 8 m sail.

I can understand the reasoning of "a tight and full-length contact of the front and back rounded tapers inside the box" alas this would mean you could only use a foil and board of the same manufacturer since I doubt make A is going to align its box to a foil of make B .

Then there's the personal preference and the changing conditions which can require a different mast angle.

Remember whe're no longer using deep tuttle boxes designed for fin's only but specifically reinforced FOIL BOXES.

So please stop re-animating this ID of perfect "out of the box" fitment : it's never going to happen.
bel29
bel29

395 posts

28 Mar 2024 11:01pm
I've had no problem using "single" shims on fanatic/duotone foil boards either (both steel and plastic shims). That said, the point loading is real; some of my most used shims from F4 in hard plastic have started to disintegrate (the inside side of the shim).

While it adds an additional step to the (dis)mounting process, I still prefer the looser ones to those that get wedged into the box because I use different ones depending on conditions.
SA_AL
SA_AL

313 posts

1 Apr 2024 2:08pm
My half shim fits snuggly to the tuttle box. I only needed to move slightly using a screw driver to position with openings. If you need to take it out ,go under the shim by a flat head screw driver. If your shim is too loose in the box, you may consider using thin aluminum foil tapes with sticky surface that is used for pluming, comes in various thickness, available on amazon. By the way the take is also good for perfectly fitting the mast to tuttle box if that becomes an issue. Also make sure the angle of the mast is at desired by digital level as mentioned before.
There are also full length shims that seems to be better but it was hard for me to find on commercial sites.
jusavina
jusavina

QLD

1494 posts

4 Apr 2024 12:45pm
Select to expand quote
segler said..
Mark _australia is referring to a pet peeve of mine: mounting DT foils with shims inside the box. The tuttle design, and good engineering, requires a tight and full-length contact of the front and back rounded tapers inside the box. Anything else introduces point loads. Point loads lead to box failure.

Shimming inside the box is a big part of that "anything else."


To be honest, this is very true with a traditional Deep Tuttle fin box.
I've shimmed my formula board fin box and the foil started to crack it under little time.

On the other hand, recent foil boxes are now strong enough to be shimmed. After 3 years with my IQfoil board, I have never had any issues.
Last IQ world championship saw more than 200 racers with most between 80 and 100kg, all shimming their foil boxes and no issues either.
All the PWA racers shims their foil box the same as well.

So basically, check if you have a Deep Tuttle or a foil box before shimming it.

P.S: some big slalom boards reverted to Deep Tuttle because the foil box was too "heavy".
segler
segler

WA

1658 posts

5 Apr 2024 12:32am
But be careful about semantics. A "foil box" is basically a deep tuttle box with a lot of extra reinforcing.
jusavina
jusavina

QLD

1494 posts

8 Apr 2024 1:03pm
Select to expand quote
segler said..
But be careful about semantics. A "foil box" is basically a deep tuttle box with a lot of extra reinforcing.


Yes, it is easier to call it a "foil box" than "deep tuttle box with a lot of extra reinforcing"
jdfoils
jdfoils

435 posts

8 Apr 2024 11:41pm
Glue the shim to the top of the foil mast using a flexable adhesive such as e6000.

Could also glue it into the bottom of box, but it will be easier to inspect and modify if it is on top of the mast.
aeroegnr
aeroegnr

1747 posts

9 Apr 2024 12:49am
Select to expand quote
jdfoils said..
Glue the shim to the top of the foil mast using a flexable adhesive such as e6000.

Could also glue it into the bottom of box, but it will be easier to inspect and modify if it is on top of the mast.


Maybe my technique is bad but I'm finding that I want the shims out of there in light wind conditions (especially when flat) as it makes pumping and getting going a lot easier than if I have additional rake for higher wind/chop. Seems like you'd want something a little less permanent? Good idea with something more on the tacky side as it seems that is a "permanent" one?
Paducah
Paducah

2792 posts

9 Apr 2024 1:15am
Select to expand quote
aeroegnr said..
jdfoils said..
Glue the shim to the top of the foil mast using a flexable adhesive such as e6000.

Could also glue it into the bottom of box, but it will be easier to inspect and modify if it is on top of the mast.


Maybe my technique is bad but I'm finding that I want the shims out of there in light wind conditions (especially when flat) as it makes pumping and getting going a lot easier than if I have additional rake for higher wind/chop. Seems like you'd want something a little less permanent? Good idea with something more on the tacky side as it seems that is a "permanent" one?

Used to use this when I did more art. www.dickblick.com/products/krylon-easy-tack-repositionable-adhesive/

Don't know if anything like this comes in a tube, though. Or maybe a touch of silicone caulk, etc?

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