Daggerboard dimensions

Thread starter #1
Hi; I'm new to this forum and have a few questions about daggerboard dimensions. I just bought a sunfish and am missing the daggerboard. I'm making one per forum's specs but the specs do not tell you what the radius size of the leading and trailing edges are. I figured on 1/4" radius with a 6 1/2 degree angle for the 1 1/4 dimension. Also how much does the handle stick out from top of hole? What are the handle dimensions? What are the handle bolt sizes and spacing? What size is the radius in the handle?

Thx
 

Wayne

Member Emeritus
#2
I just bought a sunfish and am missing the daggerboard. I'm making one per forum's specs but the specs do not tell you what the radius size of the leading and trailing edges are.
Would you first please let us know which of the daggerboard designs you've chosen for your pattern.

 

Wayne

Member Emeritus
#5
Hmmmm... edit mode timed out :rolleyes:

Try again...

Thanks..., here you go.


... the specs do not tell you what the radius size of the leading and trailing edges are.
1/2 D which is = to the board's thickness, right?

I figured on ... a 6 1/2 degree angle for the 1 1/4 dimension.
You can angle this however much you want up to 17*, beyond which you shorten the 1-1/4" dimension..., which is ok too, just less of a taper. Don't make a razor sharp point, it'll just ding up too easily.

What are the handle bolt sizes and spacing?
Originally brass wood screws, use any reasonable size as replacements..., stainless steel works too. Space them evenly at the ends, but note the slight off-set per side so they don't interfer with each other
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Thread starter #6
So the handle is 1" tall by 7/8wide with a 5" radius? How high does the radius go?
Your pic shows the 9 1/2 -8 1/2 taper side goes towards the bow. I thought the straight side did.

Thx for the info
 
#7
I'm thinking about asking a carpenter friend of mine to make a new daggerboard for my sunfish... Is there an advantage to any of the styles? My current daggerboard is the Barrington Style.
 

Wavedancer

Upside down?
Staff member
#8
The racing style board will give the best performance. See Wayne's first post (or the Sunfish Bible) for a picture.
 
#9
Part of the reason I'm planning on asking my carpenter friend to make a new one is i'm going to try and keep the original feel of my 1977 sunfish. Would it be better to have a new wooden one made in the same style as the old and get a second polymer daggerboard for racing? Any suggestions?
 

Wayne

Member Emeritus
#10
I'm thinking about asking a carpenter friend of mine to make a new daggerboard for my sunfish... Is there an advantage to any of the styles? My current daggerboard is the Barrington Style.
I would only replicate the composite or the Barrington no matter what year Sunfish I owned, except if I had a pre-'72 and wanted to retain the classic style. The "Shadow" style was ruled a poor design and superceded by the Barrington.


Would it be better to have a new wooden one made in the same style as the old and get a second polymer daggerboard for racing?
That's what I'd do if you don't have budget constraints to pick up the composite board too.

BTW, you can probably find a dealer who still has a Barrington board new.

.
 

Wayne

Member Emeritus
#12
How high does the radius go?
I'd personally just use a router and make a relief to my own liking rather than fool with being exact in duplicating the original. I switched to the composite and don't have a wood one to measuer, but eyeballing it I'd say 1/2 way up the 1" face.


Your pic shows the 9 1/2 -8 1/2 taper side goes towards the bow. I thought the straight side did.
That's by the setup manual. We've debated the pros and cons (when no difinitive taper has been added) and some people like it the other way around. An original board is radiused on both edges..., no taper. The taper is an allowance in the racing rules and the owner adds it to their liking. Try it both ways before you taper one edge to be the trailing edge.

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Thread starter #14
Okay so I have a roughed in shaped barrington style board. I'm thinking on modifying it to the race version. What size radius is the leading edge? The big radius is towards the front (bow)correct? The foil profile is thinnest at the front(bow) and gets thiucker towards the rear(aft)?
 

Wayne

Member Emeritus
#15
Okay so I have a roughed in shaped barrington style board. I'm thinking on modifying it to the race version.

What size radius is the leading edge?

The big radius is towards the front (bow)correct?

The foil profile is thinnest at the front(bow) and gets thiucker towards the rear(aft)?

In section A-A you are back to 1/2 D (thickness), but in B-B you now have a true hydrodynamic foil with three converging radii, sides and nose. ... and the sides are really a complex changing radius over the distance. This would need to be plotted out from a centerline every 1/4" or so along the surface just to get a rough profile...

note: A-A ends and B-B begins at the hull line.

...anyone have access to a coordinate measuring machine they can plot their blade with?

Without getting sophisticated about a wing shape, I think it's best to just round the leading edge, leave the sides flat for 2/3rds of the blade, then do a straight taper of roughly 1/3 the thickness per side. You'd simply approximate the foil and your real gain would be the additional 4" of length (increased surface area).
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Thread starter #16
Thx Wayne for all the info. I read somewhere that Interlux is prefered for the finish. Which one? Everything in the West Marine catalog says not for underwater use.
 

Wayne

Member Emeritus
#17
Thx Wayne for all the info. I read somewhere that Interlux is prefered for the finish. Which one? Everything in the West Marine catalog says not for underwater use.
Quality topside coatings work for trailered boats. The "below the waterline" precaution is aimed more toward boats that are moored all season.

...I wonder what moored boats paint their waterline stripe with? :rolleyes:
 
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