Tiger260

melges 24 keel movement

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Hi

New to Melges 24. When sailing upwind in waves I can feel the keel moving. Also visible movement of the lid above the keel. Is this normal ?

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Should add - the delrins need to be shaped both to fit and to position the keel in the max forward/down position allowed by the class rules - I've seen cases where people did DIY delrin installs and did not shape them (this is slow - in my boat quite a lot of material had to be removed to get the keel in the right spot).

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I know this was posted a year ago but i am currently having the same issue. I believe the vertical delrins need to be moved further aft on the keel by a couple mm to force the keel to fit tighter forward. I talked to someone who said that I could bore or file the fwd edge of the holes on the verticals and then use something to fill the gap on the other side of the holes. I never asked what i could use to fill the gap, it should only be a few mm gap. Is there some kind of epoxy that bonds to delrin or should I make a metal spacer or something. Anyone else have to do this?

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Do you have the strap in place and tight to keep the keel down?  You do not need to move the delrans; I would recommend new ones.

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Yea the keel is strapped down tight. Its a fore aft movement of the top of the keel, can be seen with the deck plate off. the delrins were all new last year. Problem initially was very slight, but recently has gotten significantly worse - in light air and some slop you get a lot of keel knocking.

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Couple observations having done a few.

New delrins both Vertical and horizontal are not plug and play.

 Verticals usually need holes filled and re drilled. Huge room for future movement if filler doesn't closely match keel strut density and if filler doesn't fill previous void.

 Horizontal foils need shaping, I use carbide razor blades as a spoke shave, tedious but yields smooth scratchless surface.

 It's important to completely fit the horizontal foils from foil side. I've seen a few that were forced over strut, showing signs of partial inside effort then sanded to fit the box from outside. 

 

 

 Keels I've seen wobble had loose/floating top delrins (not fastend to trunk,) Delrins forced and sanded on outside edges and most commonly elongated vertical holes with pulverized filler. Unmolested outside surfaces fit tight in the molded keel boxes. Sanding outside to force fit the box will create future movement.

 

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There are two ways of doing the delrins.  If you are handy, you can make your own by templating your existing.  Or buy from melges.  Both require fine tuning to get keel in correct location. We shimmed the top delrins to get keel in correct spot, then used packing tape on the delrin and epoxy to fill the gaps. We have a tight fit and no movement at all, side to side or fore/aft.

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Do you know why the lower delrin sold by Melges Europe is so different from the keel profile? Has there been different keel profiles through the years?

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3 hours ago, argh said:

Do you know why the lower delrin sold by Melges Europe is so different from the keel profile? Has there been different keel profiles through the years?

I asked that question to an official measurer. He had no templates and there is not an official class template.  I have a file from RP of the fin that I used to make sure our fin was correct.  However that template only works when there is no paint on the fin.  As soon as you add paint the fin gets thicker.  

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On 7/27/2018 at 10:15 AM, PeterRoss said:

Couple observations having done a few.

New delrins both Vertical and horizontal are not plug and play.

 Verticals usually need holes filled and re drilled. Huge room for future movement if filler doesn't closely match keel strut density and if filler doesn't fill previous void.

 Horizontal foils need shaping, I use carbide razor blades as a spoke shave, tedious but yields smooth scratchless surface.

 It's important to completely fit the horizontal foils from foil side. I've seen a few that were forced over strut, showing signs of partial inside effort then sanded to fit the box from outside. 

 

 

 Keels I've seen wobble had loose/floating top delrins (not fastend to trunk,) Delrins forced and sanded on outside edges and most commonly elongated vertical holes with pulverized filler. Unmolested outside surfaces fit tight in the molded keel boxes. Sanding outside to force fit the box will create future movement.

 

Peter thanks for the response. If i want to move the verticals aft on the keel strut can i do this by just shaving the fwd edge of the holes on the verticals and filling the aft side of them? I only to move them like ~3-4mm.  If so what can i use to fill the 3-4mm gap on the other side of the holes. Id prefer not to have to drill through the keel strut Hopefully I'm making sense and apologize I'm not well versed in this. 

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2 hours ago, dasher12 said:

 

Peter thanks for the response. If i want to move the verticals aft on the keel strut can i do this by just shaving the fwd edge of the holes on the verticals and filling the aft side of them? I only to move them like ~3-4mm.  If so what can i use to fill the 3-4mm gap on the other side of the holes. Id prefer not to have to drill through the keel strut Hopefully I'm making sense and apologize I'm not well versed in this. 

Moving the verticals aft may create side to side wobble.

There should be full contact:

Hull at Delrin recess - outside horizontal

Inside edge of horizontal foil at vertical notch (fore and aft surface) - outside vertical delrin

Inside vertical delrin to strut

That full contact registers the keel and prevents sideways wobble. 

If the keel fits the trunk fully seated then moving verticals aft may alter the tight register.

Fine tuning the vertical position really needs to be done using all the delrins and following the fill and re drill efforts, after final race coating keel strut.

 

 Message your contact info and photos. I'll share photos of the process and see if you might have options.

 

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