Daggerboard Ballast?

[gerrykite2fly]

I´m toying with the idea, to drill a hole into the top of the daggerboard, hoping that it might be completely hollow and I can drop some 15m of 8mm anchor chain there to make the boat more stable and less heeling in strong winds. I know it sounds a bit adventurous but I think, it could work pretty well. The beauty of that idea is, that the chain can be used for anchoring as well or taken off completely in light air. Does anyone have any idea, how the M daggerboard is set up?

Greets from Koh Samui, Thailand

[James V]

some people have tried somthing like this. Please do a search to find the 3 to 5 threads on this.

[Gerald Gordon]

That sounds very practical.

[Frank C]

Yes, discussed many times, and tried at least 3 times. There's no magic in the plan.
(it's a very simple search ... on weighted daggerboard, & click 'all terms')
Two members have done so, Richard (baldbaby2000) and Leon (delevi).
Edit to correct ... Daniel, not Richard!
(sorry D.)

Their two attempts described within following (incomplete) list of prior threads.
Perform the search to fill in the gaps.

Weighted Daggerboard

Weighted Keel-Jury is out

Daggerboard Update

Weighted keel on 26M...again

Weighted Keel

[gerrykite2fly]

Frank, thanks for the links.
I´ve read most of that already before I opened this thread. Maybe someone came up with a removable weight already, but then i must have missed that out.
The big question for is, if the M daggerboard is hollow inside or if there are a number of closed chambers. This would be very useful to know, so I can decide to take my stock board or build a custom one...

[delevi]

The stock board is hollow-sort of. There are some cross sections of fiberglass for support but essentially it has hollow tubes. Not sure if they're big enough for chain. All in all, I think the idea is a bit risky since the chain would move around some and the board itself is not very strong, thus a clanking chain may actually dammage the board. The amount of added weight isn't anything worth dealing with as far as removing it. The gains are marginal and the affect on light wind performance or motoring is negleagable, so I would look for a permanent solution. Daniel (Baldbaby) used lead shot and added something like 75lbs to the stock board. I had a board made with 150 lbs solid lead in the botttom 15". If I could do it over again, I would probably go with a 250 lb bulb. Not sure how much ballast you would gain with chain, but I would recommend to think along the lines of one of these two examples.

Good Luck,
Leon

[Frank C]

Gerry,
I think those posts indicate how fragile the factory board really is.
Leon had to replace his factory board several times for trailing edge damage just due to the pressures from sailing. That was before adding any ballast.

I think it's clear that you'll need a stronger, hollow board for your plan. The stronger you make the board, the less interior space available for chain.

Further, although the idea of removable ballast is interesting I believe it's impractical. In order to add enough weight to impact stabilty you'll need something much more dense than chain ... Daniel added lead shot, and Leon's board, IIRC, has solid lead. I might be over-complicating your tasks, but I think a practical, ballasted board will need to be fully dedicated to that objective.

EtAdd: guess Leon was typing while I was. Story's the same.

[baldbaby2000]

I think those posts indicate how fragile the factory board really is.
Leon had to replace his factory board several times for trailing edge damage just due to the pressures from sailing. That was before adding any ballast.

It is fragile. I've damaged mine several times by striking rocks. Normal sailing doesn't seem to hurt it.

I added 55 lbs of melted lead shot for ballast. Before pouring the lead in mine I added a stainless steel pipe along the front of the internal support partition for strength.

Leon described the internal structure. There is a support running lengthwise at the widest part of the board. This support is itself hollow and is about 3" wide fore and aft. Either forward of or aft of the support it's hollow but for your idea only the forward part would be usable. Fortunately this is the stronger part but I don't think you'd get enough weight to make it worthwile and the chain might get jammed.

After I recently damaged mine I repaired it and promptly hit another rock. Fortunately my repair was stronger than the original and the board survived although still suffered damage.

I've done a lot of unintentional experimenting and have found the common failure modes! The trailing edge is the weak point although a good hit will also split the board at the top lengthwise.I'm thinking of adding a couple bolts sideways through the top to prevent this splitting. I'm be tempted to just fill the board with epoxy to strenghten it but that would be a bit pricey.

Daniel

[gerrykite2fly]

I realized the weakness of the board already. I think, this is intended to a certain extent. Something must give in, if you hit something. However, my board got damaged a couple of times (trailing AND leading edge) in normal sailing conditions - nothing was hit. I address that to the looseness it has in the trunk, so I attached a layer of heavy duty rubber gasket around the area that stays in the trunk at all times. No damage since then, also the annoying noise at anchor disappeared. The only downside is it doesn´t deploy fully, there are about 3-4 inches I have to push it fully down with the boat hook.
As I can´t follow the statements against a weighted keel, I will go ahead an get a copy of the board built in wood, drill a hole, make a "trunk" at the bottom that houses the chain. Cover everything with 1-2 layers of glass and try it out.
I´ll keep you in the loop on that...

[baldbaby2000]

I address that to the looseness it has in the trunk, so I attached a layer of heavy duty rubber gasket around the area that stays in the trunk at all times.

Can you give some details on this?

[gerrykite2fly]

Can you give some details on this?

With pleasure. If you drop the board, there´s obviously still 7-10 inches of daggerboard in the trunk. I wrapped a layer of 5 millimeter (sorry can´t translate that to US measurements) rubber gasket around that area (only leading + trailing edge) and bolted it on to keep it permanent. I carefully measured the spare space the trunk leaves and then figured out that plan. It works pretty fine. The deployed board now is a stiff unit connected to the hull, which is a good thing both under sail and at anchor.

[baldbaby2000]

Thanks! I had gotten an inner tube and slipped it over the end once. It didn't last very long. I think it was a little tight. Sounds like you found a good solution.

[delevi]

obviously still 7-10 inches of daggerboard in the trunk

Actually it's 14-15 inches in the trunk. Not to sound nit-picky but I hope you put the gasket in the right area. The board should drop 57" below the deck level. The board is 69" long. The DB trunk is 72" long. I had to take all these measurements when ordering my custom board.

Leon

[gerrykite2fly]

Sounds like you found a good solution.

I´m afraid, no. A dive revealed that the the trailing edge "bumper" went off already and the trailing edge is broken again on exactly the same area. Tomorrow I´ll take it out and apply some layers of glass to it and maybe something to additionally enforce it.

In my days as catamaran teacher we glassed old sail battens to the hull bottom to be able to ride them right on the beach. to be honest, it annoys me, that macgregor is putting these troubles into the owners hands. This is obviously a design flaw. It should be possible to deliver a daggerboard that is made to stand the stress that it is naturally exposed.

Again: I never touched anything with the board.

[delevi]

Gerry,

It is a design flaw. I had two stock boards break. The glass on the trailing edge is paper thin and it's two pieces glued together. The vast empty space in the trunk allows the board to bang around and will get damaged under normal stress loads i.e. the board doing its job. I finally had one made because the stock was too flimsy. I also wanted to add ballast, so this achieved both goals. The new one is solid and takes up most of the trunk space without moving around. Consequently more difficult to raise, especially at 170 lbs, but that's why pullies and winches were invented.

Leon