# Build a Swing Keel from Scratch - ''74 Helsen 20'' Sloop



## branon (Mar 24, 2002)

*Build a Swing Keel from Scratch - ''''74 Helsen 20'''' Sloop*

I''m in the process of restoring a 1974 Helsen 20-foot sloop (ok, don''t laugh out loud). I''m contemplating becoming a liveaboard eventually (on a much larger boat, of course), and I figured the project would remind me about how much work a sailboat can be - it seems to be working. 

The original swing keel is said to have been a fiberglass shell with lead ingots. The previous owners apparently rebuilt the swing keel out of steel slats, lots of resin, some kind of lightweight cement material and fiberglass fabric. Unfortunately, they apparently cracked the fiberglass and the steel marinated in salt water for awhile - thus creating a swollen keel in the UP position, which wedged itself inside the keel trunk. I LITERALLY had to chip it out piece by piece - not fun, to say the least.

In any event, I now need to build a new one. According to other owners I''ve located, the original swing keel was only 100 pounds, but it is 56 inches long, approximately 10 inches deep, and 1.5 inches wide and looks like a simple daggerboard.

Obviously, I want to make sure that I rebuild it strong enough, but also less apt to get swollen and stuck again. I''m thinking of using that honeycomb polymer foam-core, and cross layered fiberglass fabric with lead toward the bottom of the leading edge for weight.

Has anyone had experience in this arena and am I off-base with in using these materials?

I also don''t suppose anyone has any specs from a Helsen swing keel? Of course, Jopie Helsen now owns a huge Hunter dealership in St Pete and apparently can''t be bothered with any of his old designs - so contacting the builder for ideas is pretty much useless.

Ideas??


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## Jeff_H (Feb 26, 2000)

*Build a Swing Keel from Scratch - ''''74 Helsen 20'''' Sloop*

If the old keel only weighed a couple hundred pounds, I would probably start out with a 1/2" steel plate and have it cut to the rough shape of the centerboard. That alone would weigh a couple hundred poinds but you can build it out to create a foil shape using closed cell foam or plywood and then glass over the whole swing keel with a couple layers of glass and epoxy resin. As long as the epoxy barrier/cloth remains intact this should last a very long time.

If you wanted more weight, I would cut a series of holes in the steel near the bottom of the keel equal about a quarter of the steel area, build a simple buried mold, stand the steel on end and centered in the mold and cast the tip of the keel in lead right around the steel plate. Build out the top in closed cell foam or plywood and glass over the whole board with a couple layers of glass and epoxy resin.

Good luck
Jeff


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## rbappelbaum (May 12, 2008)

*Helsen 20*

I resently purchased a 1974 Helsen 20 that needs some work. It also has a stuck centerdoard but I think I will be able to get it out more or less intact. I am hoping to contact any Helsen 20 owner that has information on the boat. I am particularly interested in information on the mast step.


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## TSOJOURNER (Dec 16, 1999)

And another new owner of a '74 20' Streaker. One of the previous owners cut out the fore seats (from just behind the keel pivot forward) and made a cabin. Unfortunately, that didn't last long (rotted?) and now the boat has 1/2 the seating as original, at least from what I can tell from my forensic investigations. The mast was also shortened some to make use of a mast step in the interior of the cabin, but that's another problem. Luckily the keel seems to be not stuck.

I am contenplating putting the fore cockpit back to original, but can only find one clear photo of the interior on the web 

If the others on the thead would reply with some photos (via email) of the fore cabin and cuddy design, that would be more than greatly appreciated.

Randy


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## rbappelbaum (May 12, 2008)

*Helsen 20 foredeck*

I will try to attach some pictures of the foredeck and hatch. The mast steps on the plate on the seat just aft of the hatch. I am sure that there is supposed to be a mast support from under the step to the flat (flotation?) area in the bow. It would have been about 13 inches long. It was missing when I got the boat. I would like to see a picture of one. Let me know if you need additional pictures.


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## TSOJOURNER (Dec 16, 1999)

Thanks! Those are a tremendous help! I was wondering what to do with the top of the cuddy - the one photo that I saw was using a snap cover of some sort. 

I would post some photos of what I dealing with, but need to post more messages.  

A couple of photos of the centerboard trunk (if there are some inspection ports on either side for access to the pin) and if there are supposed to be lockers in that area would be a great help also.

Thanks for some of the only documentation that exists!


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## TSOJOURNER (Dec 16, 1999)

Here's my blank canvass that I am working with. 

Sorry, I can't tell if there was a support under the step, or if there was any floatation under the cuddy floor, not without a good wask first.

Can see a 'bulge' on either side near the transom and the 2 stringers on either side of the center board trunk.


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## TSOJOURNER (Dec 16, 1999)

Let's try again..


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## Hudsonian (Apr 3, 2008)

A person with skills can build a new foil but given the effort required you should avoid the plywood or steel core that others have suggested. Plywood isn't strong enough and is subject to fatigue. If steel wasand appropriate material you wouldn't be replacing the board. Read the article in building a new board by J. R. Watson www.mothboat.com/CMBA/Building/foils.htm.

If the construction techniques he describes produce an underweight board you can use a hole saw to insert a couple of lead hockey pucks near the tip before you glass the board. Each 4" diameter plug would weigh close to 6lbs.


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## rbappelbaum (May 12, 2008)

*Helsen 20*

More on the Helsen 20. The centerboard pivot pin is accessed through the seat hatches. The picture shows the cover removed. The interior picture shows the pin glassed over with the bottom of the seat left and the end of the bow flotation chamber at the top. It looks like the pin on my boat has been removed at least once since it came from the factory. I can see the bump from the glassed over pivot pin in your picture. At least the pin will be easier for you to remove if you need to refinish the centerboard.


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## TSOJOURNER (Dec 16, 1999)

Thanks for photos <again>. I am planning on removing the centerboard and refinish it, and can post some profile measurements if you need to totally rebuild it.


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## souljour2000 (Jul 8, 2008)

I dunno much about Helsen 20's but I own a 1983 Hunter 20 since July of '08 and have had to re-bed the plate that holds the pin for the keel and replace the bolts. I managed to do this with the boat on the trailer though I don't recommend doing it that way. The Hunter 20 is a nice little boat that weighs about 1700 lbs with 400 of that in the iron swing keel...A good boat for 2-3 people to camp on but really ideal for one to camp in comfort. My 5hp tohatsu pushes it along real well and I just took it a mile and a half out into the Gulf of Mexico yesterday...with a good eye on the weather I am going to go 3 miles next time to a reef. That will be my limit most likely.


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## Aqualung76 (May 16, 2009)

*Swing Keel*

Hello I am new to this forum and new to sailing as well. I have Macgregor 25 which I just launched for the first time. Believe it or not as I was lowering the keel the winch lock gave out and the keel free fell. There must have been a crack by the pivot bolt because the keel is now at the bottom of the River. I am having trouble finding a replacement keel. Is it possible to use a different keel that would fit on my boat. Thanks in advance.


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## TSOJOURNER (Dec 16, 1999)

*Helsen 20*

I have completed restore just missing paint !I also have a spare mast in St.Pete Florida
Have a great day


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## brehm62 (Mar 27, 2011)

branon said:


> The original swing keel is said to have been a fiberglass shell with lead ingots. The previous owners apparently rebuilt the swing keel out of steel slats, lots of resin, some kind of lightweight cement material and fiberglass fabric.
> 
> In any event, I now need to build a new one. According to other owners I''ve located, the original swing keel was only 100 pounds, but it is 56 inches long, approximately 10 inches deep, and 1.5 inches wide and looks like a simple daggerboard.


I know that this is an old thread but this description seems to match my keel which I'm quite certain is stock. My boat appears to be a 1980 Helsen derivative.

My keel weighs 80 lbs. This is not from a manual; I weighed it.
You can see that it is 56 inches long.
It is 10" wide.
It is 1 3/8" (1.375") thick.
It is a simple center board with rounded nose and tapered trailing edge.

I estimate the density at about 90% heavier than concrete or about 60% of solid iron. I will probably have to repair the cable attachment point because it is a simple embedded flat metal strap that has been bent several times. I would probably replace this with a stainless steel eye-bolt. Obviously if I strip the end to fix the strap I'll find out what the interior is underneath the fiberglass. I agree that it must have lead of some kind to increase the weight.

I've wondered how strong the stock keel might be. Finding out what the interior is made of might show how strong is. This could possibly help if someone else with a Helsen design needs a keel repair or replacement.


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## brehm62 (Mar 27, 2011)

I used a belt sander with coarse grit to remove part of the end of the centerboard. You might wonder how I knew which side to sand since the lead weight is not centered. Basically, I sanded on the side where it was cracked.

You can see that the original embedded stainless strap was too thin. It bent like a pretzel under load from the winch.

The dark gray is regular fiberglass. The light gray is nothing but polyester resin.

They used stainless steel screws to attach the strap to the lead weighting before it was covered.

You can tell that it is lead because I can easily scratch it with my fingernail.

This hard attachment point will have to be replaced with something sturdier. What you can't see here is how the end of the centerboard cracked due to stresses from the strap. This apparently happened both because the flexible strap allowed forces to concentrate at the tip and because the fiberglass was not thick enough. For example, I don't believe that any polyester filler should have been used within the span of the strap.


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## brehm62 (Mar 27, 2011)

I estimate the original hard attachment as 1/16" x 5/8" stainless steel. I did buy a stainless steel eye-bolt but I changed my mind since it would tend to concentrate the forces when pulled to the side.

Since none of the hardware stores carry stainless stock, I decided to use aluminum which is readily available. I bought this piece at my local hardware store. It is 1/4" x 1" aluminum. It appears stiff enough to me to avoid cracking the end as the old piece did. Obviously I'll use more glass fabric to attach it rather than just lots of polyester resin like the old design. I bought new pan head stainless screws to attach it to the lead plate. The original used two flat head and one pan head. However, since the stainless strap wasn't deep enough for countersinking the flat head screws didn't serve any purpose in stabilizing the piece. I mostly want to replace the screws just to make sure that any end force is not relying entirely on adhesion from the epoxy. I could possibly groove the aluminum for extra grip.


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## brehm62 (Mar 27, 2011)

*Re: Build a Swing Keel from Scratch - ''''74 Helsen 20'''' Sloop*



Chris12345 said:


> Have you considered making a new keel out of solid aluminium plate?


The original posting is from 2002.

I began posting in this thread because I have a Helsen design boat and I am currently working on the centerboard. I thought it might be useful if someone else needed to do some centerboard repair.

Solid aluminum plate would not be heavy enough. At only 58% of the necessary density my 80 lb keel, for example, would only weigh 46 lbs.



> If you want it ultra cheap, I would try ferro-cement first


I estimate my keel to be nearly twice as heavy as concrete. I assume that the ferro part would be rebar. To get enough density you would need about 42% of the volume to be rebar.



> painted with epoxy I think it could last forever


The problem is that if you get a crack that lets water in the steel will rust. The rusting steel expands and makes the crack worse.

My centerboard retracts into a slot so it isn't easy to inspect either when in the water or when on the trailer.


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## brehm62 (Mar 27, 2011)

Here you can see that I've sanded off more of the polyester resin. I've also cut a piece from the aluminum stock. I used the original strap as a guide for the holes. However I did still have to adjust the holes a bit to get them to line up. You can also see where I did put some small notches and grooves in the aluminum to give it a little more grip on the fiberglass.

Basically, I mixed up a batch of epoxy thickened with fumed silica (petrified snow). I put down a layer over the lead both to glue the aluminum to it and to fill in the slight unevenness of the surface. Then I put the screws into the holes in the aluminum and hand tightened them with a screwdriver. I just wanted them snug.

Then I did a sequence of batches of epoxy and layups over the aluminum. I think the next picture is after three 3 ounces batches of epoxy with a number of layers of glass fabric.


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## brehm62 (Mar 27, 2011)

This picture is four days later so I would have sanded and put on some more glass on the second day and this would be two days later after some more sanding. I typically waited two days after a layup to sand.

I wanted to test my boat rather than wait until everything was perfect. I had to cut about 3/4" off the length of the aluminum so it would fit within the length of the slot. I wasn't sure of the exact length until I had it in the slot and obviously I couldn't drill the hole until I knew the length. I drilled a hole and sanded the corners off so that the end was round. I found that the piece was a bit thicker than the swagged fitting on the end of the cable so I did sand some more to make it thinner. The last picture is with the cable attached.


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