Re: Hollow free flooding keels (Chebacco, Micro)

--- Inbolger@yahoogroups.com, Pat <patjah@...> wrote:
>
> I calculated that my long micro keel would contain approx 70 litres of
water
> (approx 70lbs).



70 litres of water = 70 kg= 154lbs (approx)

Cheers

Peter
Why not seal the keel completely and ad a bit more ballast.
I calculated that my long micro keel would contain approx 70 litres of water (approx 70lbs). If the keel is  laminated with polyester and epoxy It will not leak. One may have to worry about a bit of condensation, but I dont think it would be a problem. It would certainly be better than complete wet and dry cycles from repeated launching.
Cheers
PAT
How how

Sent from my Verizon Wireless BlackBerry


From:"dennislancaster36" <dennislancaster36@...>
Sender:bolger@yahoogroups.com
Date:Mon, 28 Mar 2011 14:44:30 -0000
To:<bolger@yahoogroups.com>
ReplyTo:bolger@yahoogroups.com
Subject:[bolger] Re: Hollow free flooding keels (Chebacco, Micro)

 

I don't know about the Micro flooding keel design, but my Old Shoe is designed with a wood frame that separates the lead from the flooding chambers. The lead is incased and sealed in epoxy and fiberglass.

We are dealing with wood boats and wood boats do not last forever. Good preventative maintenance will extend the lifespan, but ultimately, the ply is gonna delame, the wood is going to rot and the chainsaw is gonna end it all. In the meantime, I think that Phil would want us to get out on the water and enjoy the heck out of his wonderful designs and..... keep building more!

Fairwinds,

Dennis OldShoe "Pearl"
Bellingham, WA.

--- Inbolger@yahoogroups.com, Stefan Topolski <public@...> wrote:
>
> Whether Borates fully kill or simply very well inhibit growth of mold is a question to be answered with microscope and petri dishes. They certainly do what needs doing.
>
> As for the very inert Lead block in the keel, i'm imagining the level of lead ion in the water in and around the wood. Until we test it I suspect that the keel flushing in use would very likely lower the lead concentration in those flooding compartments and their surrounding wood.
>
> The drying in those compartments over time between launchings should be reassurance and most attempts at mold.
>
> The non-draining bilges of your other boats, on the other hand, do get the full treatment. I'd guess most of us do the same. One caveat - i dissolve my borates in ethylene glycol instead of water for some extra insurance.
>
> All the Best,
> Stefan
>
> "One gathers peace as a feather in the palm of one's hand." -anonymous
>
> Stefan Topolski MD
> Assist. Professor, U. of Massachusetts Medical School
> Clinical Instructor, U. of New England
> Founder and Director of
> Caring in Community, Inc. 501(c)3
> 1105 Mohawk Trail
> Shelburne Falls, Ma.
>
>http://www.cottagemed.org
>
>
>
> On mar 27, 2011, at 12:17 pm, masonsmith@... wrote:
>
>
> What about sodium borate treatment once in a while in flooding keels? After the boat has been in the water for a while and then comes out, we could flood the keel with a borate solution, and give the borate it a little time to follow wherever the wood is wet. If the wood's sealed and the solution goes nowhere, fine. If the sealing is breached, the borate will follow the water and kill rot spores. If and when the keel dries out, crystals would remain until leached out by further cycles wet/dry. Then another treatment. I do something equivalent with my 50' mahogany sailboat and my 60s cedar lapstrake I/O Old Town: Flood the bilges with solution after take-out in the fall and let it dry out. I figure that I start each season, at least, with rod spores dead. Have not done the keel on my Micro as above partly because I presume the presence of all that lead is a great protector. What do others think about the lead's influence? --Mason
>

I don't know about the Micro flooding keel design, but my Old Shoe is designed with a wood frame that separates the lead from the flooding chambers. The lead is incased and sealed in epoxy and fiberglass.

We are dealing with wood boats and wood boats do not last forever. Good preventative maintenance will extend the lifespan, but ultimately, the ply is gonna delame, the wood is going to rot and the chainsaw is gonna end it all. In the meantime, I think that Phil would want us to get out on the water and enjoy the heck out of his wonderful designs and..... keep building more!

Fairwinds,

Dennis OldShoe "Pearl"
Bellingham, WA.

--- Inbolger@yahoogroups.com, Stefan Topolski <public@...> wrote:
>
> Whether Borates fully kill or simply very well inhibit growth of mold is a question to be answered with microscope and petri dishes. They certainly do what needs doing.
>
> As for the very inert Lead block in the keel, i'm imagining the level of lead ion in the water in and around the wood. Until we test it I suspect that the keel flushing in use would very likely lower the lead concentration in those flooding compartments and their surrounding wood.
>
> The drying in those compartments over time between launchings should be reassurance and most attempts at mold.
>
> The non-draining bilges of your other boats, on the other hand, do get the full treatment. I'd guess most of us do the same. One caveat - i dissolve my borates in ethylene glycol instead of water for some extra insurance.
>
> All the Best,
> Stefan
>
> "One gathers peace as a feather in the palm of one's hand." -anonymous
>
> Stefan Topolski MD
> Assist. Professor, U. of Massachusetts Medical School
> Clinical Instructor, U. of New England
> Founder and Director of
> Caring in Community, Inc. 501(c)3
> 1105 Mohawk Trail
> Shelburne Falls, Ma.
>
>http://www.cottagemed.org
>
>
>
> On mar 27, 2011, at 12:17 pm, masonsmith@... wrote:
>
>
> What about sodium borate treatment once in a while in flooding keels? After the boat has been in the water for a while and then comes out, we could flood the keel with a borate solution, and give the borate it a little time to follow wherever the wood is wet. If the wood's sealed and the solution goes nowhere, fine. If the sealing is breached, the borate will follow the water and kill rot spores. If and when the keel dries out, crystals would remain until leached out by further cycles wet/dry. Then another treatment. I do something equivalent with my 50' mahogany sailboat and my 60s cedar lapstrake I/O Old Town: Flood the bilges with solution after take-out in the fall and let it dry out. I figure that I start each season, at least, with rod spores dead. Have not done the keel on my Micro as above partly because I presume the presence of all that lead is a great protector. What do others think about the lead's influence? --Mason
>
Whether Borates fully kill or simply very well inhibit growth of mold is a question to be answered with microscope and petri dishes.  They certainly do what needs doing.

As for the very inert Lead block in the keel, i'm imagining the level of lead ion in the water in and around the wood.  Until we test it I suspect that the keel flushing in use would very likely lower the lead concentration in those flooding compartments and their surrounding wood.

The drying in those compartments over time between launchings should be reassurance and most attempts at mold.

The non-draining bilges of your other boats, on the other hand, do get the full treatment.  I'd guess most of us do the same.  One caveat - i dissolve my borates in ethylene glycol instead of water for some extra insurance.

All the Best,
Stefan

"One gathers peace as a feather in the palm of one's hand."    -anonymous

Stefan Topolski  MD
Assist. Professor, U. of Massachusetts Medical School
Clinical Instructor, U. of New England
Founder and Director of
Caring in Community, Inc.  501(c)3
1105 Mohawk Trail
Shelburne Falls, Ma.




On mar 27, 2011, at 12:17 pm,masonsmith@...wrote:

 

What about sodium borate treatment once in a while in flooding keels? After the boat has been in the water for a while and then comes out, we could flood the keel with a borate solution, and give the borate  it a little time to follow wherever the wood is wet. If the wood’s sealed and the solution goes nowhere, fine. If the sealing is breached, the borate will follow the water and kill rot spores. If and when the keel dries out, crystals would remain until leached out by further cycles wet/dry. Then another treatment. I do something equivalent with my 50’ mahogany sailboat and my 60s cedar lapstrake I/O Old Town: Flood the bilges with solution after take-out in the fall and let it dry out. I figure that I start each season, at least, with rod spores dead. Have not done the keel on my Micro as above partly because I presume the presence of all that lead is a great protector. What do others think about the lead’s influence? --Mason



On 03/27/2011 12:17 PM,masonsmith@...wrote:
 

What about sodium borate treatment once in a while in flooding keels? After the boat has been in the water for a while and then comes out, we could flood the keel with a borate solution, and give the borate  it a little time to follow wherever the wood is wet. If the wood’s sealed and the solution goes nowhere, fine. If the sealing is breached, the borate will follow the water and kill rot spores. If and when the keel dries out, crystals would remain until leached out by further cycles wet/dry. Then another treatment. I do something equivalent with my 50’ mahogany sailboat and my 60s cedar lapstrake I/O Old Town: Flood the bilges with solution after take-out in the fall and let it dry out. I figure that I start each season, at least, with rod spores dead. Have not done the keel on my Micro as above partly because I presume the presence of all that lead is a great protector. What do others think about the lead’s influence? --Mason

My thinking is this, that wood that is constantly submerged will not rot even the cheapest kind of wood. If the boat is stored dry there will be some rotting as the keel dries as soon as the moisture gets below about 15% I believe the figure is, the rotting will stop. The rotting goes on this way but it will take a long,long time for the keel to rot. IF the boat stays in the water worms will get in because you can't paint the inside with anti fouling paint so the joints are protected. You can't crawl inside and paint.:-)  The inside of the boat is likely to rot befor the keel, as it is constantly wetting and drying assuming the boat stays in the water.  If the boat is epoxied inside and out the tinyest little leak will allow water to get into the wood and it will be slow drying out. During the time the correct amount of water is in the wood it will be rotting.  If the keel is made of plywood and if it is not marine plywood and the wood is not completely sealed with epoxy there may well be delamination.  I would plank the sides and bottom with planks and leave the seams open rather than drill holes.  This way you can take a plank off and paint with anti fouling on the inside of the keel.  By the way,if you get a worm in the wood heat it up with a paint stripper and he will back right out then you can plug the hole.
Lead kills everything. We used red lead paint as an anti fouling paint when I was a boy. It did the job as good as copper we also used house paint also had lead in it and we loaded  it with arsenic or any other deadly poisen we could find. No wonder the whole world is polluted.  There are insect poisons that can be put in bottom paint.    I know of no one that recommends that.                                                                                                               Doug

What about sodium borate treatment once in a while in flooding keels? After the boat has been in the water for a while and then comes out, we could flood the keel with a borate solution, and give the borate  it a little time to follow wherever the wood is wet. If the wood’s sealed and the solution goes nowhere, fine. If the sealing is breached, the borate will follow the water and kill rot spores. If and when the keel dries out, crystals would remain until leached out by further cycles wet/dry. Then another treatment. I do something equivalent with my 50’ mahogany sailboat and my 60s cedar lapstrake I/O Old Town: Flood the bilges with solution after take-out in the fall and let it dry out. I figure that I start each season, at least, with rod spores dead. Have not done the keel on my Micro as above partly because I presume the presence of all that lead is a great protector. What do others think about the lead’s influence? --Mason

The pressure treatment will leach out when in contact with moisture and the floading/emptying of the keel will also wash out the treatment over time. If you do use it remember the treatment is done with a strong poison so remember to read and follow the directions for handling, cutting, etc. Children using playgrounds made with this stuff have been shown to have the poison in their systems with no other reasonable explanation for it being there.
David

--- Inbolger@yahoogroups.com, "Eric" <eric14850@...> wrote:
>
> If you want to be able to inspect the inside of the keel build the keel so one or both side panels of the keel are removable, and build it out of pressure treated lumber that will not rot during the lifetime of the boat just to be sure. Embedding bronze bolts in epoxy on which to bolt on the panels, or gluing in pvc pipe to bolt through keel side to side and attach the panels will entirely eliminate water contact with wood.
>
> I think the lapstrake Chebacco is an exquisitely beautiful boat, and well thought out boat that performs well. Phil messed with this boat (right from the beginning) and I don't think the messing improved things in any way worth the trade off. Us lesser mortals are likely to fair worse.
>
> Eric
>
>
>
>
> --- Inbolger@yahoogroups.com, Pat <patjah@> wrote:
> >
> > If you really plan to trailer your boat then the flooding keel may be of
> > some benefit weight wise.
> > I feel however that it is not a well thought out solution. I would prefer a
> > solid timber keel and a bit more lead. The box keel may be easier to build
> > but you cannot inspect the inside of the keel. I have decided to plug the
> > flood holes and close the keel.
> > Why not laminate solid fiberglass/polyester panels of the same shape to the
> > framing of the box keel?
> >
> > Pat
> >
>
If you want to be able to inspect the inside of the keel build the keel so one or both side panels of the keel are removable, and build it out of pressure treated lumber that will not rot during the lifetime of the boat just to be sure. Embedding bronze bolts in epoxy on which to bolt on the panels, or gluing in pvc pipe to bolt through keel side to side and attach the panels will entirely eliminate water contact with wood.

I think the lapstrake Chebacco is an exquisitely beautiful boat, and well thought out boat that performs well. Phil messed with this boat (right from the beginning) and I don't think the messing improved things in any way worth the trade off. Us lesser mortals are likely to fair worse.

Eric




--- Inbolger@yahoogroups.com, Pat <patjah@...> wrote:
>
> If you really plan to trailer your boat then the flooding keel may be of
> some benefit weight wise.
> I feel however that it is not a well thought out solution. I would prefer a
> solid timber keel and a bit more lead. The box keel may be easier to build
> but you cannot inspect the inside of the keel. I have decided to plug the
> flood holes and close the keel.
> Why not laminate solid fiberglass/polyester panels of the same shape to the
> framing of the box keel?
>
> Pat
>
Let's just say that warming epoxy will reduce its viscosity.

Joe T

--- Inbolger@yahoogroups.com, John Weiss <jrweiss98020@...> wrote:
>
> To "thin" epoxy, simply heat it up. I put the jugs in a sink of hot
> water for a while before mixing.
>
>
> On 3/24/2011 06:53, sirdarnell wrote:
> > Do not thin epoxy. Thinned epoxy has more and bigger holes in it where
> > the thinner evaporated. Based on various research there is not a good
> > reason for thinning epoxy. I.e. doesn't really penetrate further.
>
If you really plan to trailer your boat then the flooding keel may be of some benefit weight wise.
I feel however that it is not a well thought out solution. I would prefer a solid timber keel and a bit more lead. The box keel may be easier to build but you cannot inspect the inside of the keel. I have decided to plug the flood holes and close the keel.
Why not laminate solid fiberglass/polyester panels of the same shape to the framing of the box keel?
Pat

Robb White wrote that he would heat the wood by closing the shop and allowing the temperature to rise above the ambient background.  Then when he started his epoxy work he would allow the temperature to slowly fall back to the outside temperature.  He was of the opinion that the contracting of the wood cellular structure actually sucked the epoxy into the wood.  This required patience as the process of heating the wood takes hours to achieve but he felt that in his construction this was a viable means to improving the bond between.  This was in a MAIB article prior to his departure from the earth.

 

~Caloosarat

 

From:bolger@yahoogroups.com [mailto:bolger@yahoogroups.com]On Behalf OfJohn Weiss
Sent:Thursday, March 24, 2011 10:01 AM
To:bolger@yahoogroups.com
Subject:Re: [bolger] Hollow free flooding keels (Chebacco, Micro)

 

 

To "thin" epoxy, simply heat it up. I put the jugs in a sink of hot
water for a while before mixing.

On 3/24/2011 06:53, sirdarnell wrote:
> Do not thin epoxy. Thinned epoxy has more and bigger holes in it where
> the thinner evaporated. Based on various research there is not a good
> reason for thinning epoxy. I.e. doesn't really penetrate further.

To "thin" epoxy, simply heat it up. I put the jugs in a sink of hot
water for a while before mixing.


On 3/24/2011 06:53, sirdarnell wrote:
> Do not thin epoxy. Thinned epoxy has more and bigger holes in it where
> the thinner evaporated. Based on various research there is not a good
> reason for thinning epoxy. I.e. doesn't really penetrate further.
Do not thin epoxy. Thinned epoxy has more and bigger holes in it where the thinner evaporated. Based on various research there is not a good reason for thinning epoxy. I.e. doesn't really penetrate further.
David

--- Inbolger@yahoogroups.com, "dnjost" <davidjost@...> wrote:
>
> I have not heard of any problems with the Micro I built many years ago having issues with the free flooding keel. Nor from other builders. I did put 7 coats of epoxy on with the first one thinned, then glassed the outside as well as I was having similar thoughts as the same stage you are at in the building process. Start planning now how you will position the lead slug, I found that the trickiest part.
>
> If I were to do this again I would probably use Mahogany or Locust below the waterline for peace of mind if nothing else. White oak is ok as well, but is not as happy when gluing stuff to it. Having ruminations on building Chebacco instead of continuing with the Birdwatcher idea. Birdwatcher mast is still hanging in the garage.
>
> David Jost
>
On Wed, Mar 23, 2011 at 7:45 AM, dnjost <davidjost@...> wrote:
>
>
>
> I have not heard of any problems with the Micro ... free flooding keel.

Ditto, I can not recall hearing of any problem with a free flooding
keel from a Micro owner. Lots of 'expressed concerns' from people
thinking of building, but no actual reports of problems from owners.
I have not heard of any problems with the Micro I built many years ago having issues with the free flooding keel. Nor from other builders. I did put 7 coats of epoxy on with the first one thinned, then glassed the outside as well as I was having similar thoughts as the same stage you are at in the building process. Start planning now how you will position the lead slug, I found that the trickiest part.

If I were to do this again I would probably use Mahogany or Locust below the waterline for peace of mind if nothing else. White oak is ok as well, but is not as happy when gluing stuff to it. Having ruminations on building Chebacco instead of continuing with the Birdwatcher idea. Birdwatcher mast is still hanging in the garage.

David Jost
Coat all surfaces with epoxy, using no fillers or thinners. Use 2 or 3 coats, coat before installing if that is easier, but all sides of all pieces must be coated so that no wood comes in direct contact with water. Yes, some water vapor will pass through the epoxy, but it can't cause rot. Rot requires, spores, moisture and air. All 3 cannot fit through the tiny pores in the epoxy at the same time so no rot can grow.
David

--- Inbolger@yahoogroups.com, "Andrew" <a.c.l.yen@...> wrote:
>
> Hi all,
>
> I am about to start making the full length keel on my Chebacco 25. The plans call for a hollow keel with drain holes to allow it to fill with water.
>
> Originally I didn't like the concept and planned to make a solid keel built up from plywood. However I have rethought the advantages of the hollow keel and am coming around to this simpler construction.
>
> My questions for Chebacco and Micro builders/owners:
> - has anyone actually experienced rot problems inside such a keel (I know there has been discussion on this forum about it being a fear)
> - Is a more durable timber than Douglas Fir (Oregon) justified for the "spacers" between the outer ply panels, top and bottom of the keel? What have other builders used?
> - What size drain hole is recommended and is one required at the top of the keel cavity as well as at the bottom?
>
> Thanks,
>
> Andrew
>
I fully agree with those who say: Build as designed.

My Chebacco plans clearly show drainage/vent holes top and bottom of both the fore and aft flooding keel sections.

On Oldshoe (now second year) and stored dry for 10 months of the year, I have seen no sign of trouble yet. I did epoxy the interiors but I also used marine ply which should be a singnificant step in the right direction. We'll see in the long run.

I used 10mm (approximately 3/8") holes and bored straight through. This means that when I pull the boat out at the end of the season I can poke something through the holes and make sure they are clear and the compartment drained.

I assumed there was no need for the spaces to fill/empty particularly quickly (probably really the reverse), so I went for as small as I could poke something through easily.

David
No don't think that will do it. I was thinking about My Bolger Wolftrap that had a keel about 8 inches wide and a foot deep 25ft long.

On 03/21/2011 09:25 PM, Andrew wrote:
 


--- Inbolger@yahoogroups.com, "Walter"<walter@...>wrote:
>
> FOLLOW THE PLANS......
>
Thanks for the feedback everyone.

One interesting thing about building a Chebacco is that there are multiple variants of the plans and parts of one design can be incorporated into another. The Chebacco 25 is an older design and there have been a couple of updates to Chebacco designs since. One of these updates is a solid plywood keel, the outer layers being good marine ply, the inner layers are made up of scrap pieces coated in epoxy and fitted together to fill the space. It is a clever alternative to traditional deadwood construction. But I can see the benefit of the simplicity of the hollow keel system.

Regarding holding tanks in the keel - The Chebacco 25 keel space is about 200mm by 35mm by 1500mm. Would 35mm be wide enough for a bladder?

Andrew


--- Inbolger@yahoogroups.com, "Walter" <walter@...> wrote:
>
> FOLLOW THE PLANS......
>
Thanks for the feedback everyone.

One interesting thing about building a Chebacco is that there are multiple variants of the plans and parts of one design can be incorporated into another. The Chebacco 25 is an older design and there have been a couple of updates to Chebacco designs since. One of these updates is a solid plywood keel, the outer layers being good marine ply, the inner layers are made up of scrap pieces coated in epoxy and fitted together to fill the space. It is a clever alternative to traditional deadwood construction. But I can see the benefit of the simplicity of the hollow keel system.

Regarding holding tanks in the keel - The Chebacco 25 keel space is about 200mm by 35mm by 1500mm. Would 35mm be wide enough for a bladder?

Andrew
I built my Chebacco 20 as designed and have not had any problems in the 5 years since completion. I used douglas fir marine plywood and timbers; I fiberglassed and epoxied the interior surfaces because it made me feel better to do so, but I'm not sure it is necessary on a boat that sits on a trailer most of the time. Half inch drain holes (sealed with epoxy after drilling) top and bottom to allow free flooding and draining.

I think you have a greater chance of delamination and eventual rot by building the keel solid from plywood or solid boards...

Bill
I have been thinking for some time that it might be a good thing to design a boat around a head instead of designing a boat and sticking the most Obnoxious thing I can think of someplace inside and then adding another insult by putting a stinking holding tank inside. You sleep and eat in a small space only a few feet from a tank full of wast and it's odor permeates the whole boat.  We carry around inside our living space a breeding tank for disease.  The holding bladder in the keel adds to the stability of the boat and is an improvement in every way I can think of.     Doug


On 03/21/2011 10:09 AM, dennislancaster36 wrote:
 


Be sure that the interior of the flooding chambers are epoxied well. I believe that I used 1/2" for my drain holes on my Old Shoe. Will this boat be dry sailed?, if so.... rot will not be an issue. Be sure to use penetrating epoxy and then no less than 3 coats of regular epoxy on those flooding chambers. Interesting thoughts on utilizing those spaces for holding tanks.

Regards,

Dennis
Old Shoe "Pearl"
Bellingham, WA. USA

--- Inbolger@yahoogroups.com, "Andrew"<a.c.l.yen@...>wrote:
>
> Hi all,
>
> I am about to start making the full length keel on my Chebacco 25. The plans call for a hollow keel with drain holes to allow it to fill with water.
>
> Originally I didn't like the concept and planned to make a solid keel built up from plywood. However I have rethought the advantages of the hollow keel and am coming around to this simpler construction.
>
> My questions for Chebacco and Micro builders/owners:
> - has anyone actually experienced rot problems inside such a keel (I know there has been discussion on this forum about it being a fear)
> - Is a more durable timber than Douglas Fir (Oregon) justified for the "spacers" between the outer ply panels, top and bottom of the keel? What have other builders used?
> - What size drain hole is recommended and is one required at the top of the keel cavity as well as at the bottom?
>
> Thanks,
>
> Andrew
>


On 03/21/2011 09:52 AM, Walter wrote:
 

FOLLOW THE PLANS......

--- Inbolger@yahoogroups.com, "Andrew"<a.c.l.yen@...>wrote:
>
> Hi all,
>
> I am about to start making the full length keel on my Chebacco 25. The plans call for a hollow keel with drain holes to allow it to fill with water.
>
> Originally I didn't like the concept and planned to make a solid keel built up from plywood. However I have rethought the advantages of the hollow keel and am coming around to this simpler construction.
>
> My questions for Chebacco and Micro builders/owners:
> - has anyone actually experienced rot problems inside such a keel (I know there has been discussion on this forum about it being a fear)
> - Is a more durable timber than Douglas Fir (Oregon) justified for the "spacers" between the outer ply panels, top and bottom of the keel? What have other builders used?
> - What size drain hole is recommended and is one required at the top of the keel cavity as well as at the bottom?
>
> Thanks,
>
> Andrew
>

Andrew, If you are worrying about rot go to a saw mill and buy some Locust wood.  It will not rot in a hundred years or more, even burried in the ground.  Wood worms won't eat it, so you don't have to paint it inside or out unless to keep barnicals off if the boat is to stay in the water.  If you build the whole boat out of locust you can leave it to your great,great,great Grand children.  Wouldn't that be something.                              Doug
Be sure that the interior of the flooding chambers are epoxied well. I believe that I used 1/2" for my drain holes on my Old Shoe. Will this boat be dry sailed?, if so.... rot will not be an issue. Be sure to use penetrating epoxy and then no less than 3 coats of regular epoxy on those flooding chambers. Interesting thoughts on utilizing those spaces for holding tanks.

Regards,

Dennis
Old Shoe "Pearl"
Bellingham, WA. USA


--- Inbolger@yahoogroups.com, "Andrew" <a.c.l.yen@...> wrote:
>
> Hi all,
>
> I am about to start making the full length keel on my Chebacco 25. The plans call for a hollow keel with drain holes to allow it to fill with water.
>
> Originally I didn't like the concept and planned to make a solid keel built up from plywood. However I have rethought the advantages of the hollow keel and am coming around to this simpler construction.
>
> My questions for Chebacco and Micro builders/owners:
> - has anyone actually experienced rot problems inside such a keel (I know there has been discussion on this forum about it being a fear)
> - Is a more durable timber than Douglas Fir (Oregon) justified for the "spacers" between the outer ply panels, top and bottom of the keel? What have other builders used?
> - What size drain hole is recommended and is one required at the top of the keel cavity as well as at the bottom?
>
> Thanks,
>
> Andrew
>
FOLLOW THE PLANS......

--- Inbolger@yahoogroups.com, "Andrew" <a.c.l.yen@...> wrote:
>
> Hi all,
>
> I am about to start making the full length keel on my Chebacco 25. The plans call for a hollow keel with drain holes to allow it to fill with water.
>
> Originally I didn't like the concept and planned to make a solid keel built up from plywood. However I have rethought the advantages of the hollow keel and am coming around to this simpler construction.
>
> My questions for Chebacco and Micro builders/owners:
> - has anyone actually experienced rot problems inside such a keel (I know there has been discussion on this forum about it being a fear)
> - Is a more durable timber than Douglas Fir (Oregon) justified for the "spacers" between the outer ply panels, top and bottom of the keel? What have other builders used?
> - What size drain hole is recommended and is one required at the top of the keel cavity as well as at the bottom?
>
> Thanks,
>
> Andrew
>
On 03/21/2011 08:21 AM, Andrew wrote:
 

Hi all,

I am about to start making the full length keel on my Chebacco 25. The plans call for a hollow keel with drain holes to allow it to fill with water.

Originally I didn't like the concept and planned to make a solid keel built up from plywood. However I have rethought the advantages of the hollow keel and am coming around to this simpler construction.

My questions for Chebacco and Micro builders/owners:
- has anyone actually experienced rot problems inside such a keel (I know there has been discussion on this forum about it being a fear)
- Is a more durable timber than Douglas Fir (Oregon) justified for the "spacers" between the outer ply panels, top and bottom of the keel? What have other builders used?
- What size drain hole is recommended and is one required at the top of the keel cavity as well as at the bottom?

Thanks,

Andrew

Andrew this hollow keel thing is something I have thought about a bit.  For a boat with a head on board a holding  tank BLADDER could be put into the hollow keel. The free flow of water into the keel would keep the keel full of water and the bladder collapsed. The keel would provide ballast in a knockdown for a short period of time before the keel drained.  If the bladder were full from head use it would still provide the sme ballast.  This seems a way to have a really large holding tank with no ill effect on the boat.  I would like to see a twin keel on a flat or slightly v bottomed boat. In this case the water ballast would come into play much faster when the boat heels as the keel on the windward side would begin to lift out of the water and become better ballast.   The holes in the keel need to be fairly small so the water does not drain out too quick as the keel comes out of the water if knocked down.         Doug
Hi all,

I am about to start making the full length keel on my Chebacco 25. The plans call for a hollow keel with drain holes to allow it to fill with water.

Originally I didn't like the concept and planned to make a solid keel built up from plywood. However I have rethought the advantages of the hollow keel and am coming around to this simpler construction.

My questions for Chebacco and Micro builders/owners:
- has anyone actually experienced rot problems inside such a keel (I know there has been discussion on this forum about it being a fear)
- Is a more durable timber than Douglas Fir (Oregon) justified for the "spacers" between the outer ply panels, top and bottom of the keel? What have other builders used?
- What size drain hole is recommended and is one required at the top of the keel cavity as well as at the bottom?

Thanks,

Andrew