Thanks Jerry- knowing the hump is separate from the keel cavity eliminates all my worries. Other than sealing a few spider web cracks in the gelcoat around the pivot pin, I think I'm good to go sailing! And Burton, unless I see new water, I'm going to assume the water was from overzealous spraying as the previous owners grand kids prepared the boat for sale. Why worry now when you can worry later? Overall amazed at what good condition this boat is in for 32 years old. Now on to more important things, like buying a hiking stick so I can slide around to keep the boat trimmed to 55% aft- Jerry, your mini-lessons in naval architecture and how these boats were constructed is invaluable! Alex On Tue, Apr 16, 2019 at 10:48 AM <jerry@jerrymontgomery.org> wrote:
The "lump" under the fwd berth is trim ballast and not part of the keel ballast, and is put in place and glassed over AFTER the keel ballast is installed and glassed over, and is in front of the keel ballast anyway. it's well forward because it's for the sake of trim to compensate for weight in the cockpit.
A problem with small cruisers is that the cockpit is in the back of the boat, and the more weight in the cockpit the more the boat trims aft, which slows it down for a couple of obvious reasons. Sailing dinghies don't have this problem because the skipper and crew sit in the center of the boat, wherever they need to be to trim the boat for best performance. Early in my boatbuilding experience, I was fortunate to be hired to help Lyle Hess make the plugs for the original Balboa 20, which he had designed and was his first fiberglass boat. It was a learning experience for both of us; I learned a tremendous amount about boat building and design, he learned to be patient with a million stupid questions. We strip planked the hull, and as it was taking shape I questioned why the after sections were so full. (hi volume). his answer was that it needed the buoyancy because of weight in the cockpit, to keep the boat from burying the transom. This made sense but I always questioned it a bit. Later, in my studies, I learned that the ideal fore-and-aft center of buoyancy (LCB), in a displacement hull, in terms of performance was 54 to 55% aft, considering only the underbody of the hull. Any deviation of this slows the boat down. When Lyle was designing the M-17 for me I talked him into cleaning up the aft sections a bit and planned to trim the boat as needed using trim ballast. Both the Montgomery 15 and 17 have trim ballast, also the Sages. It worked and is one of the reasons that the M-17 is faster than a Balboa 20. I eased the run aft on the Sages even more, and I'm confident that this is one of the reasons that the Sages are faster. The M-15 and the Sages are all dead on 55%. This factor, along with the prismatic coefficient, are two major "invisible" reasons for differences in performance.
I wouldn't worry about rust in the trim ballast; it's not going to spread into the keel ballast. As Dave says, go sailing.
-----Original Message----- From: Burton Lowry Sent: Tuesday, April 16, 2019 9:43 AM To: Lawrence Winiarski ; For and about Montgomery Sailboats Subject: Re: M_Boats: M15 rusting ballast
Hi Alex,
One comforting thought is that the older Monty boats are fantastic, and are inexpensive compared to a new Sage due to the fact that certain things on them are going to need attention. Thankfully, most of these can be fixed with sweat equity and a little money. The good news is that almost none of these items are safety hazard issues, and don't need immediate attention especially if we don't need to have a creampuff for a boat.
If you get really frustrated trying to find the source of this water intrusion, welcome to the club! With only a Monty 12, I have no knowledge of the specifics of your boat. However, we have chased leaks for many years on many pocket cruisers.
The obvious suspects are where holes are drilled in the deck and the bedding has failed, hatch boards, and vents.
However, the insidious ones for us have usually been the hull to deck joint. The outside seal would have failed, allowing water to sit against the joint under the rub rail, and the inside looked perfectly sealed, as it was resin and tape, but not gel coated. The water could then seep through all along the joint in very small amounts, but would eventually collect in the bilge.
If you are in an area where there is a significant freeze/thaw cycle it can be important to take care of these sorts of leaks so that water expansion does not do serious damage to the boat. Or, make sure your boat is good and dry and then get it covered well before the freeze.
Burt
Sent from my iPhone
On Apr 16, 2019, at 12:08 AM, Lawrence Winiarski via montgomery_boats <montgomery_boats@mailman.xmission.com> wrote:
H'mm You know, maybe we've been looking at this all wrong. Maybe the water that causes the rust comes from the inside through other means (condensation etc..) and soaks through the polyester resin?
In that case, perhaps a coating on the inside (epoxy or paint could be a good thing) Or a good winter cover....
On Monday, April 15, 2019, 6:48:22 PM PDT, Alex Conley <conley.alex@gmail.com> wrote:
I ike that answer! And knowing the ballast is in resin helps me feel comfortable with the sail n monitor approach (I’d imagined a sloshing mess of rust soup...).
Looking again, I can see a bathtub ring where water sat at one point ahead of the bulge. What would be the likely paths for water to even get in there under the v birth (other than someone hosing off the interior)? Hull deck joint looks solid, and it looks like the bulkhead around the bulge separates it from the rest of the bilge...
Thanks Dave, for all the shared knowledge,
Alex
On Mon, Apr 15, 2019 at 6:31 AM Dave Scobie <scoobscobie@gmail.com> wrote:
Alex:
Simple answer is, as the board goes up and down with no problems, GO SAILING.
Monitor the situation and if things change then look for options.
More details -
You wrote, 'ballast getting lighter'. It is not unless you start jackhammering it out ;-)
Look along the joint where the trunk joins the bottom of the keel for any cracks. If any are present this is a possible place where water can enter. Cleaning and prepping for an epoxy repair of the cracks (again if any) is an option. Share pictures of what you find. The bottom of the keel photo you shared shows no immediate concerns.
There are some pictures here about repairing the trunk-bottom-of-keel-joint in this MSOG post -
http://www.msog.org/how-to/centerboard/cbrepair_johnson.cfm
ONLY look at the bottom of the keel photos as the in-cabin things, in my opinion, don't relate to your situation.
So when you touching the 'steel hump' you get oil/rust on your hand?
#4 question - the ballast was poured in a couple of layers to limit heat build up as the resin kicked. The hump was then piled up and covered with the glass as you see. The ballast was suppose to be saturated with resin. Injection of anything will only make problems. At this moment, as written above, leave it alone.
#5 - drill NO holes at this time!
#6 - look for damage to the keel and any issues around the rotation pin. Any weeping rust? (Based on what you wrote there are none.). See notes about e looking for cracking along the keel and trunk joint.
Did the prior owner talk about the rust? Can you ask him/her about it? Is this new or has the situation been stable for years and years?
:: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/
On Sun, Apr 14, 2019, 10:31 PM Alex Conley <conley.alex@gmail.com> wrote:
I finally opened up the fore peak on my new to me M15 and pulled out the flotation to look at the hump over the ballast, and found it to be rust stained and oozing some mix of rust, oil and water There is some rough glass roving over the hump, with some rusting ballast pellets tangled in it (see photo 1012). The centerboard is not binding, and there are no other signs of leaks/rust stains etc- the boat is otherwise in amazing shape. It does look like someone may have reworked the hull/trunk join in the past(photo 0999 attached) and pivot pin is not original .
My questions for all of you: 1. Given that the board is not binding, how much should I worry about this? Is the rust causing other damage (other than the ballast getting lighter :)) 2. Are there steps that should be done to stabilize the situation? What are the options? 3. Is it critical that it be dealt with before I put her in the water (I think its been a few years since her last launch)? 4. Is the hump and the keel all one big connected space? Are there enough voids in the fill to inject an oil or other rust preventative? Are the pellets just loose, or in some kind of matrix (now I'm imagining cutting into the hump and using a magnet on a rod to remove pellets...) 5. If one were to drill a drain hole, what is the best location? 6. Any guides out there for resealing the hull/centerboard trunk join and the interior of the trunk? Other areas to look at re water entry to the ballast?
I've heard people mentioning going whole hog and removing the steel and replacing it with lead. Can anyone point me to more info on what is involved in doing that for an m15? I tried searching the photo site but came up cold..
Many thanks for all your thoughts-
Alex Conley