Adding hard ballast, Perils and pitfalls?

[HeelBoy]

Wondering if anyone has tried adding a few hundred pounds of hard stuff, low in the boat. The goal being just to make the boat less tender, more comfortable. Not water ballast.

Setting aside the technical details of casting removable lead or cement blocks to fit the bilges:
-They're removable, meaning they could rocket out of the bilges in a knock-down and damage the cabin and the people in it.
-They weren't a part of the boats design, meaning the place you put them may not enjoy them being there.

Has anyone played with this and had success? Has anyone played with this and regretted it? lol

 

[Siamese]

What kind of boat are you considering modifying?

 

[HeelBoy]

What kind of boat are you considering modifying?

Macgregor 25. Trailering around the inland lakes is fine, but when it hits bigger water with some wave action, its going to ride like a big empty dinghy.

 

[Leeward Rail]

when it hits bigger water with some wave action, its going to ride like a big empty dinghy.

Define bigger water.
Have you actually sailed the boat in rough conditions?

I would likely upgrade the rudder.

Talk to macgregor owners here:

Ask A Macgregor Owner

 

[PaulK]

Based on the builder's reputation, your concern about extra weight impacting structure of the boat sounds justified. The material would need to be well secured. Before going wild casting lead ingots it might be better to lash something heavy in the bilge somehow and see how the boat behaves with the added weight first. Cement is generally considered not dense enough to be worth much as ballast, btw. People add lead shot or steel punchings to it to increase the density. Riding like a big empty dinghy might enable the boat to avoid getting buried in wave crests. Adding too much weight could make the boat sluggish and slow to respond, which could be dangerous.

 

[capta]

The Thunderbirds racing on Frisco Bay had an extra 500# on their keel because of the conditions on the bay. It was, of course, designed by the original designer, not on the whim of an owner. I don't know anything about your particular boat, but I should imagine your problem would be much more easily and cheaply accomplished by your learning to reef your sail.

 

[jssailem]

Perhaps a useful weight might be and advised. Lead acid batteries come to mind. At 65lbs or more a piece you could add weight and electrical power at the same time. Strapped down would stay put. But removable.

 

[HeelBoy]

Cement is generally considered not dense enough to be worth much as ballast, btw. People add lead shot or steel punchings to it to increase the density.

Indeed, Concrete is actually lighter than aluminum. It's sole perk is its availability and ease of use. Funny thing is, I've done all of my craziest gale sailing dinghy's, so having something that behaves like one may be a familiar experience.

Jssailem has an interesting idea. 200lb of cheap batteries is easy to come by... however there's the issue of hold downs and potential acid spillage.

 

[rgranger]

Perhaps a useful weight might be and advised. Lead acid batteries come to mind. At 65lbs or more a piece you could add weight and electrical power at the same time. Strapped down would stay put. But removable.

 

[dlochner]

Adding hundreds of pounds of weight to a light boat built to a price does not seem to be a particularly good idea. Boats are designed to sail within certain parameters both for performance and strength. Significantly altering those design parameters in the absence of good engineering may well result in a poorly sailing boat that is more unstable and less comfortable.

The shallow bilge will require the weight to be placed pretty high. This will affect the center of gravity of the boat, likely in a negative way. Think about the lever arm of weight added 2 feet below the CG and weight added 4 feet below the CG. Adding weight very low, like in a keel bulb, will reduce the amount of weight added to the boat and might slightly improve performance. In order to achieve the same benefits it would take substantially more weight added to the bilge. This would have an adverse effect on the ultimate stability of the boat and could cause the boat to be more stable upside down, a position not generally regarded as suitable for sailing. Even if the boat remains upright, the amount of added weight necessary to achieve some stability would turn the boat into a pig. (The folks over on Sailing Anarchy would probably have less polite ways of expressing this.)

The MacGregrors were designed and built for inland lake and protected bay sailing in relatively benign conditions. They were neither designed nor built for coastal or offshore sailing in more sporty conditions. It is important to match the boat as designed to the conditions it will be sailed in rather than trying to make a boat sail well in conditions it wasn't designed for.

 

[HeelBoy]

Significantly altering those design parameters in the absence of good engineering may well result in a poorly sailing boat that is more unstable and less comfortable.

For better or for worse, I am an engineer, however I am not a naval architect and understand that I will have blind spots. Thus I posted this topic.

A keel bulb was my first choice. My worry there comes back to the construction of the boat. I don't entirely trust the keel hardware to handle any significant weight addition. The hinge pin is not impressive, and I can't say for certain how well the keel locker is built up around it.

 

[dlochner]

You are right to be concerned about the scantlings. Some older boats are over built, Macgregors are not in that category. There are a number of good books on yacht design that you may wish to consult, Skene's Elements of Yacht Design and Bob Perry's Yacht Design According to Perry (Amazon Links) would be good places to start.

In addition to scantlings, pay particular attention to the effects of the Sail Area to Displacement ratio and the Length to Displacement ratio. Both of these numbers are performance and safety indicators.

 

[stickinthemud57]

The consensus seems to be against the idea of adding ballast, and I agree. dlocher covered most of what I am saying here, but here goes anyway.

I think the OP was smart to note that the boat "might not like it". In order to keep his trailer sailers trailerable, Roger MacGregor' went for relatively thin fiberglass shells for the hull and thinner interior liners. Enough to make a reasonably durable boat, but not enough "strength in reserve" for blue water sailing or experiments that center a lot of weight in one place.

Any ballast would need to be quite heavy and securing it would almost certainly involve drilling holes. The questions "where", "how many", and "what is the effect on structural integrity" would keep me up at night.

Adding weight in the bilge would lower the boat's center of gravity, but only slightly. Think of the boat's center of rotation when it is bobbing side to side. Pretty much lines up with the waterline, right? Weight in the bilge simply is not going to help much.

Even if one were to add a torpedo-shaped weight to the end of the keel, issues would complicate things. Not the least of these would be how to install and remove a 100+ lb. weight several feet underwater. If you were able to figure that out, then the question of whether the structure at the trunk could handle the extra side-to-side stress such a weight would introduce in "bigger water"

Echoing dlocher's comment, the Mac 25, while a wonderful and popular boat, is not the boat you want to be on in when seas are big and winds are high. Better to seek a boat designed for these conditions.

 

[rgranger]

You could go the opposite direction and experiment with reducing weight above the waterline. Replace your mast with a carbon fiber mast and your standing rigging with dynema. Loss of 50-75 lb up high like that will certainly make your boat stiffer.
But the cost of doing that … you could just buy the boat you want ready to sail. (Unless you build the mast yourself) Go play with this boat. The macs are fun, easy to customize .. easy to sail… great gunk-holling boats… get a new sail with two sets of reef points and use this boat up. I used to have a Mac 22 and sailed it all up and down the chessy and OBX.

In a few years… if you still have the off shore bug… sell and get a different boat.

 

[HeelBoy]

In a few years… if you still have the off shore bug… sell and get a different boat.

That's the idea! Having a manufacturing/fab/carpentry background, there's quite a bit I want to do, however a CF mast is out of my pay grade. lol My larger-boat experience thus far has been on a Cat 25, however their displacement is greater than the Mac+trailer weight. This will be not only a tool for getting more miles of my own, but also to take friends out and get them hooked it.

What's keeping me from getting the Cat that I want: I can tow the Cat with my 2012 Pathfinder, however there are no good midsize SUVs being built with 6000lb tow capacities anymore. At 225,000mi My Pathfinder will need replaced soon, and owning the Cat will require me to go up-market to a thirsty fatass SUV. Compounding costs!

 

[Hayden Watson]

The first McGregor 25 I ever saw was in a dealer's yard. Its keel had been modified with a chunk of lead bolted to each side of the bottom of the keel and shaped to create a bulb. It was very nicely done.

 

[stickinthemud57]

The first McGregor 25 I ever saw was in a dealer's yard. Its keel had been modified with a chunk of lead bolted to each side of the bottom of the keel and shaped to create a bulb. It was very nicely done.

Was it trailerable that way?

 

[HeelBoy]

Was it trailerable that way?

There are a few way to maintain trailerability. One nice thing about the original swing keel is that it's solid iron, meaning you can drill/tap some pretty strong holes in it. If you're brave, you can cut the tip of the keel off, drill/tap a few holes, and bolt a lead keel tip back onto it. That's a 35% weight increase over whatever you removed... provided the hardware holds.

There's also the fact that, even if a torpedo keel tip doesn't fit back into the trunk, you've probably only gained a foot or less of draft because the OE keel didn't go all the way in there either.

 

[Hayden Watson]

Was it trailerable that way?

It was a fixed keel boat.

 

[rgranger]

Jamestown Marine sells CF cloth. You could build a mast. That would be a cool project and one we would all love to watch.