Bootstripe or No Bootstripe?

Glenn McCarthy

Glenn McCarthy
While we have made the decision, just like to toss it to ya'all to hear your answers. The bootstripe was high at the bow, and low at the back end. I'm taking it off to raise it at the back end (it turns green and slimly in summer) and lower it at the bow, so it is parallel to the waterline. Leave it off and have the bottom paint end at the white topside paint, or put a new bootstripe on once the new "level" is ascertained?

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toddster

Curator of Broken Parts
Blogs Author
I “raised” mine a bit last year when I put on new bottom paint - with mixed success. (Sounds better than failure...) The starboard side waterline was right at the stripe, but due to the slight port list (and all the crap I have on board) the port side waterline was slightly into the stripe.

Lessons learned:
The boot stripe (on my boat) is a transparent gel coat that seems particularly blister-prone, once submerged. If it is going to be “wet,” then the first thing to do is barrier-coat it. But when I stripped the hull down six years ago, I only ran the barrier coat up to the bottom of the stripe.
The bottom paint that I used doesn’t seem to stick particularly well to the stripe material. It’s already flaking off. Again, probably should have been barrier coated.
 

Parrothead

Member II
I think the bigger question is why isn't the boat on her marks? Is the laz loaded with heavy gear? Can some of it be relocated forward to get her sitting right? The factory boot stripe is where Bruce King specified and I suggest squatting at the stern is affecting your performance.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
My factory boot is now covered in bottom paint, which keeps the white just above water. (There's a factory molded line that ought to have been ground off, because you can see it).

Boats today seem to have much higher bottom paint lines than in the '80s. Live and learn.
 

Glenn McCarthy

Glenn McCarthy
I “raised” mine a bit last year when I put on new bottom paint - with mixed success. (Sounds better than failure...) The starboard side waterline was right at the stripe, but due to the slight port list (and all the crap I have on board) the port side waterline was slightly into the stripe.

Lessons learned:
The boot stripe (on my boat) is a transparent gel coat that seems particularly blister-prone, once submerged. If it is going to be “wet,” then the first thing to do is barrier-coat it. But when I stripped the hull down six years ago, I only ran the barrier coat up to the bottom of the stripe.
The bottom paint that I used doesn’t seem to stick particularly well to the stripe material. It’s already flaking off. Again, probably should have been barrier coated.
The prior owner did a lot of projects to the boat, a few well, and most poorly. He moved the bootstripe, I have no idea what his logic is. We race the boat, so there is little "stuff" stored in the boat.
 

toddster

Curator of Broken Parts
Blogs Author
No idea if it’s relevant to your boat, but one reason that my waterline came up is that a PO (who allegedly did race) added ballast by filling in the hollow aft part of the keel with... some material. (I’d have to drill a core sample to figure out exactly what it is. I’m guessing lead shot poured into Bondo, or something like.) This also shifted COG aft a bit.

https://www.ericsonyachts.org/infoexchange/entry.php?96-Superman-s-Underwear
https://www.ericsonyachts.org/infoexchange/entry.php?661-Day-Ten-Back-In-Black
 
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Glenn McCarthy

Glenn McCarthy
Thought I'd make a game of this, not working out.

My Dad, sister and I could argue over the color of summer grass. In the shortest discussion ever, all three immediately agreed that:
Without the bootstripe, the boat looks:
Bigger
More modern
More powerful
Cleaner

And I will add, save me a metric s-ton of work putting a new one on.

We go without a bootstripe in 2020.

Twice on Sunday, I walked away from the boat to the head, and to my car, and both times walked passed the boat not recognizing it without the red stripe. The change is dramatic.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Simplest Solution. prevails... again....!
"Occam's Razor".

He would have approved!
:)
 

garryh

Member III
"The factory boot stripe is where Bruce King specified and I suggest squatting at the stern is affecting your performance. "
My 35-2 is also noticeably low at the stern and not loaded. I do not know why. I was going to move tanks (new ones needed anyway) to the bow to offset the squat but I do remember several threads by Seth who commented that these boats do not do well with weight forward and it seriously affects sailing performance. I must confess I do not know what to do : |
(and whatever happened to Seth anyway..? )
 

Parrothead

Member II
I was going to move tanks (new ones needed anyway) to the bow to offset the squat but I do remember several threads by Seth who commented that these boats do not do well with weight forward and it seriously affects sailing performance
If you ever try relocating equipment or stores to get the boat on her marks, you may have to adjust the mast rake in the new hull attitude. I wonder if Seth's comments on performance considered that.
 

tenders

Innocent Bystander
When I moved to a Hudson River mooring about 20 years ago it became burdensome to maintain the bootstripe every single winter after it would get scraped and banged up every year on the mooring hardware. Raised the bottom paint to cover the bootstripe. I've since moved to much calmer waters, but I never missed the bootstripe, and never looked back (or down).
 

bgary

Advanced Beginner
Blogs Author
fresh water... which changes the picture.
It does.... but not dramatically.

Salt water is about 2% more dense than fresh water.... which means that (taking for example) a boat that displaces 10,000 pounds, in fresh water it would be "deeper" by about the same amount as if it displaced 2% more (i.e., as if you'd added 200 lbs of fuel or gear or people, distributed equally around the boat). Not likely it would be noticed unless you were really looking for it.

(**) note, that's not the real math, thats an approximation. The real math would involve the area of the LWL waterplane and would give you a number the yacht designers call "pounds per inch immersion" (PPI, more commonly called "sink"), which is the number of pounds required to sink a boat 1" below its lines. If I use 150 sq-ft as a guess for the waterplane area of my Ericson 32-III, it would take 795 lbs to sink my boat an inch deeper in salt water, versus 780 lbs to sink it an inch deeper in fresh water.

Flipping that around, if I put 795 lbs of stuff on my boat, it'd sink an inch deeper in salt water, and 1.02" (795/780) deeper in fresh water. Again, not a difference that would likely be noticed.

For-sure not the 3" in that article...

If you want to geek out on the numbers, there's a good starting point here: http://tedbrewer.com/yachtdesign.html

$.02
Bruce
 

toddster

Curator of Broken Parts
Blogs Author
I figure the order of magnitude of the FW/SW waterline change should be a little more than an inch for 30-ish foot Ericsons. As Doc Brown says, "If my calculations are correct..."

One long winter night, I set up a spreadsheet for my boat, to calculate the various performance ratios, as a function of cargo. It was tied to a speculative manifest spreadsheet with the weight (known or guessed) of various additions, cruising gear & consumables. And some rule-of-thumb I found for the prismatic coefficient. Anyhow, I figured that it takes about 700 lbs to raise my waterline an inch. Empirical evidence suggests that this is within the realm of reality. I decided to ignore the freshwater/saltwater thing, but hypothetically, it means that the 700 lbs would raise the waterline 11/16 inch instead, in temperate sea water.

Put another way, the boat (empty) should float 32 mm (1 1/4") higher in sea water, which would put the (original) boot stripe high and dry all around, despite the resting list. Or 42 mm (1 5/8") higher with the maximum amount of cruising and diving stuff and provisions that I can imagine (but still 2" down). Which would be about the place where I attempted to re-draw the boot stripe.

Doesn't seem to make a difference as far as waterline trim, that I can see, however. The list disappears if I sit on the starboard settee. Or fill the water tank and hang the kayak on the starboard rail.

Oops. Beat me to it. Interesting that we come up with similar numbers. Great minds think alike?:egrin:

edit again: rule of thumb from Wikipedia article on Plimsol lines: The freshwater line should be (D/4T)mm above the temperate seawater line, where D is displacement in metric tons and T is the immersion in cm/ton at that draft.
 
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toddster

Curator of Broken Parts
Blogs Author
Oops. I forgot to plug in the "4." You're right - it's less than half an inch difference.
 

bgary

Advanced Beginner
Blogs Author
Great minds think alike?
Jeez, NOBODY wants their mind to work like mine. Get help while you can (laughing)

As a completely random aside... back in the IOR days, owners went nuts trying to find ways to tweak their boats to try to get a slightly-more-advantageous "rating". It was part of the game (some would argue it is what killed the game, but) in general it involved making the measurements come out in a way that made the rule think your boat was heavier and slower than it really was.

One high-end program took that to an extreme. When "Jubilation" (a brand new custom Frers 50-footer) was due to be measured, the owner had it trucked up to Lake Tahoe so it could be measured in fresh water. The boat sank ever-so-slightly deeper in the water than it would have in salt water, so according to the math it measured out as a "heavier" boat and got a rating that was 1-2% better than their competition. Then they trucked the boat down to San Francisco for the Big Boat Series, where their rating purportedly helped them win their division. (in truth, probably not much - their crew was stacked with the best of the best, and they sailed a brilliant regatta, but that 1-2% rating difference makes for a better story)

Protests ensued and the end result was that the IOR measurement ended up with a new part of the process - forever more, the IOR measurer had to measure the specific density of the water the boat was floating in when it was measured, so that nobody else could get through that 1-2% freshwater loophole ever again.

Ah, the good old days...
 

Parrothead

Member II
. . . . but water density has no effect on the fore/aft or port/stbd trim, where this thread started. It hasn't been mentioned yet but if trying to trim the boat I prefer moving equipment over trim ballast by far. May as well get additional benefit out of trim weight.
 

Leslie Newman

Member III
My E380 squats ever so slightly in the stern and I don't have hardly any gear on board right now. When I have the Honda generator, our folding bikes, stern water tank full, full tank of fuel, it squats much more. I've also considered raising the anti-fouling paint line a bit.
This was this past weekend. We sailed over to Onancock for one last outing before haul out.
 
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