Boot top thickness advice needed

[snow(Alan H)]

Is there a 'formula' for the ideal boot top thickness?
Raindance is getting a long overdue paint job. We will use a laser to set the position but wondered if there is a 'correct' size. The boat is 29'.
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[outofthenorm]

I'd say dead straight and about as wide as your rub strake. Beautiful vessel.

- Norm

[Breakaway]

I'd play with it a bit using tape to delineate proposed lines. You may want to make it a skooch wider up near the stem, since, from side-on, that part is further away and will APPEAR narrower if the same width as the rest.

That may not be the best example, and of course a boat gets viewed from many perspectives, but the concept of tapering the boot is one I would consider. After all, once you do it, its done.

Kevin

[will tracey]

i think it is best to first establish the waterline and mark it using your laser level. then choose your thickness, say the same as the rub strake as suggested, or wider or narrower (it's completely personal preference), and mark that width at the beamiest part of the boat. this will be the top line of the waterline stripe. then establish the rest of the top line using your laser level. the width (up and down) of the waterline stripe will increase with any angle change like toward the bow where the hull hollows out. using the laser level will assure that the stripe looks the same thickness everywhere, which it will not necessarily be, but will appear so from any angle. some people also like to deliberately (and gradually) widen the stripe for the last 12 or so inches toward the bow. here is an example of that:

https://picasaweb.google.com/willt50...01941950947426

i hope this helps!

[snow(Alan H)]

I'd say dead straight and about as wide as your rub strake. Beautiful vessel.

- Norm

Thx for the compliment - she looks a lot nicer in the water

[snow(Alan H)]

i think it is best to first establish the waterline and mark it using your laser level. then choose your thickness, say the same as the rub strake as suggested, or wider or narrower (it's completely personal preference), and mark that width at the beamiest part of the boat. this will be the top line of the waterline stripe. then establish the rest of the top line using your laser level. the width (up and down) of the waterline stripe will increase with any angle change like toward the bow where the hull hollows out. using the laser level will assure that the stripe looks the same thickness everywhere, which it will not necessarily be, but will appear so from any angle. some people also like to deliberately (and gradually) widen the stripe for the last 12 or so inches toward the bow. here is an example of that:

https://picasaweb.google.com/willt50...01941950947426

i hope this helps!

It sure does - thanks Will

[donald branscom]

It sure does - thanks Will

DO not paint a boot stripe!
Just more work and more expense.
Just bring the bottom paint up 2 inches all around, It will look just like a boot stripe and cost less on each haul out.

[Soundman67]

I personally like to leave 2 inches between bottom paint and bootstripe and then a 2 or 3 inch stripe depending on size of boat. And I like the stripe to get bigger at the bow. Its not that much work. Tape off the stripe while painting the white then next day tape off the white to paint the stripe. On my 40' it amounts to about and extra hour of time taping.

[RFNK]

The boat looks beautiful in and out Alan! I like the boot top to be quite wide so that you get no possibility of buildup of slime on the topsides paint. On your boat, I'd be raising the height of the boot top near the bow by about 20 mm. This"ll ensure that the boot top doesn't appear to droop at the bow - a common optical illusion.

Rick

[David G]

You must be frustrated by the responses. Everyone wants to talk about the width of your bootstripe, when you are concerned about the thickness. For thickness... I'd make it about the same as any coat of paint - maybe just a bit thicker to take the abuse that can happen at the waterline.

Of course - it's never to early to also think about the width. In that department, I'd do sorta what Rick said, but swoop it up a bit at both bow and stern. That way, a weird load and resulting unusual trim won't be accentuated. And it looks for graceful overall.

[RFNK]

I wondered whether you'd need to lift it at the stern as it's such a perpendicular transom. But I agree, it might be an idea to lift it just slightly as I guess it's the sheer rather than the ends that create the illusion.

Rick

[wizbang 13]

DO not paint a boot stripe!
Just more work and more expense.
Just bring the bottom paint up 2 inches all around, It will look just like a boot stripe and cost less on each haul out.

Graphics are for ugly boats. Yours does not need graphics.

[MiddleAgesMan]

You must be frustrated by the responses. Everyone wants to talk about the width of your bootstripe, when you are concerned about the thickness. For thickness... I'd make it about the same as any coat of paint - maybe just a bit thicker to take the abuse that can happen at the waterline.

We think alike, left-coast twin.

[David G]

We think alike, left-coast twin.

Maybe... but you're not usually such an idiot as to take your literalism public <G>

[Lew Barrett]

The question was put as "is there a formula for the width of a boot stripe (top). And the answer is a qualified "yes."
Chapman's on Seamanship and Piloting suggests that the boot top be 1" per ten feet of boat length. That means, if you buy Chapman's as an authority, that a 30 foot boat will get about 3" on average, but there is the question of proportion along the hull, and that means there is some art in laying it out. Some boats may look better with the top tapering or expanding slightly depending on hull form.
Overall, I think Chapman's suggestion is a good starting point for most power boats.

[Wooden Boat Fittings]

And as far as widening the stripe goes, I'd do so both at bow and stern, half as much again at the bow, and quarter as much at the stern. So if you're going to set the mid-point (ie widest-beam) width at 3" as Lew suggests, then I'd taper it up to 4 1/2" at the bow and 3 3/4" at the stern (using a fair curve in projection of course, not two straight lines.)

The idea of bringing the bottom paint up to the final curve curve has some merit, but I think a contrasting-coloured stripe looks better.

Anyway, once you've chosen your line, however you do it and whatever it finally is, I'd suggest you scribe it into the hull with a bradawl so you can find it again next time you paint.

Mike

[snow(Alan H)]

Thanks guys for all the answers.
Lew - thank you (again) I thought there must be a calculation, but 3" (on my boat) seems quite wide but I'll dummy it up with tape & see.
Mark - as we stripped her back to bare wood we discovered 3 lines scribed. In her past life she has been a - long line commercial fishing, cruiser etc & several different, engines must have seen her floating on different lines.

[Draketail]

If I'm not mistaken, there was a fairly detailed article on just this topic in Wooden Boat four or five years ago.

[Phil Y]

1" per 10' seems to wide (thick) to me

[will tracey]

1" per 10' seems to wide (thick) to me

maybe it's like ties, in some eras wide is good, some eras thin...

[Lew Barrett]

It is the formula that Chapman gives, agree or disagree as you will. But just for the record: if you look at it from a distance of 18" while laying out and painting, you aren't seeing the whole picture. You have to look at it from the perspective you would look at the boat from. In other words, stand back.

Here, somewhat closer up, is what a 5" boot top on a 50 foot boat looks like.



Here, in perspective is the same boot top. Looks different when you step back a few feet, doesn't it? Your perspective matters!



"Everyone is free to have their own opinion of course.....and entitled to mine as well!"

Added: Most frequently what I see are painted boot tops that look too..... thin...... to my eye. Chapman's suggestions are just that; suggestions, but they are not a matter of style, more of tradition, I would say. Once you get a feel for the 1" for ten foot thing you realize how much at least approaching the notion that scale is involved in this decision makes sense. If your idea of scale is different, so be it, but scale matters and personally, I'm not one to argue with Chapman.

[Jay Greer]

Tradition for boats of the age of yours was that no boot stripe was painted. However I have always liked the look of a boot stripe especialy one that has some sheer on the upper edge. Although modern painters may choose to use tape for this process, I still prefer to work to a scribed line. This means that one must use a good brush for laying in the line. In any case, the line is best layed out using an accurate sheer drawing or photograph of the boat. The boat itself needs to be level to the LWL in the stalks both fore and aft and athwartships. Shooting the base line is a no brainer if one has a transit or a laser to shoot the line which is then layed on by tacking a batten that is verticaly plumb. This is then scribed into the hull using a back saw in order to scribe a fairly fine line. My own favorite tool is a Japanese Azebiki saw as it will cut on the pull and is much easier to control than a Western back saw. Once the water line is established, a height of the midships line is marked. From the sheer design. A height for the forward and after ends is also marked on the hull. This, of course is ascertained from the sheer drawing. Personaly I like to work with heights that come in odd numbers rather than even for these heights. An example would be that if the height of the midships waterline thickness is three inches then I might choose seven inches at the bow and five at the stern. This gives a pleasant sweep of the boot stripe sheer from fore to aft. Now comes the challanging part of the job. One needs to set up supported tapered guides that are level to the bow height and that of the stern that are square to the center line of the hull and at such a distance to allow a string or wire to be swung from the midship point to both ends of the hull along an inclined plane that is the height of the midships mark and then to the extreme ends of the upper water line. This takes at least two persons to do the job. The line or wire is swung along the planes so that marks can be made along the hull where it touches. On a sail boat, most often the after line will swing drasticaly under the tuck and be very wide when viewed from below. Even so, this will be a pretty accurate layout of the upper line with added sheer. Tacking a long fair batten along these marks, using a spirit level to keep it plumb, will create a fair upper line. But, judicious sighting of the batten will often be needed in order to make it right. Fine battens under the tuck are often needed in order to swing the shape. Once one is happy with the sweep of the sheer in the upper line, the batten is again used as a quide for sawing the line. After the line has been established, it is now just a matter of painting in between the upper and lower scribed lines. No tape is needed once you gain control of your brush providing you have a good brush in your hand.
Jay

[snow(Alan H)]

Many thanx Jay

[Jay Greer]

Incidently Alan, my friend Chris McMullen "Mcmullen Wing Co.", who is from your neck of the woods in Auckland, has a boat very simular to yours that he sets great store by. It is his favorite boat.
Jay

[snow(Alan H)]

Jay
I also know Chris & the boat Wirihana is on my 'bucket list', truly one of the great NZ classic launches - to my eye almost perfect in every way.

Cheers Alan
ps & no boot stripe

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[Jay Greer]

Yes, she looks just fine with out a boot stripe. Less hassel to maintain too!
Chris and his wife Raewyn were just here in S. California two weeks ago. They should be back home by now.
Jay

[Candyfloss]

That is a true Kiwi Classic, Snow. Near perfect. Should I put a boottop on my Piedy? Des draws it on, 100mm at the front to 50mm at the back. Lots of them don't have it.

[Slacko]

I want to put one on mine yacht using a hard antifoul.
I was hoping to use the dark blue Altex No 10, but it is out of stock at the moment as they apparently can't get one of the ingredients.

[Jay Greer]

An interesting fact is that boats in the Eastern U.S., especially those of Herreshoff, did not always have bootstripes. In fact, Herreshoff boats that were under thirty feet in length almost never had them. In california nearly all boats do have boot stripes of a darker color than the topsides which, shows less of the scum that collects on it from sludge in the water. A dark boot strip also, makes it easier to scrub off the grunge. However, California waters are clearing up, a lot, due to much greater public awarness of the problem. Maybe we will all go back to painting boats without boot stripes; that is, if something can be done about the fall out of jet fuel.
Jay

[Cogeniac]

Alan; You folks have some really pretty old cruisers down there!!!

I have about a 3-3 1/2 inch stripe on Makoto, and it seems to be about right.

I had not heard of the variable height stripe, but it makes sense. The "racing stripe" used on cars is done this same way. it gets wider from the hood (bonnet?) front to the cowl, and also wider from the boot end to the rear window.
Here is the "official guide"



On a car it is really a perspective thing. You can't really see the width of the stripe accurately from the side, and from the front or rear, the perspective is pretty severe. So the lines get wider as you go toward the center of the car to compensate.

I wonder if the boat situation is related to the angle of the hull and the fact that the stripe is getting visually farther away as you go toward the bow. WHat I don't understand is how the non uniform stripe might not look odd when viewed from the front (i.e. excessively perspective).

On the other hand, it might also be due to the visual mass of the boat which is larger midships and becomes smaller at each end...

[Tom Lathrop]

I also like a bootstripe. I use the ratio based on 4'' at the stern, about 3" midships and 6" at the stem. These are vertical projections and the actual width will be dependent on the local hull shape. Actual width should also be related to the length and height of topsides. It may not be critical but, when it's right, you know it.

[snow(Alan H)]

She might be 84 year old but the latest technology is used to re-set her waterline :wink: Shanghaied the services of one very talented Adrian Pawson to laser shoot the waterline. When taking her back to bare wood we found 3+ 'old' lines. And following Jay's heritage advice ( backed by the fact that the guru Herreshoff always said that boats that were under thirty feet in length should not have one) there will be no boot top.[/color][/b]


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[TR]

They had/have a formula at S&S. It gave heights in inches above DWL in feet. These heights were given at station #0, 7, and 10 of a ten station waterline with 0 at the stem/waterline intersection.

The top was to be .245 - .145 - .173......The bottom is .145 - .089 - .10......A modified bottom line is .100 - .056 - .073........These are from forward (highest) to aft, with the low point (narrowest) at station 7. To my mind this line is too narrow for most boats, but it may be left over from the low freeboard days of the 1920's-30s.

My own thoughts on this are here.......http://blog.tadroberts.ca/2010/12/drawing-the-boottop/

[snow(Alan H)]

Thanks for that Tad, the link was good.

Cheers Alan