Raising the water line?

Tim Good

Tim Good

Well-Known Member
Joined
26 Feb 2010
Messages
2,888
Location
Bristol
Visit site
Since moving aboard and putting quite a lot of kid aboard I need to raise my waterline between the gel coat and antidotal by about an inch or two.

Has anyone got recommendations for doing this? I was told of some sort of paint that I could add as a stripe above the anti foul which acts like an anti foul but does need to be submerged continually.
 
northcave said:
Since moving aboard and putting quite a lot of kid aboard I need to raise my waterline between the gel coat and antidotal by about an inch or two.

Has anyone got recommendations for doing this? I was told of some sort of paint that I could add as a stripe above the anti foul which acts like an anti foul but does need to be submerged continually.
Click to expand...

Raised my waterline with a boot topping 6 years ago, problem with using antifoul if you need to clean the waterline from say any scum it wears the boot topping,
I used one coat primer plus 4 coats of Toplac, still good after 4 years

View attachment 61797
 
I increased the depth of my boot topping to cover some scuffs in the gel coat. Use a piece of wood about 12 inches long and about an inch wide, lay it along the existing waterline and draw the new line with a pencil. You'll find the short length means you don't get angles where the pencil lines meet and its much easier to get a definitive line to follow the existing waterline which you'll find isn't straight due to the curvature of the hull. Then two layers of masking tape - along the existing waterline and along the new pencil line. Using a mini roller you'll apply the new finish in a trice. Even two coats is easy - I always use self eroding anti foul as it helps prevent growth round the waterline and its easy to reapply every year. Dries in an hour or so so you can apply the second coat after a visit to the marina bar.
 
Last edited:
Simply mask off a band 50mm above current AF, clean, apply two coats of primer and then a dedicated boot top aF international Trilux 33 or Hempel to choice.

If the newly submerged area is likely to permanently underwater then raise the AF level first to the new wL then apply the boot top. 50mm is the normal width, anything less does not look good on a larger hull.
 
I have never bothered with 'proper' boot-top antifouling. I have put on plain International Perfection and find that it is hard enough to be scrubbed if necessary. There is no real fouling on it because unless I am sailing it is never really immersed.
As for marking you only need a couple of marks on each side to serve as a guide. Choose a windless day and use painters' masking tape. Unroll lengths of at least 1 metre and 'float' the tape lightly onto the hull where you need it, unrolling more as you go along towards the stem. Now walk off for about a boat-length and look back in line with the hull. Sight along the tape and any 'dips' or 'bumps' will be immediately apparent. Correct as necessary until the line is a fair curve. Repeat on other side and when all seems ok go over the tape rubbing it down with a clean piece of rag.
Apply tape on the edge of the antifouling.
Rub the gelcoat between the tapes with 320 wet-or-dry and apply a coat of undercoat/primer and two full coats in the colour of your choice. I use white as undercoat but mixed with some of the top-coat to aid opacity.
Peel off the tape and stand back to admire.

IMG_0367_zpsyjazgetb.jpg


IMG_0368_zpsc1ski98q.jpg
 
northcave said:
Can you elaborate on that one please?
Click to expand...

You can see it just about on the pics in the post above - but it is an optical illusion because of the rake of the bow. Some bow shapes look better if you deliberately widen the boot top at the bow. I have this on my boat as it is hard chine and the widening band for the last couple of feet hide the chine blending into the forefoot. Tool me ages to get it right!

Don' think I would bother with your bow shape, you will get that optical illusion with the rake of the stem and a constant width above AF. Stick to the proper boot top AF particularly if you ever leave the boat on a swinging mooring as the movement of the boat encourages fouling spreading up from the waterline. Easy to scrub off with the proper stuff.
 
The 'constant width' isn't really what's needed when adding a boot top. What's required is constant height above the waterline. The actual painted width of the line varies with the curve of the hull. For example on my boat, with a roughly 60mm width amidships, the boot top widens markedly as it disappears under the stern and ends up as maybe 160mm wide. This gives the appearance of a straight edge to the top of the boot top.
I also agree that most boats benefit in looks from the boot top gradually getting wider as it approaches the bow. It's all very subjective. My 60mm strip widens, from about 2-3metres behind the bow, to maybe 100-110mm at the bow.
 
I'm not sure what boot topping is supposed to achieve but have applied it once and it looked good. I marked a line 60mm vertically above the top of the antifouling. As someone has pointed out , the actual width varies according to the angle the hull makes to the vertical. Under the stern it was about 8" wide!
I used white eroding anti foul as I had some in the shed which I'd been given.
 
I'd never thought about the sheerline aesthetics in such detail -- very interesting!

Also don't forget that the stab calcs will need to be redone, and it might be worth mentioning this 'mod' to your ins co.
 
You must log in or register to reply here.

Share this page

Top