re establish boot and shear stripe!!!??

Hey Folks
A new guy here, and I have a question for you painters. I have an old fiberglass boat that needs new paint. I would like to know how, after you clean, prep, sand, and prime how to reestablish the boot and shear stripe. The shear stripe will be kind of straight forward-I can measure, but the boot stripe isnt uniform though out its length, and it really is a nice boot stripe. I've heard people say to etch a line, but here again what tool can etch a straight line in fiberglass? Thanks
Ed

 

Etching a line isn't necessary. The bootstripe is hopefully an inch or two above the waterline as the boat sits empty----- if it's going to sit in the water full time. Often (when the boat is small like a runabout) this line can be located by floating the boat.
Larger boats such as cruisers usually already have a reference line so I assume your boat is a small open boat.

 

A whole book could be written about how to make both boot and cove stripes look right. The highlights would include the boot is usually a few to several inches above the actual LWL. The bottom of the boot is often dead straight, but looks better with a slight sweep or sheer in it. The top of the boot also has some sheer in it, typically quite a bit more than the bottom of the boot stripe. There are several reasons for this, but looks, loading and trim variations and optical illusion are the main reasons this is done.

The cove stripe, if more then just a line (pin stripe) also is treated differently, then just being the same width stripe from one end to the other. The cove generally is tapered at each end, more so forward than aft. It also has sweep (sheer) and depending on the boat's shape and design, may be more or less sheered then the actual sheer (deck line).

What type of boat are these stripes going on? The ends of a cove stripe are often "treated" with some sort of garnish too. This can be as simple as a slash cut on each end or elaborately incorporating the boat's name or some other artwork (like that attached). A good looking cove doesn't usually run full length, but is stopped before each end. If you just measure down for a cove stripe from the sheer, it'll look odd on most boats, which is one reason they are "sheered" and tapered to some degree.

Have you an established LWL, such as stains left by the previous one? If you don't, but still have the stains from the old one, establish a LWL and mark it. I always try to mark them, so it's always there. There's a few ways to do this, but if you're going to paint, scribe a LWL or use a Sharpie to mark it, then over coat this with epoxy or clear coat, before you do the final paint. This way, it's there for the next guy that has to paint the boot. Just mark the LWL, which is different then the boot. The LWL is a dead straight line from one end to the other and serves as a reference, but a boot is a sweeping stripe, with a different bottom and top boarder. A lot of folks just sweep the top edge of the boot stripe, which looks fine, until the boat is bow down or up, because of trim or loading changes.

The easiest way to get a dead bang LWL is with a laser level. Some will have you try a water level and they work, but trust me, once you go laser, you'll never fill a plastic hose with water again. To make a LWL reference, the boat needs to be level in both directions. Do the athwartship leveling first and use the trailer jack to get the fore and aft level. Once satisfied with the level, see if the laser will hit what's left of the old line. I usually angle off the transom corner, so the laser strikes a line on both the hull side and the transom.

Can you post pictures of your project? Maybe PhotoShop some thoughts of your boot and cove?

 

what PAR said.

If you have the original lines and you want to replace them just measure with a ruler/measure vertically down from gunnel. Note where the point were taken from!(under every stantion perhaps if you have these? otherwise just every couple of metres).

Once its painted just place stickers at the points then using proper fineline tape (not normal masking tape as this gives a jagged line. You'll pay 3-4 times more for a roll but you won't need much) try to set the tape on as long fluid line ie don't stick the tape on pressing between the points - you'll end up with wonky line. It's always useful to have someone else to help you tap the tape on as you unroll it as far as you dare.

When you unroll the tape, make sure you hold it perpendicular to surface. Try to unroll it evenly so as not to get distortions in tape which will show up in final paint line.

The width of the line varies as the true vertical height varies with the angle onthe hull...as well as any design flourishes as PAR said.

Buy a range of thicknesses of masking tape to use as guide. You can get 19mm, 25mm, 38mm, 50mm standard with 3m. You can use this as guide and tape the line with proper tape.

 

mastcolin and PAR
You guys are the greatest! Thank you for your suggestions. Its kind of what I figured. The project is a 1975 Tartan (TOCK: Tartan Offshore Cruising Ketch, 40 LOA, 12.5 beam, 27000 lbs). The lines are currently there, but the old gal needs sanding, gelcoat repair and painting. I don't want to keep retaping the lines. The sharpie with epoxy will work I think, and the good tape is good to know about. The junk I've been using is ..well.. junk.
Thanks
Ed