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View Full Version : How long should varnish cure before applying masking tape?



Paul McCuish
04-06-2018, 04:44 PM
I've applied my final coat of Epifanes clear varnish to my topsides, and am ready to apply paint to the bottom. How long should I let the varnish cure before putting masking tape on it?

jackster
04-06-2018, 05:31 PM
As long as possible, of course! :)
I think Epifanes recommends at least 24 hours.
But if there is no boot stripe, how about cutting the bottom in by hand!?
Otherwise, wait until the very last hour(s) before launch. Tape the top of the boot and freehand the bottom.
If you apply the tape and press hard only at the very edge and remove the tape as soon as you can..ie when the bottom or boot is touch-dry... you should reduce any lift-off.
With wooden boa... carvel/ lapstrake boats, a waterline was etched in with a race knife https://cdn.shopify.com/s/files/1/0978/7942/products/381777_1000x.jpg?v=1497016873 To simplify the freehand job.

Paul Schweiss
04-06-2018, 06:23 PM
Ah...the race knife! Brings back memories of applying acres of bottom paint without benefit of tape, I wasn’teven An apprentice yet, just summer help angling for a position. Copper Racing Bronze, Woolsey soft Red, made for some scrubbing because there were no throw away gloves either.
When the groove from the race knife filled up with paint, out came the batten, hammer and nails and she got cleaned out. Often times the top of the boot stripe had another race knife groove. It all made for quick turn around for launching boats off the ways in order to get the next one hauled out of the water.
You can with practice cutting in a nice line with a sash brush and eliminate the tape, the topside coat can even be almost tacky, but a mistake will yield a big cleanup problem.

Paul McCuish
04-06-2018, 06:54 PM
It's a Cosine Wherry--only 14 feet, and it's worth taping. And, yes, I know the longer I wait the better. And Epifanes doesn't have a recommendation that I can find. Thanks anyway guys.

jackster
04-06-2018, 07:00 PM
Jamestown does give some instructions...
https://www.jamestowndistributors.com/userportal/document.do?docId=953

Bob Cleek
04-06-2018, 07:10 PM
Better than a race knife because it wants more to cut a fair line up against a batten... or not... than a race saw is a old-fashioned flooring saw. If you don't have one, any similar handsaw will do, but not quite as well. The saw cuts a square-sided hole, unlike the race knife. You can set the depth, somewhere between an eighth and a sixteenth of an inch, by sticking a piece of masking tape to each side to register your desired depth.

https://www.antiqbuyer.com/images/2015-1-ARCHIVE/IMG_8859.JPG

Remember that if you are going to cut a waterline and/or boot stripe, you need to make sure it's perfectly accurate. Usually, but not always, the previous line is accurate. Boot stripes on anything other than perhaps a "Bolger Box," will properly vary in width from widest at the bow narrowing slightly to the stern and, of course, must be laid out by eye with a good batten. Obviously, the stem has to be pretty much perpendicular so your boot stripe doesn't end up lower on one side and higher on the other when the boat is launched. You can't do it with rulers. As the shape of the hull at the waterline moves towards the centerline of the boat at the bow and the stern, the ends, which are farther away from the viewer who's looking at the boat broadside, will appear to be smaller than amidships sections closer to the viewer. If you just measure two or three inches between two pieces of masking tape the length of the boat, it will look funky when you're done. (The equally spaced tape will yield a stripe of equal width that will appear to narrow at the bow and stern because there it will be farther from the viewer's eye. The actual waterline itself, i.e. the bottom line of a boot stripe, will be parallel to the water and, hence, straight. The extra width results from a curve in the upper line defining a boot stripe.

I'm not a big fan of cutting in bottom paint for two reasons. First, there's the tendency for the paint to run down into the heel of the brush and, ultimately, all over your hands. Secondly, and more importantly, there is a tendency when cutting in to apply less paint and right above the water and the boot stripe or topside paint, where the bottom paint is exposed to the sunlight, air, and friction of water moving alongside the hull is where it wears off first. Also, since it's in the sunlight, that is where you will get the most fouling if the boat is kept in a berth. You want to put an extra coat or even two of bottom paint down about a foot from the bottom of the boot line or topside paint to compensate for this area of extra wear. It's a lot easier to do that with a piece of good quality painter's tape marking the edge so you can focus on applying the paint more than keeping the line straight. One trick for a good sharp edge without any paint bleeding under the tape is to paint the edge of the tape with the same type of paint the tape is covering so the same paint or varnish that's on the area covered by the tape won't be noticed if it bleeds under the tape, and, of course it will. Then you just paint over that, remove the tape properly, and you should have a pretty much perfect line. (Removing masking tape properly requires doubling back the tape being peeled so that it comes off making a sharp turn, rather than by "lifting" the tape, which creates a much greater likelihood of pulling paint up with it.)

Bob Cleek
04-06-2018, 07:13 PM
On the other hand, if it's a small boat such as yours, you might want to forget the saw entirely and just mark the line with a scriber. That scribed line will fill with paint and be fairly easy to find if ever the paint needs to be stripped entirely. Yes, you are correct... it does require tape. For a small "piano," I'd advise using automotive-grade masking tape. Something like 3M FineLine. It costs more, but it really makes a difference. If it's applied carefully, there won't be any bleeding under the tape.

Lvis
04-08-2018, 09:38 AM
You can rub the sticky side of the tape on your pants before applying. Its not a lot of fun, but it does reduce the tack.

Canoeyawl
04-08-2018, 11:23 AM
You can buy "Low Tack" masking tape...

http://multimedia.3m.com/mws/media/765009O/iatd-product-info.pdf