Pete, your fears are well founded.  If you leave the tape on throughout the process, you probably will have some difficulty getting it off without peeling layers.  Personally, I always pull tape almost immediately after I finish the coat. It's a pain if you're going to put on another coat(s) because then you'll have to mask to that first line but, in the end, will avoid peeling final layers.  Barring multiple taping, you can trim closely along the tape edge with a razor knife but then you're cutting through your carefully applied layers of protection and could allow water infiltration.  I'm sure others will chime in with their solutions.

Hi Pete,

I taped off some areas of the Skerry before I painted. I took the chance and left the tape on for primer and 2 coats of paint.

When I removed the tape, the little paint that overlapped the edge of the tape caused the tape to tear and left little bits of green tape under a bumpy edge. Also, some of the green colour had imparted itself onto the jagged painted edge. Perhaps I was not using the correct tape? Perhaps I let it dry for too long before removing it?

Here's a neat trick I took from another forum: if you're worried about paint or varnish running over the tape, curl half the tape up to catch any minor amounts. Here's a picture:

http://picasaweb.google.com/pbjsndwch/BuildingTheSkerry#5482747878896970146

Good luck with the build!

Jean.

My experience in this area is limited but I will tell you that I left the tape on my Wherry through 2 coats of Interlux primer and 3 coats of Brightside polyurethane. sanding in between coats. The paint job came out beautifully and the tape peeled off with no problem and left a razor sharp edge.  I then taped over the paint and applied 3 coats Interlux Schooner varnish to the adjacent strake. The tape again peeled off clean and left a perfect edge. I wouldn't do it any other way.

PS. Don't know if this makes a difference but my paint job was completed in about 5 days not including the varnish. So the tape was in place for that time period. If you plan on doing your painting over several weekends maybe better to remove the tape as the paint will have more time to harden and maybe cause a problem with the tape.

Great Forum subject--it is timely as I will be getting into the graphite-epoxy bottom and the poly sides and top. I was told that I need to mask in both applications and keep thm seperated from each other. One thing on this forum subject that I was hoping to find but has not been mentioned is tape preferances. Standard masking tape-- blue masking--shipping tape and the stripping tape to name a few. What type and for what applications---thanks----CZ

Good question CZ. I just finished graphiting the bottom of my hull and what I did was use fine line (found it cheaper localy at an autobody repair and detail store) tape for the orginal "paint" edge then made it wider using 2" blue  tape. It's been hot enough here (Utah about 95 degress) that I laid the first coat of graphite on with a roller then tipped it out with a foam brush and came back and did it again 4 hrs later. After the second coat I took all tape off and it looks perfect.

My question is has anyone tried frog tape? I know it works with laytex based paints, and the blue tape doesn't realy do that good of a job for a real fine lines. But forg tape is cheaper, but I was too excited to finally do the graphite I didn't care to test difference between frog tape and fine line tape. If I get around to it, and no else has yet, I'll have to try it. If you had to do a lot of taping than frog tape would really be cheaper if it worked right.

Jason

Well, I left the tape on through 1 coat primer and 2 coats of Monourethane and it came off cleanly without pulling  or tearing the paint's edge.  The tape was 3M painter's tape for delicate surfaces (Lowe's).  It was on for about 2 weeks.

A big part of this depends on using tape that is designed for this application.  3M products specifically for boat painting (ie 218, 256) and their website offers info on how long they can be left down without causing some of the issues noted above.  Using the tape inside or outside is another important factor.  218 appears to be the best for sharp lines, but everything I've seen indicates it is it shouldn't be left down for an extended period, and not outside.  Interlux has a DIY forum where I'm waiting to confirm I can lay down 256 for 2 coats primer, 3 coats brightsides without having to remove and retape.  It's in the repair & maintenance>topsides.  I will share when I get an answer from them.

Follow up from prior posting, here is my Interlux question and response:

"One other question regarding taping.  This is from bare material so I'll need to apply 2 coats primer and then 3+ coats paint over multiple days.  According to 3M, the 218 shouldn't be left down for that long.  Re-taping multiple times would be painful.  Is there another tape I should consider like 256 that I could leave down for multiple days?  Other solution?

Hi,
Perfect lines are always an advantage, but not always feasible, so the closer you can get to perfect, the better off you will be in the long run. With regards to the taping the 256 would be a good choice as it can be left for up to 5 days or you could look at the 471 which would also work well for you and can be left up to 30 days. Hope this helps some more!"