Taping and varnish question

When varnishing exterior trim i.e. rub rails, eybrows, etc. do you folks leave the protective taping on while drying and then recoat using the same tape job? Or....do you tape, varnish, remove tape, let dry, retape recoat, etc.??? Don't want to pull up new varnish but not looking forward to retaping under my rail 8 times...

I use Bristol finish that dries quickly and I can put on up to 4 coats in one day generally so no need to take any tape off. I would not leave masking tape on if rain is predicted or heavy dew over night. It tends to make the tape extremely hard to remove.

Thanks. Plan on using Epifanes as it is already on and in good shape with a couple of exceptions due to rubs. "Back in the day" when I did my last serious varnishing, leaving the tape on was a no-no. Rain was a huge no no. Made that mistake on occasion. However, I think tapes have come along way since the early 80's. I think. Just wondering what everyone does given no rain. Can I get through 2-3 coats without removing.

Use a quality tape and leave it on.

You can even survive a rain, so if it happens I don’t lose my mind, but try not to plan on it. I’ve left blue tape for 4 or 5 coats and even gone a little over a week. Buy good tape though, no value saver, I always buy 3m if I can.

Was planning on spending the $$$ on some. Just not sure which. 3M, Frog tape, etc. I see some versions are...plasticized...but haven't used that type for anything. I would think that after all is said and done a razor blade to cut along the edge, through the varnish that gets on the tape, would be required?

firstbase said:

Was planning on spending the $$$ on some. Just not sure which. 3M, Frog tape, etc. I see some versions are...plasticized...but haven't used that type for anything. I would think that after all is said and done a razor blade to cut along the edge, through the varnish that gets on the tape, would be required?

Click to expand...

3m blue 2080 is good for weeks. Has the orange verbiage on the tape. As far as coats go I think 4 coats is enough for one application of tape then re tape.

If I leave blue painters tape on for more than a week it's a pain to remove because the paint/varnish is now rigid and the adhesive seems to set. I now try to get at least 2/3 coats per day and get tape off asap while varnish is still soft. I would not use masking tape.

firstbase said:

Was planning on spending the $$$ on some. Just not sure which. 3M, Frog tape, etc. I see some versions are...plasticized...but haven't used that type for anything. I would think that after all is said and done a razor blade to cut along the edge, through the varnish that gets on the tape, would be required?

Click to expand...

Jenn-you-wine 3M Blue tape, just plain tape. I tried the "improved" stuff with the printing on it, it's crap. I do 3 refresh coats & leave the tape on until it's complete. If going to wood, I'll re-tape when half the coats are on to minimize buildup & tearing the varnish. Rain doesn't seem to bother it, but as others said, it may leave some residue. It comes off with acetone & a rag.
I'm not a fan of razor blades near green varnish, it depends on the circumstances, but I've not had trouble with removing masking tape unless it's in a position that's prone to high build.

Greetings,
Slight thread drift: I've found the "removability" of tapes to be more a function of their age rather than touted quality. If a store does not rotate their stock you run the risk of getting a roll of tape that may be many, many months old. Add to that, sitting on board for a few more months and you have trouble with removal after a short period of time.

RT Firefly said:

Greetings,
Slight thread drift: I've found the "removability" of tapes to be more a function of their age rather than touted quality. If a store does not rotate their stock you run the risk of getting a roll of tape that may be many, many months old. Add to that, sitting on board for a few more months and you have trouble with removal after a short period of time.

Click to expand...

Good point.

Taping over an oxidized fiberglass surface is also asking for residue.

RT Firefly said:

Greetings,
Slight thread drift: I've found the "removability" of tapes to be more a function of their age rather than touted quality. If a store does not rotate their stock you run the risk of getting a roll of tape that may be many, many months old. Add to that, sitting on board for a few more months and you have trouble with removal after a short period of time.

Click to expand...

Good point. That is why I usually buy my tape from Amazon since their stock probably turns over quickly.

Thanks guys, all good points and very helpful. Now...who is coming over to show me EXACTLY how it works?? RTF? Yes? I have a Red Devil with your name on it.....

Color of the tape means little. You want to know how Long a release period the manufacture recommends. Buying your tape at Home Depot and expecting a long release period is a mistake. Going to an auto paint supplier like Wesco will cost more but you will know how long your tape’s release period is rated for. Tape life is affected by direct sun and temperature. What works in the PNW won’t work in FL.

The enemy of tape is the sun. 3m blue tape out of the sun on clean fiberglass can be removed easily after a year! RT is correct about the age of the tape, makes a big difference. And yes the improved blue stuff is crap.

Between two boats and and an old house I use a ridiculous qty of the stuff yearly.

I recoat using the originally applied tape unless for some reason I must pull it.
Usually it stays untill I have all coats on, up to 5/6 and sometime 10 if I'm rebuilding after a stripping.

A bit of care will prevent varnish pull up which is not usually a problem. In heavy areas I use an Olfa type knife, the small ones, with a newly sharp blade to score the varnish. It is not needed to really cut through but just a score will help hugely if the varnish shows any sign of pulling.

Don't try to pull wet tape, allow it to dry, or the paper will come free of the adhesive making a mess.



I use only the 3M 2090 tape. It will last up to a week in solid Vancouver, B.C. sun. I do test by pulling a bit as the stuff approaches a week. If I know I will be longer I will lay some test pull strips in full sun and use those to guage if I need pull and retape. If retaping is needed I do it as the consequences can be miserable.

I have used the 3M 2080 tape and liked it too but the last time I went looking for it [last summer] , it was noted as discontinued. There is old stock available but the 2080 , although better , was not enough better to be a problem.

I have seen and used products competitive to the 3M 2090 and some were ok and comparable at a slightly lower price but not enough for me to change. I use about 20 rolls yearly so the extra cost is workable and I can be reasonably sure of what to expect.

You do need to know how long it, any tape, is expected to last out doors. The 3M is quite clear about that. If you don't use a long period outdoor tape there will be trouble getting the stuff off, sometime major trouble. I have seen a couple boats where folk used a painter tape intended for indoor use and they had a heck of a time removing it.

In southern sunshine I would expect you need to be more cautious than I about testing how the tape removes so it does not stay too long. Even the 3M has its limits.

Having a coat of wax on first will help removal greatly. Where I not been ahead on the wax I have later had to go after some adhesive residue. That was one reason I also liked the 3M 2080 as it did not seem to leave residue but if no longer available reliably then there is no choice, at least long term.

For some comparison my varnish takes about 100 hrs yearly and a really major can be almost 200 hr. Yeah , I do keep a rough track.

Interesting, I see the 3M 2080 tape all over down here, South Florida. It's still listed on the 3M website as well. I ffound a Practical Sailor review of the major types. The exterior winners were 2080 and 3M 471, one of plasticized versions by a pretty wide margin. I do have 4-5 rols of 2080 but they were purchased 18 months ago and have been sitting around in the Florida heat. 3M lists shelf life of 1 year. Good purchase Firstbase. Like most things I bet it would be fine past its expired date but not something you want to learn is true to its shelf life and not expensive enough to chance.

I don’t know who makes my tape. I can only tell you that it is yellow, rated for outdoor use and has a 14 day release rating. I get my tape from the same guy who supplies Nordic Tug, American Tug, and Cutwater/Ranger with abrasives and masking supplies.

I’m off the boat for the holidays but I’ll look up the brand when I get home.

I’m not making a case for or against any one type of tape. Just know your release period.

For the halibut I looked up both the 3M tapes, 2090 and the 2080. Both say indoor use. 2090 2 wks indoors, 2080 60 days indoors.
They don't say cannot use outdoors but neither does 3M say you can.

Years ago when I started they rated it, 2090 , as up to 1 week outdoors. That was on the label.
I got onto these tapes from Rebecca Whitmans book , a pro varnisher out of Seattle, Wa. Although her book was a coffee table type it had serious varnish info in it.

THe tape I have now says 2 weeks indoors. However I did not have any trouble last season unless I went over the week. Even then it was minimal and came off clean, just was bit more exacting about technique. But I also have really never pushed it past the week or I would retape those areas needing it.

Guess I will need to do some more looking just be sure 3M has not monkeyed it.

And yes, or no, this time I don't see any warning of discontinuing. ????



Tiltrider, if you think of it please post what you are using now.


Firstbase: I suspect you would be fine using your stock of 2080. Just do so where it is not so exposed and where you don't need to leave it on for long. Test it for release often and as soon as it shows trouble pull it. I guess you will be able to use it all. I know on my boat there are areas of varnish that they do not get all day sun. Other areas do.

3M #2040 is a nice basic tape and inexpensive. Keep it out of the sun and away from moisture, like doing interiors, you can leave it on for weeks

LaBomba said:

I use Bristol finish that dries quickly and I can put on up to 4 coats in one day generally so no need to take any tape off. I would not leave masking tape on if rain is predicted or heavy dew over night. It tends to make the tape extremely hard to remove.

Click to expand...

I like you tag line! How true!

3m blue tape at H Depot is $4.00. Use it for awlgrip, bottom paint, varnish, hell I've used it for a temporary band aid. I"ve left it on for up to 3 weeks(not the band aid) in Fl summer and winter. If it rains, let it dry, don't pull it wet. I seldom have problems but if you get into a tough piece and it takes an extra 5 minutes think about how long it would take to pull and re-tape and the cost. I've used up to 5 rolls of tape on one boat pulling tape and re tapeing with 5 more rolls.
All blue tape is not is not the same going cheap will cost you in time and aggravation. Pay now or pay later but you will pay.

Southx10 said:

3m blue tape at H Depot is $4.00. Use it for awlgrip, bottom paint, varnish, hell I've used it for a temporary band aid. I"ve left it on for up to 3 weeks(not the band aid) in Fl summer and winter. If it rains, let it dry, don't pull it wet. I seldom have problems but if you get into a tough piece and it takes an extra 5 minutes think about how long it would take to pull and re-tape and the cost. I've used up to 5 rolls of tape on one boat pulling tape and re tapeing with 5 more rolls.
All blue tape is not is not the same going cheap will cost you in time and aggravation. Pay now or pay later but you will pay.

Click to expand...

Can't get much cheaper than $4 a roll at Home Depot!!

Another question, silly I guess, do you tape before sanding or sand first and then tape? The major piece I am doing is my toe rail. Need to sand up to where it meets the hull. Just curious on what others do.

Tape, then sand, then touch up the tape where I gorilla’d too much.

Rebecca Whitman has a great tip to put your new tape in a ziplock so the edges don’t pick up a bunch of crud. While I have zero experience actually following this advice, I have lots of expensive tape full of crud on the sides to appreciate the tip.

Wow..lots of experience talking here! My experience is that tape is one thing where you get what you pay for...if cheap tape is all you need for the particular job go for that 3m blue but don’t leave it too long...a day at most. But if the lines are crucial then go for the extra quality. In BC I use “frog tape” (that’s a brand name) when it matters a lot....never bleeds under and comes off after a week no problem.

ghost said:

Tape, then sand, then touch up the tape where I gorilla’d too ...

Click to expand...

Frog Tape is available everywhere down here. In the past I taped prior to sanding just because it seemed better, the thing to do. As long as I used a flat sanding pad with no sand paper wrapped up or on the sides it seemed to not goof up the tape much. Just curious.

I tape first, primarily to protect the fiberglass or windows. Our saloon windows have sanding marks from a PO. He was sanding next to the glass and sanded on the glasss several times. The tape also protects the painted hull when we’re refinishing the cap rail. It’s easier to go back and retape an area that it is to repair the fiberglass.

I sand before taping. I use a wide, about 5 ot 6” putty knife and lay it flat on the gel coat and sand so that the putty knife takes the abuse from the sander and protects the gel coat. Eventually the putty knife will sand away but they last a long time and are much easier to use than tape and having to retape again. Also sometimes you can accidentally sand through tape but it is much harder to sand through a putty knife.

Thanks Dave. If you are sanding through a putty knife then you are doing a LOT of sanding!