Paint masking

[mikemech]

I screwed up again.

About a month ago I masked off the fin tubes on my Super NeonXL. Shot the main BT and fins lightly (fluorescent orange). Repeated a week later. And repeated a week later (final coat). Last night I removed the masks and found strings of masking tape adhesive stuck to the fin tubes. A few pulled off, but every fin tube has an obvious ridge of adhesive showing where the edges of the masking tape was located. Alcohol doesn't touch it. Sandpaper (320) takes off some primer, but not the adhesive. I'm assuming that I left the tape on too long. I haven't seen this problem before. Haven't found this in forum searches.

Thanks for all your past and future help.

 

[samb]

Try wiping the area with a paper towel dipped in vegetable oil. So, the mask was on for two weeks ? Any reason why you couldn't shoot subsequent coats within an hour and get that tape off sooner ?

 

[tightwad]

What kind of tape did you use?

 

[luke strawwalker]

Yep, you always want to "untape" as soon as possible...

Some tapes state that they are 'designed' to be left in place for relatively long periods of time and come off clean, but basically regardless of the tape, the sooner you can get it off, the better your results will be.

Later! OL JR

 

[mikemech]

samb
"Try wiping the area with a paper towel dipped in vegetable oil. So, the mask was on for two weeks? Any reason why you couldn't shoot subsequent coats within an hour and get that tape off sooner?"
The tape was on for over a month. The only other time I used fluorescent paint, it was still balling with 400 grit sandpaper after three days. I wanted it completely cured. Dumba$$. (Me dumba$$, not you)

tightwad
"What kind of tape did you use? "
Regular 3M masking tape. It was holding down paper masks.

 

[tightwad]

I would recommend using the blue painters tape or the green frog tape instead of regular masking tape. I have never had these tapes leave adhesive behind, even after sitting for days awaiting for the paint to gas off.

 

[samb]

Yeah fluorescents are hard to control for me as well. Three light coats over a white base and leave it alone. Some folks clearcoat, others don't. I've never actually took sandpaper to it though. Anyway I always try to get the masking tape off quickly;within an hour if not sooner.

 

[hornet driver]

Hmmm, Ok, one thing at a time. First--don't leave the tape on so long--you've figured that out already. Best bet-use blue painters tape. When you spray, let each coat tack off and then lay another coat--don't wait days or weeks--when the last coat tacks--this takes a little practice-- pull the tape off at a 45 deg angle INTO THE PAINT. Any paint ridge can be knocked down with a quick moist sand with 400-600 grit wet or dry. clear afterwards or polish as you like. As far as fluorescents go--they really only look right if they are cleared with flat clear--maybe satin--As far as the adhesive goes--samb is dead on balls with the veg/oil. most anything else will bust up the paint except mineral spirits--use at your own risk-- In the end you may have to repaint following the preceeding directions. Do Not sand the adhesive into the surface---whole nuther bag-o-worms----H

 

[TopRamen]

The Rocket God Paul T.(AKA Sodmeister), uses "Tamiya Tape". Perhaps that's worth looking into?

 

[JohnCoker]

The Rocket God Paul T.(AKA Sodmeister), uses "Tamiya Tape". Perhaps that's worth looking into?

Yeah, this stuff works really nicely, but I still removed it as soon as the paint was dry (see my Simple Painting video).

 

[Anthony Bean]

I usually pull the tape after the final coat goes tacky. Leaving strong adhesive tape such as masking tape on for long periods will cause problems. It can also lift the paint from the unmasked area if the paint is completely cured. You may find your straight paint edge is not so straight as the cured paint on the tape (the overspray) is bonded to the cured paint on the unmasked area. Depending on the type of paint and and the number of layers I want to shoot my masked areas don't usually stay on for more than an hour. I usually shoot wet on tacky so each layer will bond with the lower layer and then immediately remove the tape when the final layer is tacky into the paint as mentioned earlier.

 

[o1d_dude]

I pull my masking tape off while final is still wet. No lift and the paint can still self-level.

Wear gloves when you do this as the paint will get on your hands and ~never~ lose control of the tape while pulling it off.

via Forumrunner/GS4

 

[foamy]

I pull my masking tape off while final is still wet. No lift and the paint can still self-level.

This^^^

 

[mikemech]

Try wiping the area with a paper towel dipped in vegetable oil.

How do you remove the vegetable oil film? Soap and water?

 

[samb]

How do you remove the vegetable oil film? Soap and water?

I'd probably grab one of my handy, unscented baby wipes but soap and water or alcohol would work also. I take it you got the adhesive cleaned up ?

 

[mikemech]

Thanks for all your advice and ideas.
The fin tubes are now ready to be masked and painted. I used vegetable oil, mineral spirits (turpentine), acetone (her nail polish remover), and alcohol.
I didn't have any lighter fluid to try.
Since I have six fin tubes I could try all of them.
Mineral spirits worked best on the adhesive, but damaged the primer. I'll have to sand and re-prime that tube.
Vegetable oil worked very well and no paint damage.
Acetone worked, but took a lot of rubbing. No paint damage.
Alcohol (70% isopropyl) was useless. No paint damage.
Bought some Frog paper tape. Primed one damaged tube tonight. Tomorrow afternoon, hopefully, I will mask, paint, and REMOVE THE TAPE.
Thanks to the Forum, my tuition at the School of Hard Knocks was quite low.

 

[dave carver]

I would recommend using the blue painters tape or the green frog tape instead of regular masking tape. I have never had these tapes leave adhesive behind, even after sitting for days awaiting for the paint to gas off.

I have 2 rolls of Duck brand blue tape that don't stick to nothing, not even itself Post-it's have better adheasion than this crap....

 

[TheTellurian]

The best tape I've used is cheap vinyl electrician's tape. It stretchs, conforming to mild compound curves, peels off easily and lightly burnishing the edges seals the paint out. Try it but don't get the air nozzle of spray guns too close to the edge or it may lift i.e. spray from the tape to the rocket.


Richard

 

[JohnCoker]

I think most brands of tape can work well. I've even used "scotch" (clear) tape for ultra-fine lines.

For me, the trick is "sealing" the edges with a light coat of the underlying color before painting the next color. This way, even if paint does wick under the tape, it's the same color.