When to remove masking tape?

[Bob.M]

I am adding a small square painted area to the side of a passenger car. It is about 0.9" by 0.5". I have been waiting about 24 hours before removing the masking tape, and on about 1/2 of the attempts, the paint sticks to the tape and makes a jagged line with about 1/16" "teeth". I tried 2 things: Using a different brand of paint and using less of it. Better, but still a problem. I am using glossy white. One can says it is enamel, but the Krylon doesn't say what it is.

Question is: Should I remove the tape before the paint is dry?

[sir james I]

I remove the tape as soon as the paint appears set. You already know what happens when you leave it on too long.

These new formula paints set fast so just kinda pull a little tape and see how it goes.

[Phoebe Vet]

I pull the tape immediately after applying the paint.  Are you sure that the paint is being pulled and not wicking under the tape?  If the latter is the case try a different brand of tape and burnish the edges when you apply it.

[rtraincollector]

also you may try very lightly cutting along the tapes edge then lifting the tape you don't want to cut into the car but enought to cut the thin layer of paint.

[gunrunnerjohn]

I pull the tape off after a few minutes to allow the paint to setup just a bit.

[stebbycentral]

OK, masking 101. 

1) Always use low-tack tape, like blue painter's tape.

2) One way to prevent bleed-under is after you apply the tape, spray a thin coat of the same color being masked.  This seals the edge of the tape, and any amount that does bleed under is invisible.  Obviously you have to let this coat dry thoroughy before proceeding to spray the top coat.

3) When removing the masking tape, bend it back at as sharp an angle as possible.  So that if you took a 30 drafting triangle and set the point where the tape is coming off the surface, the removed tape would touch the top of the triangle.  Pulling straight up, or at less than a 90 degree angle will almost always guarantee a frayed line.

 

[rtraincollector]

stebby just an idea going from yours if you don't have the color to match how about using a light coat of clear coat.

[stebbycentral]

That's certainly do-able should you run out of the original color. 

The striping on this locomotive is not a decal.  First I painted a band of red, then I covered it with striping tape, and sealed it as described with an overcoat of red.  When that was dry, I did the yellow sides.  After they dried I masked them with another level of regular painter's tape and sealed that with a coat of yellow.  Finally I painted the grey roof.   The striping tape did not come off until all layers had completely dried, but it didn't stick to the original layer because it is a low-tack tape specifically designed for this kind of use.

Which is another tip.  Always apply your colors in layers from from lightest first to darkest last, if you possibly can do so.

 

[Bob.M]

stebbycentral

2) One way to prevent bleed-under is after you apply the tape, spray a thin coat of the same color being masked.  This seals the edge of the tape, and any amount that does bleed under is invisible.  Obviously you have to let this coat dry thoroughy before proceeding to spray the top coat.

Thanks to all for your knowledge. I was not having a problem with bleed-under, but that suggestion above sounds like a good idea.

[Bob.M]

Here is the result of the project involving a small rectangle. Removing the tape after a few minutes solved the problem of jagged edges.

 

Here is a picture of the prototype:

[Gray Cat]

my 2 cents..

Don't forget to dust the colors on lightly and in multiple coats as opposed to hosing it on! Applying the paint too wet and heavy can cause it to bleed under the tape and make it too thick which causes more problems when pulling tape.. When dealing with small areas on toy trains I find using an airbrush and model paints with finely ground pigments works best. Airbrushing is not always an option though so remember to shake your rattle can well and it always helps to warm it up in a bowl of warm/hot water. This helps the paint flow and increases can pressure which in turn helps atomization.

Good tip on using blue tape, but another trick to make tape less sticky is to cut your piece to length and then stick it to your t-shirt first.. that little bit of lint on your shirt can oftimes cut down the sticky!