Paint question

[gejettest]

Hi all,

Question about why masking tape, Scotch Blue, leaves an impression on the paint finish.

Background:  I sprayed Rust-Oleum 2X paint, dried about a week.  I did some masking, sprayed my accent color, removed tape and paper.  I was shocked at the "pebble" finish where the tape was.  I verified that it wasn't tape residue.

The mottled appearance began to fade away after a few days, but it is still there.

I know, maybe BLAH_BLAH_BLAH_BLAH rattle can paint, but heck it's Rust-Oleum?

Any thoughts?

Thanks!

[Dpate]

It looks like when you burnished the tape down it flatten the gloss coat which looks like a semi gloss from the pics.  That pebbly look is really bad orange peel & print of the tape.  Just look at pic #2 the gloss part has orange peel all day same as the spot you removed the tape.  Did you get anything on the tape? I use tamiya washy tape and never had this issue, but i don't use rusto either.  I know you said it was drying for a week, but was it truly cured? Touch try doesn't mean cured.  If you must use that tape i would try the delicate kind.  It's pink and not as tacky. It's washi tape, but i don't think as good as tamiya though.  But your problem can be easily fixed with sanding and compound.

Edited August 17, 2022 by Dpate

[stitchdup]

It looks like the paint may have still been soft. Did you use primer? and are they enamel paints? they sometimes take a while to fully cure so I use low tack tape for enamels if i'm using them. I've also had that happen when the thinners from the paint leaches into the tape so even with the low tack tape it has to come off as soon as the second colour has set enough, even before it is touch dry so its a careful job sometimes. I mostly use acrylics now for these reasons but some colours i can only get in enamels so i wont fully swap over

[yh70]

your paint was not dry...

 

[StevenGuthmiller]

7 minutes ago, yh70 said:

your paint was not dry...

 

No doubt.

 

The reason that the texture seams to be slowly fading is because the paint is continuing to cure and shrinking as it does.

Enamels take FOREVER to cure completely, so I would feel safe in guessing that this was enamel.

 

 

 

Steve

Edited August 17, 2022 by StevenGuthmiller

[Bainford]

I've had this problem on two occasions, and I can guarantee the paint had been cured for months in both cases. Once was Duplicolor lacquer and the other time was on Tamiya lacquer. The tape was Tamiya masking tape. In both cases the tape had been left on for several days, perhaps more than a week. When the tape was removed, it left behind alligator skin texture. The texture was not tape residue, but a significant pitting or corrosion of the polished paint surface. The damage can only be removed with vigorous colour sanding and re-polishing, provided there remains enough paint thickness to save it. Ironically, on the second occasion I had applied the tape to some of the body, not for painting, but to protect it during final assembly, as it was my closest-to-perfect paint ever and I was concerned about scratching/chipping. Go figure.

I still love to use Tamiya tape, but I remove it as quickly as I can following paint application. If you use a dehydrator, remove the tape before putting the model into it.

Others have experienced this problem, too, and it has been mentioned on the forum before. It seems to be some sort of chemical reaction between the tape adhesive and the paint. It's very disappointing, especially from a trusted brand such as Tamiya, and double especially when the reaction occurs between their tape and their paint.

[NOBLNG]

I had this happen once, but I had left the tape on for quite a long time. It was just some generic or maybe 3M masking tape.  A lot of painters tapes are only meant to be used with latex house paints also.

[Plowboy]

2 hours ago, Bainford said:

I've had this problem on two occasions, and I can guarantee the paint had been cured for months in both cases. Once was Duplicolor lacquer and the other time was on Tamiya lacquer. The tape was Tamiya masking tape. In both cases the tape had been left on for several days, perhaps more than a week. When the tape was removed, it left behind alligator skin texture. The texture was not tape residue, but a significant pitting or corrosion of the polished paint surface. The damage can only be removed with vigorous colour sanding and re-polishing, provided there remains enough paint thickness to save it. Ironically, on the second occasion I had applied the tape to some of the body, not for painting, but to protect it during final assembly, as it was my closest-to-perfect paint ever and I was concerned about scratching/chipping. Go figure.

I still love to use Tamiya tape, but I remove it as quickly as I can following paint application. If you use a dehydrator, remove the tape before putting the model into it.

Others have experienced this problem, too, and it has been mentioned on the forum before. It seems to be some sort of chemical reaction between the tape adhesive and the paint. It's very disappointing, especially from a trusted brand such as Tamiya, and double especially when the reaction occurs between their tape and their paint.

Never ever leave tape on for several days. It's no wonder you had a reaction. I don't think any tape is made to stay on for a week. I always remove tape as soon as I spray the second color. Tricky to do. But, I get much cleaner lines as well as minimal buildup along the edge. 

Next time you want to protect your paint, use a tape called mar guard. It's a see through blue tape that adheres by static cling. Same concept as the clear cling wrap used in the kitchen. It can be left on for long periods.

[espo]

I would try and stay with a masking tape product designed for the type of painting and model building we are doing. Plowboys suggestion of removing masking tape is right on. I would suggest removing the tape as soon as the paint has flashed over even if the area you just painted is still too soft to be handled. Many of the "Home Depot" style masking tapes are designed for household type painting and they are used to mask different types of paint than what is usually used here and the manufactures maybe using a different type of adhesive than what we need for what we're doing.  

[Bainford]

2 hours ago, Plowboy said:

Next time you want to protect your paint, use a tape called mar guard. It's a see through blue tape that adheres by static cling. Same concept as the clear cling wrap used in the kitchen. It can be left on for long periods.

Cheers Roger. I'll keep an eye out for this stuff.

[Dpate]

9 hours ago, Bainford said:

I've had this problem on two occasions, and I can guarantee the paint had been cured for months in both cases. Once was Duplicolor lacquer and the other time was on Tamiya lacquer. The tape was Tamiya masking tape. In both cases the tape had been left on for several days, perhaps more than a week. When the tape was removed, it left behind alligator skin texture. The texture was not tape residue, but a significant pitting or corrosion of the polished paint surface. The damage can only be removed with vigorous colour sanding and re-polishing, provided there remains enough paint thickness to save it. Ironically, on the second occasion I had applied the tape to some of the body, not for painting, but to protect it during final assembly, as it was my closest-to-perfect paint ever and I was concerned about scratching/chipping. Go figure.

I still love to use Tamiya tape, but I remove it as quickly as I can following paint application. If you use a dehydrator, remove the tape before putting the model into it.

Others have experienced this problem, too, and it has been mentioned on the forum before. It seems to be some sort of chemical reaction between the tape adhesive and the paint. It's very disappointing, especially from a trusted brand such as Tamiya, and double especially when the reaction occurs between their tape and their paint.

"Tape had been left on for several days, perhaps more than a week" That's the issue not the tamiya's fault.  I'd be more disappointed in my actions, and not the type. I've never had such issue happen and that's even leaving parts in the dehydrator for few hours. Most of the time i'll just let the part sit for a few mins and remove the tape, and if one is painting right with a airbrush you wont get a paint line after removing. 

[Bills72sj]

My go to is Para-film. It has no texture and can be left on for years. It also is good for masking over things like panel lines. It can also be pushed around a bit after it is laid.

[NOBLNG]

12 hours ago, Plowboy said:

Next time you want to protect your paint, use a tape called mar guard. It's a see through blue tape that adheres by static cling. Same concept as the clear cling wrap used in the kitchen. It can be left on for long periods.

 

5 minutes ago, Bills72sj said:

My go to is Para-film. It has no texture and can be left on for years. It also is good for masking over things like panel lines. It can also be pushed around a bit after it is laid.

Do these leave a nice clean line with no bleed under?

[Plowboy]

8 hours ago, NOBLNG said:

 

Do these leave a nice clean line with no bleed under?

Mar guard won't as it sticks with static cling. 

[Metalmad]

I use Tamiya masking tape on all my masking do to the fact that all the 3M blue and green tapes leave a residue  

 

[Michael jones]

This is probably because the paint job was left out in the sun to dry(or warm place) causing the tape (even tamiya) to etch the paint... Some people believe its because the tape was left on too long, but this is not true. Tape can be left on for a week, no problem in a cool spot out of the sun.  Also if you sprayed the paint too wet, it can do the same thing...

[Bills72sj]

On 8/17/2022 at 8:12 PM, NOBLNG said:

 

Do these leave a nice clean line with no bleed under?

Yes. It is one of it best features.