Fogging under canopy painting masks

[Smajser]

Hi!

I have a problem with fogging of transparent plastic parts of canopy, after removal of painting masks.

A "fog" forms on the inside side. 

It is relatively easy to remove with a piece of cotton wool attached to the thin wire, but when access is limited the problem almost completely disrupts the appearance of the model.

For gluing transparent plastic I use Testors Clear Parts Cement.

Is there a way to solve this problem?

Thanks in advance

Zeljko

[James Rademaker]

Prior to masking the clear parts have you put a coating of Future on both sides of the clear parts? I have found that this keeps the clear parts clear. I usually glue the clear parts with Elmers white glue. In addition, I have used CA or super glue to attach the clear parts and that does not fog up the clear parts.

 

Hope this helps,

Jim

[Stevepd]

If you can easily remove it with a cotton bud - is it moisture?

[chuck540z3]

Assuming the following:

1. You are painting the clear parts after gluing them to the cockpit area
2. The area forward of the clear parts were masked off before painting

The answer is paint leakage, either at the clear part to cockpit join or in the area that was masked off next to it.  To solve this, make sure you have plenty of glue under the clear part join and use liquid mask along with masking tape when masking off areas next to it, to create a solid seal, something like this:

 

 

 

Cheers,

Chuck

[Smajser]

On 5/29/2020 at 1:43 PM, James Rademaker said:

Prior to masking the clear parts have you put a coating of Future on both sides of the clear parts? I have found that this keeps the clear parts clear. I usually glue the clear parts with Elmers white glue. In addition, I have used CA or super glue to attach the clear parts and that does not fog up the clear parts.

 

Hope this helps,

Jim

I haven't used Future for coating of clear parts. I was always afraid of unpredictable reactions between the adhesive of the protective tape, and the layer of Future.  Sometimes the interval between the installation of the tape and its final removal is 2-3 weeks.

 

 

21 hours ago, Stevepd said:

If you can easily remove it with a cotton bud - is it moisture?

It really looks like some kind of moisture, which I tried to remove by exposing the model to direct sunlight, by carefully heating it with a hair dryer, but nothing happened. That strange moisture remains in place and unchanged even after a few months.

 

 

59 minutes ago, chuck540z3 said:

Assuming the following:

1. You are painting the clear parts after gluing them to the cockpit area
2. The area forward of the clear parts were masked off before painting

The answer is paint leakage, either at the clear part to cockpit join or in the area that was masked off next to it.  To solve this, make sure you have plenty of glue under the clear part join and use liquid mask along with masking tape when masking off areas next to it, to create a solid seal, something like this:

 

 

 

Cheers,

Chuck

I paint most of the glass parts before gluing, since I often paint the inner frames as well. When the paint dries, I remove the inner protection tape and glue the transparent parts for the fuselages. The outer protection is generally well sealed with additional Tamiya tapes and liquid mask (Mr.Masking sol NEO), as in your picture.

The problem occurs in both summer and winter, so humidity is not crucial. I never wash transparent parts before use, nor do I touch them without gloves.

 

 

[spreckair]

I have had the same problem with canopies when not fully cured super-glue fogged and ruined the canopy.  Coating the canopy with Future prevents this problem.  The other solution is to make sure that any super glue in the cockpit area is totally cured before attaching the canopy.

[Smajser]

You have confirmed my suspicions that the possible cause of fogging, is the not totally cured superglue in the cockpit.

I glue all metal and resin parts with it.

The only problem is that I don't know how long it takes to totally dry ordinary superglue.

[Out2gtcha]

3 hours ago, Smajser said:

You have confirmed my suspicions that the possible cause of fogging, is the not totally cured superglue in the cockpit.

I glue all metal and resin parts with it.

The only problem is that I don't know how long it takes to totally dry ordinary superglue.

 

 

It depends on the type of CA. CA tends to set up faster the thinner it is. Also moist, warm air tends to get CA to harden off faster. If you are worried about it, I would definitely let it cure off in as warm/moist  environment as you can for 3 or 4 days, or even a week to be sure. That may be way overkill for CA dry time, but you should see no fume action after a week or so. If you do, it could indicate an issue with the CA you are using.

 

Failing that, I don't use Future for anything.......................... except coating can-O-pees. It really helps to shine things up, but mainly I use it to protect the canopy from the ultra thin CA I use to attach windscreens.  The trick to getting a nice even coat without any air bubbles or debris in the Future is three fold from my perspective.  If you have any interest in Future dipping:

 

1 - Surface tension.  When dipping the canopy, sometimes even if you have cleaned it super well, surface tension can bring teeny tiny air-bubbles, small enough to even look like debris. The key to getting rid of this I found is to take a decently stiff CLEAN brush, and brush the canopy while dipped in the Future.  This eliminates any tiny air bubbles, and releases surface tension to make a smoother Future finish.

 

2 - After pulling the canopy out of the Future dip, take a folded piece of paper towel or other absorbent material and very delicately touch the bottom  corner only of the canopy with the towel (usually where it contacts the model on a frame VS any of the actual clear parts) so that any excess or drips of Future are absorbed by the paper towel. 

 

3 - After wicking off the excess, take a plastic food container with locking lid, and place a doubled up piece of paper towel in the bottom, and set the canopy on it to dry. This will absorb any excess Future that may drip down to the bottom of the canopy during drying time. Then seal up the container with the exception of one corner to let the canopy get air, but not get dust in the Future coat so I can dry in a timely manor.  

[Bob MDC]

Totally agree with Out2gtcha it depends on the CA  the cheap pound shop stuff is ok for construction but if used on delicate parts like clear it needs time to cure due to the "fillers" used to get the price down.

I tend to use a moisture stable glue  for my delicate work Hafix or Krylex are my go to products.

 

Bob

[Smajser]

Does Future have an expiration date?

I got these two from the US a seven years ago, but I didn't find an expiration date label anywhere.

Edited August 30, 2020 by Smajser

[Out2gtcha]

Just try it on a sample first. If its still tacky after a week it's bad. 

[ChuckD]

On 5/29/2020 at 7:43 AM, James Rademaker said:

Prior to masking the clear parts have you put a coating of Future on both sides of the clear parts? I have found that this keeps the clear parts clear. I usually glue the clear parts with Elmers white glue. In addition, I have used CA or super glue to attach the clear parts and that does not fog up the clear parts.

 

Hope this helps,

Jim

This is my method too and I have same success.  After dipping the clear parts in Future, I dab off the excess with a paper towel and place them on a paper towel under an overturned plastic food tub.  Helps keep dust and debris from settling in the parts while the future is still tacky.

 

Edit: whoops, should have read the whole thread before replying... @Out2gtcha beat me to punch with a very detailed post.  So, in essence, my response is, "what he said."

 

Edited September 5, 2020 by ChuckD