1991 Lamborghini Diablo VT

That stuff will eat clear plastic.

I have never ever used clear for sealing off edges, in fact this is the first i've heard of the technique so I am a little perplexed as to why you would need to as i've always managed my windows trims with freehand brushing. You learn something new every day.
I think the blue used on this is excellent by the way and i'm sure the finished model will look really great.

Thanks for all the suggestions guy. Just have to see what it is like when it comes out of the BF.

Plastic Freak wrote:Really you never use clear? You sure have had a long string of good luck Al. I clear the edges of everything I tape. Hope Colin is right.

I think you misread my meaning Curt: ("I have never masked and cleared coated, to seal clearparts before" Masked and cleared solid styrene many times.

Shelby wrote:Al did you use automotive clear for this?  If that's the case that is likely the problem here.

Yes it was rattle can auto clear Denis. Used the same stuff on the body colour masking without any problems.

Mr Hirakawa wrote:I have never ever used clear for sealing off edges, in fact this is the first i've heard of the technique so I am a little perplexed as to why you would need to as i've always managed my windows trims with freehand brushing. You learn something new every day.
I think the blue used on this is excellent by the way and i'm sure the finished model will look really great.

Thanks for the paint compliment MrH. I retrospect the demarcation lines on this one were large enough for hand brushing but hey ho!

Clear coating over the masking tape when doing two or more body colours is a must though IMO.

Did you clear directly on the window then painted the black over it? I'm trying to understand the process you went through

Usual process Denis.

Applied Tamiya masking tape to the areas to be kept clear. Masked off ALL of the inside too but with painters blue tape. Sprayed two coats of Promatic rattle can clear. (same stuff I used on the body). Left it twenty four hours to dry. Sprayed the black with several light coats of Promatic rattle can gloss black.

I think I may have this figured out, at least in part.

Look at this photo:



All of the 'fogged' areas indicated by the yellow areas were exposed and directly sprayed with the clear coat, which must have reacted with the clear plastic, causing the fogging.

The area indicated with the red arrow, I think must be clear 'creep' and hence has also reacted with the plastic.

So I think all of the fogged areas are as a result of the clear coming in direct contact with the clear plastic.

As for the windscreen marks, I wonder if the clear coats 'penetrated' the Tamiya masking tape?

I'm going to see if I can get a replacement screen from Revell. If I do, I will, as a test, spray this one with the clear coat and see what happens.

Al that's exactly what I thought happened. As for the clear penetrating the tape it's a possibility but I've left tape on plastic parts and dunked them BF and Super Clean without any damage to the tape.
Automotive lacquer can cause more reactions with different things than even the Tamiya lacquer.

Can you not fix the clear parts by sanding off with 800 grit then working your way back up to 12 000?
It is a tedious process but I think it should work, unless you have craters in your glass.

Sorry Al, I did misread your post.

Very strange indeed, and very interesting. These are problems you want/need to find the root cause so you/we don't have it happen again.

It looks to me that it may just be a reaction between those two particular items in this case, maybe that lacquer brand has something in the carrier?
I've used halfords lacquer on lots of clear plastic with no issues, although normally use hairspray if I'm honest.

Back to the model build ..... Could you just fine sand this back and pop a tint on it Al?
I think it would look awesome against the blue

Shelby wrote:Can you not fix the clear parts by sanding off with 800 grit then working your way back up to 12 000?
It is a tedious process but I think it should work, unless you have craters in your glass.

That's always a possibility Denis but the lower edge of the windscreen does indeed have 'craters' plus there is a raised edge all around the windscreen which would make it difficult to sand up to.

I have requested a replacement from Revell, (which could take up to eight weeks to arrive) but if they cannot supplly then I shall try to polish it out.

Plastic Freak wrote:Sorry Al, I did misread your post.

Very strange indeed, and very interesting. These are problems you want/need to find the root cause so you/we don't have it happen again.

No problem Denis. When I read it again just now, I think I wasn't as clear (LOL) as I could have been.

Assuming I get a replacement, I'm going to spray the original with the clear to confirm my suspicions.

You sneaked in while I was posting Colin. LOL

Hair laquer........ interesting? Do you think it would prevent creep?

Tinting the windscreen could be a way forward if I don't get a replacement. It will be a last resort though, as it would hide all my hard work on the interior.

What would you suggest tinting with? Tamiya clears?

Tamiya has a smoke clear Al. Shame to hide that interior, you put some good time into it. You could also water down some clear blue Tamiya with their clear.

I use hair lacquer in preference to rattle can stuff, yes it does prevent paint creepage, particularly if you decant some and brush it in the corners.

I wouldn't know what stuff to use for the tint, Curt mentions some methods above, I normally just cheat and try and use some film negative I processed blank when I had the photography shop. Might have to sniff that out again for the next build.

That explains why Colin's windshields look like this...



Al - Alclad also has a smoke for tinting windows. I've been doing some experiments with the Tamiya stuff and I will take a picture to show you some of the results.

As promised pics of my tinting experiments.  Note that the only prep I did to the glass was wiping them with a damp cloth.

My first experiment was with the Tamiya smoke and I found it a little thick so I added just a little thinner and it just ran like crazy and send it to take a bath right away and didn't take a pic.
Lesson: DON"T thin the stuff!

I moved on to the blue clear for a top band tint.
NOT thinned and shot at 20psi through my Iawata.
4 mist coats and increased the paint flow with each coat.



Difficult to lay it down smoothly as you can see.


Then I decided to go for a full tint laying more coats at the 20psi but high paint flow from the start.
I quickly cleaned the brush and follow with red clear at the bottom to see if I would get a purple blend but by that time it was too late and just came out as brownish.



I did a bit of polishing with Tamiya coarse polish but it really didn't do a lot to improve thing.
Wet sanding will certainly help lighten up the tint but of course the danger is to cut through the paint and scratching the glass.



On to the red clear...I found this to lay down better than the blue and cover more smoothly using the same process and psi.



I found the red to be more transparent than the blue coat for coat.


I still have a lot experimenting to do and will get on with it when I have a little down time on my Corvette build.  Eventually I hope to be proficient enough to do a comprehensive tutorial.
I hope this gives you an idea of the path you'll choose.

Sorry I missed this Denis, been real busy with the house recently.

Thanks for showing all of this and when the new glass comes from Revell, I may well consider tinting it.

Good report Denis. I have found the blue needs to be watered down with clear, or sometimes I start with clear and add the blue.  To add, I thin all my Tamiya paint 3:1 with alcohol.

The new glass arrived from Revell a couple of days ago, so now I should be able to compete it soon.

Good luck with the restart of this Al.

Ive always found Revell to be good with Spare/replacement parts, Ill look forward to progress.
You are a MACHINE Al lol.

Skid wrote:The new glass arrived from Revell a couple of days ago, so now I should be able to compete it soon.

Did they include the forking back up lenses? I could use a spare one

I did a test spray on the old glass and sure enough, the Promatic clear coat fogged it:



Moral of the story..... don't use auto clear coat to seal masking tape edges on clear parts.

You have mail Dan.

It's too hot, good to know.

Alclad aqua clear is is my go to for sealing masking tape. dries as clear and water based so very gentle.
Glad you tested before going on Al.

I tried Alclad clear a few years ago Gary, just couldn't get on with it!!

Back on this one.

Masked up the replacement glass. Tested brushed on Tamiya clear on the roof section..... no fogging!!
Phew!!

Brushed Tamiya clear on the masking tape edges and let it dry for 24 hours, then a light mist coat and two semi wet coats!!
Happy chappie!!