A Frosty Finish

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Serjt-Dave
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A Frosty Finish

Postby Serjt-Dave » Tue Aug 28, 2018 8:04 pm

Hi All. I put the final flat finish on these two vans and they turned white. It's the sort of effect that you get if you spray on a flat varnish onto matt black.
After painting I glossed over each van then applied the decals, then another gloss coat then a matt finish. Weathered then both and then applied a matt finish and this happened.

Should I have applied a gloss coat on top of the weathering and then the matt finish?

Not sure what I did wrong, I only done it the normal way I do things? Is there any way I can save them or is it a complete strip? Any help or advice please.
01 Brake Van.jpg


01 CCT.jpg

Alan Turner
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Re: A Frosty Finish

Postby Alan Turner » Tue Aug 28, 2018 9:42 pm

I've had this happen more times than I care to think about.

Its very prevalent with Humbrol Matt varnish.

I now use Precision and so far I get better results.

regards

Alan

Philip Hall
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Re: A Frosty Finish

Postby Philip Hall » Tue Aug 28, 2018 10:14 pm

I’ve not had this problem, and it’s not a helpful answer in your present predicament, but I would not normally apply a varnish on top of weathering; however, it does look to me as though there is actually too much varnish on the model. Usually I apply decals over a gloss or polished surface (T-Cut works quite well as a polish) then a matt or satin varnish as a final coat. I quite like Ronseal as a varnish, either Mattcote, Satincote or Glosscote. The only problem is trying to get these in small tins these days. A very good varnish is a spray from the Games Workshop, like Citadel aerosol.

As to a solution to your present ills, you could try cutting back the varnish with T-Cut, once it’s really good and hard. That might remove the coat that has bloomed. Then a very thin coat of something else like Citadel.

Philip

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Serjt-Dave
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Re: A Frosty Finish

Postby Serjt-Dave » Wed Aug 29, 2018 2:10 pm

Hi Alan, I was using Precision/Phoenix Matt Varnish, even though it's a fairly new tin I did notice it was starting to gel a little. I stired for several minutes before mixing in the thinners {the correct one for this varnish}, so the varnish may have started to go off. Also coupled with the fact I was spraying early Sunday morning when it was a little chilly and damp may have added to the disaster.

Hi Phillip. I've always sprayed over a weathered finish especially if using powders just to seal them in. Like I say I'm not doing anything that I've not done before. Someone has advise me to try rubbing Vaseline/Petroleum Jelly to correct the "blooming " {sounds a bit kinky to me though}, but T cut I would think would work better and certainly more manly to use. I would be gutted to have them both sent to the stripping tank, so I'll try anyone's suggestion

Will keep you informed of progress.

Dave

Philip Hall
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Re: A Frosty Finish

Postby Philip Hall » Wed Aug 29, 2018 6:51 pm

Hi Dave,

It’s only that I have only ever applied one coat of varnish on top of transfers, apart from maybe a gloss coat to apply decals on top of, and many times I have just polished the painted surface to apply the decals to. It’s strange how, having done something many times, suddenly it goes wrong.

I have seen this effect occasionally, and it looked to me that the varnish had accumulated on the plank edges, which prompted my comment. I still think that the less coats of varnish you use the better. Powders seem to me to be reduced in their effect by putting varnish on top, and I have found that powders stick pretty well to a matt surface.

I have had similar grief when I tried to use Klear as a varnish. Some folk swear by it, I just swore at it. I never achieved a gloss finish, just satin. I have used acrylic varnish with similar results, and the problem with lots of coats of varnish is that they just build up which I would rather not have, and possibly runs the risk of the effect you have been lumbered with.

I have read in his books that Geoff Kent never uses varnish at all. True, he uses Humbrol enamel to letter vehicles, so no varnish is technically needed, but I imagine his stock gets handled from time to time like everyone’s.

Philip

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Serjt-Dave
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Re: A Frosty Finish

Postby Serjt-Dave » Thu Aug 30, 2018 5:20 pm

Hi Phillip. Your right when you say that a varnish coat over powder does reduce their effect, I tend {or bad habit} to over weather things anyway so it works to my advantage. I've had this effect on matt black paint but never coloured paint. So I think it's a combination of bad paint and poor spraying conditions.

I tried using T-Cut like you said. It worked to a degree but in the nooks and crannies it was less effective. When applying more pressure it removed the paint off the raised details like bolt heads etc more than one would want. Then cleaning over the decals it soon got through the varnish and then removed the decals. Once that happened to me it was game over. I did also try using some Vaseline, again it worked to a degree. Not in removing any layers of varnish but in soaking into it. Only problem was when it started to dry out the whiteness came back.

So it's into the stripping tank they go.

Dave

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Mark Tatlow
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Re: A Frosty Finish

Postby Mark Tatlow » Thu Aug 30, 2018 8:57 pm

Dave, I share your pain....................

img_025711-e1521637806223.jpg
Dodgy matting agent
img_025711-e1521637806223.jpg (329.65 KiB) Viewed 2170 times


Regrettably, I also have to share your solution - lots of paint stripper.
Mark Tatlow

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Serjt-Dave
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Re: A Frosty Finish

Postby Serjt-Dave » Fri Aug 31, 2018 5:17 am

Hi Mark, sorry to see this. How did you manage to do it? I just hope I've not given out some sort of virus over the internet. LOL.

Dave

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LesGros
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Re: A Frosty Finish

Postby LesGros » Fri Aug 31, 2018 5:29 am

Perhaps him upstairs is dropping a hint that you all need to build a winter scene...
:D
LesG

The man who never made a mistake
never made anything useful

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Serjt-Dave
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Re: A Frosty Finish

Postby Serjt-Dave » Fri Aug 31, 2018 5:42 am

Him upstairs better keep his nose out of it. I don't interfere with his stuff and he should not interfere with mine. LOL. Remember Les I know where he lives. :D

Dave

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Guy Rixon
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Re: A Frosty Finish

Postby Guy Rixon » Fri Aug 31, 2018 10:35 am

I think it's related to outgassing of the varnish as it dries. I once sprayed Railmatch varnish (which is generally reliable if one can get the spray head on the can to work), got a frosty finish and wept bitter tears. By the time the varnish dried - many hours, as this was in winter and the room was cold - the frosting had gone. I think that bubbles of propellant had formed in the varnish and later dispersed. It's possible that a matt surface impedes the outgassing.

Moral: going off for a long sulk may actually be the right thing if it all goes wrong.

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Serjt-Dave
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Re: A Frosty Finish

Postby Serjt-Dave » Mon Sep 03, 2018 8:49 pm

The brake van didn't do too well in the stripping tank. Apart from the bits that fell off, one part {a lower step support} has gone AWOL. We have the technology to rebuild it, well a tube of superglue anyway.
20180903_193554.jpg

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Guy Rixon
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Re: A Frosty Finish

Postby Guy Rixon » Tue Sep 04, 2018 9:08 am

The airbrush-cleaning solution "Liquid reamer" acts as a strong paint-stripper. It shifts acrylic and enamel paints very easily and also disrupts Halford's primer enough that it can readily be "dusted" off with a fibreglass brush. I don't know what this product does to plastics (I can find out if anybody wishes to know), but it's sprayed on in small volume and quickly cleaned off, so has less chance to rot the body work. Having discovered this, I'd be reluctant to soak a model in stripper.

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kelly
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Re: A Frosty Finish

Postby kelly » Tue Sep 04, 2018 9:58 am

I have only ever seen something similar in the past when i used to model in aviation subjects, it was usually due to one of the following:

different brands don't always like each other
enamels and acrylics can react with each other
paint brands change the formulas over time

Sometimes I found it occurred from paint from the same supplier!
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