Help with Humbrol Clear Matt

[Duncan Macdonald]

Hi Guys

I am having trouble with my Humbrol Clear Matt varnish. When I apply it to a model it goes on fine but after its dried it leaves white marks all over the model no matter how much I stir it. Whats going wrong?????????

[John Symmons]

Hi Duncan

Here we go again. Just check back in this forum and the General one & you'll find you're not alone. Why Humbrol continues to market this matt varnish is beyond me & even more puzzling is why people continue to buy & try and use it. Maybe if you thin it down a lot & use thin coats it might work better.

Personally I've given-up on Humbrol paints & varnishes, Even model shops in SA refuse to carry the range, I can recommend Vallejo matt varnish; as I've often said before; I know it's acrylic but it goes on beautifully & needs little or no shaking, give it a try you won't be disappointed. Then you can throw out all those tins of Matt Clear varnish & your troubles will be over.

Remember we do this for fun.                 John the Pom

[Kenneth ONeill]

To save you a search, this means there's too much flat base in the mix for the batch.

[Duncan Macdonald]

Hi 

Thanks very much for your help and advice. Really appreciated!!!!

[Braille Dave]

Thin it down to about spraying consistancy (think semi-skimmed milk) then it'll be fine. I only use Humbrol mattcote, and have been pleased with the results.

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The Mammoth Major was sprayed.

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The Jeep brushed- both with the same consistency. TBH I thin all my humbrols down to spraying consistancy, I'd rather put three coats on and achieve a fine finish, than one thick one.

[Cyb]

I have effectively ballsed up a B1-B bomb bay because of this varnish........

 

I've been chucking in so many thinners and scrubbing away that there should scarcely be any varnish left, and there doesn't seem to be because I'm hitting paint now and I don't know how long I can continue before wiping away hours of work....

I tried just putting a wash over it, but the wash activates the base or whatever is in the varnish so it only looks like it disappears.

I didn't even use that much to begin with, it was barely enough for a light dusting and I'd spent ages shaking and mixing it, I applied it the same way I applied many other varnishes both matt and gloss and I've never had a white coating as bad as this.

I am currently slapping thinners on and then putting it under a lamp to speed-dry and check if the whiteness comes back, but it always does.

 

It's not particularly humid, I used a lamp to dry it under some heat because england never has any useable sun and I still got the white marks.

At the rate I'm going I'm going to have to end up repainting the two bays almost entirely. It wouldn't be as much of a problem except they are already mounted. 

Well lesson learned for the future I guess. Never buy another Humbrol Matt Clear as long as you live, and only use the stuff I have now on white stuff, which is almost never. 

 

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Before when there was no varnish, not the best work ever because i'm still learning and using brushes, but it took a while an I was very pleased with how it turned out.

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What it looked like after I tried to neaten it up. 

Like I say since then I've been attacking it with thinners, so it has gotten a lot better, but I'm also removing paint and as the bay's main colour is white im getting smudges, which I can claim adds to the effect of grease and grime, but I'd rather make it grimy in a controlled way once I am happy with how I want it to look, than have to think every time I look at it "Yeah, that looks really bad, like I can't paint at all". 

[peebeep]

Hi Cyb, I would suggest applying a clear gloss coat, it should kill the sugar frosting. This would always be the first thing I'd try in the event of a matt coat turning to frost. Once the frost is sorted re-coat to get the desired sheen. Personally I use Tamiya Flat Base mixed with an acrylic varnish (Klear for me whilst my stock lasts), that way I get to control the amount of matting agent. Up to 20% Flat Base by volume for satin, up to 25% for dead flat, no more than 30% because it will likely frost up.

[Cyb]

Hi Cyb, I would suggest applying a clear gloss coat, it should kill the sugar frosting. This would always be the first thing I'd try in the event of a matt coat turning to frost. Once the frost is sorted re-coat to get the desired sheen. Personally I use Tamiya Flat Base mixed with an acrylic varnish (Klear for me whilst my stock lasts), that way I get to control the amount of matting agent. Up to 20% Flat Base by volume for satin, up to 25% for dead flat, no more than 30% because it will likely frost up.

Thanks Paul, I may have to take that into account for my next project, or if I do another shop for the current one, I managed to get off the worst of it, and there is now a dull dusty look to the interior of the bay, I'm lucky that the circular bomb carriers and the bombs that go with it cover over the worst of the damage, so it's not too bad, I just wish it didn't have to turn out that way.

I originally got the matt finish because I was wary of having a model that glistened in the light when it most probably should only have a dull sheen, would gloss be appropriate to get a matt finish? 

On the upside to the whole affair I was a bit overzealous with the black wash on the detail of the bombs, a lick of matt coat and it frosted up to a whitish grey, which looked a lot better, so I now have a use for it in the mean-time, that being decreasing the strength of black on white. In fact I may go back to my previous project which I used as practice for panel highlighting and give it a matt coat to fix the mess I made on the second item.

Once again, my thanks, I will keep this in mind for the future.

[Kenneth ONeill]

@Cyb I can't be certain about the "bone" but internal bays on USN types have been painted gloss white since at least the 1950s.

[Ratch]

 The gloss should get rid of the frosting, then you need to Matt again for the desired finish.

[Cyb]

@Cyb I can't be certain about the "bone" but internal bays on USN types have been painted gloss white since at least the 1950s.

That all depends on what the gloss is, I'm using enamel paints, and depending on how many layers you do and what colour it is, there will either be a dull sheen, it will be gloss, or it will actually be matt (In my experience anyway sometimes "Matt" paints act like Satin, and vice Versa). 

This might seem like it's not relevant, but the box is old, and I've been referencing some colours from the instructons with colours I could find in pictures, and some of the time it doesn't add up.

In the instruction manual it calls for a Satin Matt white. That's what I've been using since after testing it and holding it up to a computer screen to check.

What I have found is that sometimes, like you say, it is quite clearly a gloss coat 

 

http://www.airport-data.com/images/aircraft/small/000/160/160248.jpg

 

Like this for instance. But there are other times when it appears to be more like a matt.

So I've been using Satin Matt because it gives a pretty nice shine to it without being completely over the top, the seats I painted gloss were very shiny until I put a wash on them, so I decided I'd stick with Satin Matt because it worked, and I could matt/gloss depending on how I felt with it.

This, coupled with finding more matted "dirty" pictures than "Clean" glossy ones I decided to get the matt coat thinking it wouldn't be any trouble, turns out it was quite a bit of trouble. 

[fishplanebeer]

It seems that experiences vary with MattCote but all I can say is that I've used it in anger twice recently, albeit to restore two 1950's Hornby Dublo locomotives, and on both occasions it has worked a treat without any spotting or discolouration.

 

That said having read the posts beforehand on the subject I was VERY careful to thoroughly mix the varnish with a high quality modelling thinner (not white spirit or similar) and then shook the mixture vigorously for a couple of minutes before putting into my airbrush.

 

Hope this helps.

 

Kind Regards

Colin.

[peebeep]

The Cotes used to be the best available and I only stopped using them because I drifted towards other media and techniques that had been recommended to me. Having said that they could be quirky and you need to know a couple of wrinkles to get the best out of them. There's two points from posts here that stand out, to me. Dave's suggestion to thin to airbrushing consistency regardless and Colin's one of using high quality thinner. I'll add one more for when using Satin or Matt Cote, use a 'soup' of the varnish, your chosen thinner, plus a dash of cellulose (lacquer). I picked this up from an article by the master modeller Peter Cooke in one of his articles in Scale Models (back when God was a boy) and it works. It helps disperse the matting agent much more efficiently due to being a bit 'hotter' and despite the usual assertion that it will craze the surface of plastic or other paints, it doesn't.

 

Having said all that, there's no doubt in my mind that acrylic varnishes are the way to go.

[A. Smith]

I realize this is an old thread but seeing that its a subject that keeps coming up among modelers I will give the answer to this.

A frosted matt finish can happen with any clear matt varnish. There isn't a problem with Humbrol Clear Matt Varnish in itself, it just has to be applied correctly. I do not thin the varnish normally, I use it straight out of the bottle except on very hot days, but it can be thinned if desired.

If you apply a clear matt to a matt paint surface, it will most likely frost up. Spray a gloss clear coat first, let it dry and then apply your clear matt. In order to correct a frosted finish, spray it with clear gloss and then re-apply the matt over that once dried. It is not necessary to get a shiny finish with your gloss coat, all you are doing is sealing the surface so that the clear matt coat will not absorb into it which is what causes the issue.

In order to demonstrate this I purposedly did not gloss clear coat this Lysander's cowling before applying Humbrol Clear Matt Varnish.

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[SlowHandClap]

I realize this is an old thread but seeing that its a subject that keeps coming up among modelers I will give the answer to this.

A frosted matt finish can happen with any clear matt varnish. There isn't a problem with Humbrol Clear Matt Varnish in itself, it just has to be applied correctly. I do not thin the varnish normally, I use it straight out of the bottle except on very hot days, but it can be thinned if desired.

If you apply a clear matt to a matt paint surface, it will most likely frost up. Spray a gloss clear coat first, let it dry and then apply your clear matt. In order to correct a frosted finish, spray it with clear gloss and then re-apply the matt over that once dried. It is not necessary to get a shiny finish with your gloss coat, all you are doing is sealing the surface so that the clear matt coat will not absorb into it which is what causes the issue.

In order to demonstrate this I purposedly did not gloss clear coat this Lysander's cowling before applying Humbrol Clear Matt Varnish.

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Instead of applying two different types of varnish to get the humbrol matt to work, why not just get a matt varnish that works properly in the first place?