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Crackle finish


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I have been trying to work out a consistent way to produce a good matt or eggshell finish.

In most cases I have started with a Halfords primer to provide the base coat. Where appropriate, I have applied a Precision Paints colour. I have then applied Klear as a base on which waterslide transfers can be applied. The transfers have then been put on using Microsol to soften the carrier film and encourage them to blend in.

So far so good, but this is where it gets exciting! When you the apply a varnish to seal it all in, occasionally you get a crackle finish. By this, I mean that the final surface does not come out with a nice, smooth, semi matt sheen; it comes out looking like orange peel - only rougher. At this point you tend to say something like "oh bother", as you end up having to strip off several evenings' work and start again.

I have tried using a test piece before I do the item that I have been building and have concluded that the villain of the piece is Games Workshop's aerosol varnish. Sometimes it comes out perfectly; sometimes it evidently reacts with something in the previous layers and produces an instant disaster.

Can anyone suggest, please, what might be going wrong and how I might avoid it for the future?

Many thanks

Eric

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  • 2 weeks later...

and have concluded that the villain of the piece is Games Workshop's aerosol varnish. Sometimes it comes out perfectly; sometimes it evidently reacts with something in the previous layers and produces an instant disaster.

Can anyone suggest, please, what might be going wrong and how I might avoid it for the future?

Many thanks

Eric

 

 

 

 

Stopping using Games Workshop's aerosol varnish, would be a good starting point. Try Ronseal varnish can be brushed or sprayed, it is acrylic so should be OK with all paints. You can mix the varnishes to get the finish that you want.

 

OzzyO.

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Hi Eric,

My experience with 'Kleer' is after applying your decals you should apply another coat of 'Kleer' to seal them in! My armour-modelling colleagues always sealed their weathering in- and after each stage- sealed it in with further applications. I also used the same technique when I was aircraft-modelling!

If you have already done this then!!!!!!!!!!!!!!!!!!! :(

Bill.

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Guest jim s-w

as you end up having to strip off several evenings' work and start again.

 

Hi Eric

 

Are you doing all that in several evenings in a row? That might be your problem. I try to leave a week between diffent types of paints, You seem to be OK up until the last layer of varnish so try leaving your week just before it.

 

HTH

 

Jim

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Eric,

 

I found that alot of the spray varnishes ready to go off the shelf, are the worse things you can purchase.I good friend of mine spent ages respraying a Clas 60 into EWS colours to find when he applied the final varnish coating, you may as well have put paint stripper on it. It lifted the paint,and obliterated the decals he had applied.

I use Humbrol Satin Cote ( Yes,Cote is spelt that way on the bottle ),diluted 50-50 with lighter fuel

2 advantages with lighter fuel, its decal friendly, and a fast drier, so you can re coat within an hour.

Some of the thinners based varnishes are too 'angry', and will obviously just lift off your decals,and even the paintwork

 

John ;)

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Does the "crackle finish" only occur on the decals or generally all over the model?

 

If it occurs on the decals only, then try sealing them with kleer, if it is all over you are probably simply applying too much varnish, aerosol cans are horribly imprecise. Try ghosting the varnish on in really thin layers. I've not tried GW varnish but their products are usually decent, have a look on some of the wargaming forums to see if this is a common problem with this product. The other thing to do is try to spray on a warm dry day with low humidity and warm the can first by standing it in WARM (not hot) water for about ten minutes. Always spray away from the model with your first burst on the can and don't go too close.

 

Good luck.

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I've had reports of GW varnish lifting my transfers, especially if they have metallic pigments in them. I concluded something in the solvent mix was to blame. If using a spray (aerosol or air brush), a dry coat or two that will seal it and hold it all together may help, prior to something a little heavier to get a better finish. Transfers never like to get too wet with acrylic solvents. simon.

 

 

Does the "crackle finish" only occur on the decals or generally all over the model?

 

If it occurs on the decals only, then try sealing them with kleer, if it is all over you are probably simply applying too much varnish, aerosol cans are horribly imprecise. Try ghosting the varnish on in really thin layers. I've not tried GW varnish but their products are usually decent, have a look on some of the wargaming forums to see if this is a common problem with this product. The other thing to do is try to spray on a warm dry day with low humidity and warm the can first by standing it in WARM (not hot) water for about ten minutes. Always spray away from the model with your first burst on the can and don't go too close.

 

Good luck.

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Thanks to all those who have responded to this topic. Some of the comments have caused me to go back and look through the various swatches that I have prepared previously to try to isolate the problem. One, at least, shows that the Games Workshop varnish directly affected the transfers themselves and left the surrounding area untouched. The transfers were home made, using blank transfer film and an ALPS printer, so it is possible that the interaction is with the particular kind of transfer paper that was used in that batch. An overcoat of Klear might solve that. However, on another disaster, the reaction was with the paintwork itself, which, I am pretty sure, had been coated with Klear. From memory, another of the bad experiences was with a loco that had been painted months previously - so I am pretty sure that the issue was not with paint that was not thoroughly dry!

As has been suggested, the obvious solution is to stop using Games Workshop varnish - which I have done. A can each of Humbrol matt and satin have been used for the latest swatches and have demonstrated no untoward effects, so I attach below examples of the vehicles that have been varnished over the weekend.

post-9472-1281296331_thumb.jpg

This fine example of the South Eastern Railway's rolling stock used matt, and the unexpected surprise was the rather faded effect where I obviously overdid the varnish. Since I intend to weather it a fair bit, the fading is a bonus - but nonetheless a warning to keep the spray to a pretty light mist.

post-9472-128129638365_thumb.jpgpost-9472-128129640677_thumb.jpgpost-9472-128129643453_thumb.jpg

The three Brighton NPCS vehicles used the satin varnish and have all come out quite nicely - albeit pristine. The challenge now is how to weather them - given that, somewhat inconsiderately, there do not appear to be any colour photos to illustrate how LBSC varnished mahogany vehicles of the 1870s would look after a period in service. My first thought is to have a look at photos of the Bluebell Line or I of W steam railway to see how their vehicles weather when they are in traffic. (NB I had not spotted quite how far some of the brake blocks are from the wheels until I looked at these photos. Absence of buffers on the Grande Vitesse van is deliberate - the wobbly springs were not.)

Just as a final point. The next vehicle to be painted is a family saloon which has some rather exotic designs engraved on the glazing - again reproduced on an ALPS printer. I thought that a coat of Klear might help to prevent the plastic sheet from misting over when it came into contact with adhesive. Wrong. It reacts adversely with the ink from the printer and the white designs are now smeared across the glazing - misting it far more effectively than any glue ever could! Oh bother - or words to that general effect.

 

Eric

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  • 4 weeks later...

This fine example of the South Eastern Railway's rolling stock used matt, and the unexpected surprise was the rather faded effect where I obviously overdid the varnish. Since I intend to weather it a fair bit, the fading is a bonus - but nonetheless a warning to keep the spray to a pretty light mist.

The reason for this is that matt varnish is not truly transparent in the way gloss varnish is. The matting agent consists of tiny white particles (possibly talcum powder) which breaks up the smooth surface to give a matt finish. If you apply enough of it then a whitening starts to become apparent.

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