Varnishing with airbrush issues-help-Updated

[Defiant911]

In my experience, gloss varnish does tend to 'pool into globules' slightly...and you have to apply a bit more than you feel is fight to get an even finish. I might be doing something quite wrong, but have only had one issue of spraying too much, where it ran off. Matt varnish (for me) reacts very differently and I spray pretty sparingly.

PSI, I just guess until the flow looks right, as with the distance from model, depending on the surface area, but I would say 3-4 inches away. I use a slow sweeping method back and forth, starting and finishing away from the model.

Thanks Jack, maybe that’s the key, to spray more to fill the voids as it were. What pressure do you use to spray at. There seems to be a fine line with not enough pressure and the spray pattern becomes less consistent to too much pressure and blasting the model. I have been experimenting but as a rule of thumb found my self setting the psi between 15-20 psi but too be honest this seems to be subjective. Carl

[Jim R]

Hi Carl
It does indeed look as if the varnish has pooled on the surface - I imagine a water based varnish on a slightly oily/greasy surface. My thoughts would be .....
Try adding a drop of washing up liquid to the varnish to break the surface tension. This will only help if the varnish is water based. If the varnish is solvent based you'll just get a gloopy mess.
Try spraying a very light, mist coat of varnish and let it dry thoroughly before spraying the actual gloss coat.
Make certain the paint/weathering is totally dry. Leave at least 48 hours in a warm place before varnishing.

Just a few thoughts which may help.
Jim

[JR]

Carl.
Just reading what Jim has said sounds about right to me. I'd spray in very thin coats, letting each one dry, and increase the pressure to 20 psi.
The second photo by the way is great, nice weathering and not over done.:thumb2:

[Guest]

I agree with the above too, the varnish really didn't want to be on that surface so it's pooled up. Maybe the AK stuff hadn't thoroughly dried, or handling the model to apply it has left greasy finger prints on the surface.

Try spraying a very light, mist coat of varnish and let it dry thoroughly before spraying the actual gloss coat.

This would be my approach, and the one I use all the time in my day job as well. What we call "grip & rip" or the Yanks call "tack & whack". The light initial gives the wet coat something to grip to so it's much less likely to separate or pool up.

[Defiant911]

Thanks all for the great advice. I have an almost finished Messerschmitt to weather and gloss shortly so I will take this approach and hopefully achieve a better finish. The last time I made a model was about 34 years ago and there’s a lot more products on the market these days. It’s quite difficult to know what’s best. However with an abundance of YouTube tutorials and the help of this forum I hope to improve with each model and let’s face it, like most of us I’m going to have plenty of free time indoors at the moment.

[Defiant911]

Carl.
Just reading what Jim has said sounds about right to me. I'd spray in very thin coats, letting each one dry, and increase the pressure to 20 psi.
The second photo by the way is great, nice weathering and not over done.:thumb2:

Thanks John, it would certainly be easy to get really carried away with weathering but it is great fun to do even if it’s far from perfect as yet. Practice hopefully will make it better with each new model.
Carl

[Jack L]

Try on a coke bottle or something? Prime it, add some weathering as you usually would and then try a couple of varnish methods....saves potentially spoiling a model you are happy with.

[Defiant911]

Try on a coke bottle or something? Prime it, add some weathering as you usually would and then try a couple of varnish methods....saves potentially spoiling a model you are happy with.

Yes, that’s a good idea, I had thought about finding some test pieces. I must rifle through the garage this weekend for bits to spray Practice on.

[Defiant911]

Hi all, I decided to try a different varnish as an experiment. I went for the Vallego gloss varnish. This went on quite different from the Humbrol. I needed to spray more to achieve the even coating. The plus side is it seems to flatten off very well and you can almost watch any globules disappear in front of your eyes. However, the gloss level doesn’t seem as high from the first coat but I guess that could be built up over two or three if necessary. My main concern was I sprayed over the entire model including the cockpit and the glass work looks slightly opaque and not clear anymore . Is this normal for this make of varnish or do I need to spray more coats to bring the gloss back also.?

regards Carl

[rtfoe]

Hi Carl, I've never sprayed varnish directly onto canopy or clear parts knowing that it will cloud it and don't know how to remove it or shine it. The only varnish I dare use on a clear part is Future and I dip it in and let it drip dry on a piece of tissue...no airbrushing or even trying to paint the varnish with a brush. I have seen many make the mistake of airbrushing the varnish over their canopies without masking and ultimately loose transparency.

Maybe someone here may have a solution.

Cheers,
Richard

[Defiant911]

Hi Carl, I've never sprayed varnish directly onto canopy or clear parts knowing that it will cloud it and don't know how to remove it or shine it. The only varnish I dare use on a clear part is Future and I dip it in and let it drip dry on a piece of tissue...no airbrushing or even trying to paint the varnish with a brush. I have seen many make the mistake of airbrushing the varnish over their canopies without masking and ultimately loose transparency.

Maybe someone here may have a solution.

Cheers,
Richard

Hi Richard, oddly enough I sprayed the canopies with the humbrol gloss before and they stayed clear so consequently I did the same with the Vallego.
i guess the Lesson is clearly not all varnish react the same. I could probably remove the canopy and try to carefully clean with thinners but it may end up going from bad to worse if I’m not careful. I’d be interested to hear if there are any simpler solutions. Obviously in future I will add the canopies after glossing or else mask off.
carl