Airbrushing varnish: advice sought

Philip Hall
Posts: 1288
Joined: Mon Aug 10, 2009 7:49 pm

Re: Airbrushing varnish: advice sought

Postby Philip Hall » Fri Mar 11, 2016 11:52 pm

I would also make the point that it is not just useful to warm the rattle can, but also useful to warm the model, before and after spraying. I do this with a hairdryer, played over the model briefly before applying the spray. Immediately after any spray an, I return with the hairdryer. In the case of Dullcote (or any other spray varnish for that matter) I can see the varnish dry off before my eyes, and in the case of Dullcote, usually dead flat and very fine.

I also have done this outside the kitchen door in the cold, warming the model first inside with the hairdryer, on with the varnish outside in the fresh air, and quickly back into the warm kitchen for another blast with the hairdryer.

Keep persevering, don't give up!

Philip

essdee
Posts: 380
Joined: Sat Nov 29, 2008 4:47 pm

Re: Airbrushing varnish: advice sought

Postby essdee » Sat Mar 12, 2016 11:26 am

Thanks guys for the support and suggestions -the fishing sounds remarkably tempting just now.

David: Thanks for the tip that 10" is still too close; I had started the spray 'off' as you suggest and immediately realised that a fast pass was needed - but clearly not fast enough. That's an excellent point you make, about the instinctive familiarity with one's airbrush, and the 'unknown' factor of any spraycan. Clearly I am now one step up the learning curve on the Dullcote, but from my limited trials yesterday, when I moved the can backwards to some 14/15", I was still applying a great flood, and was entering 'spotty coverage' territory. Sooo...somewhere like 13", and an even faster pass, will be my next attempt. There is obviously going to be an enormous paint wastage factor.

Doug: thanks also; yes I have established 'regimes' for my cellullose spraying and am pleased with where I have reached - but this Dullcote can is a whole new ballgame. I walked away from the workbench yesterday, and today will be spraying black satin cellulose from an airbrush freshly cleaned from previous cellulose, and ready for an initial flush/test for crud/ routine application, I hope? Once that is completed, I will strip down and clean fully, before starting afresh with Dullcote from the jar, spirit thinned (or not, it seems?), until I am happy that I can get it on smooth and flat. Only then will I go back to the 'rattlesnake' spraycan and have further trials. At least, with two jars of Dullcote, I have plenty to experiment with at length in the airbrush, unlike the limited supply in the tiny spraycan.

Philip: yes I always warm the piece before spraying, as I am aware the metal surface can otherwise still be significantly colder than an ambient room temperature raised to 21+ degrees. I then check for any debris on the surface and give a gentle waft of air before applying paint. However I have not warmed again after spraying, for fear of introducing more grot; my aim is to get the painted piece into a lidded container as soon as practical. But I will trial your method of drying off the lacquer and see what goes.

Thanks all, I will report back later on when I have had another go...

Best wishes

Steve

(Waders still in the cupboard...)

jasp
Posts: 103
Joined: Thu Dec 04, 2008 9:24 am

Re: Airbrushing varnish: advice sought

Postby jasp » Mon Mar 14, 2016 1:19 am

Steve
Sorry my suggestion has been such a disaster.
As you know, I have used the Dullcote from the can, into a jar, diluted, in an airbrush with good results. I have also used it direct from the can when it appears to go on quite thick but when it dries looks fine. No problems over HMRS Methfix.
Please don't consign your Dullcote to the "Bring and buy" I will take it off your hands for an appropriate financial consideration.
Hope your experience with the bottled stuff is better, if not I will have that too.
I should, perhaps, add that I have been painting and Dullcoting in the garage at nowhere near 21Deg. with satisfactory results. Probably luck, certainly not good judgement.
See you at Wakefield, hopefully with some wagons finished with Dullcote. I will try to remember which I do direct from the can and those with the airbrush.
Jim P

essdee
Posts: 380
Joined: Sat Nov 29, 2008 4:47 pm

Re: Airbrushing varnish: advice sought

Postby essdee » Mon Mar 14, 2016 8:58 am

Thanks Jim,

Not to worry! I suspect that in the airbrush, thinned or not, the Dullcote can be controlled to do the job expected; I did not have time to get onto the varnish trials over the weekend, as priority was to get the loco and tender bodies done with the cellulose satin black - which did much to restore my confidence! I plan to finish any cellulose touching-in today, before cleaning the airbrush for further varnish trials on test pieces. Assuming success with those, I would keep the can anyway and use decanted as you suggested. But if you are stuck for a supplier I could get you Testors from local shop before we meet at Wakefield?

I went back to the 'flooded' test piece yesterday, and explored gentle rubbing with a cotton bud. This removed some of the patchiness but also restored a slight sheen to the surface, not un-prototypical, especially when using only vertical strokes -rather like a stage in weathering? Could be useful.......

See you soon!

BW

Steve

essdee
Posts: 380
Joined: Sat Nov 29, 2008 4:47 pm

Re: Airbrushing varnish: advice sought

Postby essdee » Sun Apr 24, 2016 4:46 pm

Having raised the question of using Testors Dullcote over acrylic paint, on my more recent thread concerning non-drying Humbrol enamel on a buffer beam, I have referred back to this thread, and I see that I have left my experience with Dullcote open-ended. Sorry about that, but an impending Scalefour North deadline, with the need to vacate the paint shop for the erecting shop, intervened.

However; as indicated in the last posting, I did indeed experiment with Dullcote in my airbrush, with much better results than those I obtained on my first foray with the spraycan version. From my notes, I see that I started with a spraying of the neat Dullcote, which gave the predictable halo of a dried halo around the wet area of varnish.

After experimenting with 2:1 dilution (Dullcote: white spirit), which proved reasonably tractable on flat areas, I progressed to a 3:2 dilution, ie. greater dilution, which flowed more readily and would be valuable for those awkward under-boiler and cab/firebox angles.

Warning: I did need to be assertive about removing a white residue of flatting agent when I immediately stripped down the airbrush for cleaning.

So I will indeed be persevering with Dullcote, airbrush sprayed and thinned with white spirit. A lovely matt finish that covered Methfix transfers neatly, and could be given a gentle 'buffing' with cotton bud or mop to suggest that the engine cleaners had been somewhere near it.

I will give the spraycan version another test some time, when I have some to spare; thanks again to all for the advice on distances, warming etc.

Best wishes,

Steve

User avatar
David Thorpe
Posts: 819
Joined: Tue Oct 21, 2008 11:13 pm

Re: Airbrushing varnish: advice sought

Postby David Thorpe » Sat Feb 25, 2017 9:44 am

Having at last applied transfers (lettering and lining) to a variety of locos and coaches I have built over the last few years, I decided that some varnishing would be a good idea both to protect the transfers (Pressfix) and to brighten or dull down the various paint finishes - Halfords Satin Black for locos, Precision paints (dull) for coaches.

I had the same experience as Steve using a can of Testors Dullcote, fortunately on a couple of test pieces. I used the same technique as I'd use with a Halfords rattle can but the spray was far more intense than I had anticipated and I was left with a model from which the varnish was literally dripping off. Cleaned off, I tried again, this time using a very fast single pass of the can and the result was better. I'll try some more test pieces before risking one of my locos with this varnish.

My coaches were largely airbrushed with Precision enamels (dull) and I want to bring a bit of sheen to some of them, so I acquired a tinlet of Precision satin varnish, ready thinned for airbrush use. Tried out on one coach, this went on beautifully, but has dried matt and has not provided the sheen I was looking for. While I can maybe use this instead of Dullcote on my locos, I wonder if anyone has any tips as to how to achieve a satin finish with this varnish, or has any recommendations for something to use instead. I did stir it vigorously beforehand using a homemade atatchment on an electric drill but maybe not for long enough?

I should perhaps add that neither of these varnishes had any adverse affect on the transfers.

DT

User avatar
Will L
Posts: 1656
Joined: Sun Jul 20, 2008 3:54 pm

Re: Airbrushing varnish: advice sought

Postby Will L » Sat Feb 25, 2017 10:03 am

David Thorpe wrote:I wonder if anyone has any tips as to how to achieve a satin finish with this varnish, or has any recommendations for something to use instead. I did stir it vigorously beforehand using a homemade atatchment on an electric drill but maybe not for long enough?


In my experience a failure to stir enough produces a glossier finish, as it is the matting agent that tends to settle out in the can.

Could it be that the coat was a little too thin (both in consistency and in the amount applied), and was drying on impact? This can produce a mat effect.

Will

User avatar
David Thorpe
Posts: 819
Joined: Tue Oct 21, 2008 11:13 pm

Re: Airbrushing varnish: advice sought

Postby David Thorpe » Sun Feb 26, 2017 1:22 pm

Thanks, Will. I suspect that it's just that I'm being a bit too impatient. I've been reading up about it and it seems that two or three coats may be needed, so I've airbrushed a second coat today and will probably do another later in the week (Precision varnish takes about a couple of days to dry properly).

DT

tmcsean
Posts: 32
Joined: Fri Jul 25, 2008 3:34 pm

Re: Airbrushing varnish: advice sought

Postby tmcsean » Mon Jul 30, 2018 11:28 am

For matt varnish I have been using Marabu Mattlack aerosol for many years with good results and no problem. Its advantage is that Marabu cans are very often stocked by art shops and those catering to graffiti artists, and is cheaper than Dullcote, which is aslo very good and, in my experience, risk free. Marabu spray pain is also pretty good but colourwise it can be a bit of a lottery since the coloured top to the can isn't always a brilliant guide to what comes out of the nozzle.

Tony

Alan Turner
Posts: 548
Joined: Sun Jul 20, 2008 4:24 pm

Re: Airbrushing varnish: advice sought

Postby Alan Turner » Mon Jul 30, 2018 12:14 pm

I use Precision varnish. For satin I use two parts gloss and one part matt. You must use the varnish thinners however. To use ordinary thinners runs the risk of getting a white bloom.

regards

Alan

User avatar
Andy W
Posts: 819
Joined: Thu May 21, 2009 8:11 am

Re: Airbrushing varnish: advice sought

Postby Andy W » Mon Jul 30, 2018 12:52 pm

I’ve started air brushing Winsor and Newton gloss varnish. It sprays really well and needs no thinning - so no worries about mixing to the right consistency. It’s white spirit based, but if you want one with a water base then Microscale Micro Gloss is great. It looks milky but dries clear. Again needs no thinning.

In both cases one coat gives a dullish finish, additional passes increase the gloss.
Make Worcestershire great again.
Build a wall along the Herefordshire border and make them pay for it.

User avatar
Guy Rixon
Posts: 602
Joined: Sun Mar 27, 2011 6:40 pm

Re: Airbrushing varnish: advice sought

Postby Guy Rixon » Mon Jul 30, 2018 8:12 pm

That's interesting Andy. What pressure are you using for your varnishes, and what size of nozzle?

User avatar
Andy W
Posts: 819
Joined: Thu May 21, 2009 8:11 am

Re: Airbrushing varnish: advice sought

Postby Andy W » Mon Jul 30, 2018 9:23 pm

I spray enamel paint using an Iwata Eclipse which has a 0.35 mm needle, however for varnishes I switch to an Iwata Neo. This is partly because I still don’t trust varnish in my number one brush, but also because it has a 0.5 mm needle. This gives a wider spray cone which helps me drop the pressure to around 12 - 14psi. Make sure the model is lit well so you can check that the varnish is landing wet. I spray just 2-3 inches away - but keep it moving. Once an area ha a coat move on. It’s better to do a number of light coats rather than 1 heavy pass - that way you avoid flooding and runs.

It’s a good idea to have a few models ready to spray so that you can move on and keep production moving rather than stop and clean your brush every few minutes. That way you’re not tempted to keep spraying the same piece for too long.

And cleaning after using varnish is mandatory!

As others have said practice and patience are essential.

HTH
Make Worcestershire great again.
Build a wall along the Herefordshire border and make them pay for it.


Return to “Painting and Weathering”

Who is online

Users browsing this forum: No registered users and 1 guest