Removing Airbrush Runs/drips

[Jamiel]

I have managed to create a couple of runs, (near) drips when airbrushing and would appreciate advice on how to solve the problem.
 

I have used a Phoenix Precision PQ5 grey primer, in the past I used Halfords primer which covered well but gave a slightly sandpaperish finish. The Phoenix is much smoother, but when applying the first coat of Phoenix’s DMU Green (Dull) I didn’t compensate for the smoother finish than I was used to and in a couple of places have drips/runs forming.
 

I did sand (Wet & Dry) down a couple of very slight runs in the primer, and one of these places is where the problem has persisted.
 

I used wet and dry to sand off the runs on the green spray and resprayed, but I can say this has been less than successful, please see the two images below. I have lit these to highlight the problem areas, even so I can see then when I turn the bodies to the light.




 

95% of the spray has gone well, it is really just these two areas that have not fared well, so I really don’t want to strip off all the paint and start again. I fear that might also strip off some of the plastic details I have superglued on as well.
 

T-cut might be an option to smooth the runs with a less drastic finish than Wet & Dry, but before trying anything else I though it worth mining the wealth of knowledge here on the forum.
 

I will also be applying a light weathering to the DMUs, but nothing like I would apply to a goods engine which would easily cover the areas.

Any advice would be gratefully appreciated.

Jamie

[ROSSPOP]

hi Jamie

 

Did the same as you recently on a pair of 7mm coaches.

 

leave all alone for at least three days for the paint to fully cure.

 

use a very fine abrasive and gently rub the problem areas down so that the `under coat` is just showing through. ( at the same time you can gently rub down those bits of debris you have got in your paint finish). Clean up and give a blow over with your airbrush minus paint of course.

 

Then re-airbrush the whole coach side using carefully thinned paint ( should be like milk consistency). dont hold you airbrush too close to the model and and dont pause your airbrushing as you travel down the coach side or it will happen again.

 

Then if you can, a final finish with a satin varnish ( but dont go anywhere near Humbrol products)

 

Cheers

 

John

 

PS see if you can find the runs on this one I had to rescue in the same way with two colours!!!

 

 

 

[Jamiel]

Thank you John.

You coach looks lovely. I will wait and then gently rub down the afected areas.

Jamie

[Barry O]

Jamie

 

keep the coaches warm as it will help to get the paint to harden.  ( I have been known to bake a loco in a cooling oven ie with the oven heated to 50 degrees then switched off).

 

I use very fine wet and dry before giving the area an over spray with the original colour.

 

Baz

[michl080]

Jamie,

 

unlike mentioned above, I would strip all paint and restart from scratch. On my first self painted loco, I stripped the paint three times until the result was OK. I think that sanding the runs down is too dangerous. It happens easily that some details in close proximity disappear.

 

Michael

[Jamiel]

Thanks Michael.

I am not keen to remove all the paint as there is quite a lot of detail added with plastic and glued on which I think is likely to strip off as well. Removing all the paint can be kept as a last option, but given that trying the method suggested by John and Barry can always be done as first option I will try that but keep your option if that fails.

I will post photos of the result when I have worked through the options.

Thank you for the suggestion, it is always good to hear a spread of ideas.

Jamie

[Jamiel]

Thanks to everyone for their help. Here is how the DMU bodies are looking now. I used the sand and respray with thin paint, three passes so as not to cause any new drips. I have also sprayed the roofs with their first coat of Phoenix Precision roof dirt.
 

Overall, I am happy with the results. It is not perfect, but the DMUs will be weathered so I am happy to use that to disguise any issues. The run that was in the primer between the windows was the most persistent but again I will live with that.
 

My next issue is roof panel detail. I have some lining tape which I have used around the shaped cab panel, but I feel it is too thick for the fine detail I want on the rest of the roof. I am thinking of using black lining transfers and then airbrushing over those. I will post some results when that is done.
 

 

Thank you for the replies, it was very helpful. The bottom line is do several thin coats of both primer and top coat rather than one heavy one of either. The Halfords primer was more forgiving but left a sandy texture, the Phoenix is much finer but has to be handled much more carefully.
 

Jamie

Edited January 3, 2019 by Jamiel

[ROSSPOP]

Well recovered Jamie.... a great job.

 

I`ve been airbrushing for years and still get it wrong.... thats life !!!

 

The thing is, take your time , dont do things in a rush and keep your spraying area clean and dust free.

 

In my younger days I lived in the country . I got up early to gloss paint all the windows and doors of my house o a sunny warm August. When I had just finished all the local farmers used all their combine harvesters to bring in the harvest. The paintwork was ruined!!!!

 

Cheers

 

John

[pete_mcfarlane]

Dettol seems quite good as a paint remover that doesn't dissolve glued joints, although I appreciate that the physical act of scrubbing the gunk off the model is still a risk.

 

I've used car body rubbing compound from Halfords to get rid of runs. Rub it on gently with a cotton wool ear bud, and it takes the imperfections off. 

 

https://www.halfords.com/motoring/paints-body-repair/fillers-preparation/halfords-rubbing-compound

 

I still have the tube I bought 20 years ago, so you get a lot for your five pounds. 

[57xx]

The bottom line is do several thin coats of both primer and top coat rather than one heavy one of either. 

 

This is the key learning point here. Never be tempted to rush things and use a heavy coat. Multiples thin coats are always better, no runs and no obscuring of detail.