Solution to pianting problem?

[GoCreateParticipant @gocreate]

Hi fellow Model Engineers

 

Unfortunatly part of model engineering is painting!

 

I would appreciate your thoughts and experiences as to how I can improvr my paint finish.

Background – I work overseas most of the year, during my recent 3 week visit home I was keen to complete the painting of my 3″ scale Allchin tender (excluding lining).

After 3 gloss rub downs and paint spray I have ended up with a very glossy but orange peel finish, that is, reflections in the paint surface are bright but fuzzy rather than bright and clear.The paint layer is now quite thick. I am using Precision paints enamel with 20% fast drying thinners.

 

I know there are so many variables but I think the problem (apart from my inpatients due to limited time) has been that the paint I am using is from a half full tin standing over a year and not enough thinning. (When painting the horn plates a couple of years ago I did not have a problem but the same formula has not worked this time).

 

Proposed action – I am now faced with another rub down but rather than spray again, as the paint is quite thick, I was wondering if I could rub down with 1200 wet & dry, ‘T’ cut and polish to get a flat paint finish. I would line out after ‘T’ cutting then polish.

 

What do you think?

 

Nigel

 

 

[GoCreateParticipant @gocreate]

[TigermothParticipant @tigermoth]

Orange peel effect is caused by spraying from too great a distance.

I think that all you need is more practice. I usually find that by the time I’ve finished painting a model that my spraying technique is getting up to an acceptable standard and wish that I could start again! Many light thin coats is a good idea with enamel but then you’ve got to wait for enamel to dry which is time consuming. The thin coats are easier to get to a high gloss and prevent paint build-up.

Make haste slowly!

Good luck.

Bob

 

[Steve WhiteParticipant @stevewhite78094]

Hi Nigel,

I’ve just spotted this post and hope I can help for future painting sessions.

 

Painting is one of the trickiest tasks to master and I’ve learnt from over 40 years in the paint industry that it’s not an exact science!

Bob is right, it takes a bit of practice and also time trying different techniques, paints, thinners etc, before one can become proficient.

If you are using fast drying thinners and spraying from too great a distance with too much air flow, the paint will be almost dry by the time it reaches the surface and the paint will not be liquid enough to flow out. Spray too close however and the surface will be disturbed by the air velocity and also you run the risk of getting too much on, too quickly.

The other aspect is the amount of thinners, too much and the paint will run, not enough and the paint will not atomise or break up causing yet more orange peel effect. Find a ratio of thinners and a spraying distance that works for you and stick to it. Another tip is to try and avoid spraying when the atmosphere is cold and/or damp. This will also affect the atomisation.

Try a blend of fast and slow thinners perhaps. Remember that not all paints are the same and what works for one might be different for another and here I’m talking about differences in the initial viscosity in the tin and also the solvent recipe.

Cutting back is something done in the days of car refinish cellulose finishes and it’s certainly one way of getting a flat finish, the surface however can be far from glossy (depending on the hardness of the paint) and a wax polish is used to obtain a high gloss. You could use a thin coat of varnish instead, this would also protect the lining.

You don’t say what sort of equipment you are using but with airbrush or a spray gun, take some time to get to know how changing the settings affects the spray pattern, paint/air volume etc.

I don’t pretend to be an expert on painting models, achieving a good finish without hiding fine detail is an art that I still struggle to master. You could do worse than buy Chris Vines book “How not to paint a locomotive”, It’s full of useful advice and treats the painting process seriously as part of the model build and not just a quick finishing touch. I am sure that there is a lot of useful advice on the Internet as well.

 

Good luck, hope this helps

Steve

 

 

 

 

 

[mgjParticipant @mgj]

Can you buy some 2 pack locally. Actually the stuff I got was 3 pack- paint (which will air dry for touching up), activator and thinners. You mix as per the directions for quantity and its really at our sizes difficult to get it wrong, as long as you follow the basics.

 

Viscosity is set for you – whether its perfect I cant say, but its at a fair start point for a novice.(the thinners is not a thinners as far as I know, in the conventional sense of the term)

Spray a thin wet coat, and adjust on a bit of scrap.

Spray off and then spray back on and don’t dwell.

This was made by Lechler and its a lot easier than enamel or mixing your own cellulose.

 

I did spray all my flying model aircraft with it, and it came out very smooth very glossy and diamond hard every time. What I did was to spray a light but just wet coat. Gve it 5 minutes, and then put another down, so it went onto the previous coat which was tacky/wet. Didn’t run, and built up the colour in 1 session.

 

I really am not an expert, but if I can do it, anyone can, because I am that much of a novice with a spray gun.

 

Painted outside with a mask for the elfinsafety lecturers – (I know. There are instructions that come with the cans and I can read.)

 

For your problem, short of stripping it off, you will have to polish the orange peel out I guess, but then you have all the rivet heads. Or you can accept that its going to get pretty grotty pretty quickly, and even by the time you have wiped down and polished after a session, there is quite a good possibiltiy you won’t notice – unless you are entering a competition. How perfectionist are you?

 

My own 3″TE I brush painted with Japlac, and there are no brush marks on that – in fact I have been asked how I sprayed it.. Surprisingly sucessful! You should be able to brush paint good enamel, Not that, in service you’d notice!

 

 

[DMBParticipant @dmb]

I know a model engineer who brushes his paint, using stuff thats been warmed up. This makes paint flow better without thinners and avoids brush marks.

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