matt black trouble

[unidan]

Hi all,

 

Hoping for some help as I have attempted a loadhaul 60 in N gauge 3 times now and have fallen at the same hurdle each time.

 

Basically... when it comes to spraying the black the end result comes out texturised like a fine emery board which is not great looking and is a monkey for picking up dust. I'm spraying on top of the orange and its taking about 9-10 coats to go black if thats any help.

 

I'm using phoenix matt black mixed with mangers white spirit to a 2.5 to 1 mix. Compressor is set to 20 psi, and the result is the same with a fine or medium needle set up on my badger airbrush!

 

I have experienced the same problem with a couple of other colours such as rail grey.

 

Any remedies or tips will be much appreiciated.

 

Regards

 

Marc

[micklner]

Are you priming the body before top coat?

 

 

Mick

[unidan]

Yes I prime, then do the yellow for the ends then mask off the yellow and do the orange and then mask off the required to do the black.

[micklner]

I mix paint /thinners 50 /50 I suggest you use Precision Quick dry thinners , seems to work better with their paint than turps, you may get a better result with gloss paint ???

I rarely spray Black I normally do such sections in Halfords Matt Black which gives a nice hard satin finish. You can overspray the lot when done with varnish type to taste

 

Mick

[unidan]

Cheers Mick, might be worth giving the phoenix thinners ago.

[bertiedog]

It's the thinners, Phoenix are not enamel paints as such, but synthetic coach enamel, which is dissolvable with more specific solvents, or very high octane types like cellulose thinners.

 

Coach enamel will work with turps, and I am not knocking Mangers as a brand, but it is unsuitable thinners for spraying such a paint.

 

The first and best recommendation is to always use the makers products, the behaviour of the paint becomes predictable, and controllable, when things appear to go wrong.

 

Phoenix make ordinary, and spray thinners, which accelerate the drying.

 

The trouble that you have is the paint is too thick, and with the slower turps thinners you are getting a paint build up. You can just try using more turps type thinners, the amount needed can surprise people, it may be up to 80% thinners, or even more with some paint. With brush painting the thinners are kept away from the mix, a different approach to spraying.

 

The high dilution applies even more when higher octane thinners are used, the excess of thinners promotes better matt finish, and the coats are very thin indeed.

 

A very popular thinners is petrol, the standard "lighter fluid", which will work fine with Phoenix, even when sprayed on plastic, as the coats will dry out before the plastic is attacked if you are careful!!

 

You can go the whole way and use cellulose thinners, but it needs care and the dilution is more critical to prevent build up as it dries pretty quick!

 

So basically use the right thinners at first, it is always the best way, the makers know what they are doing and will always provide the best advice, but with knowledge, and experience, you can use other types of thinners for spraying.

 

Hope this helps,

 

Stephen.

[micklner]

good info re the Lighter fluid cheaper than Precision product

[unidan]

Thats excellent news, the white spirit seems to work fine with most colours, so thats obviously where i'm finding the trouble. Couple of questions further if I dare...

 

Would the general purpose thinners PQ8 work as well as lighter fluid? and what sort of ratio to paint would I need? and I should imagine with a stronger thinners based mix that I should cut down on the amount of passes I'm making on each coat, currently about 6.

Thanks Mick and Stephen for your help thus far

 

Marc

[bertiedog]

Really the best advice is use Phoenix thinners, or Humbrol's equivalent white spirit etc, but to get the best finish the original paint makers types are always best.

 

With petrol substituted it would be about 60% thinners, same as with cellulose thinners, and about 40% thinners with original Phoenix white spirit types, or the special spray version.

 

But whatever thinners are used the airbrush should only just deliver enough paint to wet the surface and then dry off, not to land as a dry dust, and not to flood with paint, which gives orange peel effects.

 

So it is getting the balance of a wet patch under the spray centre, enough to get the liquid to survive the trip in the air as very finely atomised paint, wet grip the work, and settle out and then dry off.

 

None of these stages must be bypassed, too little thinners, and the paint will gel and build up, and take extra time to dry off. Too much thinners and it will dry in the air and go too dusty, and take too long to build up the layers.

 

Practice makes perfect, and only experience will show the best amount of thinners to work with. The airbrush adjustments and type also throws advice, they all behave a bit differently. Pressure should be higher for enamel thinned with white spirit, lower pressure with cellulose, with petrol medium pressure. Great care should be taken with fire safety with petrol or cellulose, use outdoors or well ventilated area indoors.

 

Stephen.

[unidan]

Also had brought to my attention that its best to try and avoid the matt black and use the dull version which is more satin, I was also pointed out that paint should be used within 4 weeks, because as soon as you stir air into the paint the hardeners start to react and you will end up spraying very fine hardened paint along with the rest of it. Although my paint was resealed up airtight as far as I was concerned because it had been opened 3 months before, it was probably well past its best.

[bertiedog]

Also had brought to my attention that its best to try and avoid the matt black and use the dull version which is more satin, I was also pointed out that paint should be used within 4 weeks, because as soon as you stir air into the paint the hardeners start to react and you will end up spraying very fine hardened paint along with the rest of it. Although my paint was resealed up airtight as far as I was concerned because it had been opened 3 months before, it was probably well past its best.

 

I think it is a bit miss leading to say that paint goes off quite so quickly, certainly with pure enamel, with natural oils, it might, but Phoenix is synthetic type and will last in storage very well, the thinners and stirring will dissolve the paint and leave it in correct suspension. Cellulose thinners in Phoenix will work well with paint several years old, but well sealed. Car cellulose does not go off in practical terms, simply add more thinners and mix.

 

With any matt paint, mixing should be very carefully done, use a mechanical stirrer, or stir for a very long time.

 

Satin does work as a matt surface, but if dead matt is needed then only a dead matt will work. For surfaces facing handling ten satin is a must, any handling of dead matt will show.

 

Stephen.

[unidan]

Thanks Stephen, I think I will be sticking to phoenix dull paints from now on. So really I should be looking at a approximate 1part paint 4part thinner mix, I know its a case of until its coated but about how many coats would you invisage having to spray on top of the loadhaul orange to acheive black? and do you get any bleed from the thinner mix under masked off areas? I'm currently using tamiya masking tape.

[bertiedog]

Thanks Stephen, I think I will be sticking to phoenix dull paints from now on. So really I should be looking at a approximate 1part paint 4part thinner mix, I know its a case of until its coated but about how many coats would you invisage having to spray on top of the loadhaul orange to acheive black? and do you get any bleed from the thinner mix under masked off areas? I'm currently using tamiya masking tape.

I never count the coats, just continue till covered, and the paint will be too wet and runny if it creeps under the tape. It should dry to tacky very quickly indeed, not dry, but will not creep. Go slowly and the coats should build up in micro thin amounts, first try the very thinned out paint and thicken bit by bit to taste, do tests on scrap work or cans etc., to practice the spraying technique and finding a dilution that works for you.

 

Tamiya tape is about the best at grip without risking pulling paint off.

 

Stephen.

[2512silverfox]

It may be heresy now, but I still use Xylene as a thinner and it works a treat as it has for the last 35 years! Precision actually used Xylene as its standard spray thinner until it became unfashionable to do so, or rather the Health & Safety boys got interested.

 

You must take the right precautions because it is carcinogenic, but the amount which we do as hobbyists is unlikely to do you a lot of harm. But then gloves, a mask and air extraction are really important for any spraying.

[justin1985]

I really wouldn't use any matt paint for this purpose at all to be honest. Any matt surface will make it a nightmare to put on waterslide transfers without getting the "crazed" white\milky texture around the edges. A MicroSol type product would help mitigate this, but doesn't solve the problem.

 

Instead use a gloss or maybe satin black, apply transfers etc, then put on a coat of matt or duller satin varnish. The result will be far better!

 

 

For a matt to satin black, I use spray can Gamers Workshop Chaos Black.

 

I don't know any of the techie stuff about paint but as a user it goes on lovely and dries quickly with an even finish that does not clogg up the detail.