Airbrush woes

[PiperguyUMD]

Hello All,

I finally had a free evening to spray a few projects last night.  I recent purchased one of the Micro Mark Dual action airbrushes to replace my Badger that snapped in half when I was trying to get the air hose off.  This was my first time using it, and my first time spraying Tru-Color Paints.  I live in the humid south, so I let the dehumidifier run all afternoon.  I thought I was primed for success...




The surface is dull and textured.  My air pressure was 28 psi, and I thinned the paint by 25% with acetone.  I've never had this problem before and I'm not really sure what to do about it.  This brings me to my next issue, I need to strip these and start over.  These are both 3D printed models primed with Mr. Srufacer 750, the CNJ 1000 is FUD and the hopper is HD Acrylic.  Does anyone have any experience stripping paint off of these materials?  Is there a method of stripping that will not remove the hundreds of Archer rivets on each model?

On a side note, I think the HD acrylic is great but its not for every project.  This hopper has turned out fantastic!  The layering is almost nil, and with a decent primer its gone.  Its strong enough that I drilled holes through both sides of the corner posts to add grab irons with out concern that it would break.  Can't wait to get a real coat of paint on this one!

Thanks for the help!

[C855B]

... Tru-Color ... and I thinned the paint by 25% with acetone. ...

I also just made the change to Tru-Color and am still experimenting on a handful of FUD shells. So far, I really like the results and the quick cleanup. (Scalecoat was a friggin' pain to get out of the brush!)

That said, I do not thin Tru-Color. I do believe it's supposed to be airbrushing consistency out of the bottle. I'm certainly open to correction on this, but I can't fault the results nor the way it handles.

As far as stripping the mistakes? Good luck with that. RP resins are porous, and have a lot of "tooth". I surely don't expect the Archer decals to survive an alcohol soak or any other solvent normally associated with model paint stripping.

[ns737]

HI you can not strip the fud or fxd with thinner or alcohol they will melt the shells. I always use a junk shell to test paint.

[PiperguyUMD]

HI you can not strip the fud or fxd with thinner or alcohol they will melt the shells. I always use a junk shell to test paint.

Good to know. Since there is a solid coat of primer, I wonder if a toothbrush with a little acetone would take the textured layer off without damaging the shell, then I could just respray.

[ns737]

be very careful. the reason I know I tried to clean paint off a truck cab and it melted holes in it in less then a minute. I ruined a 20.00 dollar cab.http://therailwire.net/forum/Smileys/classic/ayfkm.gif

[BobRunty]

Ive been using Tru-Color for a couple of years now and I've never had luck thinning it. If it's fresh it sprays very nice. I have noticed some of my older bottles thicken up with age and don't spray very well. Tried thinning them with the Tru-Color thinner and it doesn't spray well anymore. I just resort to buying a new bottle. They seem to be ok for awhile unopened from the factory, but once opened and used they appear to have a somewhat short shelf life as far as spraying is concerned. Still ok for brush work though. And I seem to recall reading somewhere that acetone alone is not a good thinner for it. I do use acetone to clean my airbrushed afterwards though.

Bob

[arbomambo]

I do NOT use acetone to thin Tru color...only their thinner...
However, I do use straight acetone to clean
bruce

[bnsfdash8]

I use straight acetone to thin Tru Color and have had zero issues thinning the colors (knock on wood). Now straight acetone does not work well with the clears so only use their thinner with those.

[chicken45]

Doesn't acetone evaporate like, instantly?

[wcfn100]

Doesn't acetone evaporate like, instantly?

Yeah, not knowing much about solvent paint, I'd say that the amount of thinner caused the paint to dry too quickly.

If so there are three things you can do.  Use less thinner obviously, drop the PSI a little or spray closer to the model.

In the world of acrylic based paint, you can try and use a larger needle.  I don't think that applies here however.


Jason

[peteski]

When airbrushed paint has a rough surface that usually means that the paint dries (or partially dries) between the airbrush nozzle and the model surface.  This is a common problem for many modelers. They are afraid of paint runs so much that they go to the other extreme and spray the paint on dry.

There are few variables which need to be changed to get the paint to go on wet.  Bring the airbrush closer to the model, reduce air pressure, open the nozzle up wider or add more thinner. Usually it is a combination of those factors which will result in the desired paint coverage.

I have used a Badger 200 (single-action internal-mix) airbrush (and all sorts of paints) for over 30 years and I have no problems with my paint jobs.  If I see a problem develop I start manipulating the variables I mentioned above until I get the desired results.  I actually prefer a single-action unit for painting models. I adjust the nozzle opening in the start of the session and usually keep it unchanged. With dual action airbrush I usually find myself pulling the trigger all the way back anyways, which is a bit awkward to keep on doing for the entire painting session.

As far as air pressure goes, for N scale rolling stock size objects I rarely go over 20 PSI.  I usually keep it between 12 and 20 PSI.

Piperguy, have you successfully sprayed that same paint using your old brush?  Maybe the nozzle of your new airbrush is smaller than the old one?

[PiperguyUMD]

Piperguy, have you successfully sprayed that same paint using your old brush?  Maybe the nozzle of your new airbrush is smaller than the old one?

No, this is my first experience with Tru-Color.  With two new variables, I wasn't sure which was to blame!

[BobRunty]

Curious to see what you come up with ,Piperguy.
And on another note I'm with Pete on the airbrushes. The two I use are my old Binks Wren I've had for over 40 years and use mostly for dullcoating and such and a Badger 200 for painting. I bought a dual action about 15 years ago and have hardly used it. I can see where they may be useful for weathering or shading but I have other methods I prefer for that. I know others love their dual actions but I like the simplicity to just set my needle and air and spray away without concerning myself with trigger control.

Bob

[peteski]

Doesn't acetone evaporate like, instantly?

Actually that could be part of the problem. Yeah, acetone is a very fast-evaporating solvent.  The proprietary TruColor thinner, while it does contains a large percentage of acetone, it also has other slower-evaporating ingredients.

If someone wants to go on the cheap, then I would say to try generic lacquer thinner. Those also contain a mix of various solvents which have slower evaporation rate than plain acetone.  But also be mindful that each brand of lacquer thinner has slightly different composition. Some brands might work better with TruColor than others.

[nickelplate759]

I'll second Pete(ski)'s comment - thinning Tru-Color with too much acetone makes it dry TOO fast.
so will too much air pressure.  I try and spray it at around 20 psi.  Too high PSI will make the finish seem sandy.

George