Airbrush vs. Rattle Can

[Guest]

"Finally, just because you can't smell something doesn't mean it's not there. You should wear a mask whatever you are spraying.Good point Steve, some nasty stuff in all of these paints!

Jason

And the fillers... and the glues....

Do you guys wear masks while doing that as well? Or only while airbrushing because of it being so finely atomized?

[Guest]

Some of the things I have found with my experience. These are based on Vallejo Model Air..

Use a two stage airbrush.

I always use Vallejo thinners. Not water. The thinners are designed to retard & also lubricate.

I always thin. Place the thinners in the bowl first. The small amount left at the needle end after mixing the paint & thinners will keep the needle nozzle free before use.

Make sure the paint is well mixed to give good consistency.

Found that using .4 needle/nozzle works best (I use Harder & Steinbeck brush).

Give a good full trigger back squirt on a plastic bottle before painting the real thing.

Where there is a lull dip the brush in a spot of thinners or resting the nozzle in thinner. Dry the nozzle before reuse & give a good squirt as above.

Found 18 to 20psi works well with the H & S.

Temperature below usual room temp.

Replace the cap on the paint immediately to avoid drying out.

Thin approx 20/25 percent.

Keep a cap on the cup during a session & after cleaning to avoid small hairs contaminating & to avoid premature drying out.

Use a small cup when ever possible there is less area for the paint to dry out.

Clean brush after every session. 4mins but saves many more.

Being basically water based rather than a slower drying turps sub acrylics are going to be more problematic. Although there is no guarantee with the above they will ensure, in my case, the very minimal of problems. A Bit of a pain ? Yes but all worth it to get the finish you want.

Laurie

[stona]

And the fillers... and the glues....Do you guys wear masks while doing that as well? Or only while airbrushing because of it being so finely atomized?

I don't wear a mask when filling and gluing. This is because I do have a well ventilated work space and my exposure is very low. I use thin cements which are very volatile. I keep the top on as much as possible, both to reduce my exposure and protect my bank account

The potential hazard with glues is vapour inhalation whereas with spraying paints an aerosol is created (along with the vapours) which can also be inhaled. I have a spray booth shifting more than 300l/min but still mask up for most spraying. I'll confess that if I'm doing a little touch up or very minor bit of painting I've been known not to put the mask on. I do always wear it when I embark on a job like applying camouflage, and for flushing the airbrush.

I'd hate this to turn into a this is better than that sort of thread. At the end of the day it is a personal preference which may well be based on factors such as where and how we work.

I did want to give a shout for the poor old enamels! I started spraying them when there really wasn't a choice, but now I find myself in a diminishing minority!

I find Alclads spray very well. My tip would be not to lower the pressure too much. They will spray at my usual enamel pressure of 30-35 psi and I can't be arsed to scrabble about adjusting my air pressure every time I change medium. I clean up with cellulose thinners (lacquer thinners across the pond) but this can trash some cheaper airbrushes.

Cheers

Steve

[stona]

That seems like sound advice Laurie.

I know that you are a Vallejo man but wonder if you or anyone else has tried Lifecolour paints. I've heard good things about them.

Cheers

Steve

[Guest]

Some of the things I have found with my experience...........Laurie

I am still a beginner and had a lot of trouble when starting airbrushing (Vallejo Model Air or Xtracrylix acrylics) in February: clogging, sputtering, uneven coating, especially with gloss varnish. I tried thinning (with the proper thinner) from 5% to 25%, altered pressure from 15 to 40 PSI, held the AB away from the model by between 2 inches to 10. For colour paint, I learned to do exactly what Laurie has described, including using a Harder and Steenbeck AB with 0.4 mm nozzle. For some time I have been able to reliably apply a good even colour coat at about 20 PSI with no problems. However, I am not sure what corrections I made. They just seemed to come, unconsciously. I now thin by eye, just "some thinners in the cup to milk consistency", which I was earlier on advised to do, which implies that the rate of thinning is not critical. I don't have drying at the tip but that might be because I don't normally spray for long periods, although I often brush the needle with thinner after about 10 minutes. I always thoroughly clean the AB after a session (but not between colour changes) and use an ultrasonic cleaner after every 3 sessions or so. Sputtering was cured by starting and stopping the stream off the model (although I do get the odd very small blob).

As for varnish, after difficulties, experiments and much practice, I can get a good hard glass-like surface after one spraycan wet coat of Tamiya Clear with the can about 10 inches from the model, as advised on the can. But I find that the ferocity of the spray can tends to cause pooling, especially at wing roots (where perhaps the jet is confined). Its a fine line between not getting a wet deposit and going too far.

I am now airbrushing Vallejo or Tamiya clear varnish with some success, thinned only 5%—it is so much more controllable than a spray can. I spray at 2 inches distance at about 20 PSI, further away produces no wet deposit (which seems necessary to get a gloss), only some dry powder, possibly due to the varnish drying before it reaches the model).

Its practice, practice, practice, on many ASDA or Sainsbury 2 litre lemonade bottles.

[Guest]

So update to the original post.

I received my micro-mesh pads today. I wet sanded the car body with 3600, 4000, 6000, 8000, and 12000 grit pads. The followed that up with a nail buffer. Actually ended up with a decent finish. Though it's hard to get in to some of the details with those. Definitely smoothed things out and got a much nicer finish! Unfortunately a couple of the edges got taken back down to styrene in the exercise.

Last night I laid down some coats of the gloss black acrylic on a chuck of styrene sheet I had laying around. Going with much multiple passes of much thinner coats seems to be getting better results as well. So with that lesson learned, I'll build up a couple of more thin coats on this model to get to a final finish.

All in all I think this is going to work out. So some lessons learned here (Which was why I built this car in the first place!)

1. Bad paint jobs can be recovered with wet sanding or if it's horrid, out right stripping
   
2. Lots of thin coats with acrylic are better (rattle cans I can get a nice finish in three to four coats)
   
3. It's less effort to get the paint job right in the first place! :P
   

[Guest]

Micro mesh pads did a great job of smoothing things out. Followed up with a fine scracth remover from the automotive section of a local store and I think the paint job looks good! Quick test on the hood worked out great. Now to finish the car body and apply decals. Excited to get one car off my plate! I have three sitting close to being done, each with their own issue that needs to be fixed!