Mr Surfacer in Rattle Cans

Not sure what to tell you about the final paint layer but I've had very good success with both it and the Tamiya cans.

,I prime everything with Mr. Surfacer no matter what I put on over it and have never had the slightest problem. That includes MM Acryl and Tamiya acrylic paints.

L

Which version? Apparently there are various levels of matte finish, but I dont think the cans say whether they're semi-gloss or very matte, just a #. Kinda dumb system for an expensive product.  

Primer should always be a flat finish as it provides the necessary "tooth" for the paint to adhere to.   I've used both Mr.Surfacer and Tamiya Primer and both work fine for me.  I prefer the Tamiya primer because it provides a finer finish.  I can only find Mr.Surfacer 1000 spray primer and its less fine than Tamiya.  Mr.Surfacer 1200 primer provides a very fine, velvety smooth finish but I can't find it in a spray can.  Instead I have to spray the 1200 using my AB, suitably thinned with lacquer thinner.  Given the choice I use Tamiya in the spray can simply because its easier to apply!  EVERY primer I've ever used (even cheap hardware store brand) has been flat.

I suspect the problems you're having can be attributed to paint type, paint thinning, AB pressure, spray distance, etc.....either one of these or a combination of them.

Hmmmmm.....just re-read your original post.  You're using water to thin your acrylic paint for airbrushing?  What brand paint are you using?  For Tamiya acrylics don't use water, use either 90% alchohol or Tamiya acrylic thinner and don't thin it TOO much.  The paint should be the consistency of lowfat milk for normal airbrushing pressures (10-20 psi).  Only reduce it further with thinner for very low pressures (5-9 psi)

Water is OK with Vallejo, Lifecolour and PollyScale (S) acrylics, but again, don't overthin otherwise you'll get beading and spidery runs.  Don't know about other paints like ModelMaster Acrylic and MisterKit.

Well I'm a cheap SOB so I'm using the craft store stuff. It was written up in a recent FM mag as being OK with a few suggestions. I cant resist the low price, esp with tiny bottles of MIG going for $10. Plus my AB is double action but has no reg on the compressor. I'm kinda roughing it. Just glad I'm not spraying 1/24 car models.

Sorry Bocks, can't help much with the craft store paints...never used them.  I read the same FMS article though so they seem to be a perfectly viable alternative.  I recall reading that a drying retarder is recommended as well as some type of hardening agent?  A drop of dishwashing detergent is needed to reduce the surface tension (lack of which could cause beading of the paint). 

In any event, not having an AB regulator is definitely roughing it!!  Do you have any idea at what PSI you're spraying?  Many compressors deliver in excess of 30 or 40 PSI without a regulator, which is too powerful for most model airbrushing, however it may be possible if the model is far enough away and the paint is the right consistency.