Model Paints and Baking Soda: What's the Beef?

Normally when I use it it's on larger movie props but I have used it on resin models as well.

I put on the CA than lightly sprinkle on the baking soda than add more CA so it soaks all the way through.

You can also use dental acrylic for filling seams pretty much the same way.

Dental acrylic is used a lot in the movie prop industry.

When using either don't build it up past the surface so that you don't have to fight it with the files and sand paper, just run a thin layer of spot putty over it.

Eric... 

I would be careful using baking soda as you describe.  Baking soda is sodium bicarbonate-- NaHCO3.  Eventually, all that oxygen is going to react in some form with the paints and coatings that are used.  The free oxygen will combine chemically with any metals in the paints, or with the solvent or other binders and oxidize those components.  This means that your paint is going to lift, and any adhesion experienced immediately will gradually diminish over time.  How much time?  It's hard to say, but one factor I would not discount is humidity.  I would imagine the higher the humidity the faster the failure rate (Water will act as an acid).

The second concern is using baking soda to set super glues.  IMHO, baking soda works great for very THIN applications of super glues, but when filling deeper seams or holes, an agent such as Zap-A-Gap would actually be better.  Baking soda causes set-up (reacts) so quickly, that it only affects the surface layer where it comes in contact with the super glue.  Any liquid super glue sitting underneath is essentially unaffected, and will more than likely come back to haunt you at some time in the near future, as you watch it leach out under that prize-winning paint and decal job you spent so much time applying.

Just my opinion.  Hope this helps.

Gip Winecoff

the problem that i have had in using the baking soda in weathering is that it "sometimes comes back"! some of my older builds it had come back to the surface or maybe leached out? i have an old truck and a replica of my first car that both show white spots or areas bleeding through the rust colors where the soda is. i'm not overly bothered about it, but now just more aware of it as a problem and i won't use it anymore.

Dave

Ranger2Seven wrote:

Division 6 wrote: Don't know about paint issues but it works well as a quick cure catalyst and filler with Ca glue. Makes it hard as rock.   Eric...  Now that I will have to remember!

Neat tip but remember that hard as a rock part. It's so hard it's nearly impossible to sand and a lot of effort and surrounding plastic is dispensed trying to work the stuff.

Division 6 wrote:

Don't know about paint issues but it works well as a quick cure catalyst and filler with Ca glue. Makes it hard as rock.   Eric...

Now that I will have to remember!   

Don't know about paint issues but it works well as a quick cure catalyst and filler with Ca glue.

Makes it hard as rock.

Eric...