Card Modeling Paste Formula

[Gil]

This is excerpted from the "Rotary Engine Cowls" tutorial. It will better serve everyone here where they can find it.

For sometime now, I have noticed that some of the advanced modelers in Europe have been using something other than plain PVA to fill seams in their models. One build, that was memorable, used strips of Japanese silk span and what appeared to be Spackling paste to seal the seams. This didn't really sink in till yesterday when I realized that the wall board building system popular around the World has been using this very system for a very long time now. The wall board is paper covered. Seams between panels is filled with with Spackling paste (joint compound) and paper tape. Gee, this sounds somewhat familiar..., So once again, unwittingly, I have reinvented something that's been literally all around me for awhile! This is all after sight so I can thankfully blame my lack of uncorrected vision for the whole afair...,

Terry asked the question about card modeling paste availability in New Zealand. In short, "Card Modeling Paste" is the name I use for a homemade mixture that I use as modeling paste.

The approximate formula for card modeling paste is:

Filler: 3 Parts Whiting (Marble Dust or Calcium Carbonate)
Water: As required to control the viscosity of the paste
Binder: 2.5-3 Parts PVA (Poly Vinyl Acetate or White Glue)
Lubricant: 1/32 Part Methyl Cellulose (ingredient in many products including water based personal lubricants which can be used in making the mixture)

I prefer this to the PVA modified Spackling paste which uses Calcium Sulphate (Gypsum) instead of Calcium Carbonate (Whiting or Marble Dust). It's more robust than the modified Spackle mixture.

Modifying the amount of water will control the vicosity of the paste. Adding a little more filler will also work but don't go overboard. Let the mixture set after mixing for an hour or so to allow full hydration of the mixture. I usually leave it overnight. An additional amount of filler may need to be added after the hydration period as the mixture tends to become more liquid after the rest. The result should be a very creamy paste with a viscosity to suit the modelers purpose.

The formal name I've given the mixture is "Card Modeling Paste"...,

We can all thank Leif Ohlsson for this latest spasm of reinvention for the good of the group..., Thanks Leif!

Best regards,
+Gil

[jmcdermott]

I use 2 main water based glues. One is the 3M Fast Dry adhesive which is very nice.

The other is a 50/50 mix of Elmer's and Mod Podge. Mod Podge alone grabs very fast but stays rubbery. The addition of pva makes it stronger.

I also keep a thinned down mix for brushing into seems.

I use rice paper a lot to "mud" interior seems. It really works well. One roll of rice paper will last forever and it is inexpensive.

If anyone would like to experiment with rice paper but doesn't want to order a roll, I'd gladly mail a piece. I have 30 feet of the stuff on a roll.