Personally I wouldn't touch wheat paste now.  Wallpaper paste every time about 70% to 30% PVA in thick cream.  I have no problem with separation of layers.
Also, Tammi does wonderful things with tapioca paste.  Perhaps she might consider putting her recipe on here.

Waterglass is a solution of potassium or sodium silicate in water, used as protective coating, an adhesive, and (especially formerly) for preserving eggs;  sometimes known as isinglass.  Therefore it is not gelatine, which is an animal product.
Wallpaper paste is made up from a powder.  In the USA I think it is known as hydrated cellulose (or something like that). 
I guess you could heat up your paste without problems but it might be better to make a separate batch and mix them perhaps.
PVA can be used on its own.  Try some.  (I nearly said 'suck it and see' but that might not be sensible!!)
DavidO

With the advent of "pre-pasted" wallpaper finding paste is more difficult than expected. Home Depot here has some very old and small packages of cellulose wallpaper paste. My last wallpapering was five years ago and my bucket of pre-mixed paste is now empty. Thus my attempts to make my own.

Is there a way post digital pictures of projects on this site? I take digital pictures. Might be interesting to share construction photos.

My first papermache model boat hull has shrunk:) It no longer fits backover the master plug.  However they are so easy to lay-up I'll do another one and this tme keep it on the plug until fully dried.

The boat hull is "round bottomed" so it has strength and shape stability  from being a curved structure. The cabin (deck house) has free standing flat sides. Has anyone suggestions of making flat sheets paper mache which don't warp?

I am learning. My original papermache hull was good, but thin. I decided to add a few layers of paper from shopping bags to make it stiffer and thicker. Now that is has dried it has rolled up and way out of shape. The next one I will leave on the "plug" until everything is laid-up and fully dried hard.

would coating with papermache using ground up paper instead of strips be less subject to shrinking or warping?

I've worked with fiberglass lay-ups in boat building an model building and can handle warping issues in that medium. However, glass doesn't shink, while paper does if stretched.

If you only damp the paper with the paste how do you get the paper to confirm to curves?

I thought the idea was to release the fibers of the paper by wetting. I have been building up my hull by layering the glue and paper. I brush the paste onto the surface, then lay torn strips of newsprint on top of that surface. Then using a brush I brush paste onto the paper. As i brush the paste onto the paper the paper wets out and conforms to the surface shape. In a few minutes the paper is saturated and looks wet. After a layer or two I let the hull dry. The paper does shrink and tighten on the mold.

Currently I am trying some different approaches. I laid-up three layers of paper.  Then let it dry infront of a hot air heating duct. Th layup was pretty smoothj.

I made a creamy 50/50 mix of finishing spackle and paste. Then I painted the papermache with a very thin coating of the mix and set it aside to dry.  When dried the mix had surface cracked the papermache in a couple of places (shrinkage over a hard plug). I sanded the surface to remove any high spots. Now I have addred two new layers of PM.

It is now on my bench drying. I notice there are spots where the paper has air  "bubbles" between layers. Expect when the PM dries it will shrink back and be-solid. Am I expecting to much?

dopapier: Thanks for your solution on how to deal with air bubbles. I always wondered what to do with them. I would always just push them down by trying to add a lot of paste to them. But your solution makes a LOT more sense.  :oops: