what are the different types of primer

[tkprosanjeet]

I just wanted to know about what sort of primer to use on my pepakura project
the inside is hardened with paper mache
the outside will have wall filler plaster and a coat of pva to seal but i wanted to know which primer to use on it for a smooth surface?
I have seen people use plastic primer, selft etching primer, sandable primer
i dont know the difference between them :/
cam anyone suggest something ??
Ps i live in india so tell me the type of primer to buy ;D

 

[Scotophor]

Self-etching primer is for metal, primarily aluminum since most other primers have trouble sticking to aluminum. Plastic primer would be as it says, for use on most types of plastics. Sandable primer is usually used on metal but could work on other materials. Using a primer not called "sandable" on metal, then sanding it, will often cause it to peel away when it gets sanded thinner than a certain thickness, then you can never get the edge beside the peeled area to blend in because it keeps peeling as you try to sand it thinner. Another type you didn't mention is called filler primer (a.k.a. high-build primer). It's also sandable but its main feature is that it goes on fairly thick and easily hides small defects like sanding scratches, etc.

 

[RogueTrooper]

You say your finished surface will be plaster with PVA over the top. By PVA do you mean PVA paint which is essentially water based acrylic paint.

So your sealer is a water based product, so your primer should be of similar base...water based

A water based primer can be sanded for a top coat of water based acrylic paint. For better gloss and durability you could top coat with an enamel based paint which is cheap and in aerosol.