tamiya acriylic problems

hi guys, i have a couple of problems with tamiya's acriylics. firstly, i paint a part, after handling it to fit and glue it, the edges and corners of the paint come off. should i prime the parts? if so, will tamiya fine surface primer do? or the stuff in the little glass bottles? is it some thing else? secondly, i plan to use washes to accsent shadows. i can't get hold of oil based art paints, so will thined enamels work without attacking the acriylic? thanks for any replys.

I would have to start by asking how many coats of paint are you putting on the parts and how much are you handling them. If you're putting sufficient amounts of paint on parts for even coverage and you're managing to wear the paint off the part, you sound like you're handling parts quite a lot.
Primer will help a little, but only if you handle the parts less.

As for washes, why not just use acrylics for washes too?

cheers for the reply. i only put 1 or 2 coats of paint on the part. i do handle the parts quite alot for test fitting etc. the reason why i wouldn't use acriylic washes on acriylic paint is that wouldn't the thinner used to thin the wash thin and mix the base paints and make it look messy.

1 to 2 coats isn't sufficient, you must be laying on really thick coats. Are you brush painting or airbrushing?

If you let the color coat fully cure, a light acrylic wash won't hurt anything.

i brush paint and i thought that enamel washes would be good because where i live you can buy revell enamels and thinners very easly

Enamel washes will work, the problem is enamel thinners are more likely to attack acrylics. Read through the painting section in the FAQ for paint compatabilities.

I primer every part for this very reason. Paint will not stick to shiny plastic very well, primer will help it stick.
Spray parts if you can though, brush painting is for detail only really

Enamel washes thinned with mineral spirits do not attack acrylic as fast as anything thinned with alchohol.The reason people use oils is the same as enamel.You have a good working time which allows the wash to settle into the details,and it can be wiped from areas you dont want it.Also,try and do your test fitting before paint,and it would seem your not applying enough coats.If you get coverage in two its too thick.