i HAVE A SET OF SPRAY TIPS FOR MY PAINT GUNS AND WAS WONDERING WHAT SIZE IS BEST FOR PAINTING 2K PRIMER?

I Have 1.0, 1.4, And 1.8

For that primer, at least a 1.8. A 2.0 would be a little better though.

Look at the Product sheet for the primer you are going to use, it will say. Most medium solids primers will spray just fine with a 1.4 - 1.6. the high solids primers will usually need a 1.8 or even a 2.0.

As always, the person spraying the primer will in the end decide what is needed as most individual's technique is a little different.

Larry

^^^100% agree
PPG's k36 shots just great with a 1.4. I use SPI turbo prime with a 1.4
A thicker primer like K38 will not go through a 1.4 so you need a bigger tip, 1.7 works fine for K38.

A big tip is not the answer for primer. If you spray primer with a bigger tip it wont break up the paint into a fine mist but into big blobs of paint. Those big blobs can trap solvent causing excessive shrinking and other problems.
Most people tend to ignore the flash times with primer and you combine that with poor paint break up you have just trapped a huge amount of solvent...Eric

Believe it or not i use a 1.5 devilbiss gti millinium or $10 1.4 HF. I also use mostly medium solid primers. Only high solid primers i use are the poly primers.