Hi there,
I am new to the screen printing game and am learning as I go.
I have exposed my screen based off an exposure calculator and seems to be working. However, after a few runs with ink and cleaning the screen down I have noticed the emulsion is starting to washout.

When I coat my screen with emulsion, I only do one side and smear the excess that is pushed through the screen on the other side (not applying another layer)

Is this the likely problem, in that my emulsion layer isn’t thick enough due to being applied on the one side?

It's possible that it's due to the stencil being too thin. I would do a 1/1 coat for good measure. You want to be sure the emulsion is encapsulating the mesh. You also need to be sure you're using the correct emulsion for the ink you are using. There different emulsions that are resistant to different inks. A few can do them all but usually we use an emulsion specifically resistant to the ink type like water based versus plastisol.

This also could simply be a severe under exposure especially if you're using an exposure calculator that you download online and print yourself. Those are completely inaccurate due to the varying degrees of density that will be achieved when someone prints it at home. A real exposure calculator has to be made professionally so they are all the same density. That way the printed "gauge" can actually work. A simple step or wedge test would work better.

Thanks for the advice mate

You're welcome. My pleasure to help out where I can.