Are all thinners equally "thin"?

Well, you can try more thinner, but Tamiya acrylics are terrible to use for washes though.

I did not know this, suggestions instead?

Enamels and oils work best for washes.The ratio is about 90-10

Also try craft tube acrylics, such as Grumbacher. Mix them up with water. Tamiya acrylics dry way too fast to be used as a wash. It will work, but you'll be frustrated all the way.

CarnivourousDonut

I'm trying my hand at pin washes, and while I use Tamiya Acrylics, and Tamiya thinner, I'm not getting the "thinness" I think I should be getting (in other words, the wash isn't running off the brush like I've read it should)

I've been using a 1:10 (paint/thinner) ratio as suggested elsewhere. What am I missing/doing wrong?

I suggest you use oil washes with a ratio of 1:20. Oil washes are infinitely easier to use than acrylic washes.

Thank you for the suggestions. So some oil tube paint, and Tamiya thinner will suffice?

You need a thinner for oil paints such as Mona Lisa Odorless Thinner.  

Don't use Tamiya's thinner for washes! It will take off any underlying paint.

Get a good quality oil paint as well. Windsor and newton is a popular brand and very good for oils. To thin you need something like white spirits, what I believe in America is called mineral spirits.

Are you using Acrylic or enamel paints. If the latter, you will need to protect that with a clear acrylic coat.