Matt,

You will need to add a binder to the mixing tint as it will not dry properly if used as is. There are specific mixing ratios of binder to tint. The ratios vary quite a bit, so it would be a good idea to check with your local auto paint supplier. He can look up a formula that uses mostly the tint you have and use that ratio. When I mix up custom colors (not a formula from a factory code) I go with a ratio of about 1:1 tint to binder. I'm currently using Dupont paints in my shop so I'm more familiar with them. I have used PPG in the past though and the mixing ratios are similar. One of my suppliers sells PPG so if you have any trouble getting help let me know and I'll get a ratio for you.

Chris