Wolverine

to FSM
You might want to try a light gray or white primer, considering your colors. ( yellow and blue) Also, I would suggest using many light coats of yellow with your airbrush, just in case you might be trying to lay it on thick.

Also, you might want to post these types of questions in the “Painting & airbrushing” section, as you might get more visibility to these types of painting questions.

Keep us updated!

You can also try a "heavier" type of paint, like enamel.

Best stuff i found for figure kits and other area where I need a good white or white undercoat is "Mr Base White".

For tough fitting kits depending on the fit there are a few options, not going to lsit all but there is one that is recommended for Tamiyas old Motorbike Rider Models.

1.) Put Epoxy putty on the inside of the joints before you glue the parts together, take a hobby knie and cut away the plastic on the joints till the putty is exposed.
2.) Take a bit more putty and resculpt the plastic that you cut away and after smoothing the putties edges you should have a finished model with no loss of detail and no joint lines.

Alternatively you can always use the Putty + Thinner mix to fill the gaps, but might not work for large gaps

My many thanks to all of you , as far as the primer goes , yeah a white primer probably would have been the best way to go , I didn't think about it until it was a little too late .
Living in Colorado Springs the winter is a bit unperdictable as well and I do all my modeling in the garage , I do use a 75,000 BTU kerosine heater to warm it up but can that effect the way the paints acting ?

As far as the gaps go , i have them filled now but what a great idea that is , never would have thought about that ! however the gaps in this model were very large and this is by far the worst model I've ever tried to build as far as gaps go .

Again thanks guys and any other helpful tips would be welcome , and if I knew how to post pictures I could show just how bad the gaps were .