Cant smooth out this joint

It looks to me like you’re just picking up the differences between two different materials. Was the whole unit primed first?

• It could be that the face frame has a finer finish and to match the plywood sides you may have to fill the grain with multiple coats

Yep – primed and then sanded to 220. After sanding I thought I had a perfectly smooth finish but then once I got the top coat down the joint appeared again.

What sort of pva glue did you use?

All pvas can creep but some do it more
readily than others. The outdoor rated
ones are the worst offenders I think.

Sanding the cured paint and applying another
coat may help.

Im just using Titebond 2 wood glue. Never even thought that it could be glue related. Should I be using something else?

I expect yellow Titebond 2 and 3 to creep. I use
Titebond 2 extend and I have not noticed it creeping.
I don’t know why the yellow ones are yellow and
the white ones are white, but I’ve seen the yellow
Titebond 2 creep and not the white Titebond 2e.

Claims of water resistance in pva glues are a
red flag, imo.

So you think it might be joint creeping because of the kind of glue Im using?

The 2 materials expand and contract at different rates.
It’s almost always going to show the division between the 2. Maybe not at first but 6 months – year down the road you will see it.
I always make sure I get plenty of glue at the seam and that the seam is tight. Putty can also raise.

When I want to be assured no seam will show, I knock down the material on both sides of the seam
and fill it with bondo.