I'm making cabinet doors for my son. I have 3/16" plywood. Do you think making 1/4" dado joints are to wide. Should I consider the 1/16" for expansion? Or is that too much?  I'm doing a mortise & tension joint on the corners. It would make it so much easier doing the 1/4".  I try to get 1/4" plywood when I do my doors but all these odd size plywoods anymore. 

1/4" might rattle. Plywood shouldn't expand and I doubt the stiles would change widths any significant amount. The 1/16" allowance might not be necessary.

 

Just my 2¢

It'll probably rattle. You might considder some hollow screen spline. Ace has it that's .016 thick but, being hollow it should work.

You have to get two sided MDF in 1/4 to get the best fit.thrse days even its getting thinner. A lot of outfits going to the 3/16 cutters ...for that foreign crap..

I would go 3/16" dado for match fit.  As @lew and @Gene Howe stated it will rattle otherwise.  Plywood remains stable so no worries about expansion.  Several of the doors in my shop have 1/4 ish plywood and none have ever broken for that reason as do all the kitchen cabinet doors I made 20+ years ago.  Now bashing them with a 10ft 2x4 because I wasn't paying attention, that was on me.

Thank you everyone.

I was getting ready to set up for the 3/16" and my son come over and said the 1/4" dado will be fine. He said he can put a little bit of silicone around the door to help with the little gap. 

By the way my son works for a glass company that makes their own metal frames for commercial doors and windows.

I think he knows that we are working with wood not metal?  

When we get done with the cabinet doors they will be fine and look nice!! 

I had a similar issue a few months ago.  

In my area (central NY) the blue box stocks a full 1/4" maple plywood priced about $25.  It worked great and much better to work with than MDF, IMO.

Jim

I would likely use a regular saw blade and make two passes by adjusting the fence on the second pass to end up with a 3/16" dado.

1 hour ago, Cal said:

I would likely use a regular saw blade and make two passes by adjusting the fence on the second pass to end up with a 3/16" dado.

Same here.