# Trying to make doors but 1/4" birch ply is not really 1/4" thick



## noone (Mar 6, 2012)

I just cut my first dado in a piece of polar and did a test fit with some 1/4" ply only to find out that it's more like 3/16" thick.

How do you fit your door panels?


----------



## davidmicraig (Nov 21, 2009)

This is where owning a set of calipers comes in handy. Panels are often a little thinner than their listed width. For 1/4 inch, I measure with calipers to get the true width and use a regular saw blade and make multiple passes until it fits snugly. If you overlap the cuts, you can sneak up on the proper gap.


----------



## noone (Mar 6, 2012)

I do have digital calipers. I just don't understand. All the door tutorials, even in this forum say nothing about this. Now I feel like I wasted my money on this $100 dado stack.

I just spent a 1/2 hour setting it up with a PERFECT 1/4" cut right down the dead center of true 3/4" thick poplar.

I don't see how you can make consistent cuts across multiple boards making multiple passes. Unless you're flipping the board and cutting from the other side to get the perfect thickness.

A little frustrated right now.


----------



## NiteWalker (May 7, 2011)

I'd either use 3/8" ply and rabbet the back to fit a 1/4" groove snugly, or use a regular saw blade and make two passes. To make the groove with a regular blade, do the setup with test pieces; make the first cut with the fence set slightly off center, flip the piece so the other face is against the fence, and you have a perfectly centered groove, and after a few test cuts, it will be the perfect size too.


----------



## noone (Mar 6, 2012)

So is my dado stack only good for rabbets????

I guess I have to do this-
http://www.table-saw-guide.com/building-cabinet-doors.html


----------



## ShaneA (Apr 15, 2011)

the dado stack will be good for other uses, and dadoes 1/4" and larger. you will just want to make sure to have test pieces of the same thickness to dial in your fit…be it a single blade or multiple blades/chippers and shims.


----------



## cabmaker (Sep 16, 2010)

Im a bit confused, are you talking about a plow for inserting door panels ? (where does dado come in?) There are 5mm cutters to do what I think your doing.


----------



## noone (Mar 6, 2012)

I guess it will work for dado sizes 1/4" and larger, due to all the shims that came with it. I just incorrectly assumed I could use this dado set to make doors.


----------



## noone (Mar 6, 2012)

Yes, I'm trying to build shaker doors and cabinet panels with only a table saw. No router. Figured I could use a 1/4" dado, no problem. Guess not.


----------



## TCCcabinetmaker (Dec 14, 2011)

run a test piece without the metal shims between the stacked blades, you might be surprised that it should come out just about right. because without the shims, the blades don't space out to a full quarter inch., and it should be 7/32 not 3/16


----------



## LeeBarker (Aug 6, 2010)

I think what you're dealing with is 5.2 mm ply. It's the new .25 inches.

It is possible to glue in your panels and then shim them from the back with laminate samples so they look right from the front. Take the shims out when the glue sets. No one will ever know.

Kindly,

Lee


----------



## noone (Mar 6, 2012)

"run a test piece without the metal shims between the stacked blades, you might be surprised that it should come out just about right. because without the shims, the blades don't space out to a full quarter inch., and it should be 7/32 not 3/16 "

The dado set I'm using is the Freud diablo one and the inner and outer blade stacked together creates a 1/4" gap. I don't think I can get smaller than that without just using one blade and multiple passes?


----------



## noone (Mar 6, 2012)

Lee, I'm kind of liking your idea for making panels, but I'm wondering how this will work when I apply it to doors. I'm thinking the paint won't fill the gap well on the backside. Can I use caulk on the back of the doors? I've been using caulk to fill 1/32 gaps and such where the back meets the frame on the cabinets, so I guess I don't see why not.


----------



## CampD (Nov 8, 2008)

Ahh the shrinking plywood (just like everything else, is a gallon of milk really a gallon anymore?)
Only true 1/4" plywood left is 5-7 core Baltic birch.
Anyway without a router table and a 5.2 mm cutter the only other way to cut your Daddo is to use your table saw with your regular 1/8 blade.
Make one pass, flip it over to make the second pass. Set-up takes some time and use cut-off scrapes from your rails.


----------



## Howie (May 25, 2010)

You could always use a strip of quarter round on the back side. Mitered in at the corners and let the panel float.


----------



## donwilwol (May 16, 2011)

If your going to paint them, I'd use caulk. The gap should be minor, and unnoticable after painting. If its a clear finish, the a molding may be a better fit, or a thin shim if you can get it evenly spaced.


----------



## bondogaposis (Dec 18, 2011)

Cut your dados w/ a standard blade using 2 passes, tweak your rip fence using scrap that it is the same thickness as your stock and run it through twice flipping the board end for end for each pass. This will center the dado on your stock and will correctly size it for your plywood. It will take some trial and error to get the fence set. It is very rare these days to find plywood that is actually dimensioned to it's nominal size. Your dado stack will come in very handy for many things, just not great for 1/4" plywood door panels.


----------



## mveach (Nov 16, 2011)

You can get 1/4" but it is mdf core.


----------



## noone (Mar 6, 2012)

Thanks for the suggestions. I have to use what I have since i have already spent a pretty penny on this project. I was able to get a nice snug fit, but not too tight using the one blade two pass method.

Do I need to worry about these panels moving inside the frame if I cut them 1/16" short to allow for movement?

I'm in Florida and its hot and muggy in my garage where I work . All pieces get brought inside to cold AC.

I was planning on painting the rest of this built in in situ and was wondering if there was a chance some bare would could show after I painted it.


----------



## doughan (Apr 22, 2011)

"1/4" inch plywood that isn't even close to a 1/4 inch came from the same minds that decided that not keeping score in liitle league,seven valadictorians,oral sex isn't sex and redefining the definition of is were cute ideas.


----------



## CampD (Nov 8, 2008)

Yes, leave at least a 1/16 for movement, actually the plywood is pretty stable it will be the rails that move the most.

As for painting. I might suggest bringing the panels in the conditioned house for a few days even a week before you paint them, let them acclimate. Then quickly bring them out to paint, maybe plan on a dry day to do it. FL is not to bad this time of year.


----------



## bondogaposis (Dec 18, 2011)

For plywood panels I just glue them in, plywood is stable and the styles and rails should be thin enough that wood movement is not significant.


----------



## donwilwol (May 16, 2011)

I like to paint all but final coat before assembly to avoid seeing bare wood if it moves


----------

