Another frameless cabinet question

[AtomicRyan]

Hey guys, I'm building my first set of frameless cabinets using pre-finished maple ply for the carcasses. The ply I got from my lumber yard was supposed to be really nice stuff, but once I started cutting it, I started to notice that it wasn't as flat as the baltic birch that I am most comfortable using. I scrapped the bad stuff and used what I thought would be "good enough".

Now that it's all together, one of the carcasses has a pretty good bow to the inside. I figured that once I get these installed and all hooked together, the bow would work itself out. I decided to mock it all up in the shop using clamps. With everything tight, the bow seems to disappear, but it pulls one of the cabinets out of square by about an 1/8th of an inch.

In the pics attached, the two carcasses in the center will have doors while the two on the outside will have drawers.

My question is, is this enough out of square where it will cause issues with my doors and drawer fronts? I really don't wanna spend another $90 on a sheet of this crappy ply to fix the issue if I don't have to...

Frustrated, but still having fun...

BTW, notice the crappy edge banding... This is the first and last time I'll use FastEdge... I think I'm just a solid wood edge banding guy.

[attachimg=1]

 

[AtomicRyan]

Here's a better shot of the squareness issue...

[attachimg=1]

 

[AtomicRyan]

I'm an idiot. While looking at those pics, I noticed something I hadn't in the shop. The bottom panel of that cabinet is bowed up. I put weight on it and the cabinet pulls back into square. I guess that fixes my issue.

Sorry for the stupidity folks.

 

[DynaGlide]

Hey Ryan glad to see you back at it. I think this is one of those times a giant flat assembly table would be your friend. You could throw two adjacent cabinets on your MFT and see how that helps things.

 

[AtomicRyan]

Yeah, I desperately need to build an assembly table. Right now, I'm using the floor.

I just finished building an 1950's era unisaw. After I finish these cabinets, I'm gonna think about building an outfield/assembly table for it. I might even go big so it can triple as a breakdown surface for 4x8 sheets of plywood.

 

[DynaGlide]

[member=63929]AtomicRyan[/member]

For the 4x8 sheets take a look at these solutions:

http://www.leevalley.com/en/Wood/page.aspx?cat=1,43455&p=76830

https://tracktubes.com/gallery/

I'd like a 4x8 table but it isn't happening in my 12x16 shop space. Are you going to do any more videos going forward?

 

[AtomicRyan]

Those track tubes are super interesting... I'm gonna keep those in my head.

As for videos, I did one a couple of weeks ago on the unisaw. You can see it here:


And now I'm working on one as I build these cabinets. It's really hard to make a video when you are doing something you've never done before, but I'm giving it hell!

 

[RKA]

LOL!  I actually enjoy that part about your videos (the flubs and fixes)!  It humanizes the videos and they are more personable (in other words...hey, I that could happen to me!).

 

[Job and Knock]

Yeah, I desperately need to build an assembly table. Right now, I'm using the floor.

And what's the betting it isn't perfectly flat? That doesn't help your accuracy. Concrete floors rarely are truly flat. Did you check it with a 6ft level? In terms of assembly it's easier to assemble cabinets on a 2ft high assembly table than a waist high one - less bending down to get to the bottoms of the carcasses but you can still reach the tops of the cabinets

 

[Kodi Crescent]

As Bill Clinton famously said - "I feel your pain."

My first attempt failed.  I had a similar problem.  I tried again using a different method and a different material.  This time I added 1x2 materials to the tops and bottoms to provide some stability.  I figured I'd have to add some sort of nailer and skirting for crown molding and to conceal lighting, so I may as well add it to during construction to help ensure that things stayed flat. 

I have everything installed, but I haven't rechecked it.  If it's off, I'll have to deal with it, either by finessing the doors, or leaving the cases open.

 

[Jcwoodshop]

It’s always been difficult to find flat and stable plywood, and getting more difficult over time. When planning frameless cabinets anticipate more waste then you would have expected.

I agree with J & K, the concrete floor makes for a poor work surface. Others have already mentioned assembly tables; that would be a great way to go, if you have the available space. When I need to used the floor in my shop, for whatever the reason; I put down a layer of one or two strips of melamine panel to use as my assembly table. It’s not ideal but its how I satisfy my need for a flat surface. Remember most basement and garage floors are pitched to drain, therefore, this new assembly surface will not necessarily be level…since it will conform to the level of the floor. So remember in this case, you’re not building plumb and level cabinets; the cabinet parts are being assembled square and true to the adjacent cabinet members. Ive built many cabinets too large to assemble on any of my workbench tops, and this method has work for me.

Don't lay your plywood or lumber directly on the concrete floor, thats a good opportunity for the wood to suck up any available moisture. 
I’ve had a similar experience with that type of edge banding. I was mistaken to believe that it may be a time saver….wrong. I prefer the adhesive backed iron-on type of edge banding, or solid wood applied to the panel edge.

You didn't mention the drawer and door style.  If you plan on inset doors and drawers, rebuild the particular cabinet. If you're planning to use doors that will overlay the carcass edges you may be able to use this carcass. The bow in your cabinet doesn’t appear to be that severe. Build a substantial cabinet base; pull down the cabinet bottom by pulling it to the base with screws. Make a trial attempt with a straight base member and clamps to see if that works. If you still have a problem; remove the edge banding, make a few cross cuts  3/4 the depth of the bottom. Apply edge banding after the cabinets secured to the base.

Good luck Ryan. Post a few pictures of the final build.