Woodworking Talk banner

Making cabinet door panels

1K views 11 replies 6 participants last post by  Rebelwork 
#1 ·
Hello:

I have a question you've probably heard before. When I bought the 13/16" oak lumber for my cabinet door panels, they were straight as an arrow and flat. But when I cut them to size to joint together, I found the wood had bowed cross grain, even though I took great care to prevent that. It is not severe, but it is enough to cause me to want to discard the pieces.

My question is this: Can the bow be flattened again? Is there a way to do it? Any suggestions are welcomed. Thanks!
 
#3 ·
Hi George:

I am using 13/16" red oak. For panels I try to buy oak that is at least 8" wide and usually 10 feet long. During the Summer, the conditions here are dry and very low humidity. Daytime temps range from 85 to 100+ degrees at this time of year. Thanks, Carl
 
#4 ·
If the bow is across the grain, that is called cupping. A bow is along the length.

This is a common problem with panels. Relates to factors such as stability (dryness) of wood, accuracy of jointing, how panel was stored, and the wood itself.

Not know how the wood was prepped, but I’ll offer some basics:

If lumber isn’t stabile or acclimated, it will continue to move after the glue up.

A good practice in jointing by machine alternate faces to cancel any minor error off 90°.

Once the panel is glued up, it has to be stored or “held” in stickers or cauls. Can also put them in plastic bags. On small panels I put them in stickers with either a weight on top or a strap clamp around the stack. On large panels I generally use cauls.

Flat sawn wood is the least stable, but usually the most desirable for panels, as they have the nicest grain pattern, so it’s very important to hold the panels and let them stabilize prior to assembly.

The best way IMO to fix a cupped panel is to cut it apart and start over.

Which reminds me, keep your panels oversized until right before assembly, just in case ;-)
 
#6 ·
I'm learning from this thread. I'm curious as to how long the panels should be cauled or strapped together before moving onto assembly.

So am I understanding this correctly, leave it in the caul even after the glues dry? Is this for all panels? Or only one used in doors?
 
#10 ·
Yes, when you take clamps off & maybe do a little clean up, milling or scraping etc, they go right back in the same caulks you used when you did the glue up.

I always hold panels like this off right up until I’m ready to use them

Keep in mind this is in my shop, in my climate, which is very humid, and based on my experience of finding a potato chip when I’m ready to use the panel.

I’ve also kept them sealed in plastic bags that can work too.

It all depends on your shop environment.
 
#7 ·
If I'm cutting panels for door I cut lengths , I put the panels roughly together giving myself an 1" or 2" oversize to allow for cleaning and fitting the edges on the tables saw with a glue line rip blade. All panels are stacked and ready to be glued. If the panels are less than 13" I glue and run through the planner to 5/8 iIf over 13" I run parts through the planer to 5/8 and then assemble...

I try not glue pieces up over 4-5 inches. Once there sized to be glued up I get right on it...not tomorrow but today...they can sit in the clamps for weeks..
 
#8 ·
You may end up with 3/4" thick panels....?




As mentioned above, the condition you have is called "cupping" and it occurs across the width of wider pieces more other than not. The easy way to reduce this it to either rip them down the center into two equal width panels or into 3 widths. Then as carefully as possible align the edges and glue them back together keeping them in the original order to preserve the grain. IF grain direction is not that important, you can alternate the center width 180 degrees from the original, that is flip it end for end.


The reason I mentioned 3/4" thickness is that you may need to run them through a thickness sander, but not a thickness planer because that would reduce them too much. My dual drum sander is what I use to smooth and level out my panel glue ups. Even the slightest mismatch in the glue up is noticable so it needs to be leveled out by sanding.
 
#11 ·
Bein in the prairies, it's pretty dry here. Maybe I can get away without?

I'm always looking for reasons to get more clamps though! Haha

I also imagine each individual panel I glue up will react differently? Depending on the boards I began withs moisture and what Not?

There is so much to learn in woodworking. I've hardly scratched the surface!

I've been trying to understand the different types of joints. Where I get hung up is when I need to leave room for seasonal movement.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top