Wood movement & joinery question - Woodworking Talk - Woodworkers Forum
 1Likes
  • 1 Post By OrcaSea
 
Thread Tools Display Modes
post #1 of 5 Old 06-28-2020, 03:42 AM Thread Starter
Junior Member
 
Join Date: Jun 2020
Posts: 3
View OrcaSea's Photo Album My Photos
Wood movement & joinery question

Greetings, all,

I am a new woodworker and am building a relatively simple Red Oak chest for storing knitting projects for a friend. I live in Washington state and she lives in Alabama and it will be shipped to her. My state is moderately humid and 'Bama...well, it should be "Row Tide" not "Roll Tide", BUT it will live in an air-conditioned environment, so I'm not so much worried about swelling as much as shrinkage in the dry A/C air.

FYI the grain on the attached Sketchup shot is wrong - actually the opposite. The end panels have vertical grain and the side panels have horizontal grain, and all wood is 3/4" solid hardwood and consists of glued together panels.

I'm not terribly concerned about movement on the end panels - there will be a floating 1/4" plywood floor in dados and the lid is attached with hinges on one side. Initially I was going to use 5/16" flush Oak dowels through the end panels into the side panels, but at 12" across the grain movement could be considerable (I have read up to 1/4"?).

So what is the best way to approach this? I considered gluing vertical battons to the interior of the end panels and using recessed screws through the side panels into slotted holes in the battons? Will dowels allow for enough movement if I used those? Am I overthinking this? It's a gift and I don't want the panels to split or break from the ends.

Suggestions & advice would be very much appreciated!

Thanks,

Curtis

PS - if anyone can show me a way to layout a nice compound recurve instead of the simple radius on the end panels I will recognize you as an heroic figure.

Attached Thumbnails
Click image for larger version

Name:	Kinitting.PNG
Views:	12
Size:	686.9 KB
ID:	391607  

Click image for larger version

Name:	Kinitting 2.PNG
Views:	13
Size:	502.2 KB
ID:	391609  

David Nickell likes this.
OrcaSea is offline  
Sponsored Links
Advertisement
 
post #2 of 5 Old 06-28-2020, 08:05 AM
Mike
 
Join Date: Jun 2019
Location: Lawrenceville Ga.
Posts: 112
View Pretender's Photo Album My Photos
Your drawing show the grain vertical on the front panel and horizontal on the end.
Turn both so the grain runs the same way then use whichever joinery you wish. All the movement will be in the same direction.
Let the bottom float as you mentioned.
Pretender is offline  
The Following User Says Thank You to Pretender For This Useful Post:
OrcaSea (06-28-2020)
post #3 of 5 Old 06-28-2020, 12:42 PM
CharleyL
 
Join Date: Jan 2019
Location: Central North Carolina
Posts: 279
View CharleyL's Photo Album My Photos
I agree with @Pretender.

I make a lot of boxes, some from solid wood and many from Baltic Birch plywood. The solid wood boxes do best when running the grain horizontally around all 4 sides of the box. I usually go further and make all four sides sequentially from the same board, so the grain lines match at three of the corners, and the one that doesn't is one of the back corners. With the grain running this way, the box will get slightly taller/shorter with changes in humidity, but will move the same and the corner joints will not crack or split. If making the tops and bottoms out of solid wood you cannot just glue them on, because they will change significantly in width. The grain of the box ends will not be in the same direction as the top and bottom of the box. This is called a "cross grain joint" and you will have problems if you attempt to just glue it. You will need to allow for expansion/contraction. The usual way is to rabbet a groove around the inside of the box near the top and bottom edges of the box sides. Then you make a loose panel from the solid wood to fit this rabbet. It will need a gap at the front and back so it can expand further into this rabbet when the humidity is high and retract further out of it as the wood dries out. Of course, this dimension needs some close calculation to determine how much gap you should have, so the box panel doesn't run out of space when the humidity is high or show a gap when the humidity is very low. This will be determined by the kind of wood as well as the expected variation in moisture content that can be expected. This is the calculator that I use.
http://www.woodbin.com/calcs/shrinku...(about%2028%25).

Of course, to keep the panels from rattling when the humidity is low, I glue about 1" of the center of each end of the panel into the rabbet. This isn't enough to cause problems, but does keep the panel centered during the very dry times. I also finish the panels before assembling the box, so that I never see an unfinished edge when the panel width shrinks during the low humidity times. I never glue any part of the long grain edges of these panels, since they will need to move in and out.

If you really want the ends of your box to have vertical grain and the sides to have horizontal grain, you will need to assemble your box with a method other than glue. Nails or screws will let the wood joint move enough to allow for humidity changes, but I don't usually like the look of them. Wood screws in counterbores with plugs glued in to cover the screws would be my best suggestion. Flat plugs glued into the counterbore to cover the screw with their grain turned to match the wood becomes almost invisible when finished. They also make round button plugs that look pretty nice. If you want the flat plugs, you should get these and use them in your drill press to cut them from a scrap of the same wood, then cut or break them free as you need them. I frequently put blue tape over them and then just rip the wood on my table saw to cut them free. With the tape, they remain together until I need one. Using dowel rod will show the end grain and will not be nearly as invisible as these tapered plugs, when finished.

https://www.infinitytools.com/1-4-ta...ug-cutter-4050

These are available in sets or just one from many woodworking supply sources. The link is to show you what they look like. Straight plugs frequently don't fit tight. The tapered plugs fit very tight and stay in well with glue. You then just trim or sand off their tops to make them flush.

Charley
CharleyL is offline  
The Following User Says Thank You to CharleyL For This Useful Post:
OrcaSea (06-28-2020)
Sponsored Links
Advertisement
 
post #4 of 5 Old 06-28-2020, 03:23 PM Thread Starter
Junior Member
 
Join Date: Jun 2020
Posts: 3
View OrcaSea's Photo Album My Photos
Thanks for the replies, folks!

Unfortunately, I already have the panels roughed out, dimensionally. I should have considered the grain direction & movement, but as I said, I am a new woodworker

My end panels might be square enough to rotate; I am about to head out to the shop and see if I can make adjustments. If not, and I have to go with my end pieces as oriented (they are different than the SketchUp shot - I cant figure out how to change grain direction in SketchUp Maker) with the vertical grain and horizontal on the front/back, Charley, I kinda like the look of wood plugs, especially on something as simple as this chest. It lends itself to the Colonial/Shaker look, I think. I would think wood dowels might be slightly more yielding to dimensional movement than metal fasteners? Opinion? Maybe one every 3" and no glue on the butt joint.

Thanks for your time and thoughtful reply!

Curtis
OrcaSea is offline  
post #5 of 5 Old 06-28-2020, 03:30 PM Thread Starter
Junior Member
 
Join Date: Jun 2020
Posts: 3
View OrcaSea's Photo Album My Photos
Quote:
Originally Posted by Pretender View Post
Your drawing show the grain vertical on the front panel and horizontal on the end.
It's actually the opposite - horizontal grain on the front & back an vertical on the end panels. I can't figure out how to change grain direction on SketchUp Maker
OrcaSea is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome