Warped new Plywood? - Woodworking Talk - Woodworkers Forum
 3Likes
  • 2 Post By hawkeye10
  • 1 Post By Vbryanv
 
Thread Tools Display Modes
post #1 of 15 Old 03-20-2018, 02:39 PM Thread Starter
Member
 
Join Date: Feb 2018
Location: Western Pennsylvania near ZIP 15632
Posts: 73
View PA WOODCHUCK's Photo Album My Photos
Warped new Plywood?

That said I purchased a 4 x 4 piece 3/4 sanded plywood from Lowes and it's warped as all was that is on their shelf. Any tips to flatten it for use?


thanks

Retired VW Tech, performance boats until 9/17 STROKE! Now making sawdust to keep busy!
PA WOODCHUCK is offline  
Sponsored Links
Advertisement
 
post #2 of 15 Old 03-20-2018, 03:13 PM
Senior Member
 
hawkeye10's Avatar
 
Join Date: Feb 2015
Location: Murfreesboro, Tn.
Posts: 1,107
View hawkeye10's Photo Album My Photos
Quote:
Originally Posted by PA WOODCHUCK View Post
That said I purchased a 4 x 4 piece 3/4 sanded plywood from Lowes and it's warped as all was that is on their shelf. Any tips to flatten it for use?


thanks

I would take it back. I don't think you can straighten it.
amckenzie4 and 35015 like this.

Don in Murfreesboro, TN.
hawkeye10 is offline  
post #3 of 15 Old 03-20-2018, 04:55 PM
Vbryanv
 
Join Date: Mar 2017
Location: New Jersey
Posts: 90
View Vbryanv's Photo Album My Photos
Im Pretty new to wood working and have found that I can't but plywood for any of the big box store with it already being slightly warped or warping within a day or 2 of getting it.. I started making sure I cut it to the size I needed the day I got it but sometimes it still wasn't 100% flat..

You have to buy high quality plywood for somewhere other than Lowe's. Took me 2 years of wasting money and fighting to get things square to get out of the habbit of buying wood from places like that out of comfort and convenience. As of the last 2-3 weeks I'm only buying my plywood and wood from places that specialize In wood.

About a week ago I bought a sheet of five by five 1/2 inch Baltic birch plywood for I think $47.00 cut it into pieces 3 ft + 2 ft and it's been sitting in my garage and it still straight. I would have never been able to do that with the Home Depot stuff.. I know it's apples and oranges comparing Baltic Birch to the sand plywood. But I can almost guarantee that if you would have purchased a higher-quality plywood from somewhere else it would still be straight now. And you can be surprised that it's only like another 5-10 bucks if that more expensive..
Joe Lyddon likes this.

Being happy is doing the things you love to do with the people you love to do them with.. Even if that someone is just you and a power tool.
Vbryanv is offline  
Sponsored Links
Advertisement
 
post #4 of 15 Old 03-20-2018, 05:06 PM
Senior Member
 
Join Date: Sep 2011
Posts: 25,991
View Steve Neul's Photo Album My Photos
I would do like Hawkeye suggested and take it back. If you manage to get it flat there is no guarantee it will stay flat.

If you are going to try, lay the wood on sticks so air can circulate around it and wet the concave side. Warpage is normally caused by an imbalance in moisture content from one side to the other.
Steve Neul is offline  
post #5 of 15 Old 03-20-2018, 06:13 PM
Senior Member
 
Join Date: Jul 2008
Location: Florida Panhandle
Posts: 11,852
View GeorgeC's Photo Album My Photos
I have bought oak plywood and construction grade plywood from Lowes and have had no problems with any of it.

George
GeorgeC is offline  
post #6 of 15 Old 03-20-2018, 09:14 PM
Vbryanv
 
Join Date: Mar 2017
Location: New Jersey
Posts: 90
View Vbryanv's Photo Album My Photos
Quote:
Originally Posted by GeorgeC View Post
I have bought oak plywood and construction grade plywood from Lowes and have had no problems with any of it.

George
The only thing that I'm semi-decent luck with is three-quarter inch plywood. But still by the time I go to use it it's not a hundred percent straight and who knows it could just be me or my garage.. I started buying better stuff just a couple weeks ago so I'll know in a few months if I still have the same problem.

As long as it's not cut I would also do what others have said and return it. I don't think I would mention that you're returning it cause its warped cause they may give you trouble

Being happy is doing the things you love to do with the people you love to do them with.. Even if that someone is just you and a power tool.
Vbryanv is offline  
post #7 of 15 Old 03-20-2018, 10:10 PM
Senior Member
 
Join Date: Nov 2012
Location: Syracuse, NY
Posts: 321
View Tom-G's Photo Album My Photos
The other day I needed one sheet of 3/4 inch 4x8 maple ply. Went to Lowes and there were only 2 sheets available. Both badly warped. The lumber guy saw me and offered assistance. They had a new, unopened pallet high on the racks..., fork lift ..., they cut the bands, unwrapped it. Set the top two sheets aside, the third sheet was flat. I checked it with a 4 foot level in several spots / directions. They cross cut off 12 inches, then two 36 inch pieces for me. Took it all home. Just needed a 36 x 48 inch piece for a project. 2 hours later I sent one on the table saw to trim to final size. One corner across the diagonal was 1.5 inches out of plane than the other!!!! ????? Grabbed the other 36 x 48 piece and it was about 1/2 inch out of plane across the diagonal. Used that one. First one will be cut into smaller pieces when I need some 3/4 inch ply.
Tom-G is offline  
post #8 of 15 Old 03-21-2018, 02:01 AM
Ancient Termite
 
Join Date: Mar 2018
Location: Huntington Beach, California
Posts: 537
View NoThankyou's Photo Album My Photos
Try Baltic Birch. Rockler, McKnight Road in Pittsburgh carries it.

I've rarely seen it warp even after years in the shop. But my humidity variances in Huntington Beach are not as volatile as when I lived in McMurray Twp.
NoThankyou is offline  
post #9 of 15 Old 03-21-2018, 09:53 AM
Senior Member
 
Join Date: Aug 2017
Posts: 2,070
View Tool Agnostic's Photo Album My Photos
I am new to woodworking, and I have a lot to learn about plywood. When I got a table saw last year, I needed some inexpensive wood to practice, build jigs, etc. so I bought the cheapest wood I could find: 3 white SPF (softwood) boards, a poplar (hardwood) board, and one sheet of the cheapest 1/2 inch plywood they had. All I wanted was a flat sheet that I could use for projects and practice.

I had remembered plywood from the 1970s. I expected gaps, knotholes, and other imperfections, but I expected flat. I ordered the plywood at the lumber desk, and I specified two cuts so that it would fit in my small-ish SUV. Next, I drove around to pick up the plywood, and was stunned at how warped and twisted it was. I felt like they had chosen the very worst board for me, but it was already cut, so I took it home. The warp was many inches between corners, much worse than reported above.

I took one of the cutoffs and tried to flatten it as a test. I wetted the concave side with the hose, placed it face down on the concrete garage floor, and stacked paving stones on it to weigh it down and flatten it. I left it for two days, but had no luck. There was no change in the board.

What worked was time. Not knowing what else to do, I placed the plywood with my other boards. They are vertical, touching the concrete on the bottom; they are bungy-strapped to a folded ping-pong table. Over time, the plywood flattened itself reasonably well, just standing up, sandwiched between other boards. It was never perfectly flat, but it was flat enough to build things with it. I am using it for shop projects, such as the cyclone/shop vac cart I made from it:

http://www.woodworkingtalk.com/attac...ion-system.jpg

The rest will get used for shelf supports in the garage:

http://www.woodworkingtalk.com/attac...upport-2x2.jpg
http://www.woodworkingtalk.com/attac...ng-end-2x2.jpg

Don't think that just because you buy expensive, premium-grade plywood that it will be (or stay) flat. I bought a piece of 1/4 inch genuine Baltic Birch to become drawer bottoms, and it warped in that same ping-pong table storage that I am currently using. How you store your wood counts, too. I am planning to put the boards on shelves with wood stickers (for airflow underneath the boards) in the near future, and make a rolling storage cart for the flat stock, such as plywood. Hopefully the warped pieces will straighten themselves out over time.
Tool Agnostic is offline  
post #10 of 15 Old 03-21-2018, 10:20 AM
Member
 
Join Date: Oct 2017
Posts: 32
View highfigh's Photo Album My Photos
Quote:
Originally Posted by PA WOODCHUCK View Post
That said I purchased a 4 x 4 piece 3/4 sanded plywood from Lowes and it's warped as all was that is on their shelf. Any tips to flatten it for use?


thanks
I stopped buying sheet goods and lumber from the big box stores because it always warped. I use one lumber company and the products have been far superior- I would look for a local supplier that doesn't sell the same brands. Full sheets that are warped are OK for construction because they're easier to flatten, but when cabinets are being made, flat is king.

My mechanic told me "I can't fix your brakes, so I made your horn louder".
highfigh is offline  
post #11 of 15 Old 03-21-2018, 01:48 PM
Senior Member
 
Join Date: Apr 2016
Location: Pennsylvania
Posts: 668
View gj13us's Photo Album My Photos
Quote:
Originally Posted by PA WOODCHUCK View Post
That said I purchased a 4 x 4 piece 3/4 sanded plywood from Lowes and it's warped as all was that is on their shelf. Any tips to flatten it for use?


thanks
What're you going to use it for?
gj13us is offline  
post #12 of 15 Old 03-21-2018, 09:34 PM Thread Starter
Member
 
Join Date: Feb 2018
Location: Western Pennsylvania near ZIP 15632
Posts: 73
View PA WOODCHUCK's Photo Album My Photos
Quote:
Originally Posted by gj13us View Post
What're you going to use it for?

Making a TS out-feed table so it should work just fine. My posting is more of a rant than anything.

Retired VW Tech, performance boats until 9/17 STROKE! Now making sawdust to keep busy!
PA WOODCHUCK is offline  
post #13 of 15 Old 03-22-2018, 10:46 AM
Senior Member
 
Join Date: Apr 2016
Location: Pennsylvania
Posts: 668
View gj13us's Photo Album My Photos
Quote:
Originally Posted by PA WOODCHUCK View Post
Making a TS out-feed table so it should work just fine. My posting is more of a rant than anything.
I get it. I try not to buy the warped stuff, but sometimes it can be o.k. if it'll be flattened by how it's used.
gj13us is offline  
post #14 of 15 Old 03-22-2018, 08:25 PM Thread Starter
Member
 
Join Date: Feb 2018
Location: Western Pennsylvania near ZIP 15632
Posts: 73
View PA WOODCHUCK's Photo Album My Photos
Almost finished as I may add some side edging/trim. Made with 2 hinges on fence angle along with swing-up legs. Comments welcomed as I'm a rookie?
Attached Thumbnails
Click image for larger version

Name:	IMG_1796sm.jpg
Views:	67
Size:	182.1 KB
ID:	350378  


Retired VW Tech, performance boats until 9/17 STROKE! Now making sawdust to keep busy!
PA WOODCHUCK is offline  
post #15 of 15 Old 03-24-2018, 05:56 PM
Ancient Termite
 
Join Date: Mar 2018
Location: Huntington Beach, California
Posts: 537
View NoThankyou's Photo Album My Photos
It looks good. The only thing that I would do is, at a minimum, round over the edge facing the saw. As you are feeding wood through the saw you don't want a sharp corner to snag the wood being cut.

Rich
In furniture 1/32" is a Grand Canyon
NoThankyou 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



Similar Threads
Thread Thread Starter Forum Replies Last Post
Best blade for cutting only plywood? Danny870 General Woodworking Discussion 15 05-26-2018 11:55 AM
Help with Plywood Stand for aquarium UsAndThem General Woodworking Discussion 10 01-21-2018 06:45 AM
Expansion - I need an education please....! new2woodwrk General Woodworking Discussion 29 01-08-2018 10:33 AM
Working With Plywood Jordan Dior General Woodworking Discussion 10 12-11-2017 11:41 PM
Sealing plywood joins/gaps in a plywood sided shed gak1952 Design & Plans 8 12-17-2015 07:13 PM

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