I bought an 8x4 of 1/2" birch plywood at Home Depot the other day to cut up to serve as part of the table top for my L girder bench work. I had them cut it into two 4x4 so I could fit it in the car. Lo and behold when I get home I see that one of the 4x4 appears to be a little bowed (didn't look that way in the store of course). I just ripped up some work I did because the piece of 1/4" plywood I had it based on had a hump in it that I didn't see and don't want to repeat that experience. Any suggestions on how (if) I can flatten out that 4'x4' to make it useful?
Cut it more times where it humps, and then screw the %*S$& out of the pieces when attaching to your framework? Not sure if your frame is rigid enough?
What type of ply did you get? The cheaper stuff that is used for sheathing homes is prone to warping and thats okay because it straightens out when nailed into the studs. If you bought quality sanded ply I would return it and get a good piece. You can put it on the floor at HD and see if it is warped. If you want to clear out the warp in what you have, you could attach some STRAIGHT 1X3 or 1X4 to the bottom by running screws through the top of the ply. Edit: Just saw that you bought birch ply. Return it, get your money back, and go to a lumber yard and get some good ply. I've never been a fan of Home Depot and most of the wood they get is cheap and dried too quickly. Eric
Most plywood is made of veneers spirally cut from a spinning log. (Think of toilet paper unrolling from the roll). Those veneers naturally want to maintain their original curled shape rather than their forcefully flattened state. When they change moisture content, they can change shape pretty noticeably. If you want something that will stay flat consistently, don't use 1/2" plywood. Furniture grade plywood, availabe at real lumberyards (not big box stores), has flat cut veneers and is very stable, yet pricey. I've paid $60 per sheet for 25/32" A-A birch ply. Lowes, Menards and Home Depot usually carry medium-density fiberboard (MDF). 3/4" MDF sells for around $25 per sheet in east central Illinois. It is totally flat, pretty stiff and heavy. It is excellent for paint-grade cabinetry and interior trim. Sounds to me like you're expecting too much from your plywood.
Welcome to HD!! If you want the good unwarped sutff you have to break a sweat to get to it. I've never bought a piece of lumber at HD that I didn't have to dig at least 10 pieces down into the pile till I found a piece that is acceptable. That goes for furnature or layout material. Once you've had it cut good luck returning it. One option you may have is to kerf cut the underside length wise half way through and then, as mentioned earlier, screw the "#$*%&#" out of it into your benchwork and hope that takes the bow out. Other options are: 1. Have an expensive bonfire and start over again 2. Model around the hump and call it nature at its best. Hope you find an answer to your delema. Brian
Plywood I've purchased the HD birch plywood for both Facilities cabinetry work and home shelving. Close to 3/4" thickness, 7-ply, Made in China (fine print). The plywood warps waiting for you to cut it. Cut sections of this inexpensive plywood are too expensive to straighten or aligned. Go to a real lumber yard for a better quality of wood.
One of the many reasons why I have given up on wood. When I built my last layout, I used PVC piping and foamboard. It was light enough to pick up a 2'x10' section of mayout that was fullu seniced with one hand yet strong enough for me to sit on. Best of all, the materials cost about 2/3rds that of wood and do not expand, contract or warp when wet like wood. I am a few years away from waterproofing my basement so it will be a while before layout construction, but when I do, you beter belive it will be PVC/foamboard again.
Like many here, I've never found good lumber at Home Depot. I do have good luck at Lowe's--but I still need to dig down 8-10 sheets into the pile. I use 5-ply, and 5/8" thick. Despite my best efforts, there is always just a little warping. It's wood, after all. It turns nice and flat with a rigid frame and some judiciously placed supports and screws, along with a nice long level to check things. I'm very happy with the final product.
Agree on the PVC! So easy to be accurate, stable and true thru all adversities. My layout is on an unenclosed , but roofed, patio and have not experienced any of the bad things that would occur with wood framing in that environment.
Sounds like an interesting idea. You've probably talked about this before and I just missed it. I can understand how the pvc pipe might be used for the legs and bracing, but what fittings or attachments do you use to get a flat base to support the foam sheets? Thanks Ed
I remember having this issue when I built my bench work, although maybe not quite as bad. Mine straightened right out after screwing it into the frame. I started on one side and worked over to the other using plenty of drywall screws. Solved my problem. I'd have to back to my bench work manual to re-familiarize myself with the different styles, but I'm wondering if the "L-girder" style is not giving you enough of a frame (mainly cross members) to screw into.
