Million Dollar Question!

[gracewriter]

If you could only afford about $30.00 per 4' x 8' sheet of plywood (not MDF, MDO, but actuall plywood) at 1/2" thick what would you use?

I am trying to make interior signs/wall hangings. Used sandeply for the first one but noticed it warped a little. What type of inexpensive plywood would you recommend that is stable and will stay flat. the signs are 24" x 48" and some will be 24" x six feet.

Need them not too heavey, but 1/2" thick.

[signtist]

MDO is the best for the finish. Especially for interior, where you see it up close. ($43 here in San Diego)
PS. . . .they all warp a little.

[Gary Campbell]

Jude...
There are virtually no inexpensive plywoods that will stay flat. There are very few expensive ones either.

You dont mention if you are painting, staining, carving or applying letters to the sheetgoods. Try to get flat sheetgoods, cut to size, stack overnight, then apply a sealer to both sides and all edges, let dry and restack.

If you are painting and not V carving, as John says, MDO is great to paint. If you are staining, try a MDF that is veneered on both sides. If you need to stain or clear finish and V carve, I would use stress relieved wood staves, tempered after glueup. We have some of them hanging on a nail or 2 for over a year in our humidity with no warps.
Gary

[harryball]

About the best I've been able to do is 1/2" ACX which fits your price range. It varies, but I find it generally flat if the vendor stores it properly. Keeping it flat when stacked is important and because it is exterior grade it resists moisture better. Still warps though, you'll have to secure it well.

/RB

[gracewriter]

Thanks for your responses. I'm handpainting them with stencils. Also did a gold leaf for the first time but ruined it with a cheap acrylic spray.

MDO if it's anything like MDF is way too heavy and more expensive. When I get more established off line, I'll start using the more expensive materials. Right now I need cheap and flat.

Never heard of ACX. Does it have a smoothe finish or would it require a lot of sanding to get it smoothe? The sandeply has a smoothe finish, just sort of "fuzzy" even after sanding it.

Thanks!

[chodges]

The material you want is LusterBoard: marine-grade plywood, with aluminum laminated to both faces. The aluminum has a baked-on white enamel finish. This only comes in 1/2" thickness where I live (Memphis, TN), and it is VERY rigid, so it stays flat much better than plywood.

We buy ours at TubeLite.

The only problem is the cost - wholesale is about $120 per sheet.

[gracewriter]

What is flat sheetgoods. I can't find a definition. Also none of the lumber yards know what ACX is.

[gracewriter]

How much does the lusterboard run?

Thanks!

[blackhawk]

Jude - ACX is a type of plywood. "A" means that one side is of top quality. "C" means that other side is of low quality, knots, small cracks etc. The "X" designates that it is manufactured with eXterior grade glue. I am surprised thay your lumber yard has never heard of it. The A side should be sanded very smooth from the factory.

[harryball]

I have to doubt the aptitude of a lumber yard that does not know what ACX plywood is.

I've found Lowe's carries it in some stores.

/RB

[gracewriter]

I went to HD, Shell's which is an authentic lumber yard, Sheridan lumber, which is another authentic yard, called Causeway lumber, called a few other lumber places down here and none of them knew what I was talking about with the ACX.

Are we just a bunch of dumb sh*ts down here or what?

I "picked" as many brains as I could about lumber/plywood today, figuring they know more than I do, right? <---they do NOT! The end result was stick with MDO or sandeply.

The guy who said to stick with sandeply said it was just as flat as and strong as MDO, so what did I do ? I bought another sheet of sandeply, had it cut into quarters and it was warped before I even got it home. The MDO appears to have made the trip home without warping, but tomorrow I'll be able to report if it warped or not. He even said the MDO may warp? Hello? I never heard that before (but he didn't say that until after I purchased it!?). Took my confidence in the $50.00 per sheet MDO next to zero!

[tuck]

LOL, Jude, what did you say?

[Gary Campbell]

Jude...
The Sandeply is as strong as MDO and when sold, maybe as flat. However, the 2 layers of resin coated paper on both sides give it both a great surface to paint and stability. The MDO will stay flatter. Use the methods I listed above.

If you are working in AC then it may help to buy from one of the big box stores. If not buy from a yard that has a non AC'd warehouse. Sealing and stacking in the AC with weight will help them stay straight, but takes a couple weeks.

Reinforcing the edges will help the panels stay flat. Try using staight material, preferably a hardwood at least an inch square, machine a dado to accept the plywood in one side, then make a mitered frame to surround the plywood panel. Glue up and seal all sides well. Good Luck
Gary

[beacon14]

The sad fact is that there is no 1/2" plywood panel that will stay flat, period. Some will bow, some will warp (twist), some will cup, but none will stay flat. You might find that some stay flatter than others but you are fighting a losing battle. The very nature of gluing all those layers together with the grains running at right angles in every other layer introduces stresses into the panel as the wood expands and contracts due to changes in humidity. Wood moves more across the grain than along the grain as the humidity changes, and nothing you can do will stop that. So all those layers are fighting one another, trying to move in two directions at once, and the result is that the plywood will take on a different shape tomorrow than today.

You might try 1/4" plywood, reinforced with a frame, but I think you would need a fairly wide frame profile if you really want to ensure that the plywood stays as flat as possible - something like a 1x4 on edge (sticks 4" out from the wall. Assuming you can find straight 1x4's - good luck with that.) Most if not all plywood is sold with the idea that the end use will usually involve attaching the plywood securely as part of a larger construction, like a cabinet or a building, which will keep the panel flat, or at least as flat as it needs to be. Very few people use plywood by itself, just hanging on a wall like a picture. Now you know why. And the fine folks who work at lumberyards (not to mention most other businesses) usually know a lot more about selling the stuff than using it, which is understandable.

Sorry I couldn't give you the answer you are looking for, but you did ask for someone who knows plywood and wood to tell you the straight story. Gary is right that the paper and glue layers help stabilize and stiffen the MDO so you might have better results with it. The only time I used it was many years ago and the sheet I got only had the paper on one side - warp city. Never used it since.

Maybe that's why painters use canvass instead of wood - no warping.

[artisan]

Hi David.....Actually, most Professional Painters prefer wood panels to canvas. They use canvas because it costs less. Professionally prepared wooden painting panels far outlast canvas....D

[tuck]

Hey Jude, don't make it bad...
Take a sad song and make it better...


Seriously, I may have the ultimate answer for you, but it's gonna cost. If it just HAS to be 1/2" and warp proof, there is a product we use in the sign business called 'Nu-Alum'. It's 1/2" exterior grade plywood laminated with thin aluminum on both sides and it WON'T warp:

http://www.alumapanel.com/products.cfm?step=1&lines_ID=290

If what you're wanting to do can be about 1/4" thick, you might think about "Polymetal" 6mm:

http://www.alumapanel.com/view_product.cfm?step=1&lines_ID=292&name=Polymeta l%20%2D%20Black

Both of these products are very stable and I can attest to that. They are just more expensive than what you want to spend but, Hey Jude, you get what you pay for. Naaaa Naaaa Na Na Na Na, Heeeey Jude! ;-)

[tuck]

Add to say, Jude, I don't know why my links won't work. Let me try again, please?

Nu-Alum: http://www.alumapanel.com/products.cfm?step=1&lines_ID=290

Polymetal 6mm: http://www.alumapanel.com/view_product.cfm?step=1&lines_ID=292&name=Polymeta l%20%2D%20Black

[gracewriter]

Thanks A LOT everyone!

Shew! I really needed to vent. So now that I know the whole story, I know my competitors are having the same problems (and seriously doubt they are using anything as expensive as MDO. And that's probably why none of them are making signs out of wood much larger than 24" wide. Probably just pick through the lot and choose the straightest ones, paint, cross fingers, and ship.

I picked up two different kinds of MDO. One is already primed on both sides (never in my life have I seen primer put on that thick) and the other has the "paper" on both sides, I haven't pulled them out yet today, have them stacked flat on the floor in my office, (hope the lower humidity doesn't mess them up before I have a chance to paint) but if they look good enough, then I can charge a whole lot more money for the ones that stay straight. The rest I can cut smaller signs.

I'm just trying to get started online where I know I can make a little money. I have no idea how to sell these things in the real world. Hopefully I'll figure that out after a while.

The signs have a unique finish using crackled paint. I have a cutter that will cut all types of vinyl I use as stencils (by the way if anyone needs anything cut for a small sign, let me know. I have some marine grade black at the moment and a few other colors in the cheaper grade. I'd gladly do it for free at this point if the job isn't too big and I don't have to go and buy more vinyl. I could use some experience.

Funny thing is, just the rough low grade plywood seems to stay straighter than the sandeply. I can use that, just wanted to do some finer finishes in black which won't work with that material.

Attaching the larger ones to a frame seems the way to go. The guy at the lumber yard said Mahogany and white wood were the way to go with putting a frame on the underside. He said the white wood was harder than the Mahogany.

Is this true? He also said the sandeply would stay as straight as the MDO, which it incredibly inaccurate.

If I knew the type of wood many picture frames are made out of would be helpful. I used to own a frame shop and some of that wood was amazingly strong and straight.

Any ideas other than a 2x4?

Thanks!

[gracewriter]

Sorry, I see I already asked that question in my earlier post.

Darrell,

What type of wood panels do those artists use?

[waynelocke]

Plywood is not warp free in any grade. It is dimensionally stable which means that it does not change dimension in the width and length of the panel and stays straight along these dimensions. I think this is where the notion of flat panels come from. If you can cut the supports from the plywood they should be straight. Perhaps they can be set in a few inches from the edges to create a reveal — if you can't fix it, feature it.

The real test of a panel is in the core. Cheaper grades of ply have lesser quality cores. The face veneers, excluding the mdo and aluminum faces, etc., have almost nothing to do with strength or straightness. Rest assured that the cheap Oak has a cheap core. Comparable grades from the same manufacturer usually have the same cores, i.e. the only difference between the walnut, mahogany, oak, etc. plywoods they offer are the face veneers. The notion that oak or any other species of plywood is stronger than another is ludicrous. Anyone passing that info off is either ignorant, dishonest or both. Oak ply from manufacturer A may be stronger than from manufacturer B but the oak has nothing to do with it.

Avoid chinese plywood like the plague. It seems to be preformed for boat hulls. For the best plywood, spec domestically produced. It is almost always better (with a big*).

How are these hung? If they are screwed to the wall, your problem is nearly solved.

Finally, to try to keep the painted panels as flat as possible, you need to paint or finish the backs with the same stuff as the fronts.

[joe]

Scooter Board

[gracewriter]

Thanks Wayne. That was incredibly helpful.

The reveal is an interesting idea.

[gracewriter]

scooter board?? Most women love men of few words. Can't imagine why.

[jdoug5170]

Jude, look up Sintra via google...I think you will find this a material that will best fit your bill...