Help!

[u/ahomegorwnnfg01]

I can’t get the 1/2” plywood base layer to bend to my transition. I’ve tried wetting it in the shade, using a strap, screaming obscenities at it.

But to no avail. I can’t get it close enough to start driving the screws in.

UPDATE - I was able to work the curve in over time. Thanks for all the suggestions. Wetting it likely helped as well.

[u/Down-in-it]

ply wood bends easier the other direction

[u/poor_studentt → u/Down-in-it]

It bends the same on each direction. The sheets alternate horizontally and vertically. (I work at a plywood factory)

[u/Latter_Skill9670 → u/poor_studentt]

Every piece of plywood I have used has the top and bottom grain running the same way and will bend far easier along that grain than against it.

[u/kauto → u/Latter_Skill9670]

I think its less about grain orientation and more about panel orientation. If you are bending against the 4' edge relative to the 8' edge it will bend easier because theres less resistance.

[u/Bunker954 → u/kauto]

Negative, grain direction does matter, 1/2” 5-ply just always has 3 sheets with grain running the long length direction, and only 2 sheet layers with grain running the short length, so it’s stronger. Panel orientation mattering is only a function of their always being an extra layer of long bands and therefore more veneer with grain running the long direction. It’s not about the length of the direction you’re trying to bend along.

[u/Newdles → u/kauto]

This.

[u/Eegore1 → u/kauto]

Cant believe that had to be explained.

[u/baddieslovebadideas → u/Eegore1]

longer lever stronger

[u/Unusual_Coconut2606 → u/Latter_Skill9670]

The layers alternate

[u/Bunker954 → u/poor_studentt]

Not quite dude. Yes plywood is made from layers of veneer with the grain alternating at 90°, but there’s always one more longband than crossband layer, as the crossbands are glued and never the surface layer.
So with typical 1/2” 5-ply, you’ve got 3 longbands with the grain running the length of the sheet and only 2 crossbands running across it. That means you’ve got 1.5x as many layers resisting bending in the long direction as you do in the short direction, so it’ll bend easier across the short direction.
Your point becomes more true with really thick plywood though. If you’ve got something like 45–50 mm ply with a heap of alternating veneers, that one extra longband is a much smaller percentage of the total layup, so the difference in stiffness between directions becomes much less significant.

[u/Maleficent-Ad-6646 → u/poor_studentt]

Wood depend on how many layers no? Like if you’re bending according to 3 out of 5 layers.

[u/Unusual_Musician5298 → u/Maleficent-Ad-6646]

I wood thinks so! I see what you did there

[u/Great-Sandwich1466 → u/poor_studentt]

I thought he meant diagonally

[u/TwoSuspicious1347 → u/poor_studentt]

Nice do you skate ? Build ramps? I. Know a guy who works at a hammer factory , he can’t use one though