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bending 1/4" oak plywood

PostPosted: Sun Feb 13, 2011 5:15 pm
by LDK
I'm using 1/4" oak plywood for my interior ceiling and I'm having issues with it. The front radius is 25 inches and I knew before hand it would be a bear to bend so I'm using two sections. I'm hiding the seam in the front cabinet. The reason I'm going with 1/4" is because I couldn't find 1/8" locally. I'm trying to bend it against the grain about 8 to 10 inches from the edge. I don't have to bend much, just alittle. Any input would be appreciated.
Thanks

Re: bending 1/4" oak plywood

PostPosted: Sun Feb 13, 2011 7:32 pm
by KenC
LDK wrote:I'm using 1/4" oak plywood for my interior ceiling and I'm having issues with it. The front radius is 25 inches and I knew before hand it would be a bear to bend so I'm using two sections. I'm hiding the seam in the front cabinet. The reason I'm going with 1/4" is because I couldn't find 1/8" locally. I'm trying to bend it against the grain about 8 to 10 inches from the edge. I don't have to bend much, just alittle. Any input would be appreciated.
Thanks


I've read that using hot towels placed over the area you want to bend helps, I'm not at the build point of my headliner so I have no experience with it, also bending with the grain instead of against it creates less resistance as well, so I've read.

PostPosted: Sun Feb 13, 2011 8:26 pm
by Wolffarmer
Water+heat+muscle.

It is a contest of brute strength.

As Ringo said "You know it don't come easy"

Randy

PostPosted: Sun Feb 13, 2011 8:46 pm
by LDK
Image

I refuse to give up!!!!! :lol:

PostPosted: Sun Feb 13, 2011 9:01 pm
by Wolffarmer
You will get it yet.

"You don't have to shout or leap about"

Randy

PostPosted: Tue Feb 15, 2011 7:29 pm
by Bucko6
Try making some relief cuts on the other side. Try on a scrap piece first. I did a 24" radius with 1/4" birch. I cut about 2/3 of the way through every 1", used hot wet towels, rachet straps and a few choice words. Finally got it.

PostPosted: Tue Feb 15, 2011 7:41 pm
by LDK
Bucko6 wrote:Try making some relief cuts on the other side. Try on a scrap piece first. I did a 24" radius with 1/4" birch. I cut about 2/3 of the way through every 1", used hot wet towels, rachet straps and a few choice words. Finally got it.


I can't really do kerfs because this is the interior ceiling. When I do the outer skin, if it doesn't want to bend I'll most definitely do that. :)

PostPosted: Tue Feb 15, 2011 7:48 pm
by Bucko6
Cut the reliefs on the side of the plywood you won't see.

PostPosted: Tue Feb 15, 2011 11:33 pm
by LDK
Bucko6 wrote:Cut the reliefs on the side of the plywood you won't see.


I think the kerfs are suppose to be cut on the inside of the bend. I never actually cut any so maybe others that have could chime in on this subject. :thinking:

PostPosted: Wed Feb 16, 2011 12:41 am
by droid_ca
do you already have your spars in cause there is one way that I saw on here where the guy pre attached his spars to his ply and put on some temporary hangers to keep the ceiling up nice and snug looked like a good trick

here it is for those interested
http://tnttt.com/viewto ... ht=#792925

PostPosted: Wed Feb 16, 2011 5:39 am
by H-Balm
I just posted how I did mine a little while back.


http://www.tnttt.com/viewtopic.php?t=36429&start=15


The inner skin is up!

Image

So, how did I get the plywood to go up in December in the cold New York Winter?

Voila!

Image
Image

Car jack tipped on a side.
Pressed onto a large scrap board strung between the doors.
On the jack, a 4x4 post pushing on an old plank.
Every 20 minutes go crank the jack a bit, then go watch tv/read a book. Slowly it will get up there along the way I would apply glue as it got closer to the spars.

PostPosted: Wed Feb 16, 2011 7:07 am
by LDK
Those jacks come in handy sometimes.

Image

I ended up using drywall screws and fender washers to make sure the ceiling stays put. They will be hidden inside of the back cabinet anyway.

PostPosted: Wed Feb 16, 2011 10:35 am
by cuyeda
Only a suggestion, and have yet to perform this myself on a larger sheet of plywood. I've always thought steam was used to soften wood for bending. Combined with the hot towels to help soak the plywood, heat from a clothes steamer may help.

PostPosted: Mon Feb 21, 2011 9:06 am
by Classic Finn
I bend almost all my ply in the famous Sauna which is a part of the Finnish Culture. It will bend anything. Even the person using it if not careful. Plenty of heat and moisture. :lol: :lol: :lol: ;)