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Bending for Curve how to?

PostPosted: Tue Mar 06, 2007 6:53 pm
by Lynn Coleman
Hi all,

We have a quarter curve on the top of the Inkwell. We have a 1/4" luana(Which is slightly less than 1/4) and can't bend it around the curved sides.

Do we need to steam the wood? Can we just soak the wood in a pool?

Should we purchase a 1/8" luana? If so how do you glue the two sheets of luana together? Do we need to make a mold?

Let me know how you all have handled this, I'd hate to cut those beautiful matching curves off and angle them straight as we originally had planned.

Thanks for the help,
Lynn & Paul

PostPosted: Tue Mar 06, 2007 7:00 pm
by madjack
Lynn, the 1/4 will bend much easier on the width than the length...if that is nor possible then steaming is a good way...have ya got one of those home steam cleaners or like Heikki, a sauna...if not, lay some towels on the ground...pour boiling water on them, then the ply and then more towels and more boiling water...repeat if needed.....
madjack 8)

PostPosted: Tue Mar 06, 2007 7:10 pm
by Lynn Coleman
madjack wrote:Lynn, the 1/4 will bend much easier on the width than the length...if that is nor possible then steaming is a good way...have ya got one of those home steam cleaners or like Heikki, a sauna...if not, lay some towels on the ground...pour boiling water on them, then the ply and then more towels and more boiling water...repeat if needed.....
madjack 8)


Wow, Madjack towels and boiling water will work, awesome. Yes we had to use the length because the Inkwell is 79.5" wide on the outside.

Will gluing and screwing it down be enough to hold it in place or do we need some sort of clamp system?

Lynn

PostPosted: Tue Mar 06, 2007 7:19 pm
by Classic Finn
Lynn Coleman wrote:
madjack wrote:Lynn, the 1/4 will bend much easier on the width than the length...if that is nor possible then steaming is a good way...have ya got one of those home steam cleaners or like Heikki, a sauna...if not, lay some towels on the ground...pour boiling water on them, then the ply and then more towels and more boiling water...repeat if needed.....
madjack 8)


Wow, Madjack towels and boiling water will work, awesome. Yes we had to use the length because the Inkwell is 79.5" wide on the outside.

Will gluing and screwing it down be enough to hold it in place or do we need some sort of clamp system?

Lynn


Lynn that should work as Madjack stated, I used a lot of inexpensive clamps so it would dry to the radius or close and installed it before it was totally dry. Us Finns are Sauna Loving people as you most likely know... and thats what I did was steam our ply in the Sauna... 30 minutes at about 85 celcius sure got that ply to bending in no time...plus it was clean as well as the Finn himself... :lol: :lol:

Image

Best regards
Classic Finn ;)

PostPosted: Wed Mar 07, 2007 12:41 am
by asianflava
When we checked out the RV show last weekend, there was a travel trailer that had an infared saund in the nose. It amounted to little more than a woon lined closet, but it sat 2 people. Just when you thought you'd seen it all.

PostPosted: Wed Mar 07, 2007 2:05 am
by madjack
Lynn Coleman wrote:
madjack wrote:Lynn, the 1/4 will bend much easier on the width than the length...if that is nor possible then steaming is a good way...have ya got one of those home steam cleaners or like Heikki, a sauna...if not, lay some towels on the ground...pour boiling water on them, then the ply and then more towels and more boiling water...repeat if needed.....
madjack 8)


Wow, Madjack towels and boiling water will work, awesome. Yes we had to use the length because the Inkwell is 79.5" wide on the outside.

Will gluing and screwing it down be enough to hold it in place or do we need some sort of clamp system?

Lynn



...glue and screw should work just fine...why clamp something that is ALREADY screw down :D ;) ........ 8)

PostPosted: Wed Mar 07, 2007 2:29 am
by Podunkfla
Lynn... Having looked at your album pix... That is a pretty tight radius for bending 1/4" luan methinks. First off I would suggest you add a spar at the center of the radius on both ends to give you something to bend it around better. If you have trouble using 1/4" ply, you can get 1/8" luan doorskins at most big-box stores cheap. They come about 3' x 80" size to recover most doors. So, I think they would work fine for your TTT. You can use cargo straps to hold them in place while your glue dries. Laminating two plys is a good idea too... add the second ply after the first one sets up movernight. I'd prolly use PL urethane glue for bonding that second layer. It comes in a caulking tube. You can also wet the doorskins and roll them up with the cargo straps to "pre-bend" them a lot even before you cut out your pieces to glue in place... letting them dry overnight.

Best of luck... your TTT is lookin good. :thumbsup:

PostPosted: Wed Mar 07, 2007 9:47 am
by Keith B
That's a pretty tight curve... I'd probably go w/ two sheets of 1/8"...I had to on my back curve because it was a little to tight.. If you bend ply to tight and hear any cracking or see splitting you've split the fibers, which eventually w/ time will seperate the lamination w/ humidity, etc.. thus you need steam or something like MadJack told ya..GO SLOW...if you use 2 sheets of 1/8" and even if you get a little ridge, you can fair it out w/ some epoxy later... I would use a backer board when glueing and screwing down and use a waterproof construction adheasive and let 'er sit for a couple days... if you check out my album you can see the "backboard" I'm talking about when I did my roof, you just have to fill the screw holes later... no big deal. I used Leech F-26 - Liquid Nail is very similar.
Image

PostPosted: Wed Mar 07, 2007 10:11 am
by madjack
Lynn, the gize are right...you may have to go with 1/8th but if you have the 1/4 already, try the boiling water/towel method (doit a couple of times) and see what happens...you will probably haveta use some tiedown/winch straps with some backer boards to get it to pull into place...and even then??????? .......good luck
madjack 8)

PostPosted: Wed Mar 07, 2007 11:01 am
by Keith B
Lynn... I just looked at your album again... your curve is prett tight...but I don't think you have enough spars in the curve area... personally, I put my spars 6" apart on a 2' curve and 3" apart on the back, a 7" curve... I might not see them in your album...but you need spars in the curve, otherwise the plywood is going to try and follow then "bend" on your walls, but in the middle where there are not spars, it's going to want to straighten out and/or pop up, and you have NO gluing surface....as you probably know, and are worried about, the curve is crititical to have tight and secure which means you need glue surface... I'm sure the more experienced guys can tell you exactly what needs to be done as far as spars...but I'd add at least 2-3 in that curve area. Guys.. you might look at his album to make sure I'm giving correct advise...if I'm not, I'll delete this post and slap myself for speaking out of turn... :lol:

PostPosted: Wed Mar 07, 2007 11:09 am
by madjack
Keith B wrote:Lynn... I just looked at your album again... your curve is prett tight...but I don't think you have enough spars in the curve area... personally, I put my spars 6" apart on a 2' curve and 3" apart on the back, a 7" curve... I might not see them in your album...but you need spars in the curve, otherwise the plywood is going to try and follow then "bend" on your walls, but in the middle where there are not spars, it's going to want to straighten out and/or pop up, and you have NO gluing surface....as you probably know, and are worried about, the curve is crititical to have tight and secure which means you need glue surface... I'm sure the more experienced guys can tell you exactly what needs to be done as far as spars...but I'd add at least 2-3 in that curve area. Guys.. you might look at his album to make sure I'm giving correct advise...if I'm not, I'll delete this post and slap myself for speaking out of turn... :lol:



...you are correct Sir............................... 8)

PostPosted: Wed Mar 07, 2007 11:54 am
by Keith B
Lynn: Here's a photos of my spars in place... again, my space was 6" apart on the 2' curve, 12" apart everywhere else and 3" apart on a 7" curve (back)... I used 1/4 everywhere except at the 7" curve, I then used 2 sheets of 1/8", applied 2 days apart. The height difference between the 1/4" and the two 1/8" pieces is MINIMAL, and will easily be faired out w/ epoxy later. My album has more photos of the install if you care to peak at them.
Image

PostPosted: Wed Mar 07, 2007 12:08 pm
by Todah Tear
This method was suggested in one of the threads. I used it and it worked. Put a tarp down and lay your material on it. Wet it down. That will make it more flexible for bending.

Todah

PostPosted: Wed Mar 07, 2007 6:14 pm
by Lynn Coleman
Keith B wrote:Lynn... I just looked at your album again... your curve is prett tight...but I don't think you have enough spars in the curve area... personally, I put my spars 6" apart on a 2' curve and 3" apart on the back, a 7" curve... I might not see them in your album...but you need spars in the curve, otherwise the plywood is going to try and follow then "bend" on your walls, but in the middle where there are not spars, it's going to want to straighten out and/or pop up, and you have NO gluing surface....as you probably know, and are worried about, the curve is crititical to have tight and secure which means you need glue surface... I'm sure the more experienced guys can tell you exactly what needs to be done as far as spars...but I'd add at least 2-3 in that curve area. Guys.. you might look at his album to make sure I'm giving correct advise...if I'm not, I'll delete this post and slap myself for speaking out of turn... :lol:


Hey Keith,

Thanks for taking a second look. You're right there are no spars, yet. :R

We plan on having some 3/4 ply curves in the middle, 2 more per curve. Which will be slightly more than 1.5' between each curved piece. Do you think we'll still need spars with that short distance?

Lynn

Here's another question

PostPosted: Wed Mar 07, 2007 6:18 pm
by Lynn Coleman
What about making grooves approximately 1/4" between each cut? Then adding TiteBond III in the grooves just before we put it up on the frame? What do you all think about that?

Lynn