Bent plywood lamination building mentor wanted

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Hi,
I'm looking for someone that has done this type of wall construction to either talk me out of it or Help walk me through it, I've got some spefic questions and might need a couple phone calls for explanations that get to wordy for print.
My gratitude and some beers is about all I can pay.
MS

[tony.latham]

Hi,
I'm looking for someone that has done this type of wall construction to either talk me out of it or Help walk me through it, I've got some spefic questions and might need a couple phone calls for explanations that get to wordy for print.
My gratitude and some beers is about all I can pay.
MS

Are you talking about creating a solid piece of plywood, bent to a teardrop shape that's 1/2" to 3/4" thick or are you thinking of laminated ribs laid up in a form/mold and glued into a lamination?

Tony

[bobhenry]

http://www.wikihow.com/Bend-Plywood

A note: I needed a fairly sever bend in the chuckwagon build. I tried 4 layers of 1/8 and they kept splitting. I moved to 1/4" and it resisted the shape needed to the point I didn't even try and force it. It was June and hot as hell so I took a kiddy pool weighted the sheets with a cement block and soaked the sheets under a black piece of Visqueen for 2 days. I sawed up a form and draped the soaked layers all at once on the form and cinched them down with 3 ratchet straps. Gave them 2 more days to relax and dry out somewhat. I then separated them to dry thoroughly so they could be glued. Replaced them on the form one more time to relax and the next day glued the devil out of them and reclamped. It was only about 1/2 hour every day or two so it wasn't nearly as labor intensive as it sounds. The end product passed muster with my needs.

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My plan is to use 1/8? Inch plywood in 1 1/2 wide strips (width depends on the least waste) bent around a continuos form front to back glued etc. I made tobbogins for the kids it's not the bending part but more the details like feathering the ends at the bottom plate gauging spring back if any and so on. I'm building 3 complete trailers to start so I wanted to continue building more walls as I go and let things dry and work the rest of the build.

[tony.latham]

My plan is to use 1/8? Inch plywood in 1 1/2 wide strips (width depends on the least waste) bent around a continuos form front to back glued etc. I made tobbogins for the kids it's not the bending part but more the details like feathering the ends at the bottom plate gauging spring back if any and so on. I'm building 3 complete trailers to start so I wanted to continue building more walls as I go and let things dry and work the rest of the build.

Your ahead of me with that toboggan.

I recently built a small table-shelf for my wife's recliner using several layers of 1/8" Baltic birch glued into a 90º "bend" (an inch thick). It came out great and has no spring back of course.

Are you laminating like this or just planning on bending 1/8" plywood? I'm a bit unclear on what your plan is.

Tony

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Hence the problem with my written word. How about this, take a large soft cover book and bend it to form a teardrop trailer profile shape with the pages being the pieces of plywood forming the wall?

[Xanthoman]

I have never myself done a bent lamination of this extent but I have read up on them to a very high degree and have friends who have. I am also planning on a unique method of making my teardrop which may use some of the same methods. I do best with a piece of paper in front of me so skype or FaceTime might work best. Feel free to call/text and we can set something up. 719.761.5o27. ~Joshua


Sent from my iPhone using Tapatalk

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Joshua, just sent you a PM
MS

[tony.latham]

Are you planning on a male and female mold?



Tony

[KCStudly]

I made laminated edge pieces to cap the foam of my galley walls. You can read about my exploits cutting slats here, a ways down this build entry and building the jig and glue up here.

The two biggest lessons learned were: 1) That I should have made the slats wider than the desired finished width of the piece. Due to irregularities in the fir dimensional lumber I used and a less than perfect table saw I ended up with irregular surfaces on the edges of the glue up that had to be planed down after. That left the pieces too narrow and I ended up scabbing 5mm ply ribs on to get the thickness back. It didn't matter on my build since they were buried under epoxy/FG and eventually paint, but it was more work than it would have been. 2) I should have waited to build them until I was ready to install them. I did these ahead because it was something I could do while waiting for other materials. When they came out of the jig there was essentially no spring back, but 8 months later when I finally went to install them they had flattened out significantly. I had to use long pipe clamps to pull them into the wall, and up until I glassed the outside of my walls I think they were still moving around enough with weather and sunlight changes that it affected my work trying to get the hatch gasket gap right; it was a moving target (not that you wouldn't have the same problem with most any wood, but I felt the internal stress may have been an issue).

There is another build here, although incomplete, that uses steam bent wood extensively. I wish I could remember the name.

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First off I can't figure out how to link to a YouTube selection but it's rancher12121

Tony, I think a little of both but mostly using pressure from clamps to draw in the strips? But I had planned to use wedge shape pieces pushed against an upper block to save on clamps kind of like shimming a door ( >=< )

KC, I'm planning on using plywood strips but I have made long miter slot table saw jigs to rip thin pieces before so getting uniform strips is more a matter of how much waste I can afford. I read through part of your build and honestly I hadn't given a thought to bending everything at once I one giant bend, my plan was one or two strips at a time and covering the entire jig one layer at a time from the bow curve at the sill plate to the aft end sill Im building a modified benroy ish thing.

questions
1; how to secure the bent layers to the bottom sill as I go
2 can I make thinner ribs front to back (like canoe ribs but length wise) install all the spars, bracing etc then cut out the sections that are in the way similar to jack and cripple studs in house framing.

For the cost of some plywood and my time I willing to try it to see if it's a workable plan, most of the time what works in my head does not follow in reality, so all ideas, critisisims, suggestions whatever please fire away

[tony.latham]

I think you're trying to make this thing toooo complex... besides, insulation in a teardrop more-or-less does away with the condensation problem.









That's 1/8" Baltic birch, inside and out.

Tony

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Sorry Tony , it's my attempt at trying to explain it and ask the approximate questions that's at the heart of the problem, really all I'm trying to do is make a laminated bow in the shape of each wall (1 5/8s wide) and skin that. One of my engineer friends came by yesterday and after a few beers we had most of my issues worked out of the design, I'm told first time builders tend to over build and over think and under estamate the time involved.

Only question that still remains is,if cost of the ply is not a consideration what is the best material? I have access to any material I want, but buying a full bunk if I'm the only buyer is out of the question.
MS

[tony.latham]

Having built three teardrops, I'm extremely satisfied with the 5x5' 1/8" Baltic birch sheets that I can get in this one-lumber yard town that I live in. (I'm three hours from the nearest Lowes/Home Depot).

The stuff has no voids and you can throw a scrap piece in a bucket of water and it won't delaminate after weeks. I don't recall how many I order for a teardrop, (10? 12?) but the local yard has the number of sheets for me the following week. I think $15 a sheet or some such price. It's really high quality. Brand? I don't know, but I haven't read anyone here having problems with it. The yard here also stocks a few sheets of 3/4" and 1/2" and it too is of the highest quality. Makes AC plywood look like seconds from the CDX pile.

As I mentioned, I laminated nine 3" strips into a 1" thick "bent" piece with an 8"--90º curve. Worked great using two molds and lots of clamps. The stuff really wants to bend (in one direction).

I suspect if you ask your lumber yard (not a box store) to order the sheets for you, it won't be a challenge to get without having to order a bunk.

A lot of people on this forum use lauan plywood for there builds with varying levels of success (great to not-so hot). It's my two-bit theory that lauan is a generic term with great ranges in quality. It's the near- 1/8" ply that Home Depot sells. But I get this so-called knowledge about lauan from reading the posts, not from using the stuff.

Take some pics!

Tony

[noseoil]

+1 on the 1/8" Baltic Birch plywood. I get mine from a cabinet-shop distributor locally (hardwoods & veneer plywood for the building trade). It's great stuff to work with as Tony said, bends into a nice radius. Smallest radius I had was just 2', but it did it very easily with no breaking of popped veneer.