How to do Bent Lamination

[@barryirby8609]

Thanks for posting, lots of great ideas. Many years ago I built a spiral stair, long before the internet and KZbin. I bent the railing around the pickets on the stairs. Oak, about a quarter inch thick. Literally bought every clamp in town. Not nearly enough. Made a bunch of shackles out of short pieces of oak, front and back, and fastened them with pieces of All Thread rod. Worked really well, would work even better ndow with a deep well socket and a drill to drive it. That was in the early 70's and it's still there. Took me a while to figure out the railing is a straight board bent. I think the shackles would work better than the hand screws. Thanks again for posting, I feel something bent creeping up on me again.

[@WoodByWrightHowTo]

Now that sounds like a fun project.

[@markbaker9459]

Aloha James, Let's Get Bent !!! I loved forming bends and making compound bends. In my 5 Koa Wood Rockers, I bend the Rockers rather than waste the wood of a larger piece of Koa. The strips of wood were first milled and prepared and thin sawed from a Band resaw, run through a wide belt sander to an equal thickness of about 3/32's, this way there was a much easier time bending and gluing the rocker's parts. PVA glues were never used since the wood would 'creep back or spring back slowly over time, away from the shape of the curve desired. The 'relaxed' curve was not something you ever wanted to happen to a chair that you were making and then sending through 'Fed-Ex' to some faraway place in the world. We were making and sending out 5 rocking-chair per week of Koa, from $3500-5000+ shipping. We never had a recall. Of my best reading on the subject of 'bentwood', constructions were 'Old Iron Sides'. It took 200 acres of New England White Oak to make a British Man-o-War. But 'OIS' was needed sooner and white oak was much too dear to make the whole ship out of, so they used 2 foot thick[total] layers of White Oak of the outside with 3 foot thick layers of Red Oak to the inside of 'OIS' to equal 5 foot thick of the Haul of 'OIS's' !!! White oak was waterproof, Red Oak is not but with the outside sealed with White Oak, they were able to form the cost-saving needed to make a better ship in quicker time as well.

[@Kabob_King]

The reason wood 'creeps' over time with PVA glue is because it is water based. You are basically making the wood wet. Even after the glue dries the wood is at a much higher MC than before gluing. You need to basically re-acclimate it to your shop before you let it off the form. Could be weeks. If you do let it fully dry, there is zero creep. Not necessarily practical for a business, but e glue itself is not e problem, it is the water left in the wood. FWIW I use epoxy because who has time for that. Experience: built laminated wooden bows for roughly 10years. Same thing happens with bows that have sinew applied with hide glue. Even after sinew is applied, bow needs to dry for weeks or months before it has shed all the moisture.

[@TotalBoat]

great video, James! Bending wood is so common for boat building but this is a great lesson on the different methods and bonding techniques. WE always vote for EPOXY!

[@WoodByWrightHowTo]

Right on. I love seeing the different methods employed between boat building and furniture building. So many different ways to do the same thing in different applications.

[@Lecon60]

I used to do custom furniture. This is how I did my bullnose. The table was 2" thick with 4 inch 1/8. The bullnose was worked with a hand plane.

[@Kabob_King]

Hey James. Very nice build. I like that you're incorporating the bent lamination into it. I have experience in bent lamination because I've been building laminated wooden bows for about 10years. Overall I think you did an awesome job, but I would like to give some suggestions. First, I've tried every glue spreading contraption around, and by far the best for getting the proper amount of glue is a plastic knife. The serrations just naturally lay down a nice thin even layer, and the curve of the blade naturally spreads the glue from edge to edge. Plus they are extremely cheap and basically ubiquitous. Second, one thing you can do to prevent your outermost lamination from getting a gap is to use what I call a pressure strip. Basically a strip of flexible straight grained wood as wide as your laminations, at least as long as your laminations, and slightly thicker than your laminations (so it is stiffer which will distribute clamping force better). This pressure strip would go between your oak laminations and the strap, in your example. If you're using 1/4" oak lamination strips, the pressure strip could be 1/4" hickory (stiffer) or maybe 9/32" white oak. You get the idea. Cover the pressure strip with masking tape to help prevent marring the workpiece. You can also use a pressure strip on the inside of the curve between the form and the workpiece. Third, apply masking tape to the outside surface of your outermost and innermost lamination to prevent getting epoxy on it. Then lay down the plastic wrap, apply glue to all your laminations, wrap the plastic wrap around all of the laminations of your workpiece. Then put the pressure strips on either side so they are now outside the plastic wrap and won't get glued to your workpiece. When it comes off the form, the pressure strips fall away, most of the plastic wrap peels off, and you just clean up the squeeze out. Then remove the masking tape and your workpiece will be super clean. The pressure strips can be reused many many times, for the same or similar curvatures. Just make sure your pressure strips are very smooth on every face and relieve the corners to reduce the chance of them splitting. The pressure strips are not junk wood, they must be super straight grain, super clean. I hope that made some sense and hope you try some of those suggestions out.

[@WoodByWrightHowTo]

some good tips there. thanks Ben.

[@aliesamorrow3585]

Love this! I want to make a huge arch, so this “mold” with points of contact is far more efficient for what I’m looking to do. Very helpful ✌️

[@landengillespie236]

Good job James my boy

[@ConcreteLand]

That could be the best looking hammer on KZbin. 👍👍

[@rodmattison6381]

Thank you for sharing the great video walking through the process. I'm curious about how much spring-back to expect with the epoxy adhesive.

[@WoodByWrightHowTo]

Bent lamination has far less spring back than steaming. In this case over the 26" it opened up about a half inch at one end. So there's not much at all

[@martijnbavelaar3683]

Thanks for the lesson teacher!

[@hassanal-mosawi6049]

Thanks for sharing that

[@WoodByWrightHowTo]

My pleasure.

[@walterrider9600]

thank you James . yup looks sticky to me i am just too bent out of shape to respond now .

[@WoodByWrightHowTo]

Lol thanks Walter.

[@linosilva7646]

Hi. I´m doing a project that requires "extreme" bending. The guys from West Systems ( my source of epoxy) recommend moderate pressure clamping as, going too far with pressure, can glue starve the joint. Did you experienced any starved delamination in your projects so far ?

[@WoodByWrightHowTo]

Correct. With epoxy you don't really need to clamp it down as you do with a PVA glue. In this application it is a bit different. I do not smooth the joint perfectly in between the boards so there's always a bit of a gap in space from the texture of the wood. And that way I'm never squeezing the glue out of the joint completely. In this case the clamps are only put in place and spaces where there are still large gaps between the wood and I can use the clamp to squeeze the gap shut. In the end the difference between starving the joint and leaving enough glue is in many cases of woodworking a perfectionistic endeavor. The amount of strength difference is not as great as it would appear and for most applications there really is no fear of it. It's only under extreme structural connections where that is a fear.

[@ryanallthewiser]

This is a highly bent viewpoint! I’m all out of shape over this topic. 🤣. Actually, great video and instructions as usual!!

[@WoodByWrightHowTo]

Lol thanks man. Looking forward to putting this whole thing together.

[@davidcoxon1914]

Was the frame for forming it made only with hand tools?

[@WoodByWrightHowTo]

Yes. With the exception of driving the screws in with a drill. I just got lazy and breaths and grabbing the brace lol

[@gary24752]

How do you cut the wood into strips and prep it for laminating? Is there a link for the ratchet strap?

[@WoodByWrightHowTo]

Here is the video on that. kzbin.info/www/bejne/rnmUlKSOYq6Sq5o The method is called resawing. I have a few videos dedicated to that.

[@BrentDaughertyMe]

What about the construction adhesive options?

[@WoodByWrightHowTo]

In every test I've done it has failed long before any wood, glue or epoxy. I do not trust it at all. For woodworking. I have several glue tests if you want to see more on it. It works okay in gap filling and in loose connection joints but for standard tight wood joints it is trash.

[@AramisWyler]

Is there a minimum number of laminates required to make the bend stick?

[@WoodByWrightHowTo]

It depends on the lamination but in most cases you can get by with just two. But three makes it a little better.

[@massmanute]

Maybe I missed it, but is there a good way to estimate the amount of spring back when you release the clamps?

[@WoodByWrightHowTo]

With bit lamination there really is not much spring brack at all. On this one it may have moved 1/8 in total. If you do steam bendings then there is a bit of spring pack. But there isn't a way of mitigating that. It's just the way the wood works.

[@massmanute]

@@WoodByWrightHowTo Thanks.

[@reforzar]

I may have missed it. Did you mention if it is air dried lumber?

[@WoodByWrightHowTo]

Air dried would be better but this is kiln-dried.

[@ninjadeathoverlord3254]

So when is the joergsprave collab coming?

[@WoodByWrightHowTo]

Lol now that would be fun!

[@doriankal9800]

if you want to close the gaps does it matter where you start clamping. do you need to start at the end and work you way around. or do you need to start at the middle and work to the ends?

[@WoodByWrightHowTo]

It does not matter. I like to start in the middle and work out as that makes a shortter distance for bubbles to travel.

[@mckenziekeith7434]

Well, you can start from the middle or one end. But don't lock down both ends and then try to close the middle. If you see what I mean.

[@myrawright282]

How many times can you say "holdfast" or "hold" in the first five minutes! 😂🤣❣️ About as many as clamps that a person needs! 😂❣️

[@Lecon60]

People underestimate the plane

[@brianmcleod1487]

When gluing bent laminations can you not use a water activated glue like Gorilla so that you can steam it or soak it in hot water so it bends easier?

[@WoodByWrightHowTo]

You could but that gets really complicated. At that point you might just Steen bend it.

[@edwinghysebrechts9377]

Was thinking in the same direction: I usually cut the wood in thin strips, end at around 3mm (minimum thickness of my planer), soak them for 10min in hot tub and put them on the mould to dry so they are pre-bend when i do the final glue-opp. Using PU-glue might be an idea since it uses the remaining moisture to activate, and it’s very strong, the squeeze-out might be a mess to clean up though

[@bob_frazier]

I've glued wet wood laminations with success. Wet the wood and preform it in the clamps, let the fibers relax, then disassemble, glue and clamp.

[@g1mpster]

Sorry...what was that word again? “Holdfast”? 😂

[@WoodByWrightHowTo]

One of my favorite tools in the shop.

[@g1mpster]

Wood By Wright How 2 couldn’t agree more. Keep up the great videos!

[@myrawright282]

❣️

[@TheDistur]

You bending that wood by hand is giving me anxiety.

[@WoodByWrightHowTo]

Lol I keep wanting to launch an arrow with it just to see what would happen.

[@lucasvignolireis8181]

@@WoodByWrightHowTo collab with Joerg Sprav? Hand tools cross bow?

[@bob_frazier]

"Can't glue wood when it's wet." I beg to differ.