Bending Pallet Wood the "wrong way"

[VenomBottle]

Hello, I'm new around here. I've also never bet wood before and am yet to get myself sorted out with the equipment I need.

But before I move forward, I wanted to call on others' experience in wood bending.

For the project I have in mind, I want to bend some pallet wood planks along the thick edge as shown in the attachment as opposed to bending across the thin edge.

Does conventional steaming allow for such a bend or would I need to take extra measures?

Any advice highly appreciated. Thanks.

 

[MikeG.]

With pallet wood? I predict a failure rate of higher than 90%.

 

[Phil Pascoe]

Higher than 99.9999%

 

[VenomBottle]

:wink:


Pallet wood specifically? Or just this kind of bend?

 

[MikeG.]

What are you trying to achieve?Why couldn't you just cut the shape you want to achieve out of a piece of wood, or multiple pieces of wood glued together?

 

[VenomBottle]

I want to build something like this.

Bending wood is partly for my own enjoyment but if its not advisable I'll find a workaround.

 

[MusicMan]

Can you put a scale on that? Are we looking at a matchbox model or a cathedral?

 

[marcros]

Is that a shepherd hut type structure? The commercial ones are usually cncd from ply I think.

 

[VenomBottle]

Hi, sorry for the late reply. Approx height is 2.2m. Then 2.5m width.

 

[MikeG.]

Erm...........no. Just no. That's not doable in steamed pallet wood.

 

[rafezetter]

Erm...........no. Just no. That's not doable in steamed pallet wood.

I'm not sure it's doable in ANY type of wood, even ones that normall steam really well, because you're asking the fibres at the top to stretch, and wood isn't known for it's ability to stretch

You could cut kerfs in the wood so it then bends as you want, but unless you are a master at it, they will be visible if left unpainted.

If you are OK with painting then kerfing is your only realistic option as far as I can tell. Otherwise you are going to have to glue several slats together to make a wider board, and cut sections of the curved shape from that, not forgetting with all the inherent extra work required to clean up the mating edges, so you get good glue joints for the boards.

And this is apart from figuring how you'll join the slats end to end - unless you double them up and offset the joints.

That's quite a lot of work, not something I'd tackle lightly.

 

[Steve Maskery]

OK, we all agree you can't do it that way. It simply is not the way wood can be worked.
So how can you do it?

Well you could cut it out of several pieces, each a segment of the arc joined to the next one, with biscuits or dominoes. I've done this.

You could laminate each rib in three thin layers overlapping like brickwork. I've done this.

Of the two approaches the latter was more successful, by a country mile, and I would have no hesitation in doing it that way again.

The downside is that it is a lot of work, so it depends on how valuable this job is.

 

[MikeG.]

.......And this is apart from figuring how you'll join the slats end to end - unless you double them up and offset the joints......

I think that even asking the question suggests the OP isn't experienced enough in using wood to even begin to think about building something like this. The only way to double up curved bits of timber to reinforce the offset joins is to build in the manner boat-builders do, but that means flat faces and gluing along the entire length of the construction of each doubled-up frame member. OK, we probably wouldn't need to use trennals for this, but nonetheless, it would be an enormous amount of work even with decent timber. This really is a case of using the wrong material for the job, and trying to force-fit it. It simply won't work.

 

[Sgian Dubh]

Well, to all the naysayers, I'd say you're all probably wrong - it's do-able I believe, but the challenge might be a bit overwhelming for anyone with any combination of the following: limited experience, limited equipment, limited expertise, limited knowledge of wood's working properties. That VenomBottle asked if it is possible to do it in pallet wood, the wrong way, does suggest limited expertise: but there's no shame in that because everyone has to learn if they're going to develop.

On the sort of scale for the structure pictured I read curved pieces perhaps 3"- 4" wide as seen from the front view provided. So, it would be possible to steam bend something like ash or European oak air dried to 20-25% MC. The sections might need to be approximately 8"+ wide by 3"-4" thick. Then an industrial steamer and some hydraulic rams, plus some sophisticated engineering to create a massively strong bending former and bending straps might do the job.

After the bend is formed, all that would be required would be a good bandsaw, perhaps one of the Mafell hand held jobs (a snip at somewhere close to £4,000) to rip four ~2" (shy) wide strips out of the ~8" wide bend.

After that, it should all be fairly plain sailing I'd say … maybe, ha, ha.

This response may have involved a hint of tongue-in-cheek on my part, Slainte.

 

[Steve Maskery]

I think we all look forward to the WIP pictures....

 

[VenomBottle]

Thanks all for opinions and insights.
I had suspected this would be pushing wood beyond its comfort zone but thought I'd check on the off chance.

If I can get use of a table saw, I'll consider the laminate method, failing that, an arch appoximation using several pieces combined with cutting and sanding to achieve the arch I'm after.

I do have limited wood working experience so once I've finished CADing everything out and inevitable start panicking about joints etc, I'll probably be back. Happy to share some WIP pics too but likely to be spring/summer by the time I get that far.

 

[marcros]

if you are going to do the project, I would look at buying some ply and cutting them from that. pallet wood has its uses, but this seems to be using it for the sake of it.

do you put sheet material inside and outside, and insulate between the beams?

 

[VenomBottle]

Hi, my thinking is to put a waterproof sheet over the frame and then layer more pallet wood across the length as one would with roof tiles. I'll insulate between the beams.
The inside I'm still considering sheet vs planks.

I'll have a look at ply as well but trying to keep costs low.

 

[MikeG.]

Hi, my thinking is to put a waterproof sheet over the frame.........

You really need to read my "How to build a shed" thread, linked to in my signature. An external waterproof sheet could reduce the life of your shed by decades.

You do realise that pallet wood isn't treated against insect attack and rot, don't you? You would be building a building with a life expectancy of 5 or 10 years, and with the incredible amount of effort you are proposing to put into the frame members, which you clearly haven't yet understood or thought through, this seems like a really poor investment in terms of your time and effort.

I can't stop you building in the silly way you propose. I am an architect, and have built, designed, guided or supervised literally hundreds of small outbuilding projects. Ignore the advice I'm giving here at your peril. What you are planning on doing is one of the very worst ideas I have come across in years.

 

[Eric The Viking]

"... trying to keep costs low."

I bought my MFT table from these people:
https://www.cncdesign.co.uk/gothic-glam ... -2400.html
I cannot imagine you could get much cheaper by DIY - they must be close to the cost of materials for anybody contemplating a one-off.

Those ribs (in the link) are plywood, CNC machined. The ply on my MFT is good quality and well finished. And, they stand behind their products - if you do it yourself and it all goes wrong, you carry ALL the cost.

You did ask, and there does seem to be a rough consensus emerging ;-)