# Bending Italian Poplar



## JohnyWhy (Jul 31, 2014)

hi

i need to bend so 1/8" Italian Poplar just a little a bit further than it wants to. It always snaps right before I get the needed bend.

As an experiment, I soaked it overnight in lukewarm water, and then i was able to bend it to the needed radius (and tighter).

Anything that could be improved with my soaking method?

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Continuing the experiment, I put some of it in a microwave for a minute. The micro'd wood offered less resistance and less spring-back than the soaked-only wood. That's a good thing, right?

Anything bad about the microwave method?

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I braced both the micro'd and non-micro'd samples on jigs.

Continuing the experiment, i put the micro'd wood in a toaster oven for 5 minutes. That seemed to extract most of the moisture. I could remove the wood from it's brace shortly after, and it held it's shape.

Will toasting make the wood too brittle, or have any other drawbacks?

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After 6 hours, i removed the non-micro'd, non-heated wood from it's brace. It is still moist, and it springs back a bit. I re-braced it, and plan to keep it braced until naturally dried, probably another day or two.

Will the naturally-dried wood be stronger or weaker than the heated wood? Anyone have experience with soaking, microwaving, or toasting wood?

thx


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## Earlextech (Jan 13, 2011)

It's heat, not moisture that allows wood to bend. I steam wood to bend it. Also, air dried lumber bends best, kiln dried not so much. There will always be some spring back especially with a tight bend. If it's a repetitive piece you're making then make your form 10% beyond the bend you actually want. Experimentation is what bending is all about.


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## JohnyWhy (Jul 31, 2014)

hi, thx for the reply.

i'm familiar with steaming, and i'm seeking a simpler, quicker, kid-friendly alternative. (i mentor disadvantaged youths in fabricating stuff).

Anyone out there worked with Italian Poplar? It's designed to bend dry, straight from the warehouse:










I'm using soaking to add just a little bit more bend than it has dry. My experimentation indicates that cold-soaking does exactly that, at least with this wood. As i mentioned, the wood bends much further after soaking overnight (without heat).

This luthier describes water-soaking as a method for wood-bending. He says the only difference between soaking and steaming is that cold-soaked wood will have more spring-back, which my experimentation supports. So, i think i'm on the right track with cold-soaking-it works for me. 
http://sempleguitars.com/thecraft/bending-wood_12.php

Question now is whether toasting can damage the strength or integrity of the wood.


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## JohnyWhy (Jul 31, 2014)

I'm getting great results at 200F or less for 15 minutes. This was baked while on the jig.

It retains a bit of spring, which i think is good-if i baked longer or hotter it becomes brittle. i'm still learning about this, but i believe brittle wood is not as strong. Also, the flex it retains means i can fine-tune the bend when i glue it-if it didn't flex a little, then i would not be able to fit it.



















(Both photos are the same piece, same curve. Curvature on the 2nd photo is symmetrical- it only appears distorted due to perspective of the photo.)


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## JohnyWhy (Jul 31, 2014)

Some of the research that helped me:

"High-temperature dry kilns operate at temperatures of 200 to 240°F. This type of kiln was developed to dry softwoods." 
http://www2.ca.uky.edu/agc/pubs/for/for55/for55.htm

In this doc, drying temps for poplar in thicknesses 8 to 16 times thicker than my 1/8" stock is given at under 200F. (i'm not understanding why they show higher temps for thinner, dryer wood-not sure how to interpret that. Feel free to help 
http://www.esf.edu/scme/wus/documents/drykilnschedulesforcommercialwoods.pdf

bending by cold-soaking and the microwave methods (and several other bending methods) are described in this academic doc.
http://www.tai-workshop.com/english/tech-2%28b%29-e.html


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## JohnyWhy (Jul 31, 2014)

(that's not a crack in the 2nd photo, just a cosmetic defect)


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