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Anyone else come across EIR that won't bend! Update.
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Author:  Colin North [ Fri Mar 17, 2017 12:20 pm ]
Post subject:  Anyone else come across EIR that won't bend! Update.
Or have I found the only d#*n piece?
Trying to bend a venetian cutaway, and I just could not get it to bend - virtually nothing.
It was thinned to 1.8mm, spritzed, held up against a hot iron (305 - 310F surface temperature) using a backing strap, and eventually it just cracked.
Then tried bending another place further up on the same cutaway portion (broken), almost nothing at all! Like steel plate.
I bent a different (trial) piece of EIR before hand, on the same iron - same temperature, no real problem at all.
After above problem, I was then able to straighten that piece, and reverse the bend.
And to add insult to injury, I was then able to then reverse it again. (all this against an Inside radius of 22,25mm.)
Given this, I don't think it's technique.
Perhaps the givaway with this set was the substantial springback I got back out of the sidebender, despite two additional cycles to set the bends.
Author:  kencierp [ Fri Mar 17, 2017 12:54 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend!
Put rag or folded paper towel on the pipe and keep it wet -- it should bend eventually. Might need a lot of pressure on the backing slat, if the wood develops ripples it becomes very difficult to bend because the cupped area adds structural resistance. Generally I don't think adding a lot of water and steam "when working EIR" is a problem but rather helps the process.
Author:  Colin North [ Fri Mar 17, 2017 3:39 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend!
Must have spend at least 20 minutes on the same bend each time, spritzed the wood 8/9+ times each try.
I started testing the iron with bubinga at 2.3mm, and had less problems....
Author:  Joe Beaver [ Fri Mar 17, 2017 4:02 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend!
I've seen sapele and bubinga that were like that. They just preferred to break before they bent. It kind of sounds like the old story of the oak and the willow.....
Author:  kencierp [ Fri Mar 17, 2017 4:46 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend!
On those tough bends I do more than spritz, I keep them soaking wet and let the steam do its thing. Whats the grain pattern? EIR way off the 1/4 can be prone to cracks caused by delamination.
Author:  Jim Watts [ Fri Mar 17, 2017 6:04 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend!
Colin, did you try heating up a lager section of wood or did you concentrate just on the immediate cut-away section? Say 3 or inches on either side of the cut away. I find this helps. Just curious.
I've also noticed that wood I overworked on the bending iron becomes difficult, almost like I'm heat treating it. When that happens I re-wet the wood over night to try to re-hydrate the cells the have another go at it, that seems to help. Anyone else notice this?
Author:  Glen H [ Fri Mar 17, 2017 6:12 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend!
I'm with Ken on the need to soak some wood. Normally a spritz is all I need but some I've had to soak in hot tap water for an hour and then it the bend like butter.
Author:  Colin North [ Sun Mar 19, 2017 7:13 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! - Feedback
Thanks for the feedback guys, I have had some success.
To outline the whole process I used, I originally bend the lower section of the side in a side bender, without any bending of the cutaway portion at the top, just the area of the upper bout close to the waist was bent.
The side was left in the bender 24 hrs, removed, and I had a fair bit of spring-back - I suspect the side wasn't wet enough originally.
I kept the blanket "portion" of the sandwich away from the unbent portion of the side, but it looks like actually a fair bit of heat got into it, as oils came to the surface all over it.
Yesterday I took the broken part of the side, sanded off the oils on the surface with 180 grit and soaked it, left for couple of hours, then sprayed it again before going back tho the iron.
With much re-wetting as required, I was able to bend it (slowly and reluctantly) to the tight radis of the cutaway point.
It looks like the overall proceedure in my case was flawed.
Perhaps the effect of the heat on the wood (heat treating? - Jim) and possibly the oils on the surface were stopping the water/steam penetrating the wood.
Just ordered a "professional" bending Iron and will try the next set on that one.
Author:  johnparchem [ Sun Mar 19, 2017 10:36 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! - Feedback
Colin North wrote:
... Perhaps the effect of the heat on the wood (heat treating? - Jim) and possibly the oils on the surface were stopping the water/steam penetrating the wood ...


I have seen wood take a set from heat such that previously bendable wood became very brittle.
Author:  nkforster [ Mon Mar 20, 2017 4:22 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
Soak it in 70/30 water/fabric softener for 20 mins.

It'll bend.
Author:  bluescreek [ Mon Mar 20, 2017 5:38 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
how thin .075 is where martin bends. Rosewood usually bends like butter
Author:  Colin North [ Mon Mar 20, 2017 6:57 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
nkforster wrote:
Soak it in 70/30 water/fabric softener for 20 mins.

It'll bend.

Thanks for the suggestion Nigel. I have some Supersoft II veneer softener. Don't like the idea of glycerine on my sides
As I said in the second post, looks like the problem may have been caused by heat from previous bending in the side bender.
Your videos have encouraged me to try another set by hand on a "bought" bending iron.
Author:  nkforster [ Tue Mar 21, 2017 2:19 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
Colin North wrote:
nkforster wrote:
Soak it in 70/30 water/fabric softener for 20 mins.

It'll bend.

Thanks for the suggestion Nigel. I have some Supersoft II veneer softener. Don't like the idea of glycerine on my sides
As I said in the second post, looks like the problem may have been caused by heat from previous bending in the side bender.
Your videos have encouraged me to try another set by hand on a "bought" bending iron.



A lot of folk avoid Supersoft or fabric softener (are they the same thing?) because they don't like the idea of chemicals in the wood or wonder about lingering after effects etc...but these worries should be added to the long list of "theoretical" concerns and questions that have little relation to reality. I've bent hundreds of sides using fabric softener and have had no glueing/finishing/strength issues whatsoever. I wouldn't consider bending BRW without it. Then, who does like snapping £1000's worth of wood that took hundreds of years to grow?...Yes, they will smell a bit of the stuff, but that fades.
Author:  Colin North [ Tue Mar 21, 2017 7:55 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
nkforster wrote:
Colin North wrote:
nkforster wrote:
Soak it in 70/30 water/fabric softener for 20 mins.

It'll bend.

Thanks for the suggestion Nigel. I have some Supersoft II veneer softener. Don't like the idea of glycerine on my sides
As I said in the second post, looks like the problem may have been caused by heat from previous bending in the side bender.
Your videos have encouraged me to try another set by hand on a "bought" bending iron.



A lot of folk avoid Supersoft or fabric softener (are they the same thing?) because they don't like the idea of chemicals in the wood or wonder about lingering after effects etc...but these worries should be added to the long list of "theoretical" concerns and questions that have little relation to reality. I've bent hundreds of sides using fabric softener and have had no glueing/finishing/strength issues whatsoever. I wouldn't consider bending BRW without it. Then, who does like snapping £1000's worth of wood that took hundreds of years to grow?...Yes, they will smell a bit of the stuff, but that fades.

Not the same Nigel, SS II is Diethylene Glycol Monoethyl Ether, classed as a wood plasticiser for this purpose, fabric conditioner contains mainly cationic surfactants, (soaps or detergents) - glycerine was my mistake, apologies - and sometimes silicones apparently.
Might try some comparison trials as my supply of SS II wil not last forever.
Author:  bcombs510 [ Tue Mar 21, 2017 9:48 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
I don't care for perchloroethylene and I don't like glychol ether. - Amy Farrah Fowler
Author:  Colin North [ Tue Mar 21, 2017 9:54 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
bcombs510 wrote:
I don't care for perchloroethylene and I don't like glychol ether. - Amy Farrah Fowler

laughing6-hehe Big Bang fan house here!
Author:  kencierp [ Tue Mar 21, 2017 10:15 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
Home brews have been the down fall of countless wood working projects. SS is engineered and marketed for our specific purpose ---- why take a chance?
Author:  Colin North [ Tue Mar 21, 2017 10:46 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
kencierp wrote:
Home brews have been the down fall of countless wood working projects. SS is engineered and marketed for our specific purpose ---- why take a chance?

I hear ya! And I have SS II.
But when a respected professional like Nigel Foster tells me
Quote:
I've bent hundreds of sides using fabric softener and have had no glueing/finishing/strength issues whatsoever.
it's got to be worth a couple of quick test pieces at the very least.
My curiousity is piqued.
Author:  kencierp [ Tue Mar 21, 2017 11:43 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
No disrespect for Nigel at all -- but his science applies to the adhesives and coating he uses. I have seen long term failures caused by chemical incompatibilty --- not pretty, not fun. $.02
Author:  Mike OMelia [ Sun Mar 26, 2017 11:22 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
That wood will bend at all (especially tight venetian curves) remains an amazing thing to me. SSII. Never had an issue.

-Mike
Author:  dberkowitz [ Mon Mar 27, 2017 6:18 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
Couple of things. I probably have one of the tightest venetians out there. So here goes.

    lay out a sheet of aluminum foil
    prepare two pieces of craft paper the full width and length of the side
    soak the craft paper and lay it out lined up with one edge of the foil-- be sure to smooth it out
    wet the side thoroughly
    align the side on the craft paper
    put another soaked piece of craft paper on top and smooth it out
    fold the foil over and trim it to the ends and along its long side
    use a razor knife to cut open the folded side to allow steam to escape
    let it sit 1 hour
    put it in your bender and heat it up for five minutes
    set the waist, then the cutaway then the lower bout
    with the cutaway do a 1/4 turn every 10 seconds or so -- you'll have to learn how your cutaway behaves with bends

I have a pair of springs that pulls the cutaway arm toward the waist so it maintains contact on the horn as it is pressed. My sandwich is spring steel, silicone blanket, wood wrapped in foil with craft paper.
Author:  Brad Goodman [ Mon Mar 27, 2017 7:28 pm ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
I have had some sides that just won't bend-no how, no way, ain't happening they just wont!

I have had it happen a few times with brazilian rosewood (ouch), curly maple and a few others.
I move on to another set of the same wood and it bends like butter.
No rhyme or reason

That's why they call it wood......
Author:  Colin North [ Tue Mar 28, 2017 3:54 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
Sorry?
Author:  Colin North [ Tue Mar 28, 2017 3:56 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
dberkowitz wrote:
Couple of things. I probably have one of the tightest venetians out there. So here goes.

    lay out a sheet of aluminum foil
    prepare two pieces of craft paper the full width and length of the side
    soak the craft paper and lay it out lined up with one edge of the foil-- be sure to smooth it out
    wet the side thoroughly
    align the side on the craft paper
    put another soaked piece of craft paper on top and smooth it out
    fold the foil over and trim it to the ends and along its long side
    use a razor knife to cut open the folded side to allow steam to escape
    let it sit 1 hour
    put it in your bender and heat it up for five minutes
    set the waist, then the cutaway then the lower bout
    with the cutaway do a 1/4 turn every 10 seconds or so -- you'll have to learn how your cutaway behaves with bends

    I have a pair of springs that pulls the cutaway arm toward the waist so it maintains contact on the horn as it is pressed. My sandwich is spring steel, silicone blanket, wood wrapped in foil with craft paper.

So when does this bender arrive so I can be in to sign for it?
Author:  Colin North [ Tue Mar 28, 2017 5:01 am ]
Post subject:  Re: Anyone else come across EIR that won't bend! Update.
So I tried 3 test pieces of this side which cracked, one soaked in water, one in 70/30 fabric conditioner, one in SSII, 20 minutes each.
Then took them to the hot iron - not one of them bent. At all!
Looks like it may have been "over-cooked" in the bender prior to attempting the cutaway, so I'll try another set from scratch when my new bending iron https://www.luthiersbench.co.uk/bending-irons arrives, just using the iron.
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