hot iron vs flowing steam for bending side

[Happy Builder]

i just tried to put my rosewood side into a pvc water pipe closed it with aluminium file and send steam into it with a flexipipe

removed it hot and steamy and pressed in into the side form

it was fantastic

i just wanted to know if steaming will have any adverse effect on sound --- the sides became plastic in ten minutes of steaming

i believe boat builders bend three inch thick wood

my question i prefer it this way willl it affect the sound quality

[Robert Bander]

Let the wood dry out until it reaches equilibrium moisture content before gluing. May take several weeks. Moisture content would certainly affect the sound among other things. Also I think I read somewhere that wood bent in that manner retains elastic memory more than if bent with direct heat.(not sure though).

- Robert

[Happy Builder]

Thanks robert just one question after it dries will the sound be optimal
and how much important is side to overall sound quality

[Everett Stone]

The sides do not add to the sound at all. The main thing about the sides is that they remain stable and support the structure of the guitar. I have read on the MIMF forum that sides are often lined by gluing cloth tape at intervals to stabilize the sides and prevent splits etc. In fact, in my latest guitar, I did line virtually the entire surface of the sides with bias selvege tape. The main contributors to the sound are the top and the back.

[Happy Builder]

hey everett
thanks for your info in that case can i make my sides 6 mm
will that be ok
since side is for support
rgds

[Everett Stone]

that would make your sides approx 1/4 inch? Don't think so. You could try.

[Robert Bander]

What you want to be optimal is that the free water in the wood is at equilibrium with the ambient relative humidity. This will minimize the wood losing or taking on water, and as a result the wood will not swell or compress because no water is leaving or entering. If wood undergoes a dimensional change as a result of changing moisture content, it may split, buckle, pull out a glue joint with the top/back etc. Not good for the sound.
Robert

[Happy Builder]

thanks robert

after cutting and bending and finally ready for glueing -- is one month enough for equilibrium

happy

[Robert Bander]

It depends on the relative humidity where you are. If it is a dry locality then it needs more time, if humid it takes less time to reach equilibrium. However since you soaked the wood through and through, it could take longer. I'm really not sure. Under normal circumstances, six weeks is a good average length of time if you had some billets of wood delivered to you. Maybe a boat builder would know more about it.
Robert

[Happy Builder]

thanks robert

i will wait for six weeks -- i live in a humid area

happy

[Happy Builder]

ok
finally i have now tried all the four different methods of bending

hot pipe
it is good to bend but has a learning curve
what i found difficult was bending exactly as per plan and also both sides are difficult to match exactly
it needs a lot of practice
also you tend to get over enthusiastic and break a few pieces
also some chance of scorching
also it is difficult to bend anything above 2mm
and anyways you need a form later for drying without springback

steaming
the sides are tooo thin to remain hot and steamy and plastic for more than 10 seconds after removing from steam box and then to get the waist and the two bouts is difficult also there is chance of cracking if it cools

boiling
same like steaming may cool off in 10 - 15 seconds but remains wet longer
too much of moisture
also if wood is not of the best grade it becomes uneven on the surface

light bulb fox bender
best as far as my experience goes
no cons or
little drawbacks
you have to wait for 30 minutes before it heats up
then load the wet wood
wait for 15 minutes for wood to heat up too
then by that time the wood is hot it dries up
then spray some water again
slowly keep pushing it will bend but be very slow but firm not pushy
will have some springback definately
so either have the form with tighter bends than required or a cooling form with tighter bends then required
always keep the wood wet when bending keep looking below the slat for dry areas and keep it wet may be you have to spray five to six times during the whole process ( i had 6 mm of thickness with 2 mm very little spraying should be enough)
i bent 6 mm rosewood sides with this bender in one hours times after preheat 30 minutes
whats helps is the two slats trap heat and moisture also they stop the sides from cracking at end of fibres and they provide heating of the entire piece uniformly
i think this is the best way to bend
yes you need a seperate bender for each size
i built mine with only scarp ar zero cost except my time which shoud take you around 6 - 8 hours build a fox or everett bender and see the light bulbs do magic
build it with ply sides or wood sides or some other heat insulation material
use alluminium or better steel or still better spring steel slats
use 3 or 4 bulbs of 100 watts each for uniform distribution of heat
my first two bulb proved to be a mistake as the bouts are far off and with four bulbs it is uniform
remember light bulbs take 30 45 mins to heat up the entire jig
dont force the wood to bend but gently and firmly mould it
also most important the centre of the bottom slat at the waist will bend down i.e. it will not touch the wood so give it some support upwards with a spring or clip it to the top slat or use a waist support system or tie it with a copper wire to the top slat or else you will crack the waist
the bottom slat heats up -- it has to touch the wood at the waist to work so some how keep the two slats touching the wood all the time for uniform heating
and for spring back just make tighter curves initially
and do not remove from the bender till dry
heat and cool three time with an hours gap should do it with last heating and drying to be done without the top slat

[Happy Builder]

i have to add something to the above note
that after removing from the bender there will be some spring back
even after two or three days there will be some more spring back
but if you heat the side on the bender once more and heat it for 30 mins after pre heat the side will have absolutely no spring back at least i did not get any spring back
so best of luck

[Pierre-Antoine Roiron]

That's what's adviced in LMII side bending jig video too.