so back in the cabinets they went! a day later and some more research i pulled them back out again lol.
now im really sure the cloth surrounds are treated with a thin wash of pva,when they are wetted you can see it more clearly as where the residue is prominant it takes a little bit longer for the water to soak in the cloth.
also where the cloth is glued to the cone there is a bead of it run over the top which from my cabinet making days tells me its pva.
after some more reading online i stumbled on a pdf file from a university in the uk that did a study on removal of various substances that are interfering with accurate carbon dating.
amoung the list was pva.
they recommend acetone followed by a warm water wash then repeat the process again.
so armed with this i tried it,along with meths,which i believe you guys in the states call mineralised spirit.
that process seems to be removing it slowly. im doing it once a day after work,i hope this turns out ok as i hate to be defeated.
if anyone has anymore info on pva used as speaker surround dope then please feel free to offer advice,.my plan is to start off with a very diluted mix and once dry check the measured t/s figures with each coat.
now im really sure the cloth surrounds are treated with a thin wash of pva,when they are wetted you can see it more clearly as where the residue is prominant it takes a little bit longer for the water to soak in the cloth.
also where the cloth is glued to the cone there is a bead of it run over the top which from my cabinet making days tells me its pva.
after some more reading online i stumbled on a pdf file from a university in the uk that did a study on removal of various substances that are interfering with accurate carbon dating.
amoung the list was pva.
they recommend acetone followed by a warm water wash then repeat the process again.
so armed with this i tried it,along with meths,which i believe you guys in the states call mineralised spirit.
that process seems to be removing it slowly. im doing it once a day after work,i hope this turns out ok as i hate to be defeated.
if anyone has anymore info on pva used as speaker surround dope then please feel free to offer advice,.my plan is to start off with a very diluted mix and once dry check the measured t/s figures with each coat.
Is it water or non water soluble? If water, then use one of those hand held clothing steamers to melt it off or white vinegar plus hair dryer to speed it up. Acetone, MEK to dissolve either.
No experience per se since only used this procedure on Altec or similar doped surrounds, but seems like just soaking/brushing the worst of it off, then running them at relatively high excursion face up and brush coating to smooth out/soften what's left, wiping excess off the brush as you go round and maybe what little is left will still be airtight, yet remain flexible enough. FWIW I use this type disposable brush: Acid Brushes - BLICK art materials
GM
No experience per se since only used this procedure on Altec or similar doped surrounds, but seems like just soaking/brushing the worst of it off, then running them at relatively high excursion face up and brush coating to smooth out/soften what's left, wiping excess off the brush as you go round and maybe what little is left will still be airtight, yet remain flexible enough. FWIW I use this type disposable brush: Acid Brushes - BLICK art materials
GM
so tonights gentle scrubbing session and i thought id share a few pics.
here you can see clearly the doping or bits of it.
the lighter shade areas are whats left of the dope.
and here's a close up of what i think is who ever doped them put a little too much on in this place or its a drip from were the glue was used to join the cone to the surround.
im dead sure its pva and it would appear to be applied from the underneath rather than on top.
iam tempted to try a very small amount of paint stripper and see if any comes off??
here you can see clearly the doping or bits of it.
the lighter shade areas are whats left of the dope.
and here's a close up of what i think is who ever doped them put a little too much on in this place or its a drip from were the glue was used to join the cone to the surround.
im dead sure its pva and it would appear to be applied from the underneath rather than on top.
iam tempted to try a very small amount of paint stripper and see if any comes off??
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well progress is slow ive even contacted the v&a museum for advice from their textile conservation dept,awaiting their reply,
in the meantime i think the mek seems to be doing something,as im endlessly swabbing away my thought are turning to what dope should i re apply?
any advice?
im thinking liquid latex or a very thin pva wash,i will try it first on an omuseumld pillow case.
in the meantime i think the mek seems to be doing something,as im endlessly swabbing away my thought are turning to what dope should i re apply?
any advice?
im thinking liquid latex or a very thin pva wash,i will try it first on an omuseumld pillow case.
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Couldn't remember the name of the clear liquid Altec and others used, so [re]found this thread which has it and more surround cleaning info: http://www.hostboard.com/forums/f700/230414-who-has-done-older-altec-woofers.html
GM
GM
well i heard back from the v&a conservation dept,the lady i spoke to said to usemethylated spirit or to you guys in the states denatured alcohol, i said i tried it and it didnt appear to be doing anything, when lightly washed on.
this was where i was going wrong, she said to roll out some cotton wool and soak it in meths,then place it on the surround and use shrink wrap to stop it evaporating to quicky,the key was to leave it on.
so i tried this method and it would seem to be working!
the spot where there was a build up of pva/dope in the photo i posted is now a faint mark so without wishing to jinx it,i may be making progress!
this was where i was going wrong, she said to roll out some cotton wool and soak it in meths,then place it on the surround and use shrink wrap to stop it evaporating to quicky,the key was to leave it on.
so i tried this method and it would seem to be working!
the spot where there was a build up of pva/dope in the photo i posted is now a faint mark so without wishing to jinx it,i may be making progress!
thanks,
so here are the specs so far,
the first time it was measured.
and tonights progress.
so here are the specs so far,
the first time it was measured.
An externally hosted image should be here but it was not working when we last tested it.
and tonights progress.
An externally hosted image should be here but it was not working when we last tested it.
Same driver? That'a a huge difference! Surprised the Qts is still so high though. At this point, Vas needs to be measured to see if it's tiny to offset it somewhat.
Don't know what DATs recommends, but ideally the added weight needs to lower Fs/1.56 for best accuracy/repeatability, so no small amount.
GM
Don't know what DATs recommends, but ideally the added weight needs to lower Fs/1.56 for best accuracy/repeatability, so no small amount.
GM
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