Re: Who has done this ?........ ( Older ALTEC Woofers )
Quote:
Originally Posted by
VolvoHeretic
You can usually buy lacquer thinner in pint containers which contains "Toluene (Toluol), Xylene (Xylol), Methyl Ethyl Keytone".
Lacquer Thinner
I however am leery, worried that harsh solvents might destroy the bonding agent between the cloth surround and basket and paper cone. I am also worried that the solvents might make the goop more compliant now, but as it evaporates out of the goop, it will dry it out and make it worse than before the application. Kind of like tire softener used for racing tires that dissolve the rubber and increases compliance and traction, but dries it out in the long run and makes it hard and creates cracks, thus shortening the tires life span.
But then again, I also am not a chemist.
Hello again VH,
I would tend to "trust" the prior experienced posters in this thread, especially if they name themselves "604man", or "mikebond" who was doing this "many times" and perhaps before Per Hasling.
The question of the need to apply a re-coating is something I also certainly had thought about, and no one yet has specifically addressed it. Maybe its time to do so now. YES, I had the same concern as you, but I intuitively trusted their postings and acted.
I also love this quote from Wm. S:
" Our doubts are traitors, that often make us lose the good we would attain, by fearing to attempt ".
So, what would these two more experienced people than me ( and you ) , who HAVE done this cleaning, say about recoating or, just leaving it cleaned with toluene or the 646 Russian solvent only.
Any helpful posts would be appreciated by ALL of us who are interested in learning the consequences of what we do.
Jeff Medwin
Re: Who has done this ?........ ( Older ALTEC Woofers )
Hello! To be clear with russian 646 solvent, it consist of:
butyl or amyl acetate 10%, ethyl cellosolve 8%, acetone 7%, butanol 10%, ethanol 15%, toluene 50%
Regards, Mike
Re: Who has done this ?........ ( Older ALTEC Woofers )
Quote:
Originally Posted by
mikebond
Hello! To be clear with russian 646 solvent, it consist of:
butyl or amyl acetate 10%, ethyl cellosolve 8%, acetone 7%, butanol 10%, ethanol 15%, toluene 50%
Regards, Mike
Hi Mike !!
That is nice to read..... factual and specific.
The question I have is, once someone cleans off most, if not all of the goop from the accordion cloth surrounds, is it NECESSARY to re-apply some sort of coating ( Per Hasling says he does - but it does not show to "my" eye in his photos ) OR, can the cloth surround be left untreated, and the gains from the higher and linear compliance remain intact over time.
To re-quote VH's concerns in post #30:
"I am also worried that the solvents might make the goop more compliant now, but as it evaporates out of the goop, it will dry it out and make it worse than before the application. Kind of like tire softener used for racing tires that dissolve the rubber and increases compliance and traction, but dries it out in the long run and makes it hard and creates cracks, thus shortening the tires life span."
I am not very sure that what he says may apply about "making the goop more compliant now, and evaporating out of the goop."
AS I see this, we are REMOVING the goop off of the surrounds, (other than a very minor residue), so how could it reharden over time if the goop's not there??. Could the accordion cloth itself harden over time, after having solvents like toluene applied to it ??
Tell me please Mike, after you apply Solvent 646, do you re-treat the cleaned surrounds, or just leave it alone?
If you leave it alone, do you find the benefits of the goop removal "reversing" itself over time, with the cloth surrounds getting stiffer in their measured compliance??
I see at least two physical factors at play here (1) a higher compliance of the cleaned surround. leading to the driver having a lower resonant frequency, and (2) importantly : a LINEAR compliance of the surround, enabling the cone to follow the voice coils' input more faithfully, due to the removal of "uneven goop and C L U M P s " on sections of the accordion.
Mike, or 604man, can I further solicit your opinion and comments on this post ( #33's ) topics?? Or anyone else who has an idea on this.
For the best answer, I really wonder what Bill at GPA and Don Davis, the vintage reconer in Texas would say ??? The experienced reconers have grappled with this on used drivers over the years, 'ain't their first rodeo !!!
Thanks.
Jeff
Re: Who has done this ?........ ( Older ALTEC Woofers )
Quote:
Originally Posted by
LowOhms
AS I see this, we are REMOVING the goop off of the surrounds, (other than a very minor residue), so how could it reharden over time if the goop's not there??. Could the accordion cloth itself harden over time, after having solvents like toluene applied to it ??
Why would you remove all but a minor residue? I thought you were just removing the amount that tends to migrate over time to the low spot on the driver. It's supposed to be there, just spread evenly.
Re: Who has done this ?........ ( Older ALTEC Woofers )
Just remove it and respread it in the right places. I'm sure the cat hair and dander will act like a nice bonding agent. :)
It's amazing that they could create goop that would stay pliable for 50 years without drying out and not be made of some banned toxic substance.
Re: Who has done this ?........ ( Older ALTEC Woofers )
You don't want to remove all of the coating. It must remain on the surround so that the surround is not pourous and allowing air to pass through. That would be like having a leaky cabinet.
Re: Who has done this ?........ ( Older ALTEC Woofers )
Quote:
Originally Posted by
zelgall
You don't want to remove all of the coating. It must remain on the surround so that the surround is not pourous and allowing air to pass through. That would be like having a leaky cabinet.
Hi Zelgall,
How you doing ?? Does it leak through a cloth surround, the cloth thats in there now ?? I don't know, ALTEC accordion cloth looks very tightly woven to me, but, what do I know..... .
Per Hasling writes that he reseals the surround, but is is visually (to me) not with ALTEC goop. I'd really LOVE to hear from some old timer reconers on this, Bill H. and Don Davis !! They have been around the block on all of this I'm sure !!
What I would want to explore using on cleaned ALTEC accordion surrounds is an old favorite " Super Z RC/56 glue made by J and Z Products" of Harbor City, CA 90710. It is used on model airplanes, to attach plastic canopies, etc. It is water based, dries clear and remains always flexible. I have used it for speaker repair. One can greatly dilute it with H2O. There is at least one other company making this same glue. On a vintage paper driver with a half roll surround, the paper could fall away from fatigue and the non-hardening glue will stay intact !!!
Anyone on this ALTEC Forum know the ex-Austin reconer, Don Davis' phone number?? ( aka "DrFieldCoil" ) I'd call him if I knew his phone number and see for us all what he says. Lost his number when he moved. He and I go back some !!!! Don is SUPERB, meticulous on restoration of vintage drivers, radios, etc.
Jeff Medwin
- - - Updated - - -
Quote:
Originally Posted by
Audio_by_Goodwill
Why would you remove all but a minor residue? I thought you were just removing the amount that tends to migrate over time to the low spot on the driver. It's supposed to be there, just spread evenly.
See Per Hasling's web pages, and look over his before and after photos.
Jeff Medwin
Re: Who has done this ?........ ( Older ALTEC Woofers )
Quote:
Originally Posted by
LowOhms
Hi Zelgall,
I don't know, ALTEC accordion cloth looks very tightly woven to me, but, what do I know..... .
I think you just made your own point. You don't know.
Sorry but to think a tightly woven cloth won't leak air just staggers me.
Re: Who has done this ?........ ( Older ALTEC Woofers )
Quote:
Originally Posted by
Old Guy
I think you just made your own point. You don't know.
Sorry but to think a tightly woven cloth won't leak air just staggers me.
The screen in my french press will hold water on top of it :-)
Re: Who has done this ?........ ( Older ALTEC Woofers )
Quote:
Originally Posted by
Audio_by_Goodwill
The screen in my french press will hold water on top of it :-)
Rotfl. Sure. But water tight is a hell of a lot easier than AIR tight. Put you hand on the other side of that screen and blow thru it. It will slow the air down, but sure does not stop it.
BTW it only holds individual drops, as the water wants to cling together. As soon as the weight of the water exceeds the resistance provided by the screen, it comes right thru.
That really is what it comes down to. Many forces are at play in many directions on a speaker. We need to learn more about them.
But engineers often tend to over think and under listen. And many good designs get watered down to suit the market, either for appearance or cost. So yes, we can strive to improve.
