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Old 13th May 2010, 03:27 AM   #1
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Default refurbishing vintage paper

Hi all,

I have some vintage SABA paper drivers. They are very faded and beginning to look a bit fragile.
My question is, do old paper drivers dry out? If so, can something be done about it without ruining them?

Kramer
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Old 13th May 2010, 03:51 PM   #2
GM is offline GM  United States
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Well, the mold release that normally makes them ~shiny/black does. This allows heat to openly attack the glue used to bond the paper fibers together and water vapor to hydrate/further deteriorate them, so in my case where the house is somewhat humid year round and really humid through much of it, my couple of truly old drivers with one piece cone/surrounds stored in a closet were slowly turning to mush till I bagged them with a few desiccant packs. The Jensen LL15 was so soft I accidentally poked a hole in the surround from the backside with a fingertip from just grabbing the frame to move it.

Anyway, not sure what's best to seal them. I've done small, cheap RS drivers with Armorall or similar and WD-40 with woofers getting coated with a tire silicone coating for vehicle apps. Highly thinned Shellac seems a good choice except that it won't protect it well enough from water, so maybe highly thinned Dammar as a compromise. Then again, water based stain or paint formulated for airbrushing artwork may be the 'hot ticket'.

GM
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Old 13th May 2010, 06:00 PM   #3
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I had thought about really thinned out dammar. Anybody tried it? Last thing I want is to make my lovely old drivers look like they were dipped in "wet look".

Funny you mention that Jensen tearing. A similar incident inspired me to write this thread. A neighbor was tossing out some "old speakers" so I grabbed them. Sadly they turned out to be white van speakers... Anyway, while inspecting them I merely brushed the edge of the paper tweeter with my finger and was shocked to watch it tear.

WD40 huh? Being a car guy I love that stuff. I already spray it on pretty much anything in my garage. Maybe it can be the bridge between my 2 hobbies!

Kramer
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Old 13th May 2010, 07:09 PM   #4
GM is offline GM  United States
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I've airbrushed it on drivers to smooth out break-up modes, but not as a preserver. Cover wise it yields a mildly satin sheen. If it's glossy, then it's normally way too thick.

Yeah, I buy it by the gallon for use in a pump sprayer as well as a few spray cans spread around the property. For serious work though, I use PB Blaster.

I use to be a auto, motorcycle guy, and learned how to design hi-perf intake/exhaust systems by studying TL, Horn, etc. theory, so the two are definitely connected.

GM
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Old 13th May 2010, 08:39 PM   #5
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Quote:
Originally Posted by mrkramer View Post
Hi all,

I have some vintage SABA paper drivers. They are very faded and beginning to look a bit fragile.
My question is, do old paper drivers dry out? If so, can something be done about it without ruining them?

Kramer
I have an old EH Scott radio from 1937. I think I got it around 1980. The speaker was fine at that time but it eventually got so dry and brittle that it has cracked into a lot of pieces and will require a rebuild.

I'm sure paper quality plays a roll in this. Plenty of books over 100 years old are fine, but the ones on cheap high acid paper have turned brown and brittle.

You might dig around on the web for references to preserving books or papers.

I wonder if furniture oils would help? My old leather bike saddles respond to neats foot oil (more of a gooey wax). Non hardening sticky glues on accordian surrounds might help. Experiment on an old cheap driver and let us know.

David
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Old 13th May 2010, 09:49 PM   #6
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If acids are a problem (i.e. H2SO4 dehydrating aka sucking out water from the the H-[C6H10O6]n -H molecules), exposing the membranes to gaseous Ammonia (NH3) should neutralize the acid. However, there remain salts of Ammonia and ammonia by itself isn't so great either...
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Old 13th May 2010, 10:40 PM   #7
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As I read your post I was imagining explaining to my wife my logical reasons behind exposing my speakers to gaseous ammonia!

It seems there are a number of reasons for paper to break down. I thought they might be dried out. GM mentioned humidity and mold. Now acids and salts of ammonia.

I think the suggestion of looking into book preservation might be a good one. Maybe there are some simple procedures archivists use.

Kramer
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Old 13th May 2010, 11:12 PM   #8
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Dammar is excellent for restoring fragile & discoloured cones, but the resultant stiffening of the cone will change the freq response...
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Old 19th May 2010, 09:36 AM   #9
el`Ol is offline el`Ol  Germany
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Everything that fades is the blue (yes, blue) colour.
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Old 21st May 2010, 04:26 PM   #10
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What blue color?
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