Rubber Surround Rot Prevention

It seems like I and many have all been under this misconception rubber surrounds cannot rot like foam. However two used speaker purchases, a JBL HLS615 and Infinity center channel have seen alarming deterioration of the rubber. In fact the jbl's 6.5" woofers looked perfectly good until you played them loud then they cracked. Touched them and the whole thing turned to soft goo, wiped away with your hand. (luckily ebay seller bootapest 2 had a set for real cheap) The infinity's have just begun, I noticed a portion of one easily tore through with just a touch.
The breakdown process is one that seems consistent with what happens to bicycle inner tubes or latex clothing and gloves if improperly stored or subjected to incidental contact with certain substances. (for instance vaseline=wetsuits a big no no)
In an attempt to stop further deterioration on the Infinitys I took some baby powder and sprinkled it liberally on the faces of the drivers as well as took the backs off and, using a turkey baster, spread baby powder all over the rear of the surrounds, shaking the excess off. I plan to repeat this about once a year or so.

It's been my experience with various natural rubber products that coating them in talc/baby powder is like giving popeye spinach. they love the stuff and you can do no wrong there.

DO NOT TOUCH THEM WITH OILY FINGERS if you are inspecting yours.

comments/rebuttals welcome.

I had infinity speakers in my car. Bought them new, they lasted 1 month before the surrounds crapped out. They did not and I wonder if they still do..make a decent surround.

I also had some nice cerwin vegas that used foam for the surround, they fell apart too.

A powder won't help the rubber one iota. It does not "seep in".

You should not have to do anything to your surrounds. If they fail, then it was a crappy speaker to begin with. My 1995 vintage polk RT600s get used every day, and still have good surrounds. I've used speakers out of the 70s last year with good surrounds.

A powder won't help the rubber one iota.

Click to expand...

Doesn't that fly in the face of the fact rubber inner tubes for bicycle and automobile tires have long been packed with talcum powder to preserve them?


As well various rubber and latex products have care recommendations such as:

When you are done for the day, you should dust your cap on the inside and outside with talcum powder, corn starch, or baby powder.

Click to expand...

http://www.swimming-caps.info/

I think the effect is that the talcum absorbs any harmful oils or grease before they can penetrate and attack the rubber- the talcum does not need to penetrate the rubber to protect it.

Sitting in bright sunlight in a room with lots of windows could speed up the deterioration maybe. Also weird atmospheric conditions in some people's houses could effect them. I can see car speakers taking a beating from the sun and high temperatures and humidity.

I am not a chemist, but I know plastics do some strange things. I am a pro disc golfer (frisbee) and in the 80's Discraft came out with an indestructible plastic for their new Phantom disc. These discs were great in that you could hit trees etc, and the plastic wouldn't warp or even scratch. Fast forward 20 years. I hang a couple of new unthrown Phantoms on my wall (see avatar) Since I have 500 discs hanging I didn't even notice that the Phantoms had turned to goo. I thought I could clean the surface goo off with some soap, but the disc just broke into little pieces as soon as I touched it.

I clicked on this thread because I own Polk Monitor 10 speakers that have (4) 6.5" rubber surround drivers. I also bought some Infinity 6.5" car speakers. I didn't have the problem that Hellanoise had with them...my rubber surrounds simple became unattached to the poly cone. I was never sure what glue to use to reattach them. Infinity used some sort of brown glue that was hard and not very pliable. It's no wonder it didn't stick to the poly cone for very long.

allsmith said:

Sitting in bright sunlight in a room with lots of windows could speed up the deterioration maybe. Also weird atmospheric conditions in some people's houses could effect them. I can see car speakers taking a beating from the sun and high temperatures and humidity.

Click to expand...

yeah could be outside factors that did this and I might mention I'm not suggesting everyone pour baby powder on perfectly good drivers. I have probably 4 other sets of rubber surround drivers in the home and 2 in the car that have no damage after 15 years and what damage happened to the JBLs and Infinitys didn't happen in my possession.

I just looked at them and realized that other rubber items like clothing, gloves, inner tubes etc use talcum powder as protection and their destruction if not protected resembles what happened to the JBLs. Like the rubber wanted to revert to its natural state of goo-ness.

Bstable said:

I am not a chemist, but I know plastics do some strange things. I am a pro disc golfer (frisbee) and in the 80's Discraft came out with an indestructible plastic for their new Phantom disc. These discs were great in that you could hit trees etc, and the plastic wouldn't warp or even scratch. Fast forward 20 years. I hang a couple of new unthrown Phantoms on my wall (see avatar) Since I have 500 discs hanging I didn't even notice that the Phantoms had turned to goo. I thought I could clean the surface goo off with some soap, but the disc just broke into little pieces as soon as I touched it.

I clicked on this thread because I own Polk Monitor 10 speakers that have (4) 6.5" rubber surround drivers. I also bought some Infinity 6.5" car speakers. I didn't have the problem that Hellanoise had with them...my rubber surrounds simple became unattached to the poly cone. I was never sure what glue to use to reattach them. Infinity used some sort of brown glue that was hard and not very pliable. It's no wonder it didn't stick to the poly cone for very long.

Click to expand...

(off topic but...) I played disc golf regularly in the 80's at Morley Field in San Diego. Not great but a solid 6 under average player. Maybe best was 12 under and got a hole in one once. Actually just a great excuse to run around the woods away from the old lady with my friends and have a beer and a joint. At this age all a memory. Except the friends that is. My circle of friends were strange in we liked to play with as few discs as possible, I used mainly a Stingray which broke right, (always my favorite) one I can't remember that broke left, and a putter. Travelled light you might say.


On topic I refoamed some Prelude PR-F's (12 drivers) and the glue was a BEAST to get off. MEK if you can get ventilation did it ok.

Petroleum based plastics are constantly outgassing, breaking down out of the chemical chains they were constructed in.
Car interiors especially.

Humidity is a killer, as is oils from fingers.
apparently the knuckle is a better "probe" where surface contamination is a problem, some glues for Hypalon and neoprene recommend testing with a knuckle, not a finger tip for glue set up/dryness.

I am suprised this has not been suggested. I have used Armor All Original on rubber surrounds since the late 1960's it does a fantastic job of protecting the rubber. I have never used it on foam surrounds, I have always avoided speakers that used this type of surround.

I use a product called Wurth Rubber Care Gel Stick on the rubber surrounds in my Sony SS-M7's and APM-22ES. It isn't actually a gel but a liquid in a container with a foam applicator on top. I just pull off the top and use a small artist's brush to apply it. The product description says it is silicone-free, biodegradable, and water repellant and that it hydrates rubber components to keep them supple, pliable and resilient. Sounds good to me.

Rubber and foam surrounds will degrade for all the reasons listed above. Ozone will also speed up the rot. Doped cloth surrounds seem to age much better.

Doped cloth surrounds seem to age much better.

Click to expand...

Yeah they do! I'm always in amazement when I see the surrounds on the Sansui speakers of the 70's with latticework grilles and doped cloth surrounds and they appear they could last forever. Why don't they all make them that way? Would they last forever and put themselves out of business? Or is it an issue of compliance? The weakness of said Sansui woofers BTW seems to be the paper cones.

On other methods of protection I like those and have enough car detailing experience to know lots of these products are great if you start using them early in the game. I don't think using armor all on a set of surrounds already deteriorating would help?

Sure would look better than baby powder.

batvette said:

Doesn't that fly in the face of the fact rubber inner tubes for bicycle and automobile tires have long been packed with talcum powder to preserve them?


As well various rubber and latex products have care recommendations such as:




http://www.swimming-caps.info/

I think the effect is that the talcum absorbs any harmful oils or grease before they can penetrate and attack the rubber- the talcum does not need to penetrate the rubber to protect it.

Click to expand...

Not sure the talcum powder was to preserve, but keep them from sticking together when they did start to decay.

I always thought the talc on inner tubes was to keep the surfaces from sticking together... not as a preservative. And also as a sort of dry lube when you get the tube into the tire so it will slide more easily when inflating.
My 1979 Norman Labs have rubber surrounds; so far so good. fingers crossed x x x
(but now i'm going to be watching more closely!)
billw

To the above (similar) posts: I found that point made in several places and it's true but it was also offered that talc provides an absorbing barrier between the rubber and materials like oil and perspiration which attack it. So in effect it is a preservative method as well. Some also offered the talc over very long periods of time can also attack the rubber but that may have referred to perfume additives in some products like baby powder.
That's the logic I've seen, open to more info of course.

I have read some speaker ads where people are using Rubber Renue. Has anyone here used this stuff?

+1 on the talc just being there on some "rubber" products to keep them from sticking together. As far as it preventing contamination by providing "an absorbing barrier between the rubber and materials like oil and perspiration which attack it" - well, then you've got oil, perspiration, AND talc contamination - heavier and more prone to restrict proper movement and possibly cause more problems than it solves. Better to just be careful when handling them?

Short version, ANY treatment can degrade the sound, which leaves you with something that may last way longer than you want it to. <G>

It's all environmental. Either keep them in a hermetically sealed climate controlled room, or let them rot and expect to have to refurbish them occasionally. Same thing happens to turntable and recorder belts, capstans, etc. - it's the price we pay to keep the tunes coming.

A few dollars and an hour to change surrounds, every 25-30 years?

Call it the cost of maintenance. I wish everything else needed so little upkeep.

Greetings, I just bought a pair of AR M5 Holographic speakers with rubber surrounds, one of the surrounds has a small rip on it and was wondering if I should replace the surrounds with rubber or foam. Has anyone switched from one to the other and did it make any difference?

Replace them with what they came with ... unless they were designed in a garage, there was some serious thought and engineering that went into the design and components used.

I suppose you could get lucky.



Well, do you feel lucky? <G>

That said ... with a SMALL rip in a rubber surround, you might be able to get away with a THIN coating of rubber cement (think bicycle repair kit) on both sides of the rip. The less the better. The sides of the rip should mate up nicely. If not, just a thin line of cement in whatever crack is left after the first application dries. Problem with that is - was the rip from abuse, or is the surround just generally ready to roll craps? If it still looks good after a few hours of fairly hard use, give yourself a pat on the back.