A bright idea for yellowed Aquaplas

[Steve Gonzales]

Good job. I must say that if you look at the first woofer I did, that it was WAY beyond bleaching,the glue was red and the dustcap(s) were faded so all one could do was use the method I developed. As for increased mass, I've got to stress that there is almost ZERO gain, a FRACTION of one gram (the LE14a has a mass of 142.6 gms). The product I use WILL NOT PEEL in time. I think that the bleach pen is a great idea!. It gives us an easy middle ground and quick fix to the problem. I have to raise one question though. I remember when I was a kid that I soaked a pair of shoelaces in bleach, not realizing the effects that it would have and when I went to get them out, they FELL APART!. I am curious to know what the long term effects of that bleach sitting in the Aquaplas is, especially since it is in a concentrated gel form. I'm not raining on your parade, I am just posing a question that might otherwise be overlooked. In any case, again, good job and thanks for sharing your new discovery!. Steve G

[dblaxter]

hi ,steve ,

i'm with you on the weight gain ,it would make no difference to me ,like i said ,i know i could not here it if it did make a difference in weight ,as far as peeling ,there is no dought in my mind ,but you know someone will try some other product .
i thought about the bleach eating up the cone also ,i did test it on a old cone and left it with too much gel and never wiped it off, it had no effect on deteriating the cone ,but on the real cones i tried not to saturate the cone ,put it on worked it in a little and wiped off all the excess and then some. when i cleaned the woofers i had, it was before you posted the paint method and for me it was a cheap quick fix and of coarse being married ,this is the best part ,my wife bought it ( she works to so she brings home some bread also)
and can you believe it we have a collision shop and work together for 9 YEARS ,i know how do we do it ,(jbl s and loud music )the shop in one building and the office in another
so i say kudos to you steve nice work i just figured here was another option for us cheap ,broke ,finacailly handicapped, you get the idea.
and thats one of so many things i like about this site is that all these people with so much great information and ideas.
thanks michael

[pmakres1]

Steve,
That really looks good...and you are right-we really care how our JBL's look!

Peter

[boputnam]

A very interesting thread, no doubt.

However, I will opine here that cosmetics are moot - what matters is acoustic performance. The woofers worked-on here are old-school. If their cosmetics are offending, then likely they need reconing too due to mechanical aging of the surround and spider.

As a last resort, if recone kits are not available, and the surrounds can be redone then do that, and ignore the cosmetics. Altering the cone mass to any degree is IMO unneccessary and of unquantifiable impact. Why bother?

Let your wifeys do cosmetic surgery to distance the past - put a grill cloth on these bad boys and simply boogie knowing that's as good as it gets...

[Steve Gonzales]

If you don't like the way it looks and you can do something about it, why not?. If a cone mass is 150 grams, for instance, and you increase it by .05 grams and now it looks good, I see nothing wrong with it. The fact that quite a few people have done this with great results, is enough evidence that cosmetics DO MATTER to them. I'd bet you $1k that in a double blind test, all things being equal, except the whitening done to one set of woofers, you could NOT tell the difference. There are people that get JBL's that are in excellent "working" condition that are in need of a "face lift" and this is just one way to achieve that. If you have some ugly speakers and can live with them, more power to you, really!. I think most people can tell when their speakers are not performing right due to a bad surround or weak spider. I don't think they're reading this thread because they think that whitening the Aquaplas is going to cure that. It's all about options and I know from experience, that MINUTE mass gain is not going to matter one bit on a already high mass cone. I've done 6 LE14 A's and H's for the L220/222 restos I've completed and would not suggest this if it had ANY ill effect in REAL WORLD performance. Actually, your suggestion of grill cloth has a bigger impact on performance than the almost NIL mass gain, think about it. If you don't use high quality cloth, it will muffle the MID/HF, I know, been there , done that. If you like ugly JBL's Bo, that's still alright with me, they're still JBL's and I'll love them too

[boputnam]

Actually, your suggestion of grill cloth has a bigger impact on performance than the almost NIL mass gain, think about it. If you don't use high quality cloth, it will muffle the MID/HF, I know, been there , done that. If you like ugly JBL's Bo, that's still alright with me, they're still JBL's and I'll love them too

My suggestion was predicated on believing that anyone on this forum would certainly use "proper" grill cloth, ideally the original.

I just like spec JBL is all.

[Steve Gonzales]

I hear ya Bo. I'm going to try and get some before and after readings. I think that would help. I will say that a small, say, LE8, with an already low mass cone would be something to worry about (maybe). Hey, good luck finding original grill cloth .

[boputnam]

Hey, good luck finding original grill cloth .

[Earl K]

Well,,,

- As stated above ( somewhere ) I intend to use this paint method on some old le14a(s) / after they get refoamed .

- I'll measure any drop in Fs that might be caused by additional paint weight .

- A future goal ( if the weight increase is negligable from a single coat ) is to attempt to paint my le14h cones black ( & likely needing 2 coats ) .

<>

[boputnam]

- I'll measure any drop in Fs that might be caused by additional paint weight .

Would be real interesting to know, Earl! Hell, maybe I can get my white cones looking BrightSmile, too!

[Steve Gonzales]

Thanks Earl, I have a good idea that the super thin film of this material would have a NIL effect and welcome the tests. As for the black. I don't think you can put enough black colorant to get it ( the 1-2-3 Bullseye) to tone down to black, but I've got a friend that used waterbased flat black sprayed through an airbrush gun and achieved a great result. An airbrush set-up is really good because it puts a superfine concentration of material so that you can keep amounts to a bare minimum. You would be suprized how far a TEASPOON of material will go in one of these guns!. Once the water has evaporated, the weight would be in the .0xx of one gram range of cured film. Steve G

[briang]

I have used steve's method on 9 units so far. I'm very pleased with the cosmetic results.

Mass: Yes, physics demands that the cone mass must change, however I am willing to assume that the mass change will fall within JBL's original production tolerances for most cones. This is to say, that not every cone produced has and identical mass and that the amount of mass added by the primer is likely to be much less than the engineer's specified allowable difference between the lightest and heaviest cone produced for a given model number.

Mass #2: We could certainly find a cone and do before treatment, and after treatment, measurements of cone mass on a calibrated mass balance. I'm willing to do the work if anyone has a "bad" cone they can spare.

[LeventVehbi]

I arrived too late. I went through the whole thread, trying to visualize everything, but alas. It seems Steve is no longer a member - but maybe somebody has pictures of this process.

Help me out anyone?

[hjames]

I arrived too late. I went through the whole thread, trying to visualize everything, but alas. It seems Steve is no longer a member - but maybe somebody has pictures of this process.

Help me out anyone?

Apparently none of his pictures were hosted here so they are all gone.
You might find him on Audiokarma if you look around there.

[bldozier]

Ditto