BBRN
Well-Known Member
Well said! Any thoughts on the butylene product I posted previously? I also posted a MSD sheet on the product as well.
Using Latex Cement for KLH Cloth Surround Doping
- Thread starter KingBubba
- Start date
Well said! Any thoughts on the butylene product I posted previously? I also posted a MSD sheet on the product as well.
Discounting of course all the correct materials and equipment required to produce the surrounds. How much do you think you'd charge if you were producing them?
Retrovert
Addicted Member
Sigh.
The nature of capitalism is to charge what the market will bear. I, in fact, would charge MORE because mine would (a) be made in America at a living wage and (b) with full adherence to environmental disposal laws.
The Chinese product costs less than sixty cents wholesale. One just has to buy a full container to get that price.
Most of the cost is markup in the US side of the supply and retail chain and profit. As I always say, most of the cost of an item is paying for it to be on a shelf and for someone to take it off said shelf and put it in a box.
Retrovert
Addicted Member
Thank you.
I did see that and thought kcbluesman's comment:
was precisely the same question I have, so I didn't chime in.
To expand on his observation, these fillers are a non-trivial percentage, as much as 2/3 of the product!
The CRL MSDS lists a wide range: 10-30% calcium carbonate, 5-30% talc, 1-5% silica, which totals 16-65%. My guess is that since chalk and talk are significantly less expensive than butylene, it's probably at the 65% level.
Now, those fillers will likely stiffen the caulk by adding body and thus have a dampening factor. Ok, so the question, as you noted, becomes: does this matter in such a thin solution applied to a surround? If so, how much? I simply don't know.
Your comment addresses this somewhat:
Perhaps, but I am not so optimistic. The saving grace is that the film is VERY thin which may mitigate many of the issues because it just doesn't have all that much to start.
On the one hand the fillers don't crosslink at all, just add a little body and mass, and one isn't using very much, so the stiffening should be minimal. On the other hand (this is why Harry Truman said he wanted a one-armed economist), we know that mass-loading the surround can raise Frs and it doesn't take much, particularly when one is adding more mass to the existing surround.
We really want to add as little mass as possible, so why apply something where 2/3 of it is dead weight that isn't sticky stuff either doing the sealing or flexing? It could be just as bad as PVA because one needs to apply twice as much. My suspicion is that filled butylene is somewhere between PVA and pure butylene in its effect.
I'd rather use pure butylene, just to avoid any issue. No fillers, no by-products, just pure beef, errr, butylene.
Brian
An Old Geezer
There are 2 thought trains here: 1) those who want to use a sealer to get a set of speakers up and running and, 2) those interested in the composition and creation of the sealer. While there is something overlap the goals are different. Hopefully in the discussions these are recognized and do not create conflict.
I am a category 1) person and never got beyond understanding water is 2h2o in its smallest part of being stable and not h2o and I use nacl on my food.
On the other hand, I dig through the dustiest of manuscripts to figure out some obscure philosophy of law or legal thinking just because I read something.
I am a category 1) person and never got beyond understanding water is 2h2o in its smallest part of being stable and not h2o and I use nacl on my food.
On the other hand, I dig through the dustiest of manuscripts to figure out some obscure philosophy of law or legal thinking just because I read something.
vinylisfinal
Super Member
with the permates aviation permatex it is very important to thin it with denatured alcohol to the consistency of chocolate syrup. one coat does it. my KLH 5's were re-sealed 7 years ago and are still tacky. the sound benefits were nothing but big improvements.
Retrovert
Addicted Member
Roy has written, on numerous occasions, that the AR-3 restoration project document originally mentioned Permatex, but that this was a mistake as it hardened over time:
He's written about Permatex numerous times. As I recall it was diluted 50%, which is substantially greater than the consistency of "chocolate syrup".
One of the great dangers of redoing surrounds, whether redoping or replacement, is reducing performance by small amounts that aren't immediately obvious without an A/B comparison. Human memory for audio is notoriously unreliable—I've read cognitive psychology papers showing acoustic memory persisting for as little as three seconds—that a slightly inferior refoaming/redoping result can't be perceived. This is a good thing, in that we're happy with the results, but a bad thing in that the characteristics have been altered in an measurable, and most importantly audible, way.
Good enough is the enemy of great.
And as long as we're on the subject, here's Roy's comment about using PVA:
I would say that if Roy writes something about sealing surrounds he truly knows of what he speaks and you ignore it to the detriment of your speakers.
Brian
An Old Geezer
It may stay flexible but what is the mass and effect on the fact of the driver. All the silicone and rtv compounds I have tried or used compared to the vintage-ar sealant is thick and has high mass.
Just because something stays flexible or you get it to just fill the pores means the mass is correct.
Retrovert
Addicted Member
Exactly.
Maybe not. As Brian noted before me:
(I added "does not" to the last sentence as I think Brian inadvertently omitted it, as the sentence doesn't make sense without it as a caution given the preceding sentence. Sorry for the liberty if I misjudged this, Brian, let me know and I'll fix it.)
Exactly. We know that adding mass to a speaker will raise the lowest frequency response curve. This is why I suggested that a filled butyl caulking (about 65% fillers) was inferior to plain, 100% butyl rubber.
Silicones are wonderful adhesives for many purposes, flexible and robust, but they are stiff. Very stiff. Very, very stiff compared to butyl rubber.
The fact is that many others learned in the art of surround reconstruction have written about their EXPERIMENTS, both here and on ClassicSpeakerPages, and their consensus was that Permatex hardens, silicone is stiff and heavy, PVA while lightweight is more rigid than others, etc. and that the only workable solution is to replicate the original butylene rubber as used by AR and KLH. This was science, with comparisons done over time.
I don't mean what follows as snark, as a nasty dig in any way, or in any way pejorative comment on anyone's hearing or taste in speakers. But the problem with redoing a surround is that one usually does not have an A/B comparison of before and after UNLESS it has been measured with a scientific instrument that provides an independent and impartial record of what was then and what is now. Human memory (and this includes mine, BTW) has been documented to be accurate for only a few seconds of acoustic memory. After that it's very fuzzy.
So we literally can't tell the difference in a before/after comparison, unless something is significantly better or worse; minor improvements or detriments aren't something we can identify, because we're made out of meat, and meat isn't all that accurate because it doesn't need to be. (Meat, however, is pretty good at not being eaten by lions and hyenas, and in making more of itself, which is why there's so many of us roaming the streets in herds.)
So if silicone drops the lowest response by about 10Hz, which is what I recall RoyC mentioning (off the top of my head, again the accuracy of meat comes into play here), one might not hear that unless one is doing A/B comparisons or has charts from instruments that can be compared. I do not believe that the laws of physics are different for different people or in different living rooms, and that loading a surround (or cone) is going to stiffen it and thus negatively impact frequency response.
Not sayin', just sayin'.
www.ebay.com/itm/ACOUSTIC-RESEARCH-CLOTH-SURROUND-WOOFERS-SEALANT-KIT-ALSO-KLH-/161505084986
The full link will start with "http://".
The full link will start with "http://".
Vintage999
Active Member
Vintage AR looks to be no more. Im not much for mixing up formulations, and I dont want to risk screwing things up royal the woofers on a pair of klh 5s I recently obtained.
Is there anything I can purchase and apply and forget about it?
Good listening.
Is there anything I can purchase and apply and forget about it?
Good listening.
Shakedown
Active Member
What are the signs of a sealant being too tight, how would I know if I ruined my woofers? When I press them down they flex the same as my other identical set of speakers with no adhesive, any audio tests to determine? I used Simply Speakers MI2000 adhesive glue on the accordion surround, should have known.
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Take a closeup picture of the surround and front of speaker. What speaker is it. Air suspension or ported? What was the reason or problem that led you to using the adhesive? Just want be clear of your goal, and wheater it matches this thread subject. Your using term adhesive. This thread is about sealant to keep air from passing through cloth surrounds, without hardening over time.