Prefered Glue for surrounds

[djcslice]

gray house and fast eddie do you guys have some tips for refoaming without shims. Everyones got me worried that i will mess up the vc and if there is a risk of doing that should i just go with shiming. I am pretty sure that i am going to have to replace the dust covers anyway

 

[Grayhouse]

It's really pretty easy refoaming without shims of course this all depends on the tolarences between the VC and motor assy. spider wear, and cone condition as well. That aside refoaming without shims is more a matter of feel. Once you have the surround glued and set to the cone and before you glue the foam to the basket you need to find that sweet spot as you gently press down on the cone. You want to find the spot where there is no contact between the VC and motor assy. Some people use a 1.5volt battery hooked to the driver to center the element. Others use a test pattern to help center it. Myself I just use my sence of touch it. If your cone, VC and spider are all in good condition it should be more than enough to find nirvana. Once you find the spot take a bunch of clothes pins and clamp down the foam to the basket along the entire surcumfrence of the speaker (about one every inch or so is fine). Make sure the cone is still centered after clamping by pushing the cone inward and outward as well. Remove about a quarter of the clamps (make sure you're still centered) and apply a bead of glue to the underside of the foam and use your finger, or a brush to spread it out evenly. Reapply the clamps and move to the next slice in the pie. One it's all glued up make sure you are still centered as before and let dry for at least a few hours before testing.

 

[Damage]

Bass test CD with single tones and sine sweeps works best.

 

[djcslice]

Bass test CD with single tones and sine sweeps works best.
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what??

 

[Fast_Eddie]

I just put on a cd and play the thing while I'm doing it. If the VC rubs, I'll hear it while the glue is still wet. Never had to worry about it much though.

I do try to move it from side to side and find the center. I just do it by feel. It's allways worked out just fine. Just move it to the left 'till it hits, then to the right. Find the middle. Rotate 90 degrees and do it again.

Ed

 

[outlawmws]

Bass test CD with single tones and sine sweeps works best.
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what??

The 1.5 battey trick is useful while getting ther glue on the outer edge (Do the inner edge to the cone first.) But I found it to be useless for centering.

I used to shim all speakers after screwing up a couple and rubing the VC. now I use a tone off of a Audio Generator. but an AG is nor required, you can download a tone off the net, burn a CD and feed that to the speaker while droping the outer edge down and squeezing the glue joint.

 

[Grayhouse]

Just keep it simple djcslice. For your first refoam I would avoid complex test tones, or any other outside electronic signals. For one thing it will allow you to devolop a feel between you and the speaker and thats what you want to develop right now. Outside stimuli will only insulate you from what you are doing. One other thing shims and electronic media are not 100% gauranteed, but I have never know one to fail by using feel alone as long you are constantly checking your work along the way. The shimless method also takes into account any small imperfections the various parts may have developed over time and allows you to compensate using the best tools at your disposal....your fingers and your brain. Shims and stimuli force the VC to center, but once you remove that crutch who knows.

You will be quite surprised how easy it wiil go once you get started. It's just getting past that first apprahensive step. Once you do that you'll be fine. Once you become more proficent you can begin to experiment with other more elaborate and complex procedures.

 

[Damage]

Shims and stimuli force the VC to center, but once you remove that crutch who knows.

I find that doing it by feel has the opposite effect. Its hard to apply even pressure to all sides at one time. But I guess maybe it takes experience in using feel.

Bass tones don't center, but rather give a distinct buzz when the coil is not centered. And once the spider/surround is crimped in place, allows you to test full travel at realistic volumes.

Just my $.02

 

[Grayhouse]

I find that doing it by feel has the opposite effect. Its hard to apply even pressure to all sides at one time. But I guess maybe it takes experience in using feel.

Just my $.02

Having very long fingers helps I guess. I just think it would be best to keep it very simple for him untill he develops the confidence to move into other more elaborate techniques.

 

[mhardy6647]

FWIW, the only re-surrounding 'failure' I had -- on a 12" C-V woofer -- was one I shimmed. The shims (provided by PE) were a bit too thick for the gap on the C-V's, I was too lazy to locate shimstock of the proper thickness, and the end result was a dragging VC. Straightforward to fix, but still a pain in the neck. The other C-V turned out OK, even with half-assed shimming, BTW.

I am no expert on re-surrounding, but I've done a dozen or so since the C-V incident without shimming (or removing the dustcap) and all turned out well. I use a LF sinewave tone at low level (from an AF signal generator) whilst I perform the surgery to help keep the VC where it belongs.

 

[djcslice]

i dont mean to be annoying or anything, but i have really never ventured down this road, and i am a little confused on how the aligning works. Maybe someone can give me a really really detailed description on how to do the shimless method. I understand most of it, its just keeping the vc from getting destroyed. from what it sounds like, i am not supposed to let the vc former touch the vc. Is this correct? I think one of the big problems is that i dont have a speaker to look at, or "feel." Will i understand what you guys are talking about when i get a speaker to see what you guys mean??

 

[robobxman]

Check out this site: http://www.citlink.net/~msound/refoam/.

If you are handy, you won't have any problem doing this. But you will need a speaker to practice or all this will just be academic.

 

[Grayhouse]

Do you have your AR-14's, djcslice? From what I understand you are gonna be replacing the mismatched woofers am I correct? Go ahead and remove that one woofer that has no surround left on it and you can use that one to play with so you can get a feel of what we are talking about. Set the speaker on it's back and with your hand spread out as wide as it will go place it on the cone and gently press down on the cone. You want to use a very light touch. If you feel any rubbing or contact simply compensate by rocking your hand in a direction where there is no contact. Now try the 2 handed method by using the thumb, index and middle fingers of both hands. Trust me you will be able to find that point without much effort. If you just passed this simple test than you are ready to refoam. Like I said earlier, once you have the foam glued and set to the cone you will be using those same basic technique to find that same place once again before you glue the surround to the basket. It only seems confusing right now because you have no hands on practice with the technique. Once you start doing it it will all begin to make sence, but you have to roll up your sleeves and get in there and fiddle with it. Alot people think they are gonna do something terribly destructive and ruin the speaker. What most people don't realize is that your average woofer is a pretty durable machine when you stop to think of the amount of energy that they are designed to deal with. It takes more than your average amount of mistreatment to trully hurt, or destroy one.

 

[dagg39]

Hi,
I had used black silicone RTV (for auto glass windshield) for rubber and foam too and epoxy resine for dust cap.

 

[Damage]

I shall add

3m Black Super Weatherstrip Adhesive (orange box) seems to work pretty well. ~$4.00 for a large tube.

 

[chekov]

Used Aleene's Tacky Glue

Last weekend I did my first refoam.
I used Aleene's Tacky Glue (less than $2.00 for a 4oz bottle- I bought it at Joanne's Frabric Store, but most Craft stores carry it)
I also bought a package of clothes pins which I used as clamps around the outter rim while the glue dried.
I got my 10" foam surrounds from "RS Sound Systems" for *** $3.50 each ***
I carefully followed the instructions on this board -the one which does NOT require removal of the dust cap.
I used "feel" to center the cone- with intermittent use of a 1 1/2 volt battery just to be sure.
Proceeding carefully & patiently, my first refoam was successful!
The drivers were from a vintage Marantz HD66- these drivers were very forgiving... they essentially centered themselves.

 

[Andyman]

C'mon guys, grow some cajhones!!! :lmao:

No shims and contact cement used here, but then again, I've prolly done close to 100.

Worst ones were some 10" JBL 125s or 127s, a fussy Ohm 10", and some Fisher 15"s I did for Kegger with paper thin cones.

I've used a 60 Hz test tone tape for some, but most of the time the spider provides enough support that a good eye and a few cycles through full extension/compression travel get it set up right.

 

[packrat]

I finally found some of that Aleene's tacky glue - it is different than Elmers and Weldbond in that it doesn't flow. It stays in a little bead where you put it. Works great. I have also tried Loctite fabric glue because it dries quickly, but the tacky glue does work better.

For some Smaller Advent surrounds I had to resort to latex contact cement, but only after practicing with how it sets up. I did the cone-surround with Elmers, but the surround to the basket on these was a bit tricky for me. I brushed on the CC to both surfaces, and then gave it all a quick wipe around with fresh cement to keep it gooey. Then I stuck them together - because it's still a bit wet, they can slide easily so I centereed it by pushing on the cone until I got no VC rub anywhere. Then let it set up after clamping with clothes pins.

 

[quantum 3]

new foam surround how-to video

Go to the bottom of the page, nice step by step video...


New foam surround video

 

[gonzothegreat]

Just some brain farts on specific driver refoam jobs...

Advent woofers with the masonite ring/DQ-10 woofers
I've only done three of these and one had to be redone before I figured out a good technique. Clean up the ring and cone with your favorite adhesive solvent. I prefer acetone dabbed on with qtips then scraped with a butterknife (the knife is quite effective at scraping the underside of the ring w/o removing it). If any adhesive remains, one last swab with qtips will usualy clean it down to the cone.

So much for the cleanup. Glue the appropriate foam with the arched side down to the top of the cone with the outer lip *below* the masonite ring. Yes it makes things a bit harder in the next step but that's how they did it at the factory and who am I to argue? Let the glue dry for 4-6 hours. Now for the big finish! Apply glue to the foam edge and wait 5 minutes for it to get tacky. Grab a 1.5v D cell (or an audio generator with adjustable DC offset) and hook it up so the cone pushes out toward the masonite WITH THE WOOFER POINTING DOWN. The woofer inversion helps counteract any spider sag. If you're using a generator, crank it up so the cone is roughly even with the ring. Now run your finger or other pointy bit along the glue seam a few times and repeat after a few minutes. Let it dry for 20-30 minutes with the woofer inverted and voltage applied. Then remove the voltage and set aside to finish drying (still inverted). Be sure to test the woofer horizontally and vertically. I've had drivers that didn't scrape until they were installed - d'oh!

As GordonW has mentioned elsewhere, Advent used liquid nails to secure the masonite ring and the spider to the basket on later models so you might want to use LN on any drivers using the red adhesive that DQ did.

Bose 901s (insert joke here...)
Royal pain to do 18 drivers but its relatively easy once you get the hang of it (and the obscene prices some places charge for 901 foam rings...). An audio generator is manditory IMHO as are some 32oz quiky-mart plastic soda fountain glasses with the bottom chopped off. Clean up the cones and baskets with a knife scraping followed by a few dozen acetone soaked qtips. Glue the foam rings to the cone first and work things assembly line style to speed it up. After they dry, apply glue to the basket and wait for it to tacky-cize. Hook up the audio generator and sweep down from 1kHz or so. Any rubbing should be easily heard so you can realign the cone. Sometimes a driver won't center properly without some help which is where the soda glass cones in. Some glasses are *just right* for holding down the outer foam edge while the glue sets. The bottom has to be cut out or else the driver won't function properly.