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View Full Version : Over-thinking a simple surround job???



LikaComet
08-23-2009, 07:39 AM
Probably one of the more commonly refered to questions on the forum has to be on the subject of refoaming/reconing drivers---but what's one more?

When removing the old surround from an older transducer cone (115A) it seems to me that it would be easy to damage the pulp surface of the cone. Wouldn't it be easier to cut the surround away and to cement the new surround to the old surround's surface left on the cone?

Or is that this is such common knowledge that I am making it obvious how green I am to this subject. If that's the case it wouldn't be the first time.

I know one highly respected contributor (Zilch) has iterated the wise words of one of this cultures more regarded philosophers:


"Be Vawie Cafuw"


certainly words to live by. . .



Is there a prefered thread on the subject?
Doug

BMWCCA
08-23-2009, 08:27 AM
When removing the old surround from an older transducer cone (115A) it seems to me that it would be easy to damage the pulp surface of the cone. Wouldn't it be easier to cut the surround away and to cement the new surround to the old surround's surface left on the cone?
In my limited experience, the foam surround has deteriorated so badly that there's little left of any substance on the back side of the cone to attach to. I've not had to resort to solvents on the cone surface and have chosen instead to carefully scrape away the deteriorated foam using different profiles of X-acto blades. I save the solvent for the basket to remove the glue there. I'm not looking for a perfectly clean surface at either location, just a secure surface for a decent bond. What little adhesive that is left will only be added to with the glue I'm using anyway. Sometimes you just get lucky and they come clean easily:
http://i31.photobucket.com/albums/c378/BMWCCA1/DSC_1389.jpg

and sometimes they don't

I can understand your trepidation but I'm pretty certain that after your first surround job you'll have developed a technique that works for you and you'll be as competent as the rest of us. If I can do it, you can:

http://i31.photobucket.com/albums/c378/BMWCCA1/DSC_1400.jpg

Here's what I left on the back of these 127H-1s:

LikaComet
08-23-2009, 09:34 AM
Nice looking work on your Vooffer BMWdriver. (I used to own a BMW K75s bike, now owned by a good friend)

I think I know what you mean about the foam crumbling away but on the woofer that I'm working with the foam material is of a different material. My aged surround material is hardened with age but structurally the surface that I think would accept the glue for the new surround makes up a good stable locating surface.

I think it might make a better job if I cut away the old unwanted surround material. The only undesirable aspect to what I have in mind is the cone would be sitting off the new surround material about .020" of an inch. The thickness of the old glue surface I have left on the cone.

. . .wutch y'all tink?

BMWCCA
08-23-2009, 02:52 PM
I think I know what you mean about the foam crumbling away but on the woofer that I'm working with the foam material is of a different material. My apology for not understanding. What does a 115A come in and/or look like? I know what a 115H-1 is. Are you dealing with a 6-1/2" woofer with a butyl-rubber surround? Maybe an L15A? Lans-aloy? Is this the LE15As in your S7 Olympus? :dont-know

I'll be quiet now and listen. ;)

LikaComet
08-23-2009, 03:49 PM
My apologies. . . yes you are correct. That's an LE-15A. And yes I believe it refered to as a Lans-aloy surround.

BMWCCA
08-23-2009, 06:33 PM
My apologies. . . yes you are correct. That's an LE-15A. And yes I believe it refered to as a Lans-aloy surround.

Well then, lots of Lan-aloy-removal threads in the Search but you may have to try it as Lans-aloy and Lansaloy, and maybe even Lansalloy. Here is some informtation:

http://audioheritage.org/vbulletin/showthread.php?t=14073

and here:
http://audioheritage.org/vbulletin/showthread.php?t=4041