Repair suggestions for "doped" guitar speaker surround

[waspclothes]

Hey guys,
I got an old Traynor 4x10 cabinet for cheap, sounded pretty spankin' good too but could definitely tell a few speakers had some tiny tears. After taking off the 60 screws on the back of the cabinet and getting the speakers out, each one of them had several 1cm long radial tears/cracks in the surround.

The surround is "doped" and feels pretty brittle.

In the past I've used tissue paper and standard yellow wood glue on speaker cones, but that was directly on paper. Since these cones are covered in black shiny "dope", I'm wondering if there's a different method or different glue to use?

I was thinking about reinforcing the entire surround with a layer of tissue and glue since they're so crusty. Thoughts?

Here's a picture of the speakers, sorry for the bad quality.

[The Dude]

If it were me, I'd just remove and replace the surrounds all together. You can get 'em cheap on eBay. This is an example (below). You'll have to measure to see if it'll work for your speakers. If not the right size, there are lots of others. If you chose to do this, remove the dust cap and shim/center the voice coil before gluing.

https://www.ebay.com/itm/Pkg-2-10-in...wAAOSwPCVYAlIe

[olddawg]

I’ve done what you said. Sometimes thinned contact cement works better. Sometimes some saturated tissue paper. You can always spray the cones with flat black rattlecan spray paint. That’s an old resale trick..

[J M Fahey]

Sorry, none of the above, which give me shivers.

Elmerīs glue and tissue paper are to repair cones, but never edges (it dries hard as a rock).

Contact cement never stops hardening, even if at a slower pace, and is specially formulated to polimerize under UV light, which is available anywhere, outside and inside (fluorescent lamps, CFL, cathode tube screens, etc.)

The proper chemical and what manufacturers used originally is latex, tiny raw rubber droplets floating in water, so liquid is milky white.

Ecxactly the same as used to repair leaks on roofs and the like, where it flows into the smallest crevices, water goes on and rubber droplets stay sticking to each other to plug the leak.

Household grade is way more watered down than speaker grade, but you may apply as many coats as you wish.

Starts bluish milky but dries crystal clear so speaker cone looks deep black.

In principle "it never dries" ; you open a NOS 1986 Celestion speaker and itīs still jet black and sticky ; once mounted of course every dust or lint particle feels magically attracted and sticks to it, killing tackyness.

If at all possible, get a long thin brush and apply it on the back of the accordion edge.

Almost forgot: those speaker edge repair kits are for Hi Fi woofers, and so are made out of polyurethane foam, completely unrelated to guitar speakers.

[The Dude]

Juan,

If you look at the link I posted, it is a ribbed cloth surround not a polyurethane foam surround for woofers. I've used these surrounds to fix plenty of guitar speakers. I do agree. You don't want to use a foam edge on a guitar speaker.

[waspclothes]

The proper chemical and what manufacturers used originally is latex, tiny raw rubber droplets floating in water, so liquid is milky white.

Ecxactly the same as used to repair leaks on roofs and the like, where it flows into the smallest crevices, water goes on and rubber droplets stay sticking to each other to plug the leak.

Household grade is way more watered down than speaker grade, but you may apply as many coats as you wish.

Starts bluish milky but dries crystal clear so speaker cone looks deep black.

I can't say I've seen latex glue available before, can you recommend any product names?

I have some tolex glue that feels very latex-y, but I just checked and it's actually neoprene (with a water base).

Am I applying this to the surround by itself, or am I using something like tissue paper to reinforce it along the cracks?

[J M Fahey]

Exactly the same as used to repair leaks on roofs and the like

Itīs not a "glue" at all; although itīs sticky.

search for local brands of:

"water based acrylic sealer for roofs"

itīs the product shown here, for speakers use just steps 6 and 7. 1:34 to 2:07

https://www.youtube.com/watch?v=FZfQtxUA70Q

You apply it with a brush all around the speaker, let it dry a little, repeat 3 or 4 times because the roof sealant version is diluted.

No need to add anything, the dried but flexible film will join both sides of the crack and remain flexible forever ; what any kind of "glue" will not.

Buy a small can; youīll always find use for it at home later.

it is a ribbed cloth surround not a polyurethane foam surround for woofers

Ok.
Still way too soft compared to original paper edge; speaker resonance will drop from, say, 100Hz to around 60Hz or even lower.

Fine for a Bass speaker (which probably already had a cloth surround anyway); acceptable for a Guitar speaker in a closed box; dangerous on an open back baffle or combo; thatīs why I advise against.

But hey, if it worked for you:

https://www.youtube.com/watch?v=qeMFqkcPYcg

[nickb]

If it were me, I'd just remove and replace the surrounds all together. You can get 'em cheap on eBay. This is an example (below). You'll have to measure to see if it'll work for your speakers. If not the right size, there are lots of others. If you chose to do this, remove the dust cap and shim/center the voice coil before gluing.

https://www.ebay.com/itm/Pkg-2-10-in...wAAOSwPCVYAlIe

I was shown a technique that sidesteps the dustcap & shimming. You first glue and let set the inside part of the surround. Nowyou glue the outer using PVA. Apply 50/60Hz to the speaker from a 12v transformer fed by a variac adjusted to get the cone moving. A 6.3V heater winding might work but I haven't tired that. You want the cone moving smoothly. Start with one clamp on the outside while carefully moving the cone side to side and listening to the sound to ensure that its not rubbing. Repeat with another clamp at 180 degrees and then clamps at 90 degrees. Add more clamps as needed. Leave to let the glue set. It takes less time to do than read!

[waspclothes]

itīs the product shown here, for speakers use just steps 6 and 7. 1:34 to 2:07

https://www.youtube.com/watch?v=qeMFqkcPYcg

Thanks J M, but should the youtube link be to "Sweet Dreams" by the Eurythmics?? 1:34 to 2:07 shows them in a field with a cow and a cello.. not sure if that will help fix my speakers?

[J M Fahey]

Oh, Iīm a cheap rat so I often answer two questions in one to save 1 envelope and stamps.
First half was for you, second for the Dude, stating that although we think different ... "who am I to disagree?"

EDIT: oh, I am SO sorry

I posted 2 videos there, the first one for you ... but I mixed the links ... typical of 4AM very sleepy posting.

This is the real one:

https://www.youtube.com/watch?v=FZfQtxUA70Q

Just checked, neither cows nor cellos, just a typical Buenos Aires house.

By the way, I donīt suggest you drop a full can of sealant on your speaker, this is just to show you the kind of product which you will brush on.
Available in Home Depot and similar places.

A couple days after it dried, you may apply narrow streaks along cracks for reinforcement, using an artistīs fine tip brush; but the basic idea is to first re-treat the whole surround to restore some flexibility, or now and then youīll find new cracks.

[waspclothes]

Oh, Iīm a cheap rat so I often answer two questions in one to save 1 envelope and stamps.
First half was for you, second for the Dude, stating that although we think different ... "who am I to disagree?"

Hah! I found water based latex "contact cement" that is light blue and dries clear. Roofing products up here in Canada are very different I think... since I'm not really attached to the speakers, I'm going to experiment with this on them and see if I can repair them. If not, I can get some 10" jensens for pretty cheap and be done with it.

[J M Fahey]

water based light blue dries clear is the kind which works, so go ahead with it.

Same product as roof sealant, just different concentration.

I suggested the home use type since itīs cheapest easiest to find, even at the corner hardware shop.
Post results

[naniabusiness]

I was wondering if diluted roofing silicone (never hardens) might also work.

[J M Fahey]

Yes, in fact itīs already too diluted compared to the dedicated speaker edge sealant.

But itīs not exactly "silicone" but artificial "latex".