How To Repair an Audio Speaker

Which adhesive should you use to repair an audio speaker cone or surround?

Selleys' answer here comes with an honest qualification attached, and it is worth repeating rather than glossing over: Selleys has not conducted any specific testing in this application. What Selleys can report is feedback from people who have successfully used Selleys Craft Glue, which is PVA based, for speaker repairs.

That matches what speaker repairers usually want. A PVA-type adhesive goes on white, dries clear or near-clear, stays slightly flexible rather than setting glass-hard, and — the property that matters most for this job — allows repositioning for a minute or more before it takes hold, which you need when you are centring a surround on a cone.

What "PVA based" means for a speaker repair

A PVA adhesive is water-dispersed. It bonds as the water leaves, either by evaporating from the open edges of the joint or by soaking into a porous substrate. Three consequences follow, and they explain both why it suits this job and where it falls down:

• Open time. Because the bond forms as the water leaves rather than instantly on contact, you get a working window to slide the part into position. This is the opposite of a contact adhesive or a super glue.
• It needs somewhere for the water to go. Paper cones and fabric surrounds are porous and cooperate. A rubber or foam surround against a metal frame is much less porous, so the same adhesive takes far longer to reach strength.
• Water resistance is limited. Selleys' published guidance on its PVA range is clear that an interior-grade PVA is not waterproof and is unsuitable for exterior or structural applications. Inside a speaker cabinet that is rarely a problem, but do not treat a PVA repair as weatherproof.

Selleys does not publish a technical data sheet for Craft Glue, so we cannot quote a set time, an open time or a cure schedule for it here. Work to the directions on the pack.

How to approach the repair

1. Work out exactly what has failed — the surround lifting from the cone, the surround lifting from the frame, or a tear in the cone itself. They are different repairs.
2. Clean the joint. Old adhesive residue and dust prevent a new bond forming; remove what will come away without damaging the cone.
3. Dry-fit and mark your alignment before any glue comes out. On a speaker, the voice coil must stay centred in the gap — a repair that is strong but off-centre is a failed repair.
4. Apply a thin, even film. A thick bead adds mass to a moving part and changes how it behaves.
5. Position the part and use the open time to get it right. Check the alignment before you commit.
6. Hold or lightly weight the joint while it sets. Selleys' guidance for its PVA wood glues is to clamp the joint until the adhesive sets, and to clean excess with water while it is still wet.
7. Leave it to cure fully before you power the speaker up. A partially cured joint will not survive its first excursion.

Where a PVA is not the answer

• Polyethylene and polypropylene. If any part of the assembly is one of those plastics, most Selleys adhesives will not bond it — Selleys All Plastics is the product formulated for polypropylene, polyethylene and ABS, using a primer pen and adhesive together. Note its own limitations: it is not suitable for glass or foam, it only works on some rubbers, and it will not work on PTFE.
• Anything that gets hot or wet. An interior PVA is not waterproof and is not for structural use.
• Rigid, high-strength joints. If what you actually need is a rigid structural bond on metal or plastic, an epoxy such as Araldite Super Strong 5 Minute Epoxy is the different tool for that job — but note that it sets in 5 minutes with a 2–3 minute pot life, so it gives you almost no repositioning time at all, and its bond softens above 60 °C.

Safety: the fallback products are much stronger than the recommendation

The adhesive family this page actually recommends for a speaker — a PVA — is the mildest thing on the page. The alternatives named for the cases where a PVA will not do are not.

Product	Classification
Aquadhere Interior and Aquadhere Exterior	Not classified as hazardous under Safe Work Australia GHS 7. No signal word, no hazard statements
Selleys All Plastics	Danger — H225 highly flammable liquid and vapour, H319 serious eye irritation, H336 may cause drowsiness or dizziness
Araldite Super Strong	Part A Warning — H315, H319, H317. Part B, the hardener, Danger — H314 severe skin burns, Category 1 serious eye damage, H317

What that means at the bench

H225 and the way this repair is done are a bad combination. A speaker repair is slow, close work: you are hunched over a driver at bench height for a long stretch, aligning a surround, with your face maybe thirty centimetres from the glue line. All Plastics is used as a primer pen and an adhesive, so that is two solvent sources open at once. The vapour is what ignites, it is heavier than air, and it settles rather than dispersing — which matters because this work happens in garages and sheds, where the gas hot water unit, the fridge compressor and the bar heater all sit at or below bench height. Open the door, and shut the pilot off before you start.

H336 is the gauge. Drowsiness or dizziness partway through a fiddly alignment is not fatigue; it is the vapour concentration telling you the room has stopped clearing. Stop and air it out rather than pressing on for the last few minutes of open time.

The epoxy's hardener is the half to respect. Part B is H314 — severe skin burns, not stinging — and with a two to three minute pot life people mix in a hurry, often with a finger. Use a spatula and nitrile gloves. Both parts carry H317: sensitisation is permanent once acquired and is built from repeated small contacts, not one dramatic exposure.

The lowest-hazard option is the one the page recommends. A PVA is the right family for this repair on its merits, and the Aquadhere PVAs are not classified as hazardous at all — no ventilation requirement, no ignition concern, and water for clean-up. Reach for All Plastics only if part of the assembly really is polyethylene or polypropylene.

Poisons Information Centre — 131 126 in Australia, 0800 764 766 in New Zealand.

Common questions

Is this a tested, recommended repair?

No. Selleys has not conducted specific testing in this application. The recommendation rests on feedback from people who have used Craft Glue successfully for speaker repairs.

How long can I reposition the part?

A PVA-type adhesive is the right family for a repair that must stay adjustable for a minute or so, which is why it is suggested here. There is no published open time for Craft Glue — check the pack.

Will the glue line show?

PVA adhesives generally go on white and dry much clearer. Keep the film thin and wipe excess with water while it is still wet.

Can I use a super glue instead?

A cyanoacrylate gives you no repositioning time at all, which is the opposite of what this repair needs. It is also very hard to remove if you get it wrong — see removing Quick Fix Supa Glue.

What about a contact adhesive?

Contact adhesives grab immediately on contact and cannot be repositioned, so they are a poor fit for aligning a voice coil. They are excellent for large area bonds where alignment is set in advance — see contact adhesives and glues.

How do I clean up?

Water, while the adhesive is still wet. That is the standard clean-up for Selleys' PVA products.

Where can I read more about PVA glues?

See PVA glue and the wood glue range, which includes Aquadhere Interior for indoor work and Aquadhere Exterior where water resistance is needed.