Hi!
Having run effectively a 30 channel hifi on an electronic concert organ for some years, some channels of which use Lowther drivers, and doing outside events using Lowther speakers for sound reinforcement, over the years I've become a dab hand at repairing the beasts.
For some time I've been lining up units needing refoaming and voice coil repairs and inspired by Lowther friends bringing me theirs, they're all getting done in one batch.
The worst job is cleaning off the old foam. It's foul. Worse, the glue: many types of which won't pull off nor be dissolved by meths or other solvent. But worse is when, especially the spider, has been smothered in a plastic glue like UHU glue or other PVC adhesive. It goes hard and if spilt on the paper cannot be removed without damaging the paper.
If you're tempted to stick cracked foams together to eek a wee bit more life out of them then copydex, a liquid latex, is quite good although does harden too much if applied thickly, or Isoflex special roofing primer which is a transparent liquid rubber. However, you can use a thimbleful of glue and the whole tin goes off in three weeks. One can paint the whole of a foam with this and it will last indefinitely.
Years ago someone gave me the tip that Damp Start plastic spray used to seal car electrics can be sprayed onto foams and this makes them last indefinitely. I have tried doing this with a foam carefully removed from a unit and it increases the stiffness of the foam. Perhaps it's possible to flex it to restore some of the suppleness but that may break down the effect of keeping the foam structure together.
Perhaps, however, spraying damp start onto new foams, provided they are manipulated to restore lost softness, might provide some degree of surface protection against the forces of decay. . . .
Best wishes
David P
Having run effectively a 30 channel hifi on an electronic concert organ for some years, some channels of which use Lowther drivers, and doing outside events using Lowther speakers for sound reinforcement, over the years I've become a dab hand at repairing the beasts.
For some time I've been lining up units needing refoaming and voice coil repairs and inspired by Lowther friends bringing me theirs, they're all getting done in one batch.
The worst job is cleaning off the old foam. It's foul. Worse, the glue: many types of which won't pull off nor be dissolved by meths or other solvent. But worse is when, especially the spider, has been smothered in a plastic glue like UHU glue or other PVC adhesive. It goes hard and if spilt on the paper cannot be removed without damaging the paper.
If you're tempted to stick cracked foams together to eek a wee bit more life out of them then copydex, a liquid latex, is quite good although does harden too much if applied thickly, or Isoflex special roofing primer which is a transparent liquid rubber. However, you can use a thimbleful of glue and the whole tin goes off in three weeks. One can paint the whole of a foam with this and it will last indefinitely.
Years ago someone gave me the tip that Damp Start plastic spray used to seal car electrics can be sprayed onto foams and this makes them last indefinitely. I have tried doing this with a foam carefully removed from a unit and it increases the stiffness of the foam. Perhaps it's possible to flex it to restore some of the suppleness but that may break down the effect of keeping the foam structure together.
Perhaps, however, spraying damp start onto new foams, provided they are manipulated to restore lost softness, might provide some degree of surface protection against the forces of decay. . . .
Best wishes
David P
