Tinsel lead repair - advice sought

I'm pretty certain the OP will be trying to use what we suspect the factory used. However the factory has some advantages. It's quite likely the cone was made on a former, and may well of stayed upon it while the VC assembly was added, tinsels, then spider. Before surround, and it being glued into the chassis. At which point the OP is faced with trying to glue it through the chassis, with nothing supporting the cone which is getting to melting point. It could go very badly, with nothing to keep the cone cool and in shape.
I do hope he can do it.

The superglue is a fall back plan. I don't know the OPs temperament, but having a plan B, can take the pressure off plan A.

I have spent too much time in the bath, reading bottles. It's type 5 in the UK. I'm not sure if that's a global marking system
https://www.spg-pack.com/wp-content/uploads/2022/04/post-4-shutterstock_197759183-scaled-1.jpg
I'm only saying PP because someone else did. I think treating it as such should be fine, but other shampoos do exist 🙂
 
  • Like
Reactions: ianbo
Yes, your symbols are the same as ours but we use the letters rather than numbers.

When I fixed the crack, I put some books down so that when the speaker was placed faced down on the books and the other side on the counter, the upper part of the cone was horizontal. I then used my hand inside a hot mitt on top of the books so I had backing to support the cone. I then cleaned the backside of the cone with alcohol, and applied the glue very quickly along the 3” crack and did the tooling as described before with parchment on my finger. About 30 minutes later, it passed the pull test. It wasn’t pretty but it was on the back of the cone. As mentioned, I also added a small bead 180 degrees on the cone for balance.
 
  • Like
Reactions: friendly1uk
There is a temperature difference of at least 20 degrees Centigrade between LDPE and PP, typically we run PP at a higher temperature.

You could in fact try adhesive tape of high quality with thinnest backing, that will work on a clean dry surface.
You can balance it, like Cal did.

Try it on PP film, or shampoo bottles, check the codes used in your area and the bottle, even a Tupperware type container is usually PP (the bottom, anyway)...
 
  • Like
Reactions: ianbo
Thanks. Any links for purchase, for future reference?

One UK supplier
https://woodworksupply.co.uk/products/copy-of-starbond-ca-glue-black-medium-ke-150-2oz-56-7g
https://woodworksupply.co.uk/products/o3a-accelerator-for-ca-glue-200ml
Use the pointy ends of separate nylon cable ties for application.
If you want to layer up the glue, use small amounts because the accelerator only acts on the thin surface layer.

If the PP cone is shiny and slippery, it might be beneficial to slightly roughen up the area being glued (use scraper/sand paper in tweezers/nail file etc)
Use the primer pen out of this:
https://www.robertdyas.co.uk/loctite-super-glue-all-plastics-2g-4ml
You could even the use that glue, but be careful, because it might wick along the tinsel lead.

The specs for the Usher says its a polypropylene cone, and as others have suggested, practice on a polypropylene object first (labeled PP or 5 )

Dont forget to make sure the existing tinsel length is sufficient for both directions of maximum cone travel.
 
  • Like
Reactions: ianbo
I think you may be off course. That is an accelerator, that can be added after the glue. PP needs a surface prep. Though that says primer, it's not for PP that I can see. Do you know what it is? I haven't seen the msds

edit: Okay, N,N-DIMETHYL-P-TOLUIDINE. It can work on some polymers, but I think PP is just a bit too resistant. I can't be sure though. I'm guided away from it, but I don't understand why myself.
I would stick to the heptane. It's a £7 kit, specifically made because the usual solutions don't work on pp
 
Last edited:
  • Like
Reactions: ianbo
Update: its fixed again - fingers crossed! Unfortunately I inflicted a minor injury on the cone with the soldering iron, this time. (Sooner or later, innate clumsiness will shine through.) But thankfully it was only a momentary touch, and didn't make a hole.

To fix the leads to the cone, I used the Bosch hot melt glue and the Dremel gun (see post#32 above). I tested them out on a PP ice-cream tub - the glue stuck really well, and there was no sign of the PP softening.

On the woofer, I had to use a hot screwdriver to get the glue into the joint, but it worked OK.

The speakers have been playing for a couple of days, now, and are sounding good again. I'll update again in a couple of weeks.

Thanks again for all the contributions.
 
I did have a go at masking the cone with some alu foil, but I struggled to get it to sit in place. I didn't think of masking tape - maybe I should have. But also masking made it more difficult to get light into the work area - shining a light through the clear cone really helped.

So I gave up on the foil, and trusted to a steady hand and a quick solder joint. First time, it worked. Second time, the solder joint took a bit longer, and then my hand wobbled.