Is this sloppy glue job fixable? updated w/ new pictures

SoundsAlike

Super Member
This is an Infinity RS-II woofer. The cone is polypropylene. Two of the woofers have a really poor refoam restoration. I believe the glue used was contact cement. What is the best way to fix it? Is this a job for a solvent?

Laquer cleaner? 3m Adhesive Cleaner? Acetone?


Quick update i'll leave here:

The glue is peeling off but it is very tedious because it is semi-hard and it breaks off in little pieces but the glue does come off the cone with a bit work (to be expected).

So far what I've achieved is removing significant portions of the glue but there's still some tidying up to do... so it looks like it is not as permanent as I originally thought. Below is a before and after so far

Before
rsIIwoofer.jpg

After: updated 9/29, finished removing all of the stubborn glue

woofer clean.jpg
 

Attachments

  • RSIIAfter.jpg
    RSIIAfter.jpg
    148.1 KB · Views: 115
Last edited:
rubber cement should roll off with your fingers . thats if the cones arent too delicate

I fixed my first post, I meant to type contact cement. The original owner told me rubber cement but the color of it is more like contact cement which has a golden hue to it -- whatever it is, it does not scrape off easily

The cones are rigid but not very fragile since they're pretty thick polypropylene -- the other woofer has a less even application of the stuff and looks worse
 
I think I'd be tempted to try a little heat, but just a little. Too much could distort the poly cone, and that wouldn't be good.

You could also try using a flat metal piece

(gapping tool from the local auto parts?)

spark-plug-gap-tool-300x234.jpg


to try and work your way under the glue. The poly probably isn't porous and it should be mostly surface contact you'd be dealing with. From there, you should be able to roll off any excess.

PS .. found this, where a guy used an old credit card, but that was just with the original foam.


I've also seen mention of rubbing alcohol being safe for the poly, but no idea if that would work with the adhesive used here. Luck wit it, eh.
 
Last edited:
some sort of solvent may work to lift it . or gentle heat . i guess its pretty hard ?

Quick update i'll leave here and in the first post:

It's is peeling off but it is very tedious because it is semi-hard and it breaks off in little pieces but it does come off the cone with a bit work. I'm not going to dive into a restoration this evening.


So far what I've achieved is removing significant portions of the glue but there's still some tidying up to do... so it looks like it is not as permanent as I originally thought. Any thoughts on a good way to clean the surface would be welcomed.
 
Last edited:
I love using lacquer thinner when it comes to cleaning up glue residue, but I wouldn't use it with a plastic composition like polypropylene. Instead, I'd use something that is not quite as "hot," like acetone or enamel thinner.

I'd be hesitant to use heat, as well. We've all seen what heat can do to plastics, and one careless moment could render your cone permanently unusable.

Probably the best solution is to mechanically remove as much adhesive as possible (by the method you've used already), then cleaning up the remaining goo with acetone (or, the noted 3M adhesive remover. Check to label to make sure it is compatible with poly cones.)

GeeDeeEmm
 
Consider yourself lucky, I had to fix a shitty refoam job that my uncle did. The speaker was a JBL Le15a that he had bought some generic accordion surround and had glued it down with F26. It took the better part of 4 hours to carefully pick every bit of that stuff off :/.
 
Acetone works fine on those RS woofers. I did a pair (RSMs) very carefully (q-tips and lots of slow and steady with a guitar pick & finger nails) and the result was 100% perfect, no dulling or blooming on the cones.
 
Grab some of the pink colored nail polish remover (non acetone) from Dollar General. It works great for many things, but be cautious though as always. Good luck.
 
Finished this cone -- Acetone worked pretty well. Unfortunately the 2nd woofer has a heavier application of glue -- it's not the difficulty it's just tiresome labor.

The hazed ring on the outside rim of the cone is from some kind of abrasion caused by a knife -- possibly when the person that completed the first refoam that resulted in so much glue. This will be covered up by a new surround.
index.php


the second woofer:
RS2woofer.jpg
 
Last edited:
Glad to see the acetone produced the desired result without damage to the cone. They should look great when completed.
 
Back
Top Bottom