Foam and glue

[Dave Cawley]

.
Yes I'm over thinking again........

Everything is fine so far, all bits removed and smooth surfaces everywhere. No foam left at all. But the edge of the cone has an almost imperceptible film of glue that rubbing alcohol or in my case Isopropyl alcohol won't remove, neither will Goo Gone.

So leave it ?

And it looks like impact adhesive remains. And yet the glue supplied with the new foam looks just like white PVA. So what should I actually use and why ? This question bearing in mind the remnants of possible contact adhesive ?

Thanks guys

Dave

[Don C]

I've seen the same situation several times. It's the norm. It works OK to just leave the glue residue on the frame and cone. The PVA seems to stick to it OK. I haven't had any that separated later.

[mech986]

It's ok to leave the old glue residue on the cone, you'd have to use something like acetone or methyl ethyl ketone to dissolve it and that can damage the cone integrity. Most repair folks I've talked to say leave it.

As for the glue, if it came with your surrounds, use it. Most of the glues look like regular PVA but my understanding is it is a bit different in tack and thickness. In the US, a popular alternative is Aileen's Tacky glue.

[Dave Cawley]

OK thanks. I do wish the know-it-all videos would say don't try to remove the glue !

I have 7 PVA & polyurethane glues on test right now !

However I'm pretty sure that the original was contact adhesive and I'm wondering why this is not used ?

Thanks

Dave

[grumpy]

re-positioning surfaces when using contact adhesive can be quite difficult.
Having a reasonable working time allows for some post-glue adjustment.

[Ed Kreamer]

Greetings From the Left Coast of the U.S.
i have done several surround jobs on both Altec and JBL speakers, and am in agreement with all here. LEAVE THE BITS AND GLUE RESIDUE AND USE THE ADHESIVE THAT CAME WITH THE SURROUNDS. Grumpy is right. You will have do some slight realignment and smooth out the the bubbles that will inevitably form when you do the job. Just be careful and take your time, and you'll do fine. Oh and follow the directions that came with the kit.
Hope this helps.

Ed

[Dave Cawley]

OK, my research indicated that all PVA is similar, some with water and others not so much. In this application it's not relevant I think. And contact adhesive is bad as Grumpy identified.

So I used the PVA that was supplied. I'm going to wait 24 hours for each section so it's going to be Monday now.

Many thanks for the help and information so far.

Regards

Dave

[Dave Cawley]

Big mistake to use the PVA supplied that was very watery and simply would not hold the foam, had to use 60 clothes pegs per driver on the ABR's. Stuck the foam to the cone just fine though.

On the 128H's foam to chassis I used the way superior Aleene's Original Tacky Glue. In a side by side test it set fast and well, unlike the supplied that was still soft at 24 hours and only semi set after 48 hours. Yes the package did come from Europe as the recommended supplier was out of stock.

The JBL L-150's are as good as ever now.

Dave

[grumpy]

:) Glad to hear the story ended well. Unfortunate about the supplied glue... Type I've received usually has the consistency of generic white glue, maybe a little bit thicker/more viscous with maybe 10-20min working time.

[Dave Cawley]

Indeed, mine was like milk !

Now the L-150's that I bought new 36 years ago, sold to a freind and bought back last month, are back in their rightful home and perfect !

Just need to do a little work on a pair of Denon POA 6600A's now ! The Class A Luxman is struggling now that it doesn't have Klipsch's attached to it.

Dave

[Ed Kreamer]

Wow I'm glad that your job had a happy ending Dave. I've never experienced that , watery glue. I feel badly that you apparently took my advice. Could have the glue become frozen or something? i don't know what kind of tariff's you chaps would have do pay, but most of us here would recommend the surrounds by Rick Cobb if you need to do this in the future. Anyway I'm glad it worked out.

Ed

[Dave Cawley]

Hi Ed

My suspicions were aroused from day one, but I stuck with it ! After the ABR's I realised that the supplied glue was a PVA of the watery type, and this is a genuine but inappropriate type of PVA, research shows this is an easy possibility.

At the time Rick Cobb http://stores.ebay.com/looneytune2001 did not have the 128H in stock. I should have waited.................

Dave