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Speaker Pod Repair

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bigboystoy
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Joined: Wed Feb 13, 2019 4:22 am
Location: Melbourne, Australia

Speaker Pod Repair

Post by bigboystoy » Thu Jul 18, 2019 12:13 am

Firstly, this job would not have been considered without the brilliant write up back in Jan 2010 by Brucey on this forum.

My covers had suffered the ravages of sun and time and had the usual distortion at the front and rear of both covers (forgot to take pictures). Separating the vinyl from the metal was easy as the glue was very weak. A quick clean up with sand paper and prep wash, then a sparse coverage of Gorilla glue on the metal and damping the cover with water and the two parts were joined.

I did one cover at a time using cloths pegs like Brucey. Around the short edges the pegs were sufficient but for the front and rear edges I used stronger clamps and ice cream sticks to pull the edges together. These help spread the clamping force. On the rear edge it was a great result but at the front the sticks were too narrow and the stronger clamps depressed the vinyl and padding. This will pop out in time but not the result I was looking for.

For the second cover, the rear and the sides were done the same but for the front I used a wider piece if aluminium under the clamps. This result was perfect with no indentation to be seen.

Another job ticked of the list. =D>
Pod4.jpg
Clamps and ice cream sticks
Pod4.jpg (43.42 KiB) Viewed 612 times
Pod2.jpg
Edge in better shape
Pod2.jpg (44.02 KiB) Viewed 612 times
Pod1.jpg
Finished result. Very nice
Pod1.jpg (49.51 KiB) Viewed 612 times
Past toys:
1979 Volvo282GT
1988 Porsche 944S
Current toy:
1986 635 CSi

brickwhite
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Re: Speaker Pod Repair

Post by brickwhite » Wed Jul 24, 2019 3:47 pm

will Gorilla glue hold in the heat? Any long term tests I need to do the same an wonder if a weldwood contact or 3m trim adhesive would be better?
- 12 535i
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bigboystoy
Posts: 51
Joined: Wed Feb 13, 2019 4:22 am
Location: Melbourne, Australia

Re: Speaker Pod Repair

Post by bigboystoy » Wed Jul 31, 2019 10:07 pm

Very good question. From the info I've been able to find, the durability is extremely good for their latest range of glues. Their cloth tape is unbelievable so I'll give them the benefit of the doubt. Its water and heat resistant but a cars interior, especially under the back window, is extreme.

Still if BMW didn't initially think a/c was essential, I'd guess the glue they used was not suited to hot climates either. I would hope all of today's glues would outperform those of yesteryear. :roll:
Past toys:
1979 Volvo282GT
1988 Porsche 944S
Current toy:
1986 635 CSi

wogden700
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Joined: Fri Mar 08, 2019 3:39 pm
Location: Massachusetts

Re: Speaker Pod Repair

Post by wogden700 » Fri Aug 02, 2019 1:46 am

The vinyl on mine looks good colorwise, except it is pulling off the metal and warping. Should I get new ones or try to glue the originals?

bigboystoy
Posts: 51
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Location: Melbourne, Australia

Re: Speaker Pod Repair

Post by bigboystoy » Tue Aug 06, 2019 1:54 am

Just remove the old vinyl covers, carefully, clean the metal surface and foam back and glue back down. If the covers are lifting it means the original glue has failed so you should be able to separate the the vinyl and metal without too much drama. I used a steel rule to assist the separation.

Here's the link to Brucey's write up. http://bigcoupe.com/phpBB2/viewtopic.ph ... ods#p80790
Past toys:
1979 Volvo282GT
1988 Porsche 944S
Current toy:
1986 635 CSi

wogden700
Posts: 13
Joined: Fri Mar 08, 2019 3:39 pm
Location: Massachusetts

Re: Speaker Pod Repair

Post by wogden700 » Tue Aug 06, 2019 2:37 am

Thanks for the response and links!

songzunhuang
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Re: Speaker Pod Repair

Post by songzunhuang » Thu Oct 03, 2019 6:07 pm

brickwhite wrote:
Wed Jul 24, 2019 3:47 pm
will Gorilla glue hold in the heat? Any long term tests I need to do the same an wonder if a weldwood contact or 3m trim adhesive would be better?
FYI - I did this repair with Gorilla Glue a few years ago. I regret to inform that the the pod is lifting again. I'll take a look this weekend to see if the Gorilla Glue is failing or if it might be the foam just falling apart.

Here's what it looks like from the inside of the car.
Pod lifting.png
Gorilla Glue failed after 3 years?
Pod lifting.png (988.93 KiB) Viewed 269 times
I'm thinking of construction adhesive or epoxy this time.
I'll report back, but it may be a while before I can be sure.
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

bpoliakoff
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Re: Speaker Pod Repair

Post by bpoliakoff » Thu Oct 03, 2019 8:09 pm

Try contact cement as Brick suggested. That is what the upholsterers use. If you gave access to it, Liquid nails
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
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Brucey
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Re: Speaker Pod Repair

Post by Brucey » Fri Oct 04, 2019 1:25 pm

FWIW using some (many ) adhesives is a bit like painting; good prep is vital. I suspect that Song's somewhat premature repeat peeling may be down to insufficiently good prep.

It is a long time (over nine years) since I did my speaker covers and I wouldn't say there is no peeling at all, but they are not yet peeling particularly badly. This is despite the car being parked with the rear facing the sun, such that the vinyl is now rather badly discoloured and needs recolouring.

Contact adhesive can be excellent stuff but there is a clue in the name; contact. One of the problems with sticking these covers down is that, once the cover is at all damaged/misshapen, they don't make contact everywhere, in which case a thin layer of adhesive cannot possibly work, no matter how good that adhesive is.

One of the reasons why the gorilla glue is good for this kind of joint (in which the gap is variable), is that the foaming action bridges wider joint gaps, thus allowing the bond to be more or less complete, even if the parts don't fit together perfectly. NB you don't get anything like enough foaming action if the joint surfaces are not dampened fully before assembly. If in doubt, do some trials on scrap/test pieces to see what works, before tackling the real thing.

[edit; the other thing I didn't stress is that it is arguably pointless using a really high strength adhesive anyway; the strength of the joint is liable to be limited by the strength of any remaining foam backing on the pod covers. If you remove this foam entirely then the covers will never be the right shape again....]

cheers
Last edited by Brucey on Fri Oct 04, 2019 11:11 pm, edited 1 time in total.
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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jps635
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Re: Speaker Pod Repair

Post by jps635 » Fri Oct 04, 2019 6:25 pm

Use this if you can get it in your parts or something similar

http://www.holdfast.co.nz/pages/product ... 0082&cat=7

http://www.holdfast.co.nz/resources/pdf ... 54_TDS.pdf

Excellent stuff - good to 90 deg C - was recommended to me by a car trim specialist.
'85 635csi JPS (RA2-66)

songzunhuang
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OK, my Bad - Brucey was right

Post by songzunhuang » Tue Oct 08, 2019 12:43 am

So this weekend I fixed my speaker pod again. There was a fine brows dust all over the metal part and also there were thin sheets of hardened glue that had clearly separated from the metal surface. As Brucey correctly postulated, I think it was all in the prep. I probably didn't clean the surfaces too well the first time I tried this. I did a little better this time. Once again, I used Gorilla Glue.

So here's the pod clamped for gluing. one side was still holding, hence the clamps concentrated on the other side.
Clamps.png
It's gonna take a lot of clamps.
Clamps.png (1.38 MiB) Viewed 181 times
After letting it set overnight and shaving off all the glue that had oozed out, here's the finished pod.
FinishedPod.png
Completed repair. Hope it holds longer.
FinishedPod.png (1.16 MiB) Viewed 181 times
I'll put more pics into my project thread as it's my source of truth for all the stuff I've done to the car.
So, in the end - false alarm and user eror! #-o
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

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Brucey
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Re: Speaker Pod Repair

Post by Brucey » Tue Oct 08, 2019 9:41 pm

from your description it might be that the foam just isn't strong enough to glue to any more? Or was the brown powder rust, in fact?

Did you take any more photos of the failed joint?

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

songzunhuang
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Re: Speaker Pod Repair

Post by songzunhuang » Tue Oct 08, 2019 10:29 pm

Brucey wrote:
Tue Oct 08, 2019 9:41 pm
from your description it might be that the foam just isn't strong enough to glue to any more? Or was the brown powder rust, in fact?

Did you take any more photos of the failed joint?

cheers
I think the "foam" was OK. It's real hard now and more like dense plastic. I think the culprit for me was the surface rust. When I wire brushed it, a LOT came off. I could see how it wouldn't stick well. That being said, I didn't repaint the surface or anything. I just wire brushed the heck out of it and then wiped it down with acetone until no more brown was coming off on the towel. Then I used a lot of glue to give it a better shot at expanding into all the crevices.

Here's the only other picture I took of the failed glue. Note that the pod cover is closed. What you see here is the vinyl/plastic cover separating pretty severely.
Podfail2.png
Speakerpod cover lifting from metal form.
Podfail2.png (1.03 MiB) Viewed 146 times
I did the best I could given what I had to work with. We will see how long it holds this time.

One annoying thing is that the fuzz on the fabric on the rear deck is coming off. I vacuumed the deck and now there are some bare spots. Any tips on where to get a replacement?
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383

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