KEF 107 Refoam ?

Hi there. I've done a really great job on my 105/3 refoams a few months back (4 drivers in total and a bunch of faff to get them out)

Here are a few of my salient recommendations:-

1. Get all the materials ready
2. Take your time
3. Get yourself to B&Q and purchase some of those multiple packs of special Stanley knife blades (they stay sharper for longer).
4. Get as much of the surround off as you can by hand
5. Clean the glue off the speaker frame with white spirits and an old micro-fibre cloth
6. Using the edge of the blade, GENTLY trim the old foam and surplus glue off the cone. Don't be too alarmed, once you get used to a very oblique angle you can scrape off the material quite quickly and... neatly too.
7. Keep hoovering up as you go ( you would not want that crud in the airgap)
8. Cut away the centre dust cap as close to the cone as you can.
9. Using fresh blades, clean up the glue so that all you are left with is a small area on the cone periphery and dust cap where glue used to be.
10. The Refoam kit should come with shims which are essentially pieces of paper of the right thickness. If not, experiment with different pieces of paper. I made my own up about 2cm wide and about 5-6cm long.
11. Make up a few because you are going to use one or two to clean the air gap (soak one in white spirits/ switch cleaner, insert carefully into the gap, and then slide up and down and at the same time slowly change the position of the movement so that you clean the entire gap.
12. Now all is clean, the air gap is clear you are ready to start refoaming. Critical job is to take time to centre the voicemail into the airbag. Some people use 4 shims equidistant but I used 3 space equidistant.
13. Insert the shims. The voice coil is now "locked" - in my case I was just able to slide it so ensure it was central.
14. The refoaming kit should come with glue- use it as its designed for this job
15. Lay the surround on the cone (no glue) to see how it sits.
16. Adjust the height of the cone so that the natural position of the new foam allows the edge to sit correctly in the driver chassis.(now you know why you need a small movement with the shims in place!)
17. Remove the foam and now add glue to the cone in a line - the trick here is to have a reasonable thickness so that when you press down on the foam, some of it comes out of the gap.
18. Here goes... Lay the foam onto the cone, pressing down with finger or cotton wool buds to ensure the glue is consistent. If any spills over too far, take the cotton wool bud, wet and use it to clean up any excess glue. I found that the foam finds its own position quite naturally but you can also take measurement from edge of foam to the chassis to make sure all is correctly aligned
19. Let dry overnight
20. Now run a bead of glue to the underside of the foam where it meets the chassis. Once you've completed this, using finger or bud, gently press down on the foam so that glue can be seen to come out from the join. Wipe away excess / add where you've missed as required
21. Leave to dry overnight. This is critical.
22. Now, the hard work is mostly behind you.. Remove the shims. You should now be able to move the cone throughout its excursion limits without any interference or rubbing. When doing this try to do it gently and using a balanced force as close to the voicecoil as you can all ok Yay ! Brilliant.
23. Run a bead of glue where the dust cap glue used to be, pop the new dust cap on, centre, wipe away excess glue and.... You are done

Repeat as many times as you need

There are a few other tips if you are super OCD (like me) such as using a thick modelling brush to paint the glue onto the foam so that the entire mating surfaces are covered in glue etc...
I also ran a small, thinned down bead of glue around where the foam meets the cone when it was all dry so that it looked really neat

If you do this, it's a really satisfying job and every time you play music on your KEF's you can smugly brag to your mates "I did that !"

Good luck

Steve
 
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efeldbau

Member
2013-02-25 5:53 pm
Refoaming Kef107s

Hi All,

Has anyone done a woofer refoam on a pair of 107's.

I've done the searches, and there are alot of dead threads, and loose ends about this all over Google.

Just thought I'd give this forum a whirl.

-dave

Hi Dave,
I just completed refoaming my pair of Kef107's. Had them since new, and after following some threads, thought they would need it. Got the Kef107 foam kit from Springfield Speaker in MO, and it was very complete with 2 types of glue (metal to foam, and paper to foam), and well fitting foam surrounds and shims.

I saw enough of the process of refoaming on YouTube, but no actual instruction of taking the speakers out of the cabinets. Finally got instruction sheet from KEF. Went easily and took pictures. If you need any further advice, send me a note.
Elliot
 

chipl75

Member
2013-03-09 8:24 pm
KEF 107 woofer repair

Hi,
I recently purchased a "sick" pair of 107's. Surrounds and donuts are history and the tweeters sound dried out as well. I have ordered the woofer repair kit from Orange County Speakers, but it does not have two types of glue as described by efeldbau in his post. I am concerned the voice coils might be damaged since I suspect these were used with the woofers in poor condition for quite a while. Advice on determining voice coil condition, use of and quality of the orange county kit, and tweeter replacement would be greatly appreciated. Have you finished your's yet Dave101260? Basically any opinions regarding getting these old girls playing again would be great. Thanks, Chip