How To
Here’s one way I found to give predictable and repeatable results. There are tons of ways to fix spakers, I prefer this one -until I learn a better way- as it does not discolor -or hardly discernable- nor stiffen the cone.
A good friend of mine is using Plio-Bond. Works equally well but it does affect the aesthetic of the cone. You must thin Plio-bond according to him otherwise it makes a big mess.
Here are three short silent videos showing how to use a glue pen to repair a tear _without_ a patch. You’ll see that the cone is still pliable, stays the same color and the tear is perfectly mended. Actually, the glue pen penetrates the paper fibers and rebinds them. Making for a seamless repair.
Note how I insist, in the third video, pushing on the tear. No patches (yuk) needed.
It can even be used on the surround (paper surround only). It also costs next to nothing as I buy my glue pen from the dollar store (In Montreal’s area but can be found just about anywhere). I heard Elmer’s also sell high quality glue pen, but the extra money is not really worth it, unless you can’t access a dollar store in your area.
I also found Clay Pot Sealer in Spray (sort of lacquer) to work wonders on very fragile cones. It also rebinds the fibers much like the glue pen, except it is sprayed on instead of brushed. Only problem is I can’t find it anymore. I save a Marconi speaker with that stuff. The paper cone was literally turning to dust. I had to spray 3 very light coat of the stuff to bring back the cone as just blowing on it created rips! Still is perfect to this day 6 or so years later…
If you find a better way to fix a cone, please share, I’m always open ears for new and better tricks!
The videos:
If the videos do not load, right click on the links and save on your desktop. They can then be played using whatever software you prefer.
Note: videos are about 700KB each. For the high speed internet impaired, be patient…
Q&A
pilkco Wrote:
I used Thompsons Water Seal clear multi-surface waterproofer(12 oz. spray can) to restore the fragile cone on a 6″ speaker(from a 42-355). I think it’s similar in composition to the Clay Pot Sealer because it’s also recommended for use on terra cotta planters. I got it at Ace Hardware. It makes the cone look like brand-new. -KarenInteresting info!
If it is indeed the same product I used years ago you can be sure I’ll buy a few cans as it was the best stuff for that purpose so far, second being that glue pen.
Once dried, does it show on the cone (gloss) and/or does it leave the cone pliable as original (or stiffer)?
pilkco Wrote:
When I first applied the spray, the paper cone absorbed the sealer rather quickly. After additional coats, the cone had a glossy black (wet look) and then after a minute or so, absorbed it. After the sealer dried(24hrs), the cone does flex when I gently press it. I was afraid to touch it before I sprayed it, because it looked very fragile. I could see light shinning through the paper(I still can, but I think that’s because the sealer is clear in color). The finished color of the cone is satin/semi-gloss black/dark grey, and before the coating, it was a flat grey. I can’t find a list of ingredients on the can, but I see it contains aliphatic hydrocarbons, harmful vapors, is extremely flammable, and smells good.Icon_twisted I’m very pleased with the sound of the speaker, but, It’s only been 3 days. So, I guess time will tell. Regards, -KarenGreat !
Thanks for the additional info Karen. Sounds like you found the right product under a different brand name. I’ll try to find it locally. My experience with this product is it usually only requires 2 light coats.
FStephenMasek Wrote:
I just watched the video, after having read Syl’s post some time ago. I was surprised that the glue is spread out over the entire cone, not just the area with the hole/tear.It is my philosophy to do it right and do it once. Just like replacing all wax-paper capacitors when restoring a radio to prevent future revisiting, covering the whole cone prevent any further degradation which _will_ eventually occur. It is up to the restorer to decide what’s best for him/her, part or whole.
tpaairman Wrote:
Syl – In the video you rubbed the brush on your hand – was there something on your hand or was just to soften the bristles?b)…AND to remove any lose bristles which may get stuck on the speaker cone while applying the glue.
Arran Wrote:
I try to avoid patches where possible, unless the speaker has a hole with part of the cone missing a smear of glue on either side of the cone usually does the trick. The one piece of bad advice that I keep seeing relayed from place to place is the suggestion to use silicone, one just about every speaker that I have run across where this was used the silicone was applied in thick gobs, was beaded up, peeling, and rattling, so I had to scrape it off. I myself have used general purpose contact cement for repairing speakers, it seems to work well if it’s applied in a thin layer, not that I don’t believe that something else will not work but I always seem to have a can available.
Phlogiston Wrote:
When the paper cone has become soft
I just shoot the cone with a few coats of flat, clear lacquer. Don’t get it in the gap or spider and avoid buildup on the suspension.