Lansaloy DOT3 Surround Treament for LE-14A and others

Since it has been about 15 months since I last treated my woofers in my L101’s, I thought I would record the procedure and post a helpful thread on applying DOT3 brake fluid treatment to you old Lansaloy surrounds. These are common on the LE-14A and others from the mid 50's to 70’s. By the way, this is just the way I do it, there are other ways and very helpful threads here…

http://www.audioheritage.org/vbulletin/showthread.php?t=871&highlight=dot3

http://www.audioheritage.org/vbulletin/showthread.php?t=5424&highlight=dot3&page=2

The problem is the Lansaloy can get very dry and brittle and therefore crack and break completely. Of course when that happens you need to install a new surround kit, but they do not make a Lansaloy surround replacement, so you must use a standard foam surround replacement in that case. There is a helpful thread here http://www.audioheritage.org/vbulletin/showthread.php?t=469 on how to do a new foam surround.

If your Lansaloy surrounds are not yet brittle and cracked, you can treat them with DOT3 brake fluid and they will soften up quite well and the sound will have a huge improvement as well. It is not known how long you can continue to treat them, but many have been doing it for years without having to replace the surrounds. You should treat your Lansaloy surrounds annually in order to maintain proper pliability and retain optimum sonic performance. Of course your first step is to remove your grills and dismount the woofer from the cabinet. Be very careful here to handle your grills and woofers carefully in order to avoid nicks and scratches. Once you have the woofers out, place them on a work surface with plenty of light.

You will need 2 QTips, and a very small amount of DOT3 brake fluid(about a capful or less).

Simply apply the DOT3 brake fluid to the surround being careful not to get any on the white aquaplas coating on the woofer cone as it will make stains that cannot be removed. Apply a generous portion all the way around the surround until it has been coated thoroughly.

Allow it to sit and absorb for twelve (12) hours at room temperature. Once it has been fully absorbed and is no longer shiny and does not appear wet, flip the woofers over and apply the same procedure to the rear side of the surround.

Allow the brake fluid to absorb another twelve (12) hours. Carefully remount the woofers into you cabinets. Your done! That was easy.

This may seem like a pain in the rear, but you will have a noticeable improvement in the performance of your grand old JBL’s. You won’t be sorry. This is especially helpful if you have a pristine pair of vintage JBL’s that are all original because it will help you retain their original condition and optimum resale value. Happy listening.!

How do your speakers look now, 13 years later? Has the brake fluid had any sort of adverse effects on the surrounds?

Quote:

---

Originally Posted by Eric M.

How do your speakers look now, 13 years later? Has the brake fluid had any sort of adverse effects on the surrounds?

---

Great question. I used this technique years ago. I noticed that more DOT3 lowered the FS more and that over time the FS began to rise again.

I eventually sold all of my collectible drivers so I don't have any info on the long term effects. I assume one could reapply the treatment again and again and preserve their surrounds, but I am only speculating.


Widget

I've heard of this trick but was always told it was a bad idea. This is the first thread I've seen of someone who has actually done it.
From time to time I'll pick up a speaker with the old Lansaloy surround that looks like it has "melted". I had always assumed it was a victims of DOT 3 brake fluid. Now it looks like that might not be the case.

It would be interesting to hear from those who have used this trick for years. How are the surrounds holding up?

Quote:

---

Originally Posted by Eric M.

I've heard of this trick but was always told it was a bad idea. This is the first thread I've seen of someone who has actually done it.
From time to time I'll pick up a speaker with the old Lansaloy surround that looks like it has "melted". I had always assumed it was a victims of DOT 3 brake fluid. Now it looks like that might not be the case.

It would be interesting to hear from those who have used this trick for years. How are the surrounds holding up?

---

Hi Eric, Somehow I missed your reply back in February. I am still treating my Lansaloy surrounds in my L101's 12 years later and they still are very soft and pliable and they sound fantastic. I pull the woofers and treat them with DOT3 fluid once every 2 years or so. I listen to them once or twice a month and them with a Carver M1.5t amplifier that has been restored. The bass response really is remarkable and they can take plenty of power without any ill effect. The surrounds are still fully intact, not discolored, and I am sure of much better quality and pliability than a foam replacement. Those are my thoughts... feel free to ask any questions. Shaan

Thanks, that's good to know. I may give it a try the next time I run across hard surrounds.

Thanks,

Eric M.

Quote:

---

Originally Posted by Eric M.

Thanks, that's good to know. I may give it a try the next time I run across hard surrounds.

---

+1

Yes, thanks for the update. I treated several LE15As years ago, but didn't keep them long enough to know what the long term results were.

From my experience, you need to be super careful with the application as the brake fluid will stain the cone if you get it on the paper. Also, I measured the Fs of the woofers with varying amounts of brake fluid applied. Applying more did lower the Fs more and ultimately the Fs was lower than spec. This could also be due to the aging spiders. All of the drivers I had were 30-40 years old at the time... of course that was in the early 2000s. Today they will be another 20 years older!


Widget