Can I make paper cones water resistant?

I'm using some cheapy bookshelf speakers out in the garage, and it often gets damp in there after it rains as the roof leaks.

Anyway, I can't really fix the roof as it's asbestos, so I was wondering if I could varnish the cones to stop them absorbing water?

Would this work or are there better things out there than varnish?
Hi Mike,

I'm with Cal. Fix the roof! And if IIRC, Cal is also the man to talk to about the roof too!

I can't imagine anything you can do to make the paper cones stand up to water without impacting the sound (probably in a negative way). Water won't do anything positive either. Should have gone polypropylene (only kidding, even though the polypropylene is water resistant, the motor and the rest of the speaker won't like water). Hence, Fix the roof!

Oh, and be careful!

Rubber cement. It's cheap, readily available, and easy to apply.
Yes, it will change the characteristics of the drivers, but anything you do to make the drivers water resistant/proof will change their characteristics. Of course, you'll need to do something about the cabinets, too.
Or you could just fix the roof...

Well, it's 1am here now, so if I went and got a pic of the roof I might get mistaken for a burgler... :eek:

I'll get a pic of the roof at somepoint... It's corrugated, and it's very thin material... There's no felt or anything like that as far as I know.

Also, I'm not really too worried about changing the sound of the speakers as were free and don't really sound very good at the moment anyway... I'll try fixing the roof first tho. :)
I used this stuff on my PA foldbacks, to keep out beer !!


  • watershield.jpg
    20 KB · Views: 257


2007-06-29 8:49 pm
I'm not recommending it, but here is something you might want to consider -

Liquid Plastic (spray on)

Plasti Dip Spray-On

Rubberize-it! (spray on)

They are all spray-on rubberized plastic coatings. Most commonly they come in can, and you dip the handle of a tool in the liquid plastic to give in a nice easy grip rubberized coating. Typically seen on the handles of pliers. However, all these are available in Spray-On.

I have a spray can of the Rubberize-it! that actually sprays a very thin coat, and could probably be sprayed on a speaker cone and the cabinet to seal it against water.

The spray I have is blue, but it is available in other primary colors and you might be able to get it in black.

These products are available in most hardware stores, lumber yards, and home supply stores (Home Depot, Lowes, Menards, etc...). Occasionally you will also find them in craft or hobby stores.

Again, I'm not guaranteeing anything. Check out a can, and decide for yourself.

Here are some links to spray and dip version - Unless they are thinned, the 'dip' versions won't work very well for you.

A bit OT, but I've used Dammar on several old drivers to restore cones, a couple of coats strengthens them and makes them look good.

However recently, with the help of SYNRTA, I've noticed a downside - the stiffening of the cone creates a resonance not unlike metal cone drivers, although somewhat broader. On the drivers i've done, this is usually between 1-4 KHz, just where it will be most annoying...

My conclusion - use it to restore guitar speakers, but not HiFi speakers unless you want to muck around with notch filters...