Cooling fan filter material

[KA2PTE]

Anyone know what this stuff is called? Its to a fan on an ACOM amp and its become brittle to the touch.
I thought maybe the auto parts store sells it in sheets, but so far no luck.

[WA2SQQ]

I have an ACOM 1000. I use 4 small magnets to hold a dryer sheet over the air intake. My wife saves a few used ones for me and every so often I change the sheet. You can’t imagine how much it catches!

[KA2PTE]

Might try this, its an assy that comes apart and the material is 120mm
so I can cut it down to fit. Seems they call the stuff "dust sponge"......

https://www.parts-express.com/Cooling-Fan-Filter-Assembly-120-x-120mm-250-072

[W1RKW]

on EPay it is commonly referred to as filter foam sheet.  And various sellers have it in various thickness and filtering ability or pores per inch. the smaller the number the less pores it has.

[K4NYW]

Home Despot has this - A/C filter material
https://www.homedepot.com/p/Frost-King-15-x-24-x-3-16-Air-Conditioner-Foam-Filter-F1524/202318549

[wa2tak]

Those plastic poly foams go to DUST with time!!
Use only OPEN CELL replacement....THIN 'slice'...least dense material...like the mike filter.

[WQ9E]

A well used dryer sheet is probably OK however the agents they release will gradually build up on screens and other surfaces.  I am not sure how much they have changed in the last 15 years but I looked at them as part of a risk management consulting project several years ago as one of the factors leading to dust buildup and resultant fires in dryer ducting.

You wouldn't want anything to build a thermally insulating conductive layer on the tube cooler.

Rodger WQ9E

[KB2WIG]

Rip a forced air heater filter apart fer parts??

KLC

[n8fvj]

A used dryer wrinkle remover sheet will work well.

[WD8BIL]

I've used scotch brite pads in a pinch.

[KD1SH]

Scotch-Brite pads are actually an excellent filter: fine enough to catch anything you'd want to keep out and durable enough to last forever, and washable, too. Their drawback is that they're quite restrictive to airflow, so you'd probably need to up-gun your fan a bit to compensate.

I've used scotch brite pads in a pinch.

[KD6VXI]

Henry sells/sold it.

--Shane
WP2ASS / ex KD6VXI

[WQ9E]

The release of "sticky chemicals" from dryer sheets is still an issue as a quick Google search will indicate.  That isn't something I would want on external anode tube coolers and other heat transfer surfaces.  Cheap and readily available isn't always the best reason to choose something. 

Example from CNET:

"Why dryer sheets are a bad idea

Dryer sheets are woven sheets of fibers coated with stearic acid or fatty acids, scents and a cocktail of various chemicals. In the dryer, the stearic acid melts from the heat, coating the clothes to make them soft and reduce static.

Unfortunately, the film from the dryer sheet also coats your entire dryer. This typically isn't a problem, except when it comes to the dryer's lint filter.

The residue from the fabric softener sheet builds up on the filter, load after load. Eventually, you'll find that lint is hard to remove because the sticky film has blocked the holes in the filter and adhered to some of the lint. "

Proper filter material is readily available...

Rodger WQ9E

[KD1SH]

I would have thought that they'd be more attracted to the plate than the screen. But then, at least, they'd keep the static off your audio

A well used dryer sheet is probably OK however the agents they release will gradually build up on screens and other surfaces. 
Rodger WQ9E

[WQ9E]

I would have thought that they'd be more attracted to the plate than the screen. But then, at least, they'd keep the static off your audio

🤣

It is sort of an evolutionary thing, first the plate cooling fins clog causing the anode to overheat and turn into a secondary emitter and then the screen captures everything  

And the tale about these used dryer sheets keeping mice away doesn't work so well on midwestern mice.  A buddy put a bunch of them around and in his convertible before storing it over winter.  When he went to get it back out for the spring, he noticed most of the sheets were missing.  He quickly found them in the intake side of the cabin air filter.  The mice really appreciated him providing nice material for building their nest.

When one of the internal cooling fan motors in my Desk KW went up in smoke, I replaced the pedestal cooling fans with Rotron Patriot fans and used the matching filter on the intake fan.  I ended up with more air, less noise, and a lot less dust.  Prior to that the grid compartment cooling fan in the RF deck module would build up a lot of dust on the shielding/screening material.

And as an added note, when a Johnson Desk KW starts smoking you can't just pick it up and set it outside until it kicks the habit.  Fortunately it was early spring so opening the windows to clear the smoke didn't result in a frozen operator.

Rodger WQ9E