Electrical insulator -in sheet form and thicker than tape?

Could someone point me in a direction for some sort of insulator material that sticks to metal that will be very underneath and very close to a PCB.

I was thinking neopreen or something similar that has some thickness to it. It seems that tape would be gouged by the sharp parts under the PCB.

-These are actually for Audix 35102's that sit very close and I hope some shielding would help.

Fishpaper with some kind of adhesive applied to one side.

Contact paper, it is available at most any hardware store.

Thanks all. The fishpaper that I got locally was expensive stuff, but most of the electronic stuff was 2x mouser as well. It came in a roll and very stiff making it tough to lay flat. Would Autozone have it?

I googled Nomex. pretty hi-tech stuff, a quick search showed at least $50 per roll.

Maybe I'll see if the ragshop has some contact paper, but I do have pointy component leads on the pcb bottom.

haha, no the nomex was that price. I bought fish paper 4-5 years ago and just recalled it being expensive. But looking online so far, I can't say fish paper looks cheap. Mouser? I'll hit up the rag shop and autozone tonight

at mcmaster.com I searched fish paper and came up with "Natural Hard Fiber" at $4 for 12x12" sheets which I assume would be one of the best prices around, still isn't cheep. -could be just a sign of aging, hard to think of spending 4 bucks on fancy construction paper.

I can't link the product but if you go to mcmaster.com and search fish paper you'll see it. The have nomex which is similar or the same as aramid paper/fabric for $30 a 12x12".

I can't really think of what contact paper is. all I saw was that an online arts & crafts place had it with pretty patterns and such.... is it like freezer paper?

Naugahide vinyl applied with contact cement. I recently ran a test using a 12KV neon transformer and it didn't arc. I also tried to set it on fire using an open flame and all it did was melt. It will melt with a heat gun too so if temperature is an issue, nix this idea. It's super cheap + Hancock Fabrics looks great on a bill of materials. :razz:

nawwww.......

Is Hanckock Fabrics where you got it from?

could you just use, like, 2 layers of duct tape?

I would suspect that any of the guitar amp DIY e-stores that cater to the fender tweed crowd would have exactly what you need (mojotone, tedweber,antiquetubesupply....etc.)

Andy

Skycraft has nylon sheet, and that brown stuff... also fish paper... I think they may have teflon sheet also.

It's not that expensive... maybe a buck a sheet (teflon excluded of course!)

Keith

The modern substitute for mica washers and heat conductive grease - are the Sil-pad type materials, available cut to normal shapes for voltage regulators and power transistors etc. Made by Bergquist and others.

It is also available in sheets - not cheap though - but should work well in your application, it is thin, will conduct heat if necessary and will insulate up to 6kV. I have used it between a heatsink and a PCB to ensure the tracks don't contact the heatsink.

Worked very well!

Kieth, I couldn't find that stuff on skycraft.

-I ended up getting some fish paper and neoprene from mcmaster. On one PCB I used neoprene since i wanted to have a little damping from vibration and the the other I used the paper.

-IIRC when I tried duct tape, it was conducting somehow. Maybe the solder points were popping through. I don't think duct/duck tape would conduct, but in this case it was a problem. I also wanted toexperiment with some different materials anyway, for referene for future projects

Thanks everyone...
-Still looking for a cheaper source for the paper

nomex:
http://www.surplussales.com/RF/RFTeflon-Mylar.html

[quote author="guavatone"]nawwww.......

Is Hanckock Fabrics where you got it from?[/quote]

I am completely serious. I could perhaps video my experiment. Basically I fired up a Jacob's ladder and dropped a sheet of vinyl in between the electrodes, it blocked the arc. Since it's furniture fabric, it must be at least fire retardant. It does not combust, but it does melt, so I wouldn't use it in a high temp application. I think I'd be hesitant to use it as a critical insulation layer where as it's fabric, and not a listed insulator.

That's cool. It just conjures funny images of a tech testing checker'd or madrass patterned material.


Where did ya get it?

It came from a local fabric store named Hancock Fabrics. My electronics buddy and I were having a discussion about our current project (which I plan to unveil soon) and our need for an insulated surface when my 13 year old daughter made the suggestion. It's definitely an "outside the box" solution that we had to test before running with it. We used contact cement to attach it to the aluminum surface.

Motor and transformer rewind houses use a plastic film called cambric film; it's sort of a flexible woven plastic sheet that they use to insulate between transformer windings. If you want to uncurl fish paper, steam it well and press flat until dry. A piece of Formica Arborite would probably do just as well.

I've used the thin foam pads that are made for putting behind wall switch plates and outlet cover plates as insulation. Easy to find at the local hardware store. Cuts easily with scissors. Holds in place with double-sided carpet tape. Works great for me.

~ Charlie

thanks all! :thumb:

a couple pics...

Fishpaper

Neoprene

Fini


-nice and quiet now.