What are the best improvised or salvaged insulators ? - Page 1
Forum section: electronics / general

author: MathWizard
author_rank: Super Contributor
timestamp: September 17, 2025, 02:39:42 am
content: I'm thinking of insulators for PCB standoffs, I'm not going to order expensive ones and I don't need Teflon ones yet. So just around the average house, or maybe at a junk yard or something you find get a sample of from a garage or business, what's the best insulator materials, better than Bakelite or average PCB material ?I'm surprised common glass isn't better rated, but I've never tried using it. Common rocks seem closer to conductors or semi-connductors.What average plastics are good ? Are white plastics generally less conductive ? What about the plastic on old wall outlets or switch/outlet covers? I have some of them I could cut or break up. Or the plastic case of a LED monitor or printer?What about rubber tires, or some other rubber off a car at a scrap yard ?? I've never tried cutting a slice of rubber off a car or tire with a knife or snips, I guess that's not easy tho. What about the outer rubber shield of a DMM like on a Fluke or Brymen ?What about ceramic dishes ?? Or pyrex dishes ??What about plumbers Teflon tape, it's just a thin roll tho, but what about wrapping that around a plastic standoff ?What about PCB materials, how much higher resistance might a CRT TV PCB be, vs an LED TV PCB ?? I suppose most PCB's have the typed on them somewhere, I'll have to check an old TV PCB that I have.What about at the utility/power company ? They must have lots of old scraps of transmission line insulators, how good might that stuff be ?? I'm just thing of making small little pebble sized pieces if possible.

author: Ian.M
author_rank: Super Contributor
timestamp: September 17, 2025, 02:53:33 am
content: HDPE - murder a new white or natural color thick kitchen chopping board!

author: TimFox
author_rank: Super Contributor
timestamp: September 17, 2025, 02:59:17 am
content: You won't find small glass insulators, suitable for PCBs.The classic glass insulators used for telegraph wires along the railroad tracks are collectible, but much larger.Most of the plastic insulators you find for sale as washers or simple tubes are nylon, which work but absorb a few percent of water and aren't suitable for electrometers.Teflon's mechanical properties are lousy, and Teflon insulators are expensive, but they insulate very well. Wrapping tape around a crummy insulator won't reduce the crumminess, but Teflon tape itself insulates. An expensive version is sold as "skived Teflon tape".Small polystyrene shapes can be bought from hobby stores, for model railroad construction: takes glue well and is an excellent insulator.Tire rubber is full of carbon black, makes a lousy insulator.Old PCBs were paper-based phenolic, modern ones are epoxy-fiberglass (reasonable insulator). I like glass-reinforced Teflon, but it's expensive.

author: coppercone2
author_rank: Super Contributor
timestamp: September 17, 2025, 03:06:19 am
content: glass is easy enough to melt into a mold actually. if its any good IDK. I think you would need to anneal it at 500c , and sand the top flat. But you can definately drip it into a graphite mold to make little glass squaresmicrowave kiln inserts are especially good at doing glass mold work, you can anneal in them too.Glass should be a pretty good insulator.

author: MathWizard
author_rank: Super Contributor
timestamp: September 17, 2025, 06:11:13 am
content: Ok that sounds promising, I don't mind spending a few $$ on a new BB, but yeah I hope I can find one at a local store made of the right stuff. I have a typical looking bright white one, ~1cm thick, I'd cut it up, but it's a few years old and contaminated I guess. I should actually check the price of a bag of real stand-off's.I'd don't mind getting something at the hardware store either, but yeah I'm not going melting glass in the basement. Someday I'd like to melt a rock with a blowtorch tho.For PCB work I bought some cyano... type superglue, acrylic contact cement and some cheap epoxy. It seems the 1st 2 aren't great insulators, but some epoxies can be pretty good. And I know, don't solder superglue, and breath it. Nor the other stuff either I'd say.Ok I looked up a resistivity chart for plastics, HDPE is around the same a Bakelite/Phenol+paper. PVC pipes might be better, but I'm sure that's not easy to cut into little pieces (maybe it is tho).But then what about Bic pens made of polystyrene ? I wonder what else gets added tho, maybe it makes them bad. But maybe I'm buy a pack.

author: thm_w
author_rank: Super Contributor
timestamp: September 17, 2025, 09:41:29 pm
content: https://www.researchgate.net/figure/List-of-dielectric-breakdown-strengths-of-insulating-polymers_tbl1_323048091https://www.aliexpress.com/item/1005004229944541.html

author: macboy
author_rank: Super Contributor
timestamp: September 17, 2025, 09:57:43 pm
content: Don't count on car tires being a good insulator. In fact they are loaded with carbon black for various reasons, and should be considered conductors not insulators.

author: themadhippy
author_rank: Super Contributor
timestamp: September 17, 2025, 10:11:57 pm
content: Quoteabout £4 a hundred for the rivet type that push into a 3mm pcb hole and 8mm chassis hole,12mm high

author: Zoli
author_rank: Frequent Contributor
timestamp: September 18, 2025, 05:49:32 am
content: LCSC has nylon standoffs:https://www.lcsc.com/category/13553.htmlfor pennies a pop.

author: coppercone2
author_rank: Super Contributor
timestamp: September 18, 2025, 06:26:11 am
content: how would you make a glass insulator ?The small glass tile can be made, possibly a cool use for a old beer bottle. But what is the best way to get it solderable? I wonder if there is a way to fuse copper and glass. Without thick film ink or electroless plating.I am wondering if you can make little copper tiles, that are blacked and bonded to the wet glass.Its too much of a hassle to make unless you are really desperate and have unique materials on hand, but its none the less interesting. DIY glass caps. For a bigger part it might be worth your time. I guess it would be some HV part. For a substantially large part, you can possibly use some kind of mechanical anchoring. by making perforations in the copper.