EPDM Rubber Test Leads - Page 1
Forum section: electronics / beginners

author: rstor22
author_rank: Regular Contributor
timestamp: January 06, 2022, 07:18:06 pm
content: Some manufacturers use EPDM rubber for their test leads instead of vinyl or silicone. Examples would be theFluke TL27,Oldaker, and perhapsElwyn 6625-01-121-0510It was mentioned in a previouspostby FlyingHacker that :"My other favorite probes are the Elwyn military surplus probes. Once you feel real rubber leads you will think silicone is rubbish... of course you have to lube real rubber every year or two to keep it from drying out. But that takes about two minutes."Would anyone have more details on what specific oil they use to prevent their rubber test leads from drying out?Attached is a picture of the Oldaker test probes that I have.

author: GuidoK
author_rank: Regular Contributor
timestamp: January 14, 2022, 10:37:00 pm
content: I doubt that epdm rubber has to be lubed up.I work on a daily basis with epdm rubber coated cables, where epdm is chosen as the insulator because its fairly compatible with strong alkalines and acids (so polar substances), but I'm pretty sure epdm is not so compatible with hydrocarbons like oils, kerosine etc.On the interwebs you can find lists with chemicals/substances that are either compatible or not with certain materials to get an idea.The bulk cable that I get from the factory also has absolutely no oils on it. In fact it has a very light dusting of what looks like talcum powder on it.But maybe there is an oil that can serve as some sort of plastisizer alhough I have no idea if that is necessairy because epdm is afaik a vulcanized substance.

author: BrokenYugo
author_rank: Super Contributor
timestamp: January 15, 2022, 02:37:16 am
content: This is the first I've heard of oiling rubber wire insulation of any type. Good rubber kept out of harsh conditions seems to last a long time. I've got a power cord from WW2 (probably some aviation grade stuff) on a drill press that was still lay flat supple last I checked, I've also seen rather old (70s at the youngest) Simpson test leads that were still soft. Biggest problem I've seen is mold/mildew loves to grow on old rubber insulation for whatever reason. I sometimes clean extension cords used in greasy garages with WD-40 but I don't think that does it any good, just gentler than acetone based brake cleaner.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: January 15, 2022, 03:07:26 am
content: If anything, Glycerine can be used to keep rubber supple and prevent it from developing cracks. This is used in other applications such as seals or gaskets, I have not made up my mind whether it makes sense on test leads.

author: Nominal Animal
author_rank: Super Contributor
timestamp: January 15, 2022, 06:22:22 am
content: Quote from: Neomys Sapiens on January 15, 2022, 03:07:26 amGlycerol [glycerine (UK), glycerin (US)] also helps prevent hands developing cracks. (It's non-toxic, and used in most hand lotions.)If your hand skin dries when doing test equipment stuff, glycerol should help a lot.You can find the stuff in pharmacies, eco-product stores (it's usually made from rapeseed and such plants), and in stores that sell DIY wine and beer kits.

author: rstor22
author_rank: Regular Contributor
timestamp: January 21, 2022, 10:56:53 pm
content: Thank you all for the advice! Fluke also got back to me regarding their TL27 EPDM test leads where I had asked the same question regarding lubricating the test leads. Their response was:"The product engineer got back to me and here is what he is saying.We recommend that our customers replace their test leads every 12-18 months and not put anything on them."

author: Gyro
author_rank: Super Contributor
timestamp: January 22, 2022, 10:46:15 am
content: Quote from: Nominal Animal on January 15, 2022, 06:22:22 amAlso manufacturer recommended for preventing your car door rubber seals from freezing shut in cold winters.

author: GuidoK
author_rank: Regular Contributor
timestamp: January 23, 2022, 07:12:35 pm
content: Quote from: Gyro on January 22, 2022, 10:46:15 amAre car door seals made from epdm? They might be (however they sometimes look aerated opposed to the epdm on cables).Glycerine (glycerol) is a polyalcohol and is hygroscopic, so it might be a good moisturizer for epdm.However the epdm cables I use seem to have no real issues drying out, at least not over a period of 5-10 years. Maybe they are of higher quality than the leads discussed here. They are much thicker though (150-400 amp)