Cover or fill pierced holes from probing?

Ask for and share advice on using the PicoScope kit to fix vehicles here.

Cover or fill pierced holes from probing?

Postby FioranoCars » Fri Jan 02, 2015 2:26 pm

Ok, so this is not a normal technical question for Pico, as it's not waveform related, but not the less an important one for anyone who uses a piercing style probe from time to time (best avoided but sometimes the only way).

We have been using a Silicon based sealant to cover/fill any hole we make, however it has been brought t my attention that this is possibly worse that leaving it open, as the silicon reacts with the wire in a bad way!

I have asked some of our electrical component suppliers technical teams to give advise but they have been unable to give any real clarity on the best solution, so I thought I'd pose the question here!

What do you use ?

Ideally want to cover the following requirements:
- good insulation properties
- good environmental seal to stop air and water penetration
- not cause corrosion (as most silicon's do react with the wire I understand ?!)
- Adhere to plastic and PVC (and polyolefin)
- Vibration safe
- Flexible once cured
- Life of 10years + (as we work on vehicles that will be around for 50 years or more)
- good skin properties (ie not sticky once applied and cured)
- Temperature Resistance (sometime might be an injector wire etc close to the engine) so -20c to +150c min ideally +200c
- Chemical resistance (oil, RTF, degreasant, salt and other typical fluids used in Automotive cleaning etc)
- Clear/neutral colour (minor point!)

We've historically always used basic silicon based stuff and that might be doing as much harm as good.

While typing, one supplier's tech team have offered the following:
- Dow Corning® 3145 RTV Silicone Sealant
which is not cheap, but seems to fit the bill.

Still be interested to hear what others use.
Thanks
Richard
User avatar
FioranoCars
Guru
Guru
 
Posts: 189
Joined: Thu Dec 13, 2012 11:26 am
Location: London, UK

Re: Cover or fill pierced holes from probing?

Postby volrem » Fri Jan 02, 2015 3:40 pm

I use PlastiDip Liquid Electrical Tape.

I haven't bee using it for a long time so can't yet tell how good or bad it is.
volrem
Guru
Guru
 
Posts: 146
Joined: Fri Jan 03, 2014 3:43 pm
Location: Estonia

Re: Cover or fill pierced holes from probing?

Postby FioranoCars » Fri Jan 02, 2015 4:06 pm

Thanks, looking online using the term Liquid Electrical Tape found this:
http://www.starbrite.com/category/liqui ... rical-tape

as we don't seem to have much of the PlastiDip range available in the UK, well not the LET stuff anyway.

I have bought a tin to try, and will order the Dow Corning® 3145 RTV Silicone Sealant to compare it to.

Will let you all know how they perform in due course ... but any other suggestions welcome
thanks
Richard
User avatar
FioranoCars
Guru
Guru
 
Posts: 189
Joined: Thu Dec 13, 2012 11:26 am
Location: London, UK

Re: Cover or fill pierced holes from probing?

Postby Robski » Fri Jan 02, 2015 4:12 pm

User avatar
Robski
Advanced User
Advanced User
 
Posts: 602
Joined: Tue Sep 14, 2010 6:36 pm
Location: Yorkshire

Re: Cover or fill pierced holes from probing?

Postby jbrheaume » Sun Jan 11, 2015 7:50 pm

I use clear nail polish, but here I So California we do not have many issued with growth of the green stuff.
jbrheaume
Newbie
 
Posts: 1
Joined: Mon Apr 29, 2013 10:21 pm

Re: Cover or fill pierced holes from probing?

Postby hexibot43 » Mon Jan 12, 2015 5:04 pm

Robski wrote:This's what I use, data sheet in link.

http://www.permatex.com/documents/TDS/automotive/85120.pdf


I've never thought that hard about this, but never read the Datasheet on this stuff. Minimum of two coats with 10 minutes of dry time in between. Really?
User avatar
hexibot43
Advanced User
Advanced User
 
Posts: 87
Joined: Tue May 10, 2011 5:27 pm
Location: Redwood City, Californa, USA

Re: Cover or fill pierced holes from probing?

Postby Robski » Mon Jan 12, 2015 9:19 pm

hexibot43 wrote:
Robski wrote:This's what I use, data sheet in link.

http://www.permatex.com/documents/TDS/automotive/85120.pdf


I've never thought that hard about this, but never read the Datasheet on this stuff. Minimum of two coats with 10 minutes of dry time in between. Really?


nah ! just a dab & forget about it, I think it's referring more to use in the marine industry.
User avatar
Robski
Advanced User
Advanced User
 
Posts: 602
Joined: Tue Sep 14, 2010 6:36 pm
Location: Yorkshire

Re: Cover or fill pierced holes from probing?

Postby FioranoCars » Mon Jan 12, 2015 10:18 pm

I'd not be too keen on nail varnish, as it's brittle once dry to start with, and I've no idea what the reaction with copper cores or other conductors would be like.

Since looking at this myself,I've found that Wurth do a similar liquid insulation product too, and they tend to be pretty Germanic about these things and test stuff extensively before releasing it, so I'm thinking these may be better than I gave them credit for. My first tin arrived today so will test it, but from putting some onto a paperclip (closest thing to hand), it appears pretty thick as a single coat, enough for small wires in a single application.

The Dow Corning is still on order, we use their DC4 lube, and they have a great reputation, so I'll do some side by side tests once it arrives ...

Any other ideas or products people care to recommend?
User avatar
FioranoCars
Guru
Guru
 
Posts: 189
Joined: Thu Dec 13, 2012 11:26 am
Location: London, UK


Return to Diagnostic discussion

Who is online

Users browsing this forum: No registered users and 0 guests