If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #3215
Joined: Sun Sept 19 2010, 08:42PM
Location:
Posts: 780
hi there
anyone has a clue about a recipe for some contact cleaner?
I was thinking about boric acid or something, but I've got no clue about this and no real time to search for now, so I figured I could start a discussion which might turn interesting for others
this is mainly for some nasty oxids formed on legs of really old logic chips or even tube and their sockets which tend to get unsolderable...
Registered Member #3215
Joined: Sun Sept 19 2010, 08:42PM
Location:
Posts: 780
I don't think it would be of much use with things like oxydated tube pins or things like that...
maybe some brands of fluxes would enable plating of the pins to refresh their condition? I'll have to make some tests as soon as I have access to a bench (currently overmessed with house modifications and a newborn child..)
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
I use dilute household ammonia and steel wool to clean valve pins and sockets. An old toothbrush and fine emery boards used for shaping nails can also be useful.
Ordinary domestic liquid brass cleaners usually contain ammonia and a very fine abrasive, and can be applied with a toothbrush.
Toothpaste itself is a very fine abrasive, and can be used for removing fine scratches from glass, though it does take time.
Valves with B7G and B9A bases, and other types where the pins go straight into the glass, can be washed with hot water and detergent in the kitchen sink. This may damage or completely wipe away any printing on the glass, so take care if that is important to you.
Valve sockets made from PTFE or ceramics can benefit from boiling in a detergent solution on the kitchen stove, but don't do this with paxolin fibre board sockets, as they may absorb water.
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
If nothing else is available, and if the oxidation isn't too bad I try Coca-cola (other colas are available).
The 'sugar free' stuff isn't as sticky, especially if you 'concentrate' the phosphiric acid by boiling the water off (phosphoric acid 'isomerises', or something at ~200 centigrade. Using it hot also helps
It takes a while, but if nothing else is available......
EDIT: You do need 'some' water in it, as, apparently, it's water that makes acid 'acidic', or so they told me at school.
Registered Member #3324
Joined: Sun Oct 17 2010, 06:57PM
Location:
Posts: 1276
Just try some copper dissolving acid, you can buy nitric and sulphuric acid on ebay, that 'ought to dissolve the outer layer of the pins, just be careful not to leave it in for too long!
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059
Oust (tm) and hydrogen peroxide works well, but has to be diluted or it becomes PCB etchant I used 1 part 30 vol H2O2 and 5-6 parts Oust, this recipe removed all the corrosion from a PCB very fast and left the copper nice and shiny. Did some minor damage but not as bad as I thought it would be, have an ice cold "stop bath" next to it to dunk the board in if things get a bit hairy.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
homemade contact cleaner?
