 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
heedh23
Joined: 05 Sep 2014
Posts: 4
Location: Washington, USA
|
 Posted: Tue Sep 06, 2022 2:43 pm Post subject: Forest of tabs - corrosion question |
 |
|
Recently on one of the Vans facebook groups, there was a picture of a homemade forest of tabs that another builder made for their electrical system. This led to a discussion on whether the aluminum rivets holding the tabs onto the copper plate would corrode, whether brass rivets were necessary, etc.
My question is this - if aluminum "sacrifices" itself when in contact with copper due to galvanic corrosion, why doesn't the aluminum sheet/structure that contacts a forest of tabs corrode? Is it the presumed lack of an electrolyte? Is it a requirement to use some magic unobtanium alloy of copper?
Thanks in advance for the education.
-Ed
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
 |
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Wed Sep 07, 2022 8:44 pm Post subject: Forest of tabs - corrosion question |
|
|
At 05:43 PM 9/6/2022, you wrote:
| Quote: | --> AeroElectric-List message posted by: "heedh23" <heedh23(at)msn.com>
Recently on one of the Vans facebook groups, there was a picture of a homemade forest of tabs that another builder made for their electrical system. This led to a discussion on whether the aluminum rivets holding the tabs onto the copper plate would corrode, whether brass rivets were necessary, etc.
My question is this - if aluminum "sacrifices" itself when in contact with copper due to galvanic corrosion, why doesn't the aluminum sheet/structure that contacts a forest of tabs corrode? Is it the presumed lack of an electrolyte? Is it a requirement to use some magic unobtanium alloy of copper? |
Excellent question . . .
The original design I crafted for B&C's products
SOLDERED strips of tabs to the base plate. This
preserves electrical integrity between bus plate
and tabs.
At the time it was designed the target mounting
surfaces were stainless and composite
firewalls.
This assembly can be mounted on an aluminum surface
that stays dry.
Riveted assemblies are not recommended.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
| Description: |
|
| Filesize: |
201.78 KB |
| Viewed: |
1956 Time(s) |
|
|
|
| Back to top |
|
|
Ceengland
Joined: 11 Oct 2020
Posts: 391
Location: MS
|
| Posted: Thu Sep 08, 2022 5:14 am Post subject: Forest of tabs - corrosion question |
|
|
On 9/6/2022 5:43 PM, heedh23 wrote:
| Quote: |
Recently on one of the Vans facebook groups, there was a picture of a homemade forest of tabs that another builder made for their electrical system. This led to a discussion on whether the aluminum rivets holding the tabs onto the copper plate would corrode, whether brass rivets were necessary, etc.
My question is this - if aluminum "sacrifices" itself when in contact with copper due to galvanic corrosion, why doesn't the aluminum sheet/structure that contacts a forest of tabs corrode? Is it the presumed lack of an electrolyte? Is it a requirement to use some magic unobtanium alloy of copper?
Thanks in advance for the education.
-Ed
As Bob & others said, riveting is far from optimal for electrical
|
connections. It's pretty simple to just 'flow solder' the tabs to the
plate by using a propane torch under the plate while adding solder to
the tab/plate intersection.
Charlie
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
Charlie |
|
| Back to top |
|
|
Eric Page
Joined: 15 Feb 2017
Posts: 245
|
| Posted: Thu Sep 08, 2022 6:32 am Post subject: Re: Forest of tabs - corrosion question |
|
|
I built mine by setting a brass plate on top of a burner on my gas cooktop. Then I smeared solder paste on the bottom of several 6-way quick-connect tabs and placed them where I wanted them on the plate. Finally, I turned the burner on low and waited for the solder paste to reflow. Photo attached.
If you do it this way, turn the hood fan on high (there's some smoke) and have some sort of heatproof tool handy to nudge the tabs into the desired position as the assembly cools, as they'll move a bit when the paste melts.
I got the brass plate for cheap on eBay and cut it to size. Here's one seller...
http://www.ebay.com/itm/293905310788
The quick-connect tabs are in stock at Digi-Key in 4-way, 6-way and 10-way versions...
4-way: https://www.digikey.com/short/q3pjw0cw
6-way: https://www.digikey.com/short/83hdh0j2
10-way: https://www.digikey.com/short/5br0n7fv
Solder paste is available pretty cheaply on eBay (or you can just feed normal solder wire into the joints once the plate is hot). Here are a couple of U.S. sellers in the $7 range...
http://www.ebay.com/itm/384953664130
http://www.ebay.com/itm/313843925100
Be careful that you don't accidentally buy paste flux; eBay sellers frequently mix up search terms in their listing titles and the packaging is very similar.
Finally, I got brass hardware at Home Depot for mounting it to the firewall and securing the negative cable on the engine side.
1/4-20 x 3" bolt: https://www.homedepot.com/p/204274747
1/4-20 hex nuts: https://www.homedepot.com/p/204274130
1/4" flat washers: https://www.homedepot.com/p/204780701
1/4" stainless lock washers: https://www.homedepot.com/p/204276509
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
| Description: |
| DIY 48-way forest-of-tabs made from 1/8" brass plate and soldered 6-way quick-connect tabs. The through-bolt is secured with washers and two jammed nuts (brass all-metal lock nuts are apparently unobtanium). A stainless rivet will prevent rotation. |
|
| Filesize: |
123.42 KB |
| Viewed: |
1932 Time(s) |
|
|
|
| Back to top |
|
|
yellowduckduo(at)gmail.co
Guest
|
| Posted: Thu Sep 08, 2022 7:24 am Post subject: Forest of tabs - corrosion question |
|
|
Steel pop rivets and solder on the tabs.
No corrosion at tabs or on aluminum where it is bolted to structure
after 17 years in an open T hangar.
Ken
On 08-Sep.-22 9:14 a.m., Charlie England wrote:
| Quote: |
<ceengland7(at)gmail.com>
On 9/6/2022 5:43 PM, heedh23 wrote:
>
>
> Recently on one of the Vans facebook groups, there was a picture of a
> homemade forest of tabs that another builder made for their
> electrical system. This led to a discussion on whether the aluminum
> rivets holding the tabs onto the copper plate would corrode, whether
> brass rivets were necessary, etc.
>
> My question is this - if aluminum "sacrifices" itself when in contact
> with copper due to galvanic corrosion, why doesn't the aluminum
> sheet/structure that contacts a forest of tabs corrode? Is it the
> presumed lack of an electrolyte? Is it a requirement to use some
> magic unobtanium alloy of copper?
>
> Thanks in advance for the education.
> -Ed
As Bob & others said, riveting is far from optimal for electrical
connections. It's pretty simple to just 'flow solder' the tabs to the
plate by using a propane torch under the plate while adding solder to
the tab/plate intersection.
Charlie
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
nuckolls.bob(at)aeroelect
Guest
|
| Posted: Thu Sep 08, 2022 8:26 am Post subject: Forest of tabs - corrosion question |
|
|
At 10:23 AM 9/8/2022, you wrote:
| Quote: | --> AeroElectric-List message posted by: C&K <yellowduckduo(at)gmail.com>
Steel pop rivets and solder on the tabs.
No corrosion at tabs or on aluminum where it is bolted to structure after 17 years in an open T hangar.
Ken |
Good data point. "Fixtured" with rivets
before soldering. Thanks!
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
