Connecting wire specification

**mathew086** · Nov27-09, 08:29 AM

I would like to solder a connecting wire to a stainless steel plate and a copper plate. Both of the plates are in and around wet environments, possibly in water. What type and size of wire could be used to solder them. Specifications???
Can i use a normal connecting wire???

**berkeman** · Nov27-09, 11:55 AM

Originally Posted by mathew086

I would like to solder a connecting wire to a stainless steel plate and a copper plate. Both of the plates are in and around wet environments, possibly in water. What type and size of wire could be used to solder them. Specifications???
Can i use a normal connecting wire???

Don't think you can solder to stainless steel. You should probably be reading about how to weld to stainless steel instead.

**dlgoff** · Nov27-09, 01:32 PM

You could use a wire "crimp-on" and make a screw connection to the stainless steel.

**mathew086** · Nov30-09, 08:41 AM

But i tried to solder the stainless steel normally and it worked. ( although some brown reddish material was formed in between.)
Also it is strong...I just need to know the type of wire that will withstand in wet conditions....
I thought of using a wire crimp on and scre it to stainless steel. But the stainless steel plate is small in dimension only 1cm width. Also the screw has to go through another thick layer of plastic which cannot be drilled. ( water can leak through the scre holes).

So any other suggestions??

**f95toli** · Nov30-09, 12:44 PM

Originally Posted by berkeman

Don't think you can solder to stainless steel. You should probably be reading about how to weld to stainless steel instead.

Sure you can, but you need to use special flux made for soldering stainless steel (I quite often have to solder SMA connectors to stainless steel coax). You don't need any special equipment or special solder, but you DO need to flux in order to make a good joint (it IS possible to get it to stick without flux but the joint are weak).

When you say "wet", what does that mean? Immersed in seawater or something that might occasionally get sprayed by fresh water.

Although If you are already using a copper plate I can't see any reason normal copper wire wouldn't be ok.

**mathew086** · Dec1-09, 06:33 AM

Wet means wthe stainless steel plate is immersed in water( rain water). I need to connect that plate to + terminal of battery via a wire. so will a normal wire wounded with insulation tape all around will work??

**dlgoff** · Dec1-09, 06:26 PM

I didn't think that the connection would be that good (maybe high resistance). But I guess it only effects strength?

Soldering Stainless steel can be soldered
using the conventional lead—tin solders but
the bond strength is often poor as is the colour
match. Better results are often obtained by
using the silver-bearing soft solders. The
silver—tin alloys with approximately 5%
silver are particularly useful especially with
the stainless steel holloware.

www.jm-metaljoining.com/pdfs.../Joining%20Stainless%20Steel.pdf

**berkeman** · Dec1-09, 06:50 PM

Originally Posted by mathew086

Wet means wthe stainless steel plate is immersed in water( rain water). I need to connect that plate to + terminal of battery via a wire. so will a normal wire wounded with insulation tape all around will work??

Can you just drill a hole in the plate, and make the wire connection via a spade lug and star washer? Seems like that would be mechanically more robust.

**vk6kro** · Dec1-09, 07:14 PM

Could you make a cut in the stainless steel like this:

Join stainless steel.PNG

Then bend the small strip of stainless steel so that it was out of the water and then make an electrical contact with it well clear of the water.

**mathew086** · Dec4-09, 05:42 PM

AT the moment i used the method suggested by berkeman. USed a spade lug and connected to the stainless steel plate.

The method suggested by Vk6kro is not possible, because the connecting wire has to be taken to upward. If it was supposed to take at the downside, then it would have been possible.

Again one more question, how is it possibel to solder a wire to coppper sheet. I treid to solder on copper, but after a few minutes, it gets removed very easily. not strong.
any ideas???

**vk6kro** · Dec4-09, 06:53 PM

Originally Posted by mathew086

AT the moment i used the method suggested by berkeman. USed a spade lug and connected to the stainless steel plate.

The method suggested by Vk6kro is not possible, because the connecting wire has to be taken to upward. If it was supposed to take at the downside, then it would have been possible.

Again one more question, how is it possibel to solder a wire to coppper sheet. I treid to solder on copper, but after a few minutes, it gets removed very easily. not strong.
any ideas???

It is very hard to heat copper as it conducts heat very well. So, you may need to use a gas flame to heat it. The copper has to be hot enough to melt the solder before it will make a good soldered joint. If you have gas in the kitchen, this might be suitable.

I would not choose to make a connection of two different metals under water if I could avoid it. Corrosion is almost certain if you do that.

Join stainless steel 2.PNG