I'm having no success at all soldering aluminum wire. Maybe someone can help.
The wire is 23 AWG and 32 AWG purchased from Magnepan to repair speaker panels. Included in the kit is a short piece of thick solder, hopefully for aluminum. It seems to have a high melting temperature.
I have read threads here and elsewhere about aluminum soldering, read papers, watched YouTube videos, etc. It seems that it is possible for some to solder it, but no success for me.
The wire is enamel coated so I remove all the insulation with 320 grit sandpaper. Seeing the removal is easy, as the wire changes from amber to a silvery color. I have used contact spray cleaner afterward to clean, or tried without a chemical clean. Getting the supplied solder to tin the soldering iron tip is very difficult, if not impossible. It mostly just beads up. Same for the wire, it will bead up but never wet the aluminum wire. There is flux inside the solder, rather foul smelling and dark.
The wire is 23 AWG and 32 AWG purchased from Magnepan to repair speaker panels. Included in the kit is a short piece of thick solder, hopefully for aluminum. It seems to have a high melting temperature.
I have read threads here and elsewhere about aluminum soldering, read papers, watched YouTube videos, etc. It seems that it is possible for some to solder it, but no success for me.
The wire is enamel coated so I remove all the insulation with 320 grit sandpaper. Seeing the removal is easy, as the wire changes from amber to a silvery color. I have used contact spray cleaner afterward to clean, or tried without a chemical clean. Getting the supplied solder to tin the soldering iron tip is very difficult, if not impossible. It mostly just beads up. Same for the wire, it will bead up but never wet the aluminum wire. There is flux inside the solder, rather foul smelling and dark.
Assuming that that stuff really is for soldering aluminium, it looks like either your soldering tip has oxidated (happens in general and really easy and thorough with solder for aluminium), and/or the temperature of your tip doesn't get hot enought.
Any idea if this might be the case?
Any idea if this might be the case?
A jeweler showed me this stuff almost 50 years ago. It's zinc chloride solution. I know it works on stainless steel but I don't
know if it is good for aluminum. It does come in handy now and then and costs very little.
Jewelers Soft Soldering Tix Flux - Soldering | Esslinger & Co
The hard part is getting through the aluminum oxide layer to get to the bare metal.
This YouTube video makes it look easy.
AlumSolder Alu Flux - use solder and soldering iron to soldering aluminium, http://alumsolder.eu - YouTube
I went to alumsolder.eu and they show the flux used along with the Youtube video link. I think I'll buy some of this.
G²
know if it is good for aluminum. It does come in handy now and then and costs very little.
Jewelers Soft Soldering Tix Flux - Soldering | Esslinger & Co
The hard part is getting through the aluminum oxide layer to get to the bare metal.
This YouTube video makes it look easy.
AlumSolder Alu Flux - use solder and soldering iron to soldering aluminium, http://alumsolder.eu - YouTube
I went to alumsolder.eu and they show the flux used along with the Youtube video link. I think I'll buy some of this.
G²
I can say that the tip has taken a beating. It was near new and worked like a charm when I started. It's not so pretty now. 🙁
As for heat, hard to say. I've tried from what is supposed to be 600F up to 850F with my Weller. That's as much as I've got.
It's hard to know what solder and flux to get. Most reviews are from people using a torch, not an iron. Some do say they can solder battery tabs. I'll have a look at the video, thanks.
As for heat, hard to say. I've tried from what is supposed to be 600F up to 850F with my Weller. That's as much as I've got.
It's hard to know what solder and flux to get. Most reviews are from people using a torch, not an iron. Some do say they can solder battery tabs. I'll have a look at the video, thanks.
Pano - I have no idea what the "solder" they gave you is, but I know a little about soldering Aluminum.
It's hard to solder Aluminum as it instantly oxidizes upon contact with air and Aluminum Oxide is almost impossible to solder to. So the trick is to avoid contact with air. Here's how to work that trick that's practical at home:
Melt a big blob of solder on a metal sheet (almost anything is OK, but Aluminum is probably best). After cleaning the wire with sandpaper put the wire into the molten solder blob (keep applying heat to the blob). While the wire is in the molten solder blob start scraping the wire that is submerged in solder (a stainless steel dental tool is good for this). The idea is to scrape the Aluminum Oxide off the wire while it is submerged in the solder. This way it is never in contact with air. After some scraping you can remove the wire and let it cool. You will see that it is now solder tinned in the places where you scrapped. It will be easy to solder to the tinned wire.
You may need to repeat the process to get all of the wire tinned. The tinned area will not oxidize quickly and you can wait days or weeks before soldering.
It's hard to solder Aluminum as it instantly oxidizes upon contact with air and Aluminum Oxide is almost impossible to solder to. So the trick is to avoid contact with air. Here's how to work that trick that's practical at home:
Melt a big blob of solder on a metal sheet (almost anything is OK, but Aluminum is probably best). After cleaning the wire with sandpaper put the wire into the molten solder blob (keep applying heat to the blob). While the wire is in the molten solder blob start scraping the wire that is submerged in solder (a stainless steel dental tool is good for this). The idea is to scrape the Aluminum Oxide off the wire while it is submerged in the solder. This way it is never in contact with air. After some scraping you can remove the wire and let it cool. You will see that it is now solder tinned in the places where you scrapped. It will be easy to solder to the tinned wire.
You may need to repeat the process to get all of the wire tinned. The tinned area will not oxidize quickly and you can wait days or weeks before soldering.
Thanks! Good tip and I'll try it. 
I did see a YouTube video where an oil bath was used to keep the oxygen out, and there was a good bit of scraping going on. Seems like a similar technique.
I did see a YouTube video where an oil bath was used to keep the oxygen out, and there was a good bit of scraping going on. Seems like a similar technique.
At work we use a brand of aluminum solder that I've been using for years, like a charm. Iirc it's an American brand, but not sure. Will look what brand and type it is and get back to you, tomorrow. Maybe that can also help.
Tip activator is an absolute must, and some (older) Weller tips don't really work well soldering aluminium. E.g. I never really got it working with the old Magnetostat Weller types.
Tip activator is an absolute must, and some (older) Weller tips don't really work well soldering aluminium. E.g. I never really got it working with the old Magnetostat Weller types.
Thanks. I'm up for recommendations of solder and flux and tips. What I have isn't even close to working.
I just tried the glob of solder while scraping to no avail. Also tried an oil bath with scraping and no luck either.
I just tried the glob of solder while scraping to no avail. Also tried an oil bath with scraping and no luck either.
The data for Magna 88 says for use on stainless steel. You use it on Aluminum? With a flux paste?
You have to do it in a vacuum. Go get your Hoover and have at 'er.
I am interested in the results you have Pano, for myself it was futile and Mom got mad when I got everything so hot I burned right through the hose.
I am interested in the results you have Pano, for myself it was futile and Mom got mad when I got everything so hot I burned right through the hose.
Years ago, when I wound aluminum wire voice coils, used this one successfully.
https://www.newark.com/multicore-loctite/629443/solder-wire-alusol/dp/15J8243#
Don´t waste time on kludgy solutions.
Ask if they have smaller spools.
https://www.newark.com/multicore-loctite/629443/solder-wire-alusol/dp/15J8243#
Don´t waste time on kludgy solutions.
Ask if they have smaller spools.
Thanks, I'll see if I can find a smaller roll. I'd likely not use a pound of it in my lifetime.
Did you use it without additional flux?
Did you use it without additional flux?
Nope.
Brand/name is:
Loctite Alu 45D 4C with Alusol Flux (don't know if that is standard or special).
LOCTITE ALU – Electronics - Henkel Adhesives
RS Online, Newark, Farnell etc all have it. I use this to solder just about anything that doesn't go well with normal solder (60/40), aluminum wire of 0,1 mm, copper clad aluminium, steel etc.
Should work, hope it helps!
Edit: I see JMFahey had the same solution, great to see!
Thanks so much. Looks like I'll have to get a roll of the stuff.
Not that I really want to spend $40 for a roll out of which maybe 1m will be used. Oh well, maybe I'll sell off the left over on eBay. 🙂
Not that I really want to spend $40 for a roll out of which maybe 1m will be used. Oh well, maybe I'll sell off the left over on eBay. 🙂
Thanks. I suspect that's all that's needed. If only I had waited 5 minutes your offer would be perfect. 
But I ordered some.
If it works, I'll offer up some of it in the swap meet for the cost of postage.
But I ordered some.If it works, I'll offer up some of it in the swap meet for the cost of postage.
That's amazing since the time between me responding and you posting was 4 minutes, and I visited by curiosity, not because of knowing by email there was an update of the thread..
Either way, if the soldering tip will be clean this should certainly do it.
Good luck Pano!
Either way, if the soldering tip will be clean this should certainly do it.
Good luck Pano!
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