Solder Electronic Components on Aluminum

Solder electronic components & wires to aluminum surfaces. No need for screws/bolts. Useful for example for aluminum electrostatic shields and heat sinks. Also suitable for plating aluminum objects for artistic purposes. Process is electroless (non-galvanic copper plating) and uses very common easy to find chemicals.

Step 1: Overview

Step 2: Watch Video

Step 3: Materials / Chemicals

Step 4: Tools

Step 5: Plating Solution

You can store the solution for a long time in a non-metallic container.

Step 6: Process

Step 7: Solder !

Step 8: For Larger Surfaces

Step 9: Finished !

Step 10: Watch Video

Comments

[Val42]

For as little as I would use this to solder on aluminum, I'm looking for small quantities of these chemicals. The salt and water are trivia, assuming tap water. I can buy 1/4 pound of copper sulfate on eBay for $4.95. The ferric chloride seems to be about $24 for a quart, but I need only a drop for the solution you give directions for. I don't etch circuit boards so I don't have any on hand. Have you experimented with other chemicals to substitute for the ferric chloride? Would a more common acid perform the function of the ferric chloride for this purpose?

For now, the solution I will likely use is what someone suggested: Apply solder then use the soldering iron to scratch the aluminum, removing the oxide and allowing the solder to adhere.

[ghazanfari.sr]

Thanks for sharing, I am about to use your method but I noticed that you didnt mention anything about the pureness of materials, for example, CuSO4 18% or 25 %, and since I already have some FeCl3 in powder I have no idea how much water do I need for the job.
I would appreciate it if you could help me with details.
Best regards
Reza

[needfulthing]

It would be even cooler if you could give some info about the chemical reactions happening here (solution with/without the salt).

[LarryG7]

Very useful technique. Since there are many cases where this would be useful commercially and it is not used I suspect some problems. Mainly the chemicals reducing the electrical conductivity of the joint. And I also suspect the conductivity would degrade over time. Anyone know?

[OMJOMJ]

Very lever. Bit i would also worry if it will last, especially In Corrosive atmosphere and galvanic corrosion. Anyone That would know If the plating would stay on or the alumina underneath would eventually break up?

[kimtyson]

OK, I don't usually post - but the aluminum soldering issue has been my nemesis for years. Kudos on this solution!! No pun intended. Thank you.

[MauriceC24]

Dommage que les explications ne soient pas hors des images.
Pour qui ne parle pas anglais, c'est impossible à traduire.

[simpletronic]

Step1:Overview
step2: Watch the video
step3:Materials / chemicals:
1) Copper Sulphate (CuSO4) used as fungicide in swimming pools
and fish tanks - you can find it in most chemistry sets.
2) Ferric Chloride (FeCl3) - the one you use for etching PC boards.
very reactive with aluminum.
3) Sodium Chloride (NaCl) ordinary table salt.
4) Water (H2O)
step4:Tools:
1) cotton swabs
2) plastic clothes peg & plastic sponge ( for plating larger surfaces)
3) various tools
step5:Plating solution:
1) put water in a non metallic container
2) add copper sulphate to the water
3) shake to dissolve as much CuSO4 as possible
4) put 7cc ( cubic centimetres ) of the CuSO4 solution in a non metallic
container.
5) add 1 drop (only 1 !) of ferric chloride and mix well with a plastic spoon
step6:Process:
1) remove all paint / anodizing from the aluminum object (if any)
2) dip a cotton swab in the plating solution
3) pick up a few grains of salt (NaCl)
4) rub the solution on the metal. This removes the oxide and prepares the
aluminum for plating.
5) remove all with dry kitchen paper
6) dip a NEW cotton swab in the solution this time WITHOUT the salt.
7) MAGIC! - copper instantly plates the aluminum.
8) repeat this step with a NEW cotton swab
9) polish the copper with steel wool.
step7:now you can solder on the aluminum object!
step8:For larger surfaces, hold a piece of sponge in a plastic clothes peg.
note: The copper-aluminum bond is not mechanically strong. use this
method for electric connectivity.

[MauriceC24]

Merci pour votre réactivité et votre compréhension.
C'est très utile, pour moi.

[simpletronic]

Je vous en prie !

[rep828]

This is a good point. It's helpful to have explanation outside of the images/videos so that non-english speakers can translate with common tools (like google translate). Is the author able to add text descriptions to accompany the images/videos?

[simpletronic]

Step1:Overview
step2: Watch the video
step3:Materials / chemicals:
1) Copper Sulphate (CuSO4) used as fungicide in swimming pools
and fish tanks - you can find it in most chemistry sets.
2) Ferric Chloride (FeCl3) - the one you use for etching PC boards.
very reactive with aluminum.
3) Sodium Chloride (NaCl) ordinary table salt.
4) Water (H2O)
step4:Tools:
1) cotton swabs
2) plastic clothes peg & plastic sponge ( for plating larger surfaces)
3) various tools
step5:Plating solution:
1) put water in a non metallic container
2) add copper sulphate to the water
3) shake to dissolve as much CuSO4 as possible
4) put 7cc ( cubic centimetres ) of the CuSO4 solution in a non metallic
container.
5) add 1 drop (only 1 !) of ferric chloride and mix well with a plastic spoon
step6:Process:
1) remove all paint / anodizing from the aluminum object (if any)
2) dip a cotton swab in the plating solution
3) pick up a few grains of salt (NaCl)
4) rub the solution on the metal. This removes the oxide and prepares the
aluminum for plating.
5) remove all with dry kitchen paper
6) dip a NEW cotton swab in the solution this time WITHOUT the salt.
7) MAGIC! - copper instantly plates the aluminum.
8) repeat this step with a NEW cotton swab
9) polish the copper with steel wool.
step7:now you can solder on the aluminum object!
step8:For larger surfaces, hold a piece of sponge in a plastic clothes peg.
note: The copper-aluminum bond is not mechanically strong. use this
method for electric connectivity.

[simpletronic]

Responding to several requests, this is a text version of my instructable, for those who wish to translate it to a different language. Hope it helps!

Step1:Overview
step2: Watch the video
step3:Materials / chemicals:
1) Copper Sulphate (CuSO4) used as fungicide in swimming pools
and fish tanks - you can find it in most chemistry sets.
2) Ferric Chloride (FeCl3) - the one you use for etching PC boards.
very reactive with aluminum.
3) Sodium Chloride (NaCl) ordinary table salt.
4) Water (H2O)
step4:Tools:
1) cotton swabs
2) plastic clothes peg & plastic sponge ( for plating larger surfaces)
3) various tools
step5:Plating solution:
1) put water in a non metallic container
2) add copper sulphate to the water
3) shake to dissolve as much CuSO4 as possible
4) put 7cc ( cubic centimetres ) of the CuSO4 solution in a non metallic
container.
5) add 1 drop (only 1 !) of ferric chloride and mix well with a plastic spoon
step6:Process:
1) remove all paint / anodizing from the aluminum object (if any)
2) dip a cotton swab in the plating solution
3) pick up a few grains of salt (NaCl)
4) rub the solution on the metal. This removes the oxide and prepares the
aluminum for plating.
5) remove all with dry kitchen paper
6) dip a NEW cotton swab in the solution this time WITHOUT the salt.
7) MAGIC! - copper instantly plates the aluminum.
8) repeat this step with a NEW cotton swab
9) polish the copper with steel wool.
step7:now you can solder on the aluminum object!
step8:For larger surfaces, hold a piece of sponge in a plastic clothes peg.
note:The copper-aluminum bond is not mechanically strong. use this
method for electric connectivity.

[Hyshinara]

Personally, I've taken a blob of solder on my iron, and scratched the surface of the aluminium with the iron.
Normally, aluminium quickly forms a thin layer of aluminium oxide wherever the surface is scratched, and I'm pretty sure the molten solder covering the scratched area prevents those from forming, which in turn means the solder can bond to the aluminium proper.
I've used this to solder jumper wires onto aluminium tape.

[discostu956]

I've read about doing this so many times, and tried it just about every time I've read about it, but I just can't get it to work for me. I've tried starting with sanded aluminium etc, then scratching through that. Still no go. What am I doing wrong?

[AlphaOmega1]

You can help further by adding a layer of oil to prevent oxidation of the "cleaned" area. This stops you "misusing" your iron as a scraper ;), and lets you use abrasives.
As you say, works well for "window tape" in alarm systems etc.
Aluminium soldering also tends to need a high wattage iron due to heat conduction (even if plated)
Good ideas from the OP & Hyshinara

[JohnC430]

Yes I have dont that too but if youre using thin Aluminum foil it is another matter. Too weak to scrape.

[lmedvesek]

This is great and reliable way to make a connection on aluminium, For quick fix you can use Bareconductive electric paint, which can glue wires to aluminium. It is carbon based, so you can't solder on it. But it is also possible to get electric paint, based on silver. You can solder on those.

[shodjaeifar]

Wonderful idea. I used to use nut and bolt till now.

[PaulD279]

Great tip, thank you. But sorry, hated the music.