Topic: I made my own Water/Fire-proof Metal Bitcoin Cold Storage, short guide. - page 2. (Read 1067 times)

Also, how about storing it in a zip lock bag with some desiccant (the sachet from my next pair of new shoes). Or rice. By preventing the moisture in the air getting to it degrading of the metal would be a lot slower. It is stainless steel so it will be very very slow, and on my first test I left the back exposed when etching and it just "pitted" rather than an all over rust.

I can use a propane torch and get it to 2000F but I'm not sure that's a fair test:


Using the propane torch to me seems more like a test of the metal quality/spec than proof of survivability. I could easily have spent 8x more on really high quality steel/titanium/tungsten to be certain it would survive but that takes it out of the realms of an affordable home project for most people.

 I got the metal business cards from ebay, and as it's a prototype it was on the cheap. I think all steel has a melting point above what my open fire produces (and a house fire), my concern is that the card softens and distorts before that melting point, if it does I would consider it a failure.

quick search says fireplaces can be 500F-1100F depending on fuel etc. house fires can be 1100F. a propane torch can hit 2000F. so if you can test it with propane torch (which are very cheap) and heat it to red hot say and have it survive that would be a good test. 

That's pretty cool, great effort, thanks for the guide.

Yes, again just a test piece. To save you time from typing in the address to check here's what's on the card:

Address: 1PiNodemHPYocq6dRw9JhN5f8N1nC2VfXQ
Privkey: 5KYbHUHB4Bwa87pEvBgb4Aqj6KsRjCGiuvgNCHruz698MNwQpDJ

You're welcome to anything on it 'cause I didn't put it there.  

As for storage though it would be sensible to obscure the private key. Stop someone finding it and taking a picture/writing down the key. I was thinking a tamper proof label would achieve this? Any thoughts?

(It's a label that disintegrates when peeled, revealing "void" in the hologram)

He has actually done a great job. When I first looked at it, I was so puzzled that why the guy has put his private key and address on it. Then I came to know, these were inactive ones. But still, it looks cool and when compared with paper wallet, it is more attractive and reliable.

I like that a lot. I'll see if I can get a good enough QR code on the back. As it got ok definition in the letters I think it could do it.


And it's ok TheGodson it's a test account, (with matching address/key pair, not sure why I bothered for this test) but I won't be using this one for funds. That would be level7 stupid.

This is a cool idea. The only downside is that once you use a bitcoin address you are advised to never use it again, because the private keys have now been exposed to a third party.

Hopefully you don't have anything stored on that address, because the private key is now available to everyone on this public forum.

So for those that were asking dimensions I had the choice of:

Solid Aluminium Rounded Corners x 1mm Thick - 84mm x 54mm

Solid Copper Rounded Corners x 0.9mm Thick - 84mm x 54mm

Solid Brushed Copper Rounded Corners x 0.9mm Thick - 84mm x 54mm

Solid Brass Rounded Corners x 0.9mm Thick - 84mm x 54mm

Solid Stainless Steel Rounded Corners x 0.9mm Thick - 84mm x 54mm

And also those that said it's not quite completely formed I don't think any of the photos quite show the clarity. The "grain" effect on the copper in the logo is the dots of the pixels from the laser etcher, and you can see the pixels in the text too. It's pretty clear, not perfect, a few imperfections but as for the text the only character that needs a double take to read is a lower case "i" after the CG in the private key . I think the flaws could be solved by using a different font, (I used Veranda for it's legibility) perhaps another defines "i" better.

The table salt in the solution does the etching, the Copper Sulphate does the plating. Because I didn't have complete coverage with the copper, and stopped because I didn't want to over etch, next time I'll use more copper and less salt. Perhaps 6 teaspoons of Copper Sulphate and 4 teaspoons of salt (pint of warm water).

As for fire, we have an open fire at home and I don't mind putting this test piece into it, I may be month or so until it gets cold enough in the house to light it, you may have to wait for those results, the best I can do is phone the supplier of the metal and ask what the metal spec was for our best guess at a melting point, although it will of course soften before that.

I think that's answered most questions, keep 'em coming.

If you don't have or plan on getting a laser etcher, you can heat transfer laser toner to do this project cheaply too. It honestly was easy.

Cool, I wish I can make one.

For a moment there I thought the BTC symbol was floating in thin air, and then I saw the wood grain of the table going in the opposite direction. This is good quality workmanship and for proper cold storage and possibly for long-term storage, this might be a better idea than laminated paper wallets. < This might last longer in a fire too >

I store my paper wallets in 3 different locations, so I will have to make 3 copies of each. ^hmmmm^

Impressed dude, it is a really good option than regular paper wallet. Have you finished all the test ? I would like to know more details about the results of the test. All the best best for your project.

It looks pretty cool. I have actually been thinking about making something like this for myself

However I didn't understand what your material was. I know it is Stainless Steel, but you didn't say what exactly. Like what type, also what was the diameters, specifically the thickness.

I currently am in possession of a couple of plates with 1.5 mm thickness of AISI 420 (1500°C=2732F) , AISI 304 (1450°C=2650F), and another one that i have forgotten what it is but it is one of those Ferritic SS 
which one do you think is best to use here?

I also would like to add that your end result has a couple of flaws. For instance your 3rd character in your address is wrong. you put "I" instead of "i" and your private key is not properly etched, in second line at the end there are 2 unreadable characters (it is easy to guess or even brute force it though).
What do you think was the reason, and what should we do to avoid it?

This is better than a paper wallet, but I don't think this material will survive from rust and it will ruined, rust will destroy the "relief" including all your wallet code.

Pretty neat job there.  It's certainly safer than a paper wallet!  Have you actually done any testing for durability in fire?  I'd like to hear the results if you have/do.

I don't sell these, it's a personal project someone here may want to repeat.  

A short guide and more pictures on my main site:
https://pinode.weebly.com/hardened-cold-storage.html

So a while back I tried to punch/stamp these Stainless Steel business card blanks with address/Private key for safe keeping. But the Steel didn't mark very well and it was very time consuming. Aluminium did stamp well but has a low melting point and has a chance of not surviving a house fire.

Prototype with test (inactive address and key, although they are a working matching pair).



It was masked with nail polish, design laser etched, and then the metal was electro-etched with salt water. Copper Sulphate added to copper plate the etch.


Surprisingly cheap and easy to do at home. (Cheaper than hardware wallets). Also very cheap if you already own a laser toner based printer. A cool project to show your kids, with electro-etching and plating.