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I am building a copper boiler 3" in dia and I need a Pickling agent, so what do you guys use to CLean copper before you Silver Solder?

Thanks, Jeff
 
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Sulphuric acid, diluted of course, is the first choice of most boiler builders. Citric acid will also work but is less aggresive and therefore less effective. It can also be considerably more costly. Muriatic acid, a dilution of hydrochloric acid used to clean masonry, can also be used, again further diluted. Muriatic is at least as effective as sulphuric and is cheap but tends to load up with dissolved oxides more quickly and becomes ineffective after a few boilers.
 

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Sulphuric acid will eat your shoes, your trousers, the wooden floor and, eventually, eat away your boiler. The only reason it's ever recommended is "because that's the way we've always done it".

In the UK, I use a kettle descaler called Ataka, which is Formic Acid, but any weak acid will do.
Mike

When I previewed this, the font got smaller and smaller - weird!
 

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I have a large bucket of dilute sulphuric acid, I top it up about every 3-4 years and have had it now for over 20 years, would not use anyhtin else.
David Bailey
 

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Hello David. You were missed at Diamondhead this year. I also use Sulphuric acid (out of an old auto battery). I made my MIX in 1968 when I started my first ride on engine. It is still in the same container and I have had to add less than a quart of water in all of those years. BE SURE TO KEEP IT IN A COVERED CONTAINER, as the evaporating part will eat up everything in the room where you have it stored. Use eye protection in case of splashing. I'm sure one of the more educated beings out there will be able to explain this in detail.
 
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>>Sulphuric acid will eat your shoes, your trousers, the wooden floor and, eventually, eat away your boiler.

Of course it will, if you use it undiluted and the boiler is left soaking for weeks. I think the board recognises that some care, caution, and responsibility is required to avoid injury and damage.

>>The only reason it's ever recommended is "because that's the way we've always done it".

Or, . . . . if it was discovered long ago that it does its job very well, as well as anything else, is freely available at a reasonable cost, has a long shelf life, and can be safely disposed of.
 

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Posted By Curmudge on 02/07/2009 12:02 PM
>>Sulphuric acid will eat your shoes, your trousers, the wooden floor and, eventually, eat away your boiler.

Of course it will, if you use it undiluted and the boiler is left soaking for weeks. I think the board recognises that some care, caution, and responsibility is required to avoid injury and damage.

>>The only reason it's ever recommended is "because that's the way we've always done it".

Or, . . . . if it was discovered long ago that it does its job very well, as well as anything else, is freely available at a reasonable cost, has a long shelf life, and can be safely disposed of.



I wrote what I did based on long experience, having had my shoes, trousers and workshop floor attacked by dilute sulphuric acid many years ago. Since then, I've always used something a little safer. As for "care, caution and responsibility", I'm still alive and in one piece after a lifetime in industry, so I reckon I know a little about that too.

The old time "experts" were not alway right.

Mike
 

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I have used Swimming pool acid [dilute] for some years now..easy to buy in pool shops and no fumes in the shop// the current jar will seeme out!

Gordon.
 

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Posted By K27fireman on 02/07/2009 1:17 PM
So what would the ratio be for say a gallon of water?

Use about 10-12 parts water and one part sulfuric acid. I got sulfuric acid from Home Depot. They had a heavy duty clogged drain opener was 89% acid. I works great. Keep the mix in a tightly covered container. I store mine outside. The fumes are corrosive will eat everything in site. If you get this stuff on your skin, clean it off quickly under running water. Otherwise you get a very irritating itch. After silver soldering, let the part cool down to room temp. Pickle copper for about 15 minutes, then clean off under running water with a brass brush. Boy, does it look nice.

Bob
 

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Hi, Bob


My preferred solution is citric acid, you can usually pick it up in the grocery store in powered form... it is generally used as a food additive to give a sour taste to candy etc. It is totally safe. It may take a little longer in the pickle bath but is totally safe. Worth a try. 
 

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Posted By Shaymaker on 02/07/2009 1:17 PM
Posted By Curmudge on 02/07/2009 12:02 PM
>>Sulphuric acid will eat your shoes, your trousers, the wooden floor and, eventually, eat away your boiler.

Of course it will, if you use it undiluted and the boiler is left soaking for weeks. I think the board recognises that some care, caution, and responsibility is required to avoid injury and damage.

>>The only reason it's ever recommended is "because that's the way we've always done it".

Or, . . . . if it was discovered long ago that it does its job very well, as well as anything else, is freely available at a reasonable cost, has a long shelf life, and can be safely disposed of.


I wrote what I did based on long experience, having had my shoes, trousers and workshop floor attacked by dilute sulphuric acid many years ago. Since then, I've always used something a little safer. As for "care, caution and responsibility", I'm still alive and in one piece after a lifetime in industry, so I reckon I know a little about that too.

The old time "experts" were not alway right.

Mike




...and some people are just lucky.
 

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Hi, Jeff... sorry... didn't realize it was you who started the thread when I posted my last reply...


If you search "Citrus Acid Pickle" on Google you'll find lots of info... used extensively by jewelers. Most recommend to start with 1 part citric acid powder to 10 parts warm water. My mix is more likely to be 1:20.. just experiment a bit to find what works best for you, citric acid powder is cheap... and again, is totally safe... great piece of mind.


The pickle does actually work best when it is warm but I've had good results at room temperature. I mixed up a gallon and keep it in a brown glass pitcher jar... it can be reused several times and I keep a small amount in a small screw top glass jar for every day use when making boiler fittings etc.


PS... One hard lesson that I learned was that you MUST wash the pickle off your workpiece thoroughly before starting heating it again for another soldering operation. I failed to do this when making a small gas tank and the citric residue ended up baking to a hard carbon glaze inside the tank... impossible to remove... I had to scrap the tank.


Here is a photo of one of my projects that has been done exclusively using citric acid pickle.


 


Hope this helps. 


 
 

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I usually use Citric Acid, but have in a pinch (Some one emptied the pail down the drain) used plain white vinegar. It doesn't work as fast, just as Citric doesn't work as fast as Sulphuric, but it does work.
Regards,
Gerald.
PS the only drawback to using vinegar is you wand Fish and Chips when through.
 

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Posted By K27fireman on 02/07/2009 9:56 AM
 
 
I am building a copper boiler 3" in dia and I need a Pickling agent, so what do you guys use to CLean copper before you Silver Solder?
 
Thanks, Jeff


Hi Jeff,
I may be wrong here, but your original question appears to be asking how to clean the copper BEFORE solver soldering.
I know NOTHING about this part of our hobby, but my understanding, as has been pointed out by others, the term PICKLING is with regards to cleaning up the part AFTER silver soldering.
As to before, I would think (and I again point out that I have little knowledge here) that a good mechanical clean with paper, or wire wool is sufficient, as in the same way with soft solder, the flux will do most of the work in making sure that the silver solder can do it's job.
If I am wrong, I am sure that one or more of you will correct me.
All the best,
David Leech, 
Delta, Canada
 

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The cleaning before soldering should remove any oils, for example by using mild detergent and then flushing with water. I'll use an ultrasonic bath for small parts.


All those comments on pickling agents are not in vain. Just before soldering, it is good to dip the pieces in your pickling bath - it removes the little oxide tarnish and activates the surface for soldering. Rinse thoroughly, flux, and solder soon after fluxing. Then use your pickling bath again.


Dilute sulphuric acid is what I use - battery acid diluted in half. If you want to have a safer form of sulphuric acid, you can buy Sparex from jeweler's supply houses.
 

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Posted By Ora Banda on 02/07/2009 4:58 PM
Hi, Bob


My preferred solution is citric acid, you can usually pick it up in the grocery store in powered form... it is generally used as a food additive to give a sour taste to candy etc. It is totally safe. It may take a little longer in the pickle bath but is totally safe. Worth a try.


Hi John: I will look for it in the store. Nice looking boiler. How have you been?? How are those 7/8 projects coming?

Bob
 
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