pickling solution

[Dom]

Hello all,
I am about to embark on my first boiler build; its a small (2" Dia) water tube boiler from an old book i have.
My question is with regards pickling; what solution do you use? My book recommends sulphuric acid, but unless i'm missing something simple like it has a different commercial name then it appears to be difficult to obtain.
I've read on this forum of people using citric acid, is this a "proper" solution or just something that works? Im sure ive also read of caustic soda being used but i can't remember where.

This being my first build i want to do everything "by the book" but the problem is my books are quite old and i wonder if some of the chemicals are still available to the public in this day and age.
I should say at this point that i'm based in the uk so anything suggested should be available here.

Thankyou in advance
Dom

 

[blighty]

i too had a look for citric acid, but when i went into shops and asked for it they looked at me like i was some sort of loony. i ended up going to a spare auto parts place and got 10lt of battery acid "sulfuric acid" and it was already diluted with water. works a treat.

while your there get some safety glasses and rubber gloves..... it nasty stuff.

 

[123RWO]

In the US, you can get sulfuric acid at an auto parts store. It is sold as battery acid. You can get the same action from swimming pool pH decreaser or "pH minus".. It is sodium bisulfate powder. You mix it with water to get your pickling solution. It is sold commercially as a metal pickle under the name Sparex. Muriatic acid or HCL solution is a common plumber's helper and is sold in any hardware store in the US. Of all the acid pickles, it is probably the easiest on human skin but still effective as a metal pickle.

RWO

 

[Dom]

Arh,
I thought there would be a simple answer to this, It didn't click that sulfuric acid was common battery acid.
Many thanks
Dom

 

[metalmuncher]

Citric acid is easy to obtain, just go to your local home brew store or go on the bay you can buy it by the kilo. Its a lot safer than battery acid and you can dispose of it down the drain when you have done with it.

 

[Mosey]

I suggest using Sparex No.2, for pickling. It is readily available from jewelers supply houses, and is made from sodium bisulphate. It will tickle your cuts, but is not nasty and hazardous like the sulphuric acid.
It is specifically made for pickling silver-soldered pieces.
Mosey

 

[portlandron]

I use Sodium Bisulfate which takes a little longer (hours not days) then the acids suggested but is safer.
It is easy to find and fairly cheap just look for pH Minus products at stores that carry chemicals for pools of hot tubs.

 

[lotsasteam]

Citric Acid can be bought at Harmans Grocery store in the spice department,its called sometimes"sour salt" many grocery stores carry citric acid ,also used to make dishwash ,canning and so on!

substitute citric acid with a concrete wash from a builders supply mart(home Depot/lowes ifa farmstores! The concrete wash works super when you get the part right when its still hot submerget into the concrete wash(not as caustic as murid acid or battery acid) but wouldn't hurt to wear some kind of protection in general(Rubber Gloves,safety Glasses old clothes and the most impotant: Keep stuff Away from Kids and never store in trinking containers!!

Manfred

 

[WCPenney]

I spent a decade or so maintaining commercial pools so I'm familiar with some of this stuff.

Just so that people are aware: muriatic acid is a dilution of hydrochloric acid. It's used for etching masonry and reducing the PH of swimming pools (and many other uses.) A swimming pool or masonry shop should carry it fairly cheaply in clearly labeled 1 gallon jugs. The Wikipedia article mentions it being used for pickling steel.

Most "magic" or "branded" chemicals available in pool stores are just marked up relabeled, repackaged, and diluted common chemicals. Something labled "PH Minus" could be any one of a number of things. Pool shops have MSDS (material safety data sheets) behind the counter and are required to make them available. Ask for one to see what is actually in the bottle.

One of the methods we used for reducing the PH was to inject CO2 into the water stream to make carbolic acid. In a nutshell, we make soda water. Safe and effective. Might be worth a shot to throw a test piece in to a container of soda water...

 

[KBC]

Arh,
I thought there would be a simple answer to this, It didn't click that sulfuric acid was common battery acid.
Many thanks
Dom

Dom,
As you are in the U.K. go to your local Pharmacy and they will get you sachets of Citric acid, it's the safest acid to use, no need for rubber gloves or eye shades.
I have used it for years and it's used in wine making , also Druggies use it to bulk up their powder so let your Chemist know what you want it for.
I have just completed a small 3" vertical test boiler here are some pics before and after, the last pic has had a rub up with wire wool.

Geo.

 

[Henry]

You can find pickling solutions in jewelry tools providers, here there are links to Gesswein and Stuller.
Citric acid is a lot safer.

 

[OrangeAlpine]

No one mentioned phosphoric acid. Does it have undesirable properties when used with copper?

Bill

 

[Dom]

Thats a great looking boiler, would you mind sharing its name and where the plans are available (assuming it is from drawings and not your own design).
Thankyou all for your input, ill try and get hold of citric acid instead.

Thanks again
Dom

 

[stewburner]

Quite a while back when I was in the Navy we pickled brass and copper parts wth unsweetened bug juice ( kool aid ) that you could mix in any concentration so that we could clean that verdigres from fire hose fittings and anything else, including the ships bell . Lemon flavor worked best and color was easly cleaned of with a fresh water rinse and a stiff nylon brush.

 

[KBC]

Thats a great looking boiler, would you mind sharing its name and where the plans are available (assuming it is from drawings and not your own design).
Thankyou all for your input, ill try and get hold of citric acid instead.

Thanks again
Dom

Hi Dom,

This is a small test boiler that I knocked up with various bits and pieces from my scrap and stock box, it's to my own design and has the vertical tubes which take up quite a bit of water space but as it is a test boiler I wanted it to be a fast steamer and it has a hand pump to feed the boiler.
Firing is by a gas ring burner with a No 5 jet and there is a steam dryer incorporated above the vertical tubes.
It's a simple boiler to make and this one was hydraulic tested to 150 psi to give me a range for oscillating and slide valve engines.

Geo.