Author Topic: Boiler cleaning  (Read 2854 times)

Offline RonGinger

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  • Boothbay Maine USA
    • Pleasant Cove Models
Re: Boiler cleaning
« Reply #15 on: August 10, 2019, 01:48:36 PM »
Thanks, lots of good info here.

I have wondered about just leaving the acid sit there, seems like it might dissolve some top layer material then it will need to be flushed off. That suggests some kind of recirculating pump.

I like the idea of mechanical tapping. I may just try some light hammer taps, just short of denting the shell.

I got some muriatic acid, sold for cleaning bricks. I think I will try putting some in, shaking and rolling the boiler for a few minutes, then dumping it out and repeating a few times. The boiler is heavy, maybe 25 pounds, so it will be tough to do it to much. I will give it a final rinse with some baking soda.

Offline derekwarner

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Re: Boiler cleaning
« Reply #16 on: August 10, 2019, 11:12:38 PM »
Spent some in in South Australia with family......ironed a white [Funeral] shirt and the conventional Sunbeam type steam iron spat out a few brown steam stains.......thankfully these were on the back of the shirt & it was winter so my jacket would cover them

After the event, I poured CLR into the iron & left it for 2 hours........emptied the CLR out via the press pump on the handle to ensure the CLR had penetrated all internal steam tubes & orifaces

Poured clean tap water into the iron & turned the machine to high/cotton selection

Brownish ooze shot from all of the iron sole plate holes :stickpoke:................depleted the water via the clean function........refilled  & waited....

Brownish ooze shot from all of the iron sole plate holes :stickpoke:

This process was repeated again the next day :facepalm:

Went to a Department store, purchased a new electric iron and a 4 litre bottle of de-mineralised water

Derek L Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia

Offline MJM460

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Re: Boiler cleaning
« Reply #17 on: August 10, 2019, 11:45:24 PM »
I finally found some information on calcium citrate, hardly soluble at all, not worth trying in my view, you need to make a soluble salt.

Acetic acid definitely worth trying, as calcium acetate is quite soluble.  Vinegar is not very strong, so it will take a large quantity applied by many rinses.  Possibly gentle rocking the boiler for agitation.

Be careful when you handle that brick cleaning acid.  Check the strength on the label as it is sold here it is really concentrated and fumes when you open the lid.  Gloves, goggles, even a face mask, and definitely out doors, remember it dissolves concrete.

Then remember the chemistry, with the molecular weights of hydrochloric acid and calcium carbonate, it will take a lot of acid if you have a significant weight of scale, it does not just ďdisappearĒ with a quick rinse.  As the limestone is dissolved, the acid is neutralised and has to be replaced.  I am guessing many times to get it all.

So as not to dissolve the boiler, you need weak acid, add acid to the water to make only about 10% strength or less.  But it will always be a balance between time and copper loss.  Think of what you see when pickling for silver soldering.  Then it will take a lot of rinsing and emptying.  Scale is probably mostly in the bottom half and around the tubes.

As Willy says an iron chloride is used to dissolve the background for pcb manufacture.  I donít know the chemistry there, but you clearly donít want it that aggressive.  Perhaps the navy uses a very weak form to keep boilers clean.

Itís not a quick or easy process as Derek has found with his iron scale.  There are many reports of the problem, not so many reports of a solution in my observation.  We all want you to win, but if all else fails, look up Ramonís amazing Wide a Wake build log for his boiler restoration.

The more I learn, the more I find that I still have to learn!