Using TSP as boiler cleaner

[barts]

As I understand it, one of the principle benefits of using TSP is that it forms a chemical buffer, helping to maintain the boiler Ph at a mildly basic level, thus helping prevent pitting style corrosion which is typical of more acid conditions.
I've not had problems w/ boiler foaming, but I've heard of others reporting such.

Removing excess oxygen is a good idea as well; this can be done by keeping the hotwell quite warm to reduce the amount of dissolved air. If you want to fill the boiler each night, a feedwater tank might be useful; you can drain to this in the morning and refill from it in the evening.

For removing oil from the hotwell, I'm considering experimenting w/ electro-coagulation. I'm switching to a non-compounded oil this year which is supposed to be much easier to remove from the condensate.

- Bart

[Lopez Mike]

Easy fix. Only fill the boiler all the way up when the inspector is around. What the eye doesn't see, the heart doesn't grieve over.


Pretty funny idea anyway. Filling your boiler up with canal water is a sure route to excess oxygen.

[smokestackmag]

PhilMart,

On Flying Cloud, I installed several household water filters. First, I have two in series after the condensate (air pump) to capture the non compounded cylinder oil. These have filter elements that are of the same material as the oil adsorbant pads. As well, I have a filter for the make up water that I draw from the lake or river to remove the dirt and organic material that might be drawn in. This last I change once a season. The former, after two to three weeks of steaming also depending on oil usage in the cylinders. I usually remove and discard the first in line, replacing it with the second in line and put a new one in there. I do observe a thin sheen of oil on the surface of the water in the hotwell from time to time. Perhaps someone can chime in here with a better solution. Oh, and I also put in adsorbant pads in the hotwell that all the condensate must pass through. These get changed once a season.

[Dhutch]

Easy fix. Only fill the boiler all the way up when the inspector is around. What the eye doesn't see, the heart doesn't grieve over.

Pretty funny idea anyway. Filling your boiler up with canal water is a sure route to excess oxygen.

Yeah, it appears to be common advice certainly in the UK steamboat circles, but personally every way I think about it the more I am convinced its nonsense.

In operation the water in the boiler will boil and all the absorbed oxygen will come out and be drawn of with the steam, and in a condensing plate, the feed water will in effect be distilled water (albeit, a bit oily) which again will have very low levels of absorbed oxygen. At which point as you suggest, just about the worse thing you can do it stuff a load of fresh oxygenated water in there! Even if you inject it or otherwise boil it, unless you draw off some steam that oxygen is now trapped in the very space you are trying to keep it out of. If the feed water is muddy, its even worse!

At which point what I do, is the total reverse. I try really hard NOT to add any fresh water to the system at all for the last 20-30mins of the day, and then seal it up tight. Like Phil we will do a few days cruising and them leave the boat for a few weeks/months, and repeat.

Incidentally, we are currently retubing our boiler after 16 years, and like last time after 19 years, all of the corrosion of the tubes is towards the bottom, A few inches an inch up from the lower tube plate (VFT like Phil's) with the steam space and waterline being absolutely perfect.

[Lopez Mike]

As a measure of how much attention I've been paying, it just dawned on me that the boat in question is non-condensing. Something that I seldom encounter since the vast majority of my steaming is in salt water. Mea Culpa.

A word to the wise about Oilsorb pads/sheets. I recently had a problem with restricted flow to my feed water pump. The Oilsorb filtering my hot well wasn't the problem but in the process of sorting it all out, I did a simple water flow test on the pads. Guess what? Oilsorb works great to trap oil but is incredibly poor at passing water! I did a simple test in my kitchen sink. I stretched some Oilsorb over a cooking pot and poured water on it. As far as I could tell the only way water was getting through was via some tiny holes that I suspect are a product of the manufacturing process. Cheap experiment. Please try it and let us know if you have the same experience.

Mike

[barts]

When we lived in the SF Bay area where it never freezes hard for any length of time, I would simply fill the boiler completely w/ water from the tap, making sure there was adequate TSP. This worked quite well; of course, Otter's boiler has copper tubes silver soldered in and the rest is sturdy pipe.

Here in WA we have real freezes, so emptying the boiler completely is a requirement.

I'm right now re-doing all the suction side plumbing; the squirrels or rats did a number on the soft hoses while the boat was laid up during COVID and our move northward.

- Bart

[Dhutch]

Easy fix. Only fill the boiler all the way up when the inspector is around. What the eye doesn't see, the heart doesn't grieve over.

Pretty funny idea anyway. Filling your boiler up with canal water is a sure route to excess oxygen.

Yeah, it appears to be common advice certainly in the UK steamboat circles, but personally every time and every way I think about it the more I am convinced it is nonsense.

In operation the water in the boiler will boil and all the absorbed oxygen will come out, and be drawn off with the steam, and in a condensing plant, the feed water will in effect be distilled water (albeit, a bit oily) which again will have very low levels of absorbed oxygen. At which point as you suggest, just about the worse thing you can do is stuff a load of fresh oxygenated water in there! Even if you inject it in, or otherwise boil it, unless you draw off some steam that oxygen is now trapped in the very space you are trying to keep it out of. If the feed water is muddy, it's even worse as per the OPs experience!

At which point what I do, is the total reverse. I try really hard NOT to add any fresh water to the system at all for the last 20-30mins of the day, just the condensate from the engine/hotwell, and then I seal it up tight. Like Phil we will do a few days cruising and them leave the boat for a few weeks/months, and repeat. Often when I come back to it there is still a mild vacuum in the boiler, but even if there isn't and some air as snuck in its still a reasonably isolated space and I would suggest very unlikely the oxygen levels in the water will become significant and or on par with fresh water.

Incidentally, we are currently retubing our boiler after 16 years, and like last time after 19 years, all of the corrosion of the tubes is towards the bottom, A few inches an inch up from the lower tube plate (VFT like Phil's) with the steam space and waterline being absolutely perfect.

Corrected a few of my typos!

[Dhutch]

I wonder, does anyone have any experience of using TSP (tri sodium phosphate) as a cleaning agent to remove oily deposits from inside a boiler? My boiler seems to collect oil whatever I do to try to keep it out! Suggestions as to strength of solution etc would be most welcome as well as info on possible downsides.

I did this with my brand new boiler.

2lbs TSP per 100 gallons water
and 2lbs Soda ash per 100 gallons.
Boiler with a light fire and open to atmosphere, boil for 1 hr.

Then a drain and rinse with water. (I think I let it cool first)

Back to the original question.

I came here following a google search on the topic, after a suggestion elsewhere (Malc Ducket, via the SBA Whatapp Group) to use TSP to clean a boiler shell prior to inspection during re-tubing.

My conclusion is that while TSP in small amounts might well be a reasonable alternative or addition to commercial boiler treatments for rust prevention (unconfirmed) and or in stronger quantities, for treatment of surface rust (a bit like a phosphate wash conversion coating), it probably doesn't do a huge amount for heavy oil deposits on it own.
For that you are likely better off giving it a good rolling boil with Washing Soda crystals (Sodium carbonate, Soda Ash) as per the post above, which is something I have done in the past with our boiler. Remove the whistle and vent the boiler through that, give it a good rolling boil at normal water level. And then we actually then pumped the water level up at the end and intentionally over topped it, which sent a huge amount of oily scum up our onto the roof! Very impressive, although next time I would do more to capture it, rubber hose over to a large bucket on the ground, away from the paintwork! We then damped the fire out, blow it all down out of the bottom of the boat, refilled, drained, refilled and steamed as normal.

However in my case the rolling boil option is now out of the running because I have removed it from the boat and taken out all the tubes! Maybe I should have done the above wash cycle before that, but from where we now are. At which point, various advice including my gut feeling and a chat with the lead chemist at work, has lead me to the suggestion of using domestic oven cleaner, while wearing eye protection. After all it is formulated for removing baked-on grease from steel, it is very alkaline which is basically all you are after, and has suitable thickening agents for spraying/soaking/rinsing surfaces you can't soak. Plus it's easy to get hold of at the supermarket!
I have also procured an extra long thin lance for my pressure washer (a 1.5m 1/4" BSP stainless steel tube basically) so once it has soaked in the oven cleaner spray I can then jet wash it to mechanically remove the loosened material, and try and wash it all out of the wash out plugs. Might hook the hose up to the hot tap too and feed it warm water for good measure.

This is all theory to date, but I shall post back in a few weeks!

[Dhutch]

At which point, various advice including my gut feeling and a chat with the lead chemist at work, has lead me to the suggestion of using domestic oven cleaner, while wearing eye protection. After all it is formulated for removing baked-on grease from steel, it is very alkaline which is basically all you are after, and has suitable thickening agents for spraying/soaking/rinsing surfaces you can't soak. Plus it's easy to get hold of at the supermarket!
I have also procured an extra long thin lance for my pressure washer (a 1.5m 1/4" BSP stainless steel tube basically) so once it has soaked in the oven cleaner spray I can then jet wash it to mechanically remove the loosened material, and try and wash it all out of the wash out plugs. Might hook the hose up to the hot tap too and feed it warm water for good measure.

This is all theory to date, but I shall post back in a few weeks!

Well, in for a penny in for a pound!

The overall outcome wasnt great to be honest.

Firstly its unsurprisingly hard to get the stuff where you want it. The fitting on the aerosol nozzle wasn't the common type, which ruled out swapping it for one a straw to get a jet rather than a mist, so I ended up just opening it out with a small (1mm I think) drill bit and doing what I could to get it on the tubes, which involved looking through one hole, spraying through another, and regularly clearing foam from the nozzle area and swapping to another hole in the tube plate having filled that one with foam. All while in disposable nitrile gloves and workshop goggles, trying really had to not get it on my skin on on my eyes. I also had a bottle of the 'tip into a bag and soak the trays' gel which I mixed with 50% water, stuck in a pump up hand sprayer, and again sprayed half blindly into the drum at the tubes, this time mainly aiming for the undersides of the tubes which I couldnt get at all with the aerosol. Photos below of the coverage.....

....left all of that for half an hour and hour, and jet washed it all off with my 1500mm extra long pressure washer lance, For about an hour, doing my very best to clean all the surfaces of the 19 stay tubes, as well as the foundation ring, and washing out all the lumps. Having hoovered out 90% of the loose stuff when it was dry.

Then I left it all to dry, and reviewed what I was left it. Well it was a bit better... ...but a long way from clean tidy nice to inspect metal.

So I then made a scraper I could get through a tube hole and run along a tube, and with that, and a good torch, almost as much by feel as visual, myself and the boiler inspector were able to gain enough confidence that the wastage after 30 years service was not significant and we could continue with the retubing.


Daniel

[Dhutch]

And the other images, as 3 per post appears to be the limit!