Descaling fun

Lard

I took the plunge and decided to descale the Weil Mclain 1180 (Big, 96 gallon water content) at the church I help maintain.  This poor thing had pushed over 180,000 gallons of makeup water through since it was resectioned four years ago. The leaks are all gone, so it was time to get rid of all those solids. I pulled the LWCO piping apart this year while doing the annual scrape-out and was enlightened when I stuck a cheap USB camera in the boiler ports.  Probably 1/4” of scale on everything below the water line, but amazingly little rust at the waterline. I am going to guess that the extreme makeup water caused the alkalinity to hit the point of corrosion inhibition.

It took 15 gallons of rydlime in a recirc setup before the PH quit rising. The water coming out looked like septic sludge. It took four solid rinses at 100gal each to get it out. It now steams 10 minutes faster AND I did not open up any holes.

I put 1/2 gallon of 8-way in it to get the PH to 9.5, will probably dump that in a month and redo since it is still stirring up boiler poo. It probably will for a year or so...

The sight glass looked like fizzy weissbier when I dumped the first five gallons of rydlime in.

CantabHeat

Big 8-way fan. Things certainly “get worse before it gets better” as the product cleans out all the junk but once that stopped I’ve been running corrosion free for several years now. My pre-season clean outs have almost no gunk and the water stays clear (purple/pink) all season. No more chocolate milk water. Get steam faster too without all the kettle sounds from junk at the bottom of the boiler.

Lard

I am going to guess this thing kettled, but it has a 1.5million BTU/hr gas power burner so hearing even your own thoughts is a challenge.

it definitely will be bad for a while.  Also keep in mind, I did NOT follow the 8-way directions.  I only used 1/2 gallon to the 96 gallons of water, just enough to bump up the PH.  Following the directions will lead to a sudden dump of 96 gallons of water into the steam mains!

ethicalpaul

I agree with the above two posts. Never follow the instructions of 8-way or it will surge all the water into your main! But it's a nice ph treatment in good measure.

In my old boiler I never did get rid of the chocolate milk, because this was hiding in every nook and cranny. I replaced the boiler before I got it all out

Lard

ethicalpaul said:

I agree with the above two posts. Never follow the instructions of 8-way or it will surge all the water into your main! But it's a nice ph treatment in good measure. In my old boiler I never did get rid of the chocolate milk, because this was hiding in every nook and cranny. I replaced the boiler before I got it all out

The water has always been clear in this boiler.  The brown water showed up when I gave it the inhibited acid descale. After flushing that crud out, it is clear pink with the light application of 8-way. It clouds up a bit while steaming as the crud continues to break loose. 

Getting rid of that Utica is the best thing you could have done! Ok for hot water, trouble for steam as we all know.

Lard

The 1/4” of scale was not rust scale, but white carbonate deposits.  I will run the camera in it again when I flush it in a month and save some screenshots this time around. Given all the churning and bubbling, that carbonate should be gone. I could hear the entire boiler fizzing for the first hour or so.