CLR salt removal experiment

[kalebsheridan]

So I've been working on an 82 mariner I picked up for $100, and while I've been waiting for parts I decided to try and clean it up. I was told the motor was used in the salt and the oxide and salt buildup in the water passages was indicative of that. Lots of salt and oxide buildup. I wanted to clean that up and saw a video on YouTube of a guy using "lime-a-way" to dissolve the salts in his motor. I found CLR to be basically the same and decided to do an experiment. I know there are other chemicals like HCL and vinegar that people use, but for 4 dollars, I thought I'd give it a try and see what y'all think. Here are the results:

 

[kalebsheridan]

Here is an exhaust plate with some water passages totally loaded with salts

 

[kalebsheridan]

In this photo, I had poured some undiluted CLR onto the exhaust plate. The CLR immediately began to react. After this however, I filled a plastic Tupperware with a 50/50 mix of tap water and CLR and submerged the exhaust plates (there are 2) for a few hours.

 

[kalebsheridan]

Here is that previous exhaust plate after a lot and hour soak. The salt buildup definitely isn't gone but it has reduced a lot. Plus, it's much softer that previous (top). Here is an exhaust plate that has soaked for an equal amount of time then lightly scrubbed with a wire brush. The salt was very easy to brush away, which as nice because I was worried about damaging the aluminum with a steel wire brush (bottom)

 

[Chris1956]

I found some scale build up on my '93, which I run exclusively in salt water and never flush. I pulled the gearcase and thermostats and pumped some 50/50 RdyLyme and water thru the motor using the water tube. I used a sump pump to circulate the descaler for 4 hours.

Unfortunately I could only examine the thermostat covers and passages, but they had less scale on them.

 

[FunInDuhSun]

My boat (twin engine inboard) lived in a saltwater environment for 20 years before I bought it. She passed survey and looked great considering her age. After bringing her home (490 miles by water), I decided to pull the manifolds and risers to check for corrosion. Surprisingly, I found some but nothing like I expected.
I intended to send them out to a radiator shop for cleaning and testing, but found that shops like that are disappearing. Like kalibsheridan, I used CLR to flush them, then “rodded out” the passageways with a stiff wire and small wire brush. After that, I immersed all the parts in CLR for about a week, re-rodding and turning them every few days. After rinsing, I blocked off the openings and did a simple (low) pressure test to confirm they were OK. They looked almost new so I re-painted them and have run them for another 20 years now (brackish water). I suppose I should think about doing it again….

 

[dingbat]

Here is an exhaust plate with some water passages totally loaded with salts
View attachment 399916

Did you do a chemical analyst to determine if the material was actually salt?

Reason I say that, salt is water soluble. Soaking in a pan of water would have removed a salt buildup.

In reality, it’s calcium. Sea water has ~ 400 ppm of calcium. Reason why CLR did the trick.

 

[kalebsheridan]

Did you do a chemical analyst to determine if the material was actually salt?

Reason I say that, salt is water soluble. Soaking in a pan of water would have removed a salt buildup.

In reality, it’s calcium. Sea water has ~ 400 ppm of calcium. Reason why CLR did the trick.

No I guess I shoulda clarified. I meant salt as in mineral salts, not so much sodium chloride. So salts containing calcium or any other salts that would accumulate on the metal surfaces of the outboard. I chose the CLR cleaner because I knew it can be used to dissolve calcium salts and deposits (hence Calcium lime rust)

 

[Texasmark]

Nice job. I know that you are tickled.