What build up is this on these pontoons?

[chrismarion]

I decided a while ago I wanted to get a pontoon boat, especially now that we have two kids and it would be easier for family outings. I bought this boat from my retired boss last May. He bought it two years prior from a guy who moved down from Michigan. So for three years the pontoon boat has been sitting on the trailer. I was told it was a lake boat up north. It needs work, which was okay because I want to do it. Its a 24 foot '86 Playbuoy Admiral.

Before I started I wanted to get this build up off the toons. I don't know what it is, but its caked on. I did some searching on here and the internet, which provided many options. I first started with water, soap, and scrub brush. That did nothing. Then I busted out the 3k psi pressure washer, nothing. Pink a/c coil cleaner (non foaming), absolutely nothing. I tried Muriatic Acid non diluted, barely anything. I literally ended up using an orbital with 60 grit sandpaper and one gallon of 100% muriatic acid so far. Here are the pictures.

This is before tying anything.




This is after trying everything mentioned above to include the 60 grit.



The consistency is like grout! It literally feels like stone and sands like stone. I dont know what this is, but has anyone seen this before? My old boss has no idea because it was on there when he got it.

Its all under the water line.








What is this stuff? I am a Florida boy, but I cant say I have ever seen something like this before. I thought maybe the guy had it sitting in salt water and coral began growing on it, but I highly doubt that. You can see the close up, that is why I said it is like tile grout. A metal scraper sounds like its on concrete. Any ideas?

 

[Mi duckdown]

Re: What build up is this on these pontoons?

Yikes. You May need a guy that uses dry ice blasting? too be honest I got No idea. I would put in the water to soften it up. .02

 

[Mi duckdown]

Re: What build up is this on these pontoons?

Are those tunes alum. are steel?

 

[chrismarion]

Re: What build up is this on these pontoons?

They are aluminum. Dirty as all can be, but aluminum. I don't know what this gunk is. I'm hoping someone will be able to help me.

I decided to go outside, since its now dark, and apply a 100% pure coat of the pink a/c coil cleaner. I let it sit for ten minutes and attempted to spray off with water. Nothing. Still feels and sounds like grout.

 

[Mi duckdown]

Re: What build up is this on these pontoons?

Yeah, Now that I look at welds and rear of the toons they are alum. Sorry.
Those toons had to be sitting on the lake bottom. I would find someone in your area that does, either walnut, baking soda ,dry ice blasting. Is there water in the toons?

 

[MH Hawker]

Re: What build up is this on these pontoons?

I would say its lime build up.

 

[hondaf12x]

Re: What build up is this on these pontoons?

That is a boat that was wet slipped in a dirty channel and never cleaned, I bought a deck boat like that, i bet it was almost 1/8" thick in places, It will clean off, The best thing i found was Works toilet bowel cleaner in a small garden sprayer. Spray on let sit for 20 min and scrub with brush and rinse, after many applications it will start to come off slowly. be careful as you are using a strong acid, use gloves and face/eye protection. i used over a gallon to finally clean that deck boat. wet down the trailer before applying the works to protect the trailer from damage. Works is a lot less expensive that the commercial type cleaners. This is a yearly ritual up north, i slip my boat on a channel and every fall we winterize it and clean the bottom crud off, only takes a hour or so if you do it yearly.
good luck

Mike

 

[Scott Danforth]

Re: What build up is this on these pontoons?

looks like it came from a lake heavy with calcium. Very common on the lake where my buddy keeps his pontoon (Clark Lake in door county). However very common on lakes and water with high limestone content, or if they are on the Niagara Escarpment.

we use kaboom bathroom cleaner. spray it on and let it sit for an hour (go drink a beer, check the lines on the dock, etc.), re-wet, let sit, re-wet......repeat for a day. then pressure wash. you can get the same results with your pink stuff (coil cleaner) or muriatic acid, however watch the concentration. remember, this buildup took months to deposit. it will take a minimum of a weekend to clean.

 

[ahicks]

Re: What build up is this on these pontoons?

I agree that's a common buildup in the great lakes area (lime, calcium, whatever). I only wanted to add that the acids mentioned in the last few notes will have a much better chance if you start with dry pontoons. Don't wet them down first! It dilutes the acid, and the job takes MUCH longer that way.

Also, I wouldn't sand on the toons. Let the acid do it's thing. With that much build up, I'd apply the acid a couple of times, then pressure wash, let dry, and start over again. A 1 or 2 gallon garden sprayer will save some work too....

 

[chrismarion]

Re: What build up is this on these pontoons?

Thanks for all the replies and suggestions. I hope to be home on time tomorrow and I will try "the works" as well.

 

[chrismarion]

Re: What build up is this on these pontoons?

double post sorry

 

[chrismarion]

Re: What build up is this on these pontoons?

After two bottles of "the works" toilet cleaner on the back, it foamed up on the stuff. I would apply it to the entire area and let it sit for ten minutes, rinse and repeat for an hour. Then I scrubbed with a brush and tried to blast off with not prevail. I did two bottles. All it did was turn that area of the toon a white color. I then decided to go with pure Pink a/c cleaner and sprayed both toons completely and let stand for twenty minutes. Didnt do much. I am thinking I may just do the best I can. I would like them to be clean, but its just not doing much. I will work at it some more tomorrow. I want to start on the rest of the boat too.

I can't take a picture as its dark, but I will take one tomorrow before I start again to give you an idea.

 

[BrianMc]

Re: What build up is this on these pontoons?

Been there,Chris. Not as heavy of a buildup as your's,but had a good 1/8" on mine. Nothing would touch it. Best method I found was to let it dry out,then sand it off. Once it's good and dry you'll find 120 grit will blow through it without plugging up. It'll take a lot of time. Depending on how far you take it,a really long time. Believe it took me 30 hrs. to get mine "buff" ready.

Even if you don't buff it on out I'd take it on down to at least 220 grit,then apply sealer to it to keep them clean.

 

[jweckley]

Re: What build up is this on these pontoons?

I have the exact same issue with a 1973 Aloha that spent its life sitting on the Mississippi River. My solution was a 3 Inch 3M Roloc Disc (White) and a right angle air grinder. The discs are pretty fine and remove it pretty well. Then I am following up with an Aluminum Brightner I got form Orielly Auto Parts for $10 a Gallon. I am using it with a green scrub pad They are coming clean and starting to shine. Not a mirror finish but clean and reflective anyway.

 

[chrismarion]

UPDATE! I was unable to post anything, as was anyone else last weekend, but I have good news! I was irritated each time I found a thread that had something to do with toon scum and no one ever updated it with what resolved the issue. I am here to say and show the difference, it was "The Works" toilet cleaner. I am truly shocked, not that I didnt believe anyone here; but a damn toilet cleaner was the answer. Here are clear examples. So far, I have used a total of four bottles over a couple days period. I started in the evening time at the front left, walk around the toons and end up on the front right. All while applying directly onto the scum. One bottle for my 24 footer. I would let sit for twenty five minutes, and spray off with a water hose. I repeated it each night (three bottles total) and then saturday morning I applied the fourth bottle. And hit it with a pressure washer. Now, I confirmed the pressure washer did nothing. It seemed letting it soak and then rinse away the excess left the scum to "lift off" on its own over night.

LEFT REAR BEFORE TOILET CLEANER :


LEFT REAR AFTER TOILET CLEANER:


RIGHT REAR BEFORE:


RIGHT REAR AFTER:



RIGHT SIDE BEFORE:


RIGHT SIDE AFTER:



I promise I did not scrub or add any other chemical. I did not pressure wash either during this time. Just applied in the evening, waiting twenty five minutes and rinsed off, repeating the next evening for three total evenings. I thought maybe pressure washing it last Saturday might "blast" the rest off, it didnt. So, I would like to stand behing the $1.50 per bottle THE WORKS cleaner from the Dollar Store! It did what Muriatic Acid and "the Pink" coil cleaner could not.

Once I get this crap off, maybe the toons will actually brighten up. I did try to also do remove a few dents this weekend, using the hair dryer and dust off method. It did not work out for me. But I am happy about the scum progress!

 

[hondaf12x]

Chris, i went thru the same thing with my deck boat, it did not seem to work then it finally broke thru the crud
i used over a gallon on my deck boat over almost a week of cleaning Make sure to rinse your trailer good as this stuff is corrosive.
now i use to clean every fall before storage and you just spray on and wipe with pole brush and rinse. and at a buck a bottle you cannot beat the
price. my local marina sells stuff for 38.00 per gallon that works as good as the works but almost 10 times the price

Mike

 

[blusket]

Chris, super post, thank you, wish I'd have seen it sooner. I was given a 1969 Riviera Cruiser. Have the same stuff, I've been trying to clean it off for several summers now, mine was a little thicker and I could barely scratch it with a screwdriver. For me, muriatic acid did work, garden sprayer, 30ish% diluted leave it on for 5-10min, then walk around and do it again (before rinsing), after about 20min I'd completely hose off and do it again (but after wet doesn't work as good). It didn't seem to work because it was so slow, but then after a few iterations it slowly started to fade.I think most stuff is the same just different levels of dilution, CLR, Lime away are weak, but will work given the nightly process that Chris said, Works is stronger, muriatic acid is stronger but can cause more problems, the main ingredient is time, it's not a saturday afternoon cleaning and you can't leave the stuff on for too long or it will hurt the aluminum. So accept it's a multiple day process or you'll go crazy. Great post Chris. I'm going to try the inside of the tunes with the works..seems safer than the acid I'm using.

 

[blusket]

Chris, super post, thank you, had the same stuff and I think to your point...the main ingredient time. I'm still in the process of cleaning mine. I'll post pics.

 

[blusket]

Chris, super post, thank you, had the same stuff and I think to your point...the main ingredient time. I'm still in the process of cleaning mine. I'll post pics.

 

[WaterDR]

This is my area of expertise. I am an industrial water treatment consultant and work for the largest industrial cleaning and water treatment company in the world. I may be able to "shine" some light on this issue that is actually pretty common for aluminum.

First, what you are likely seeing is NOT a deposit, per se, but rather is a corrosion by-product of the aluminum. This is NOT hardness scale. In order for calcium or magnesium to form scale like this, you would need to have high hardness levels AND heat....which you do not have nearly enough heat to form a hardness scale formation in crystlaine form like this.

One way to know for sure (which you already did, you just don't realize it) is add some concentrated HCl to the material. If it does NOT foam and fizz, it is NOT hardness. 1:1 HCl (just a few drops) is the industry standard method for identification of calcium-carbonate.

Muriatic acid IS HCl (hydrochloric acid).

As to why the bathroom cleaner worked, depends on what the ingredients are....I don;t know. I would need to see an MSDS which I can look up.

But again, I suspect what you are seeing is actually the result of the alumium corroding. Aluminum does not rust, but rather corrodes to a brown or even white looking very hard material. This material while nastly looking is actually protecting the aluminum from further corrosion. By removing it, you are actually acelerating the process for more corrosion. The boat is old....it has likely been there for decades and would take a long time to form again.