My experience with acid...

[icondonj]

Despite my best efforts, after only a year of salt water use, I was starting to develop some significant mill scale flowering and early signs of vinyl blistering on my 23’ 2013 Raider (my previous alloy boat was a victim of ruinous paint blistering). So over the holiday weekend I pulled the vinyl and had sanded off the corrosion using scotch brite pads, bronze wool and toonbrite (undiluted). My intent was to stop there, but I didn’t like the initial results (inconsistent patina). Out of curiosity, I applied a layer of the 3M marine aluminum polish to see how that would look and was equally unimpressed with the results. So I started over, did some additional sanding and applied another wash of toonbrite and finally and got the consistent whitish grey patina I was initially expecting. It was a 20 hour job.
Some observations –
Jetty Wolf is 100% correct about not using a direct spray application of the acid wash to the hull. I used his method of applying via a polishing pad (I was just pouring the wash directly to the pad). Doing it that way virtually eliminated any streak etching.
If I had to do over, I think I’d try it first with just bronze wool with a sprinkling of fine abrasive cleaner like bar keeper’s friend with the acid wash. I found that the green scotchbrite pads can be too abrasive and you have to be careful not to apply too much pressure. I think the brass wool is also better at conforming to the slight undulations of the surface.
I noticed that applying the acid wash to a freshly polished surface resulted in a very nice, consistent patina that I was unable to achieve after the first application. There’s some interesting chemistry going on there when applying the acid wash to a freshly polished surface. I noticed significantly more reactive “foaming” the second time around after applying the same concentration of acid wash vs. the first time around. I suppose that may have been the result of the additional fine cleansing that the polish achieved? Whatever the reason, in my case, it was worth the extra work.
Thank you all to that provided information on this subject. I don’t think I would have had the confidence to try this without the shared knowledge posted on this forum.

[welder]

Pictures of the finished product?

[goatram]

Brass Wool????????

Scotch brite Red, Green, White, Now Steel or Brass wool. The aluminum can get the fin particles inbedded in it. Bad I would Believe.

[JETTYWOLF]

Unless you apply a protectant.........stand by for a real change!

My river is super tannin and after only one trip, the water line turned all kinds of nice brown colors on me.

Not complaining. The Jettywolf is not a "trailer queen", but rather a tool to catch fish in my opinion. That's it.

One thing I have found is that if I bang a black Nylon covered dock side. Black Mark, Easily!

But at the same time (which I did just yesterday) now instead of a dock rash scuff in the protectant. Which was the original problem with the whole sides of the boat. Now I just take a old green scotchbrite pad and add some water and rub out the Black Nylon dock board scuff and yes it will shine up that area a bit. But will "TURN" again as soon as it hits the water for the day.

I may, do another acid wash with Sharkhide, and add back the protectant over the acid washed sides and keep that white look. BUT, then again. I may not. It's all about LOW maintenance for me.

I think, to protect themselves. A Company such as Sharkhide says to "spray on the acid", because they don't want you getting all over yourself.

Well.......I DID. I wore gloves and the cotton collar around the gloves got saturated with the acid as I worked like a Santa Elf and didn't really notice.

The next day The skin on my wrist and down my arm actually filled with fluid and bubbled up. And then the skin came off and left a burnt look for about a week.

But no biggy. I heal FAST. about 14 days ago i was bit by a shark on the index finger while taking the hook out that wasn't even in the shark. It was just biting down on the hook. But it caught my INDEX finger and took off a 1" by 1" chunk of meat, down to the bone. With a bottle of peroxyd and some gauze in my first aid kit. All was good. Today it's all healed-up already!

Ya sometimes have to pay to play. Every thing I do is NOT under "laboratory conditions", but rather get it done NOW, and always with a a bit of shade tree mechanics if it's a boat project. So I know I could get a injury. It's okay.

You will see a change in the color of the boat to a dark grayish color with a water line of various shades. If you're cool with that.

J-O-B well done...........GO FISH. If not. Get some Sharkhide metal protectant on the boat.

[icondonj]

Sorry, I meant Bronze wool.

[capesteve]

Threads like this make me question the idea that aluminum is "easier to maintain" than NON ALLOY. More durable yes, but as easy to keep looking like new I'm not so sure. I think Id rather strip and wax a hull that mess with all that acid BS

[capesteve]

Threads like this make me question the idea that aluminum is "easier to maintain" than NON ALLOY. More durable yes, but as easy to keep looking like new I'm not so sure. I think Id rather strip and wax a hull that mess with all that acid BS

[kmorin]

c'steve, I don't think the word maintain is the same for you as for those who use it to include the working parts but don't really care about the appearance?

Its fully possible that the different latitudes generate a different attitudes about the cosmetics of a boat? In our area time is spent to keep things running, and all the gear and engine related issues are high priority, but the paint, color, scuffs and old grey aluminum; no very much.

I use the words "low maintenance" to mean use her, tie her up and forget her, she's not going anywhere and if a neighbor in the next slip or house saw someone scrubbing a boat? I'd go over and ask what they were doing? Its just not a priority, here at least. So I think the phrase may be thought of in different context depending where you live? IN other words "low maintenance" means: "no time wasted on the appearance of the boats' outer surfaces", but your post seems to imply you think this set of words means something else like "the appearance will remain stable with little effort"?

And that is why I think the idea implied may be subject to some geographic differences in meaning? So if the phrase originated where folks "ride 'em hard and put 'em up wet" in their own local terms, that phrase may be subject to some filtration by your location's ideas about metal boats?

Cheers,
Kevin Morin
Kenai, AK

[icondonj]

Here’s some photos. It rained most of last week after I first acid washed the boat and before I could add the metal protectant recommended by Jettywolf. The result was some noticeable streaking from the rain water running down the hull off the gunwales. So I did yet another acid wash this weekend and then applied the metal protectant. I like the results and the flowering is completely gone (I even removed it from underside of the exposed part of the bracket), but it was a lot of work. I hope the protectant holds up; applying it was a snap, so I may make it a habit of applying a fresh coat every year or so.