Which 'aluminum acid wash' to use inside hull - restoration

[Saxist]

New to boats. Not to wrenching.

Ok I have a gutted 1968 16' starcraft hull with quite alot of salt water corrosion in it. I understand I need to acid wash the interior of this hull to stop continued problems. I'm also concerned with the inner ribs bracing (corrosion between them and hull)

But 'aluminum acid wash' isnt terribly specific. There are multiple on the market using various combinations of various acids!!!!

I definitely think I need something quite strong.

 

[GA_Boater]

Vinegar. Cleaning vinegar or All Purpose to be exact, 6% strength.

 

[Saxist]

Even though it's a bare hull currently and so could put anything on it I could care to with ease!?

Wow. I hate to sound sceptical seeing as I just admitted I didn't know anything hah. But with all the fancy spancy products out there that cost $$....makes me think of when I got fooled into trying 'professional' tree sap removers that DEFINITELY didn't work that great before my wife explained science to me with plain ole isopropyl alcohol...haha.

What's the science? Or is it experience (which is usually science backed anyways lol)?

 

[DarrinT]

Vinegar. Cleaning vinegar or All Purpose to be exact, 6% strength.

Pickling Vinegar is 7% - that should do the trick!

 

[Saxist]

I sprayed cleaning vinegar on an area I had previously mechanically cleaned down and kept it wet with vinegar for a good 15 minutes and it barely brightened it, elsewhere it did nothing.

I've seen vids of some pretty impressive acid washes...why are they not advised?

 

[DarrinT]

I sprayed cleaning vinegar on an area I had previously mechanically cleaned down and kept it wet with vinegar for a good 15 minutes and it barely brightened it, elsewhere it did nothing.

I've seen vids of some pretty impressive acid washes...why are they not advised?

I've also seen bleach recommended , its 5% chlorine I think , but I know pool chlorine is 14% which would for sure do the trick but you would need the special mask that could handle the gas to work with it.

 

[Saxist]

I've also seen bleach recommended , its 5% chlorine I think , but I know pool chlorine is 14% which would for sure do the trick but you would need the special mask that could handle the gas to work with it.

Not Zep-a-lume or Alumabrite? Or the half dozen other far stronger commercial acids?? I totally don't understand. Could you explain?

 

[Watermann]

Removing corrosion from pitting is extremely difficult and the home DIY guys in the Starcraft forum have used a number of products depending on the severity of the corrosion.

Some pics of what you're dealing with would help with what advice to give.

Minor surface corrosion with shallow pitting the cleaning vinegar works very well to neutralize the alkaline corrosion. First off the corrosion has to be removed, there is no magic in a can that will fix the issue it takes effort. A fine wire wheel on a drill or angle grinder does a good job of removing most of the corrosion. Once that is done you can assess the pitting and what corrosion remains.

@classiccat has the dubious distinction of being the corrosion tamer of the group and can guide you to the best acid to use. Reviewing his thread should help as he describes the process well.

Edit: This has been covered

 

[GA_Boater]

Do you want to stop corrosion or or make it look pretty?

 

[Watermann]

Do you want to stop corrosion or or make it look pretty?

He has a thread on his boat I just remembered with pics of the corrosion and has been getting repair advice in the SC section. He seemed to be doing a good job too and getting advice from classiccat.

The novice build: 1968 Starcraft SuperSport V-16 "The Boat"

INTRODUCTION! I am completely novice to boats and have been overwhelmed with learning new jargon and marine repair techniques. This has been made more difficult by the huge variety in repair methods (and huge variety in repair quality...). What's going for me is that I have ALOT of mechanical...

forums.iboats.com

 

[Saxist]

I'm honestly not sure of the best internet etiquette for this stuff. I've got the main restoration thread, but for more generalized things/questions (like finding a proper acid wash) I've made short threads in broader forums like this one. Is this a faux pas?

I certainly don't care if the inner hull looks pretty. Just want to make sure I do it thoroughly...

 

[GA_Boater]

I'm honestly not sure of the best internet etiquette for this stuff. I've got the main restoration thread, but for more generalized things/questions (like finding a proper acid wash) I've made short threads in broader forums like this one. Is this a faux pas?

I certainly don't care if the inner hull looks pretty. Just want to make sure I do it thoroughly...

It's best to keep things in one place. It avoids questions like my corrosion or pretty post. Also you end up with conflicting and confusing advice in bifurcated threads.

 

[Saxist]

Had to look up the word. Love it!

Thank you