Aluminum pitting repair

[yippykiyay]

2012 Thunderjet Luxor with raw aluminum gunwales. About 7 years ago I built a support structure to help support the winter cover from heavy snow loads. Made the mistake of using pressure treated lumber, not knowing that the copper preservatives would react with the aluminum.

Fortunately the damage is isolated to several square inches on top of the aluminum gunwales. Several years ago I sanded out the pitting, or so I thought. Now on close inspection the pits appear deeper than ever and would require a lot of material to be removed. The largest pits are smaller than a pin head, approx 2mm deep, but not blistered or black...not too serious yet I hope.

After doing some research, this is my plan...
Muriatic acid wash, rinse and repeat 3x.
Fill the pits with Devcon aluminum epoxy.
Sand smooth.

Is there a better way to permanently neutralize the corrosion?

I spend about 4 weeks per year in the salt. Would love to hear recommendations for a durable wax that will help protect the aluminum gunwales and keep them looking nice. I'm not afraid to recoat wax weekly if it works.

Thanks in advance!

 

[Scott Danforth]

You may need to. Cut out the corrosion, and weld in good metal. Depends on how much corrosion is on the back side

 

[yippykiyay]

I think I'm a long ways from a drastic repair like that. I want to try to remedy what I have first. This is not in a structural location and I can easily observe any changes.

 

[jbcurt00]

W out pix hard to say for sure, pjx posting has been a problem for more than a week. Mods notified Admin but no fix yet.

Look for Alvin Lab-Metal. Suppose to be a good product like JB Weld or Marine-Tex. It was recommended to me by another member for aluminum boat hole repair and filling in aluminum trim pitting.

Not familiar with the Devcon epoxy you mentioned

Muriatic maybe a little aggressive. Might clean w white vinegar 1st see what it does.

Heinz cleaning vinegar is slightly stronger than typical white vinegar. Try to find Heinz Cleaning.