Lazy Daze Owners' Group

Lazy Daze Forums => Lazy Daze Technical => Topic started by: Aad Rommelse on September 21, 2016, 10:56:55 am

Title: Aluminum Roof Corrosion Treatment
Post by: Aad Rommelse on September 21, 2016, 10:56:55 am
Upon checking out the roof of our 2001 Lazy Daze I noticed some slight corrosion in two different location. I assume that this problem has been discussed in the past but could not find any reference to it. Could someone guide me to this subject for its best treatment?

Aad Rommelse
Title: Re: Aluminum Roof Corrosion Treatment
Post by: Chris Horst on September 21, 2016, 12:55:41 pm
Upon checking out the roof of our 2001 Lazy Daze I noticed some slight corrosion in two different location. I assume that this problem has been discussed in the past but could not find any reference to it. Could someone guide me to this subject for its best treatment?

Aad Rommelse
Aad, it would be helpful if you would describe/define "corrosion". There's not much on the roof that will corrode if you are thinking in terms of corrosion as related to rusting of metal. A photo would help.
Chris
Title: Re: Aluminum Roof Corrosion Treatment
Post by: Aad Rommelse on September 21, 2016, 03:03:44 pm
Chris,
It appears like some pitting on the surface, adjacent to the seam sealing tape, which I applied a few years ago. I'll take a picture of it and I'll try to post it. From reading on various websites a product "CorrosionX", which can not be painted over, was recommended.
Aad
Title: Re: Aluminum Roof Corrosion Treatment
Post by: Larry W on September 21, 2016, 04:07:28 pm
I would sand the spot to bare metal, prime with a self-etching aluminum primer and paint with white paint, to match.
Then keep an eye on it or cover the repaired area with Eternabond tape.

Larry
Title: Re: Aluminum Roof Corrosion Treatment
Post by: Aad Rommelse on September 21, 2016, 05:42:43 pm
Thanks Larry. Could this be the result of standing water on a flat roof when in storage? Have you seen similar situations on other Lazy Daze aluminum roofs?
Aad
Title: Re: Aluminum Roof Corrosion Treatment
Post by: Larry W on September 21, 2016, 06:44:42 pm

Two possible causes of the corrosion are as follows. I'm sure there are other causes.

The spots, where it occurs, were not properly prepped, before painting.
Bare aluminum needs to be cleaned and etched before painting.
Cleaned to remove any dirt, oil or other contaminants, etched, usually with phosphoric acid, to open the surface up, providing 'tooth' for the paint to adhere to. 
Poor prep is the most likely source of corrosion.

Another cause seen is where the corrosion occurs in a spot that has a screw, staple or other some piece of metal next to or under it.
If the area gets wet, electrolysis, between the two dissimilar metals, can occur. Once started it never stops under repaired.

Our 1983 LD had a hole, in an exterior wall, where the aluminum siding touched a steel staple, in the plywood underlayment. 
It produced a hole, in the sheet aluminum, the size of a quarter.

Larry

   
Title: Re: Aluminum Roof Corrosion Treatment
Post by: Joan on September 21, 2016, 09:06:10 pm
Good information; thanks, Larry!  Of course, now I have to haul up there to scrutinize the roof for any pits, bubbles, or holes!  ;)

Joan