Oxidation Bubbles ??? August 08, 2005, 03:41:38 pm Yahoo Message Number: 56607I have been looking for a LD for sometime now. Called about a 1990 that sounds pretty nice. When asking my usual 99 questions, I inquired about the condition of the exterior...Which was responded to as..."The aluminum skin has a few oxidation bubbles. The bubbles were in a few places, not just by the the windows. They do not appear to be water under the coating and they did not spread like steel would. They have been described as electrolsis." Does anyone have a clue what this is on the skin.Wayne
Re: Oxidation Bubbles ??? Reply #1 – August 08, 2005, 04:36:31 pm Yahoo Message Number: 56609"Wayne" wrote:Quote"The aluminum skin has a few oxidation bubbles... They have been described as electrolysis." Bubbles under the paint on the aluminum skin of an LD usually means the metal is corroding. It's caused by exposure to moisture. This is evidence of water seeping between the walls of the coach somewhere. The source of the leak can be quite far away from the paint bubbles, not just above them. The water can be coming from outside, usually from a poorly sealed window opening or body seam. Or the water can come from a leaky pipe fitting inside the coach. Water doesn't run uphill, but if the wooden frame member is soaked, it can wick the moisture upwards.Repairing this condition can be very expensive, often requiring the removal of interior and exterior wall, and re-building the wooden frame members that have been exposed to moisture.Water penetration is not an insurmountable problem, but the seller should make a major price concession to cover the cost of repairs. Before proceeding further, I'd suggest that you take the vehicle to an experienced RV repair shop for an estimate.--oryoki
Re: Oxidation Bubbles ??? Reply #2 – August 09, 2005, 09:35:32 am Yahoo Message Number: 56631Quote"Wayne" wrote: "The aluminum skin has a few oxidation bubbles... They have been described as electrolysis."Bubbles under the paint on the aluminum skin of an LD usually means the metal is corroding. It's caused by exposure to moisture. This is evidence of water seeping between the walls of the coach somewhere. The source of the leak can be quite far away from the paint bubbles, not just above them. The water can be coming from outside, usually from a poorly sealed window opening or body seam. Or the water can come from a leaky pipe fitting inside the coach. Water doesn't run uphill, but if the wooden frame member is soaked, it can wick the moisture upwards.Repairing this condition can be very expensive, Oryoki..Wayne here Thank you so much for your expert answer...I think I will take a pass on this one.WayneQuoteoften requiring the removal of interior and exterior wall, and re-building the wooden frame members that have been exposed to moisture.Water penetration is not an insurmountable problem, but the seller should make a major price concession to cover the cost of repairs. Before proceeding further, I'd suggest that you take the vehicle to an experienced RV repair shop for an estimate.--oryoki
Re: Oxidation Bubbles ??? Reply #3 – August 09, 2005, 12:51:55 pm Yahoo Message Number: 56640Wayne: I disagree with Oryoki's diagnosis. I think that if the body sheet remains straight and firm (not bowed out or warped) and the blisters or bubbles are smallish and occur at random areas
Re: Oxidation Bubbles ??? Reply #4 – August 09, 2005, 02:54:30 pm Yahoo Message Number: 56646Thanks to mclaesse for his comments. It sounds like we both agree with this part of my original post:"Bubbles under the paint on the aluminum skin of an LD usually means the metal is corroding. It's caused by exposure to moisture."I should modify my post to read"This MAY BE evidence of water seeping between the walls of the coach somewhere."As mclaesse points out, moisture also could be entering through a scratch or pinhole in the exterior paint. Or perhaps the paint is worn out to the point that it no longer acts as an effective barrier to moisture.An inspection by a company with experience repairing water damage in RVs should determine if the damage is from outside or inside.--oryoki
Re: Oxidation Bubbles ??? Reply #5 – August 09, 2005, 05:44:36 pm Yahoo Message Number: 56652QuoteWayne: I disagree with Oryoki's diagnosis. I think that if the body sheet remains straight and firm (not bowed out or warped) and the blisters or bubbles are smallish and occur at random areas in the middle of the sheet I think what is happening is that the aluminum's natural oxide surface coating and the paint coating are overcome by environmental corrosive elements such as lots of exposure to water and/or salt water near the ocean. (The good news is that general surface attack of aluminum penetrates slowly but is accentuated in the presence of dissolved salts in an electrolyte.)If you decide to buy this coach, this is probably not a serous problem but can be a pain in the butt esthetic-wise since any repairs (especially to an older coach will be difficult to paint-match. (But Quotenote: This can happen to any LD regardless of age. All that is necessary is a scratch and frequent exposure to sea air.)In any event, surface preparation is key for any paint adhesion. Remove ALL the oxidation. The corrosion product of aluminum is a white to gray powdery material which can be removed by mechanical polishing or brushing with materials softer than the metal. Then roughen the entire surface to by painted with 400-600 grit sandpaper or a coarse steelwool pad for bare aluminum. The Mother ship has spray cans of paint that will match your coach colors back to at least (in my case) 1991. Good luck, Mike Mike, Wayne here Then I guess that if you really want the coach to look good, the fix is to sand and repaint the 1990 coach..Wow..This coach spent half its life in Ca and the other in OH. The fix sounds quite expense. Maybe I need to give this some more though...Thanks Mike for your comments.WayneQuote "Wayne" wrote: "The aluminum skin has a few oxidation bubbles... They have been described as electrolysis."Bubbles under the paint on the aluminum skin of an LD usually means the metal is corroding. It's caused by exposure to moisture. This is evidence of water seeping between the walls of the coach somewhere. The source of the leak can be quite far away from the paint bubbles, not just above them. The water can be coming from outside, usually from a poorly sealed window opening or body seam. Or the water can come from a leaky pipe fitting inside the coach. Water doesn't run uphill, but if the wooden frame member is soaked, it can wick the moisture upwards.Repairing this condition can be very expensive,Oryoki..Wayne here Thank you so much for your expert answer...I think I will take a pass on this one.Wayneoften requiring the removal of interior and exterior wall, and re-building the wooden frame members that have been exposed to moisture.Water penetration is not an insurmountable problem, but the seller should make a major price concession to cover the cost of repairs. Before proceeding further, I'd suggest that you take the vehicle to an experienced RV repair shop for an estimate.--oryoki