Window corrosion

[rwakeham]

I took a photo (link attached) of a nasty problem happening on all my salon windows. It looks like salt being deposited but (having tasted it!)it is not. Any ides and what do I do to stop it ?

Pic at http://www.wickcottage.demon.co.uk/window_problem.jpg

 

[Ships_Cat]

Looks like aluminium oxide corrosion products. Probably poultice corrosion from moisture trapped under the seal strip (looks like rubber strip and aluminium frame).

Assuming the frame is aluminium, it is bad building practice creating such areas with aluminium when possible to get wet or damp - some other examples are carpet linings glued (or sitting) onto aluminium, cloth backed vinyl glued onto aluminium, etc.

Without major replacement a solution (likely to be only partial) is to clean it all out and seal the rubber strip so no water can get in. An experienced aluminium boat builder may be able to look at it and give advice.

John

 

[Koeketiene]

Had the same problem - rubber seals worn out. Corrision caused by reaction of salt with the aluminium.

Managed to get away with it by replacing the rubber & cleaning the aluminium. Been told the rubber should be replaced at least every 10 years. Hosing down the outside of the boat with fresh water after every trip also helps a lot.

 

[Evadne]

Me too. 30 year-old rubber channel to blame. I re-seated the windows and the glass using black sikaflex, and even the most corroded frame, which had a corroded channel for the water to drip through, is now watertight. A very messy job, but worth doing.

 

[AndrewB]

Yuk! A nasty case of corrosion, probably the result of stainless steel screws/bolts used on aluminium frames. Once the seals weaken and sea-water gets in, the result is the aluminium is electrolytically attacked and dissolves into a disgusting goo of aluminium oxide, which is crystalising as it is squeezed out.

Get these frames off this winter, and have them cleaned and preferably re-anodised before replacing. (There are specialist frame restorers that advertise in PBO. Personally I would rebed into Sikaflex rather than a rubber seal). If they are left like this not only will they leak but in a year or two they'll start cracking up and then you'll have to get new frames.

Unfortunately if stainless screws have been used, it can be difficult to get the frames off intact. A search on this forum will throw up some suggestions for how it can be done.

 

[jerryat]

Hi!
I would definitely advise against re-anodising. I tried this to overcome a similar, though nowhere near as bad problem) on my windows. The pre-anodising treatment (acid bath?) brought out loads of little, hitherto unseen, blemishes that the anodising showed up appallingly! I and other gave further details during previous threads dealing with aluminium windows/corrosion/suppliers, so a search will turn up lots of info.

Cheers Jerry

 

[chrisarvor]

could this problem be caused by an anode not working?
i know the salt will corode but so will electronic action. just a thought.

 

[Evadne]

Not unless the window is permanently underwater!

 

[rwakeham]

Thanks everyone - It looks like they will have to come out then.

Richard.