Rust spots on new upvc window sills - is this possible???

[Peter S]

Plastic materials can have open cells which allow contamination to get into the material during manufacture and when installed. It is very difficult to get rid of these marks once they enter into the material even with cleaning. Maybe putting a polish or wax protection will slow down the process but a fungus type cleaner is also worth trying to see if you can kill any bacteria. I have experienced this problem and found that plastics and glazing companies do not want to visit and often have obscure answers which do not work. Did not find the FENSA guarantee covered this problem.

 

[crank39]

Fensa guarantee....what's that ?

 

[geraldthehamster]

Spider sh*t sounds right - we had loads of this on some uPVC windows I was removing; definitely spiders, and it looked exactly as you describe. I think they're just passing comment on uPVC as a building material.

Cheers
Richard

 

[Draughtsman]

Fine particles of steel will cause rust spots on uPVC. Local uPVC frames were spotting with rust a treat until the local bridge engineering works put decent filters on it's girder shot blast extractor system. No liability admitted, obvs. Steel cutting or grinding discs used close by, even when care is taken to grind away from the house, can also put enough particles in the air to cause this.

Following relevant health/safety precautions SAFETY GLASSES, PROTECTIVE GLOVES ETC (keep some water at hand, in case of spills etc), pick up 500ml of 5% solution oxalic acid online from the usual suspects. A few teaspoons in a plastic or stainless egg cup mixed with a TINY pinch of wallpaper paste, left to stand for a minute because it will thicken when actually you really want it to be still very mobile, but not able to run off surfaces. Try it on a small area 1st to check it does no damage. Apply with a small stiff artist type brush, wait for maybe 15 minutes or so (DO NOT LEAVE THE CLEANING OPERATION UNATTENDED), then gently work using the tip of the brush to remove the rust, you won't need an abrasive type cleaner. Then wash everything thoroughly with soapy water. It also works on rusty patches on stainless, where you left a steel screw on the wet drainer overnight. It works. REALLY well.

 

[opps]

I once used an angle grinder to cut a cast iron bath in to quarters so that I could get it out of the bathroom. When I got home, I had a bath you get the dust out of my hair.

The next day our plastic bath had loads of tiny rust marks. There were there for months. Gone now (as I suspect that many of the people that contributed to this 18 yr old thread are as well).

 

[HERTS P&D]

18 year old post!



Andy

 

[Draughtsman]

18 year old post!



Andy

And it'll still be the right answer in another 18yrs..

 

[Ruggers]

Iron X or similar brands for cleaning car wheels is none abrasive and eats the iron deposits away. They came from sunflower gold dash which has deposits of iron in. Also grinding steels as mentioned above goes everywhere and clings to stuff for years. Learn the hard way but theres a few cures listed now to end the post. Cheers guys.