clean lead before patination oil applied?

[trevw]

Hi,

I did some lead flashing where a tiled roof butted on to a brick wall a couple of months ago.. I was advised to use lead patination oil but was unable to find it until I searched on here and found I could get it in reasonable sized tubs from wickes..

My question is that the lead is already slightly oxidized, what is my best bet for cleaning it up before applying the oil? Hard rub with a cloth? Gentle rub with a scotch pad or fine grade sandpaper?

any thoughts?

thanks

Trev

 

[JohnD]

IIRC, rub with wire wool and white spirit, to bright metal, polish off with clean rag. Are they no instructions on the tin?

 

[trevw]

ah, sorry, wife picking up tin as we speak (type) from wickes.. I just assumed it would say apply to lead on installation.. hadn't expected tin to be that helpful

will RTFM

thanks

Trev

 

[markie]

I found out silicone ( clear) cleans lead, i spilt some on some lead and wiped if off and the lead was sparkling

 

[trevw]

cool, might give that a go!, looked on the tin and it didn't have anything on it about applying to 'old' lead so looks like it's either the wire wool + white spirit or silicon spray..

thanks guys

Trev

 

[datarebal]

If the lead is only a couple months old then a good hard rub with some sack cloth then Oil up.. applying Oil is not essential but does stop oxides formng and looks nicer.

 

[Nige F]

on church roofs they rub with sackcloth and ashes only non-essential if the run off from the lead during rainfall ,which will be white-ish is not a problem due to it`s location .......ie. it`s no more than a visual impairment of the area it runs onto .....and a sign that an itinerant roofer did the job

 

[datarebal]

strictly speaking a plumbers job....

 

[Nige F]

would be if we still had the EETPU Yours Fraternaly, Nige.......did you get the church reference

 

[trevw]

thanks all will start with the sackcloth and scale up to abrasives and spirits if I get no joy!

well, I will when it stops raining anyway...

cheers

Trev

 

[charlie101]

Patenation OIL, Oxide and Corrosion.

The word 'oxide' has been mentioned twice in this thread and seems to reflect a common misconception regarding what patenation oil is used for.
Iron 'rusts' or corrodes away, not because iron oxide forms on the surface when it is in contact with water and oxygen. But rather because the oxide has a higher volume than pure iron and therefore expands and cracks away from the surface. This allows more oxide to form thus 'rusting' or corroding the metal away.

Lead oxide on the contrary does not expand away from the surface but adheres to it. Furthermore because it has already reacted with oxygen in the environment it is largely chemically inert and therefore stable. That is to say the oxide PROTECTS the Lead from corrosion and is the reason it lasts so long as a roofing material! Lead Oxide is therefore exactly what you want on the surface. it is a GOOD thing!

However not all surface coatings are good. When lead is exposed to rain in air it forms 'Lead Carbonate' on the surface. Lead Carbonate is a whitish substance and does not adhere to the surface in the same way that Lead Oxide does. Lead Carbonate is the cause of those whitish stains on roofs and walls formed from run-off. This staining is a visual sign of your Lead corroding away.

Patenation Oil is intended to protect your lead from the rain long enough for a surface coating of Oxide to form. Lead Oxide is dark grey. So dark grey Lead is what you want to see after a period of time. Whitish lead means a layer of Carbonate has formed instead and your lead is corroding.

Lead Oxide forms on top of Lead, Not Lead Carbonate! Therefore, before applying Patenation Oil you must clean off any Carbonate present. A very thin layer may be devolved by the action of the solvent (white spirit) and rubbing during application of the Oil. However such a layer is hardly visible to the eye, if you can see a whitish lightening of the lead colour you must clean it off before applying the Oil.

 

[^woody^]

A few years back when the plumbers did the lead work, they always used diesel to both clean to a uniform shade, and ensure that it patinates evenly.

 

[charlie101]

Interesting and a good deal cheaper.
Did it remove carbonate?