sanding cast iron down pipie

[cardiy]

what type of electric sander should i use for sanding old paint on a cast iron down pipe, lidl are selling a cheap orbital sander will this do the job thanks.

 

[HERTS P&D]

Is it a soil pipe? 4"? If so it might be easy to do by hand as its round. You can cup the sand paper in your hand (if you know what I mean)

Wear a dusk mask!

Andy

 

[dcdec]

depends on the condition of existing paint system really doesn't it? If its really broken down and needs a really strong sanding then an electric sander might be useful but in all honesty you cant beat using your hands with a low grade paper, i think i used an electric sander once last year on a wall, thy are cheap enough that they pay for themselves quickly so for a downpipe an orbital sander would probably be ok.
Interesting point though - cast iron down pipes were often coated with bitumen in which case you just paint straight over with a fresh coat dont be fooled by the finish because it goes flat come the first frost.

 

[cardiy]

Thanks for the replys,the problem is the pipe has patches of rust where the paint has peeled of,can i use bitumen paint straight over rust or does the rust have to be primed first ?

 

[HERTS P&D]

Try hammerite.

Andy

 

[dcdec]

Its best not to use bitumen as its a non reversable coating, in other words once you've put it on you cant really do it any other way. You'll have to sand back/wire brush the rust and then prime these bare spots with a good quality primer suitable for ferrous metal, then usual system would be undercoat and gloss. Re the bitumen, its usually on older properties, you could scrape a bit off and if it feels tacky and has a 'tarry smell' it'll be bitumen and you can paint it straight on over rust. Obvious to decs i know but dont use any water based paints!


Oh yeah and as suggested hammerite is fine, personally don't like it but its made for this sort of job

 

[TheDec]

Don't care much for Hammerite either not very good covering power, remove all the rust and prime with a zinc phosphate primer, and then two coats of Dulux Metalshield Gloss. Take care to prime as soon after your prep as you can the rust will start to reform very quickly.

Dec.

 

[Nige F]

Can`t argue with all the replies But unless it`s horrendously rust covered and bitumen painted - then get the most of the rust off with a really coarse aluminium oxide paper - and simply gloss it black Cast Iron stack pipes are much more resistant to rust than steel railings for example - it`s in the nature of the metal - I think I`ve erected about 4 in my career - and painted a few