Undersealing?

[benwall101]

Hi guys
I am thinking about renewing my under seal as the old stuff is flakeing off, I have a few questions that I cant find definitive answers too

when removing the old underseal should I remove it compltley back to bare shinny metal ? (if there is any hiding underneath)

also is it fine to paint the under seal straight on or is it advised to use a primer first ?

And with the small rusty patches is it best to treat them with a rust treater or convertor or is this just snake oil ?

The under seal I have brought to use is this one (as recommended by a college)
http://www.halfords.com/webapp/wcs/stor ... yId_165594

Thanks
Ben

[graham1957]

what i do is to clean it all off to bare metal,treat any rusted pitted areas with kure rust or similar,then paint the lot with zinc primmer, electrox or similar,then2 coats of stonechip with the shultz gun. the zinc primmer protects the steel by cathodic protection. The hardest bit is the cleaning off to bare steel!

[PaulTubby]

You must as above clean rusty metal back to bare metal before undersealing and treat with rust killer and a undercoat before apply underseal or the like...

[midgebuster]

Get yourself a hot air gun, it makes the job so much easier. I stripped mine off in a couple of hours. I'd recommend getting a wire brush attachment for your angle grinder to get the rust off and then paint it before undersealing again.
I've got some photos on my facebook page if it helps
https://www.facebook.com/MinorRebuild