Recommend a Rust Proofing Primer Please

[andyborris]

Having read enough web pages to make my eyes bleed, I'm still no wiser!

My Triumph has patches of surface rust on the underside, I'd like a primer that can go over the 50 year old cellulose painted metal, plus the surface rust and also stop the rust getting worse.

It needs to be brushed on and I'll need to paint over it too!

A big ask, but anyone have suggestions please?

Thanks

Andy

[3point141]

If you want to side-step tackling the problem head-on I think you are asking as lot, there just are not any products on the market which will give you 100% in the way of overcoming the corrosion which presently exists and preventing further degradation in the future.

Although, If the corrosion is really only "surface" I'd give a whack over with a grinder mounted wire brush, just to knock the flakes off, this will also loosen the paint hiding even more pockets of rust you couldn't see until now.
If at this point, you still only have surface rust & not in reality opened a total can of worms by revealing even more rust.. give a good going over with phosphoric acid (or similar) rust treatment wherever you see bare rust. Treat until the rust has gone a nice silver colour, it will first go black, this is not yet sufficient to have converted all of the rust, so just hang in there & keep going. At this time of year, most organic rust conversion methods are really (really) slow. This is due to temperature, so you might wish to apply a "gel" type converter.. I swear by this:

www.bilthamber.com/corrosion-protection-and-rust-treatments/deox-gel

Blob a load on, cover with cling-film, wait a day or two. It will still take time, but it is a lot quicker than and many-times less time consuming!
After you've got the rust sorted, the world's your lobster. I assume you've looked at POR15? yep, it's good. I've used it loads. And it works. Also, a BIG fan of Bilt Hamber products (UK made), this is reallly good for under-body use...

www.bilthamber.com/corrosion-protection-and-rust-treatments/epoxy-mastic

you can paint over it.

Going on... Google JOTUN This company makes some great products, many I've used and never had anything which didn't do exactly what it claims on the tin.


Bottom line is... you cant just paint onto rust. You absolutely have to treat the rust first. You'll be glad you did, that beer afterwards will be totally earned!!!

[andyborris]

Thanks for a comprehensive answer, and the "real world" experiences.

I already use Bilt rust convertor and wax, so I'll take your advice and use their epoxy primer too. Not painful on the pocket too!

[steveo3002]

needs cleaning back to good bright metal then epoxy primer

painting over rust and old paint is just hiding it until its done right

[contrarian]

Have a read up about Bondaprimer. It's supposed to be great stuff for this type of situation.