Treating rusty steel.

[js.b1]

Indeed, freshly blasted is Sa2, bright mirror is Sa2.5.

You can get Sa2.5 on lightly corroded auto steel with a 3M clean-n- strip. An example would be a scrape which has been neglected such that paint has domed and gone brittle in the surrounding area, underneath you will find dark millscale which the 3M Clean-n-Strip cleans out to leave bright shiny metal as a broad crater of limited depth. Then either zinc product works superbly at stopping corrosion dead - but are mechanically weak. You need galvanising primer, then normal car paint, but it is still a weak underlying area.

Good and that tackles the weakness of pure zinc products (they are meant for freshly drilled or ground welds on RSJ, where you want the longest life but also where abrasion resistance is immaterial).

You can buy miniature sand blasting kits; exactly like a paint air sprayer, plug in to a compressor, will blast small areas for auto repair etc. Add-ons for pressure washers also exist of course.

[geoff]

Dave, you can always pop up and use my blast cabinet if you're so inclined

[Dave Plowman (News)]

That could be very helpful as there's no real rush. Is it sand or something more gentle? They are small enough to post. I've tried finding a local firm that can do this without success. I've heard of the domestic ones but I don't have a compressor or really anywhere to put one. The joys of living in central London. ;-)

[geoff]

In message , "Dave Plowman (News)" writes

150-250 micron glass beads is what I use

200l reservoir built out of a kitchen sink and (here's your special interest) Bass speaker cabinet

20 mins Euston to Watford by train

[Adrian]

"js.b1" gurgled happily, sounding much like they were saying:

Nice to get secondary confirmation...

IYHO, should the Rustoleum be adequate as a one-coat finish on suspension etc? From what I've read, it appears to be, but...

[Steve Firth]

For components that are exposed to spray or abrasion I'd recommend an epoxy coating. Just to throw yet another confusing option into the long list you already have, you understand. This is the sort of stuff that is used to rust-proof steel in marine environments and it has the benefit of chemical adhesion to the steel rather than a passive coating that can be rubbed off.

[Dave Plowman (News)]

sunroof and clamp the rubber seal which goes round the outside to it via self tappers. You can't even see them, as that assembly fixes to the sliding carriage. So just a good old fashioned water trap. The factory obviously didn't realise there would be a problem as they have just one layer of paint - no primer of any sort. There are three of them, one to the front which survives well - it's the two side ones which rust badly.

But that does look like a good solution. Pity it's only in such large quantities - 100mL would be more than enough. It'll cost 40 quid minimum including post.

What it doesn't say is if it can be used as an undercoat for a normal car finish like the current water based paints. If so I could do the actual sunroof as well as they are rare as hens teeth too.

I've asked them for this information via their website.

[Andy Dingley]

Or "floor paint", as it's usefully obtained when refitting the workshop. PU, chlorinated rubber or even epoxy floor paints all make good extra-wear paints for parts expecting a hard life, although only chlorinated rubber will last on flexing suspension parts.

[The Medway Handyman]

But they use water as the propellant :-)

[Dave Plowman (News)]

Got a prompt reply which is always encouraging.

'You can over paint Epoxy Mastic with most finishes, it is not a primer for body work. It is designed for use on the vehicle underside, footwells boot etc where a body finish is not required. Barrier coats are not required but the adhesion/etch primer supplied with your chosen top coat system should be used.'