What would you do about this rust.

[phopwood]

My Sherpa has developed a rather annoying strip of rust around the edge of the bottom bracket. I know it is not the end of the world, but at only 18 months old I would like to make it right.  I dont shy away from riding in the rain and it has rained a lot this winter.  That said I am sure it should not be this bad.

How would you approach this issue,  I have the little pot of paint I got with the frame and I have some emry cloth.  So would you just apply the paint over the rust, or rub it down first with some suitable under coat. I don't want to have to revisit the same issue in a few years.

All the best.

Peter.

[jags]

i think i would be gettin the wet n dry sandpaper out to rub that smooth, prime it up and a coat of paint,you will get the exact colour in a motor factors i did for my sherpa .
hard to believe it got that bad

jags

[Danneaux]

Hi Peter!

Sorry to see you're having to deal with rust, but it can be made right easily by doing as jags suggested. I would suggest also hitting the cleaned, sanded area with a conversion coating like Ospho ( http://www.ospho.com/ ...or... http://www.amazon.com/OSPHOQ-OSPHO-METAL-TREATMENT-QUART/dp/B000C02CDG ) to make sure no active rust remains.

I usually only see rust this aggressive in this place if a) roads have been salted and b) the bottom bracket has been faced, so there is bare metal beneath the edge of the cup. Once started, rust has a habit of "tunneling" under powdercoat, so you're wise to get on this sharpish now the weather is better. I think you'll come out fine.

As for paint, I found a perfect match in Krylon spray paint in Semi-Flat (relabeled in recent production as Satin Black). The touchups Sherpa and my Nomad were absolutely seamless with the original powdercoat, matching for color and gloss. I just sprayed some in the lid and then used a brush to apply it in thin layers.

Best,

Dan.

[Relayer]

Peter

There is a similar thread here,  http://www.thorncycles.co.uk/forums/index.php?topic=3895.0

with advice from Robin Thorn, which led me to get Hammerite Kurust, and Hammerite Red Oxide to prep the rusted area before painting it.

Good luck.

Jim

[phopwood]

Thanks gents I will have a look at this over the weekend,  I am sure that most of the problem relates to salt water spray over the winter.  I think I need a longer mud flap.  I will post an up date when I am done.

Peter.

[geocycle]

On a related topic. Has anyone found a supply of touch up paints? I'm after some British racing green for my new RST frame.  Thorn do not supply it. Unfortunately the chain glider has rubbed against the inside if the seat stay.

[julk]

Geocycle,
My chainglider was pushed off line by touching the seat stay.
I took a round file to the chainglider shaping the contact area to fit the seat stay slope until the chainglider sat upright at the back.
I had just gone right thru at the top corner and sealed it off with black duck tape from inside and outside.

This fix has worked well, the chainglider works properly and the seat stay has minor marks rather than the paint rubbed off and rusty.
julk

[geocycle]

Geocycle,
My chainglider was pushed off line by touching the seat stay.
I took a round file to the chainglider shaping the contact area to fit the seat stay slope until the chainglider sat upright at the back.
I had just gone right thru at the top corner and sealed it off with black duck tape from inside and outside.

This fix has worked well, the chainglider works properly and the seat stay has minor marks rather than the paint rubbed off and rusty.
julk

Thanks julk, mine is just about straight but the action of it bouncing over bumps has caused it to rub the paint quite badly. I'm using insulation tape as a temp fix but some remodelling might be needed as you suggest.

[Andre Jute]

On a related topic. Has anyone found a supply of touch up paints? I'm after some British racing green for my new RST frame.  Thorn do not supply it. Unfortunately the chain glider has rubbed against the inside if the seat stay.

That paint very likely has a match-number. Ask Thorn for it. If they can't get it for you, there's a paint available in The Netherlands that I know about because it's on my bike. It's called "Non-RAL Forest Green" and it is the closest thing to Bentley's BRG that I know. "Non-RAL" simply means it isn't listed in the RAL classification, which is the standard one. You can make it darker by adding just a speck of black on tip of a stick to a small amount on a dish. If that won't suit, track down a supplier with a RAL swatch book and take the bike along, so you can hold the swatch up right next to it; there's bound to be a match in there.

[il padrone]

My experience with Thorn's touch-up paint for the Thorn Nomad, in contrast to Danneaux's, has been very much less than satisfactory. My Nomad came with a bottle of yellow. It looked all OK, but after some time when I had a scrape on the frame I got the bottle out to touch it up. The paint needed a good shake up to mix it, but when I painted it on it was obviously far too weak. In fact it has really only given a clear lacquer to the frame. Further coats did not change this..... all despite the fact that the paint in the bottle looked quite yellow.

Basically a waste of time. I now have the frame coated but the scratches stand out. The touch up paint has even gone a discoloured shade from dirt and maybe sun exposure  

[honesty]

I have to say I'd probably ignore it. its cosmetic, and its going to be a great number of years before its structural. At which point - new frame - wehay!

[Danneaux]

My experience with Thorn's touch-up paint for the Thorn Nomad, in contrast to Danneaux's

Pete, my really good experiences with the touch-up paint was with the Krylon sprayed into the lid and then used as a touchup. It too is thin, but thickens comsiderably with the passage of a few seconds to a few minutes, depending on temperature.

Best,

Dan.

[davefife]

There is a similar thread here,  http://www.thorncycles.co.uk/forums/index.php?topic=3895.0

As Jim knows, I have done nothing with my rusty forks on my RST!  Its one of those jobs I never get round to.

The rust has not however become more visibly pronounced, obviously I have no idea whats happening under the paint.
Dave