Best way to "touch-up" paint on new raven?

[gregmacc]

My wife's new black gloss Raven Tour has a 5mm diameter chip of powder coating missing from the down tube. I've armed myself with the small bottle of paint and brush supplied with the bike but I'm wondering if there is some sort of "trick of the trade" that will result in a better finish than just dabbing it on.
Cheers
greg

[Danneaux]

Hi Greg,

Here is a method which has worked well for me in the past on common chips that are roughly round in shape or have rounded edges.  Larger areas demand a different technique, and this method works poorly on longitudinal scratches and gouges...

1) Clean the chipped area using a cotton swab and a drop or so of 99% isopropyl alcohol to remove any grease or oil at the surface.  Avoid the common "rubbing alcohols", as they are 70% alky and 30% water and sometimes, glycerine.  Work the wet alcohol into the edges of the chip, as that is where most contaminates tend to remain.  Allow to dry thoroughly, checking to make sure no cotton fibers have been left behind from the swab.

2) Take the bottle of touchup paint and shake it well to ensure it is thoroughly mixed.  Reach for a clean paper tissue and have it at-hand.  Both bottle and frame should be stable at room temperature.  If you bring the bike directly in from the cold to do this, moisture condensing at the metal surface will prevent a good paint bond.

3) Turn/rotate the bike so the chipped area is upright (think:  the chip is like a dish I will fill).

4) Getting the tip of the brush wet with a drop a bit larger than the chip, touch it to the affected area; the pool of paint will develop a lens shape higher than the surrounding surface.

5) Quickly recap the bottle, and reach for the paper tissue.  Touch a corner of the tissue to the edge of the paint "lens", siphoning-off the excess so it sits just above level with the surrounding surface.  Lift the tissue as you go, so it doesn't pull wet paint out of the chip onto the surrounding finish.  The paint will shrink about 5% as it dries, so try to leave about that much "over" what would be level with the existing finish; it isn't much.  You'll have to work fast, particularly if the touch-up paint has been used before, as the remaining carriers will evaporate very quickly.

6) Allow to dry in a clean environment, free of dust and breezes, and at room temp.  Resist the temptation to touch or poke at the repair with your fingers or rotate the bike to its normal position before the paint has dried.

This works really well for opaque colors, and should give a near-invisible, protective and durable result.  Good luck!

Best,

Dan.

[Danneaux]

Greg,

I should add the above suggestions assume there is no rust present on the metal you'll be touching-up.  If there is, be sure to clean it off first, using a pencil eraser or ink eraser or fine-grit sandpaper.  You may then choose to convert any remaining rust -- after removing any flaking rust and rust powder -- using a product like Ospho ( http://www.ospho.com/ ) and then painting over it once the conversion has occurred and stabilized.  As a hobbyist framebuilder and frame painter, I use Ospho on all bare steels before covering them with a coat of rust-inhibiting primer and then the wet color and clear coats.  It has been about 20 years since I repainted my tandem, and it looks factory-fresh to this day, thanks to careful surface preparation.  A good wet-paint job starts at the bottom, well below the pretty color coat.

Best,

Dan.

[gregmacc]

Thanks Dan ... Just the sort of advice I was after ... I have everything except the 99% alcohol ... any suggestions about where I might find some? Hardware store?
Cheers
Greg

[Danneaux]

Hi Greg,

You're welcome; hope it works out well for you!  The 99% isopropyl alcohol should be available at a hardware store or nearly any drug store.  Just try to avoid the common "rubbing" alcohols, as the remainder is either plain water (which, by the way, can leave permanent water spots on polished aluminum) or water and glycerine.

So, check a drug store (pharmacist's, chemist's) first.  If no luck, then it is often available in bulk quantities from electronic components supply firms, where it is used as an industrial cleaner.  Some of mine out in the garage came from that source.  If you still have trouble locating it, let me know and I'll try and offer more sources for your locale.  Note: Acetone is not the same as isopropyl alcohol and I have experienced some softening of cured powder-coat when using it in a similar fashion, so I would not recommend it in this instance.  Never a problem with isopropyl alcohol and powdercoat interacting in my experience.

All the best,

Dan.

[Matt2matt2002]

Sorry if it is not the done thing to bump up old threads but this one was the nearest I found to my own problem.
I have a black Raven. On the top tube are 4 or 5, 4 inch fine scuffs.
Not chips. No rust. Not deep. But I notice them every time I get aboard.

The frame is on the large size for me, so could be self inflicted. I am now more careful!

Anyway.,solution to reoccurring is me being more aware.
Solution to the scuffs?
Advice please folks.
(I do not own any paint at the moment).

Matt

[Danneaux]

Sorry if it is not the done thing to bump up old threads but this one was the nearest I found to my own problem.

Hi Matt!

If you can find a similar thread to post to and update, then it is terrific to bump it up to present; helps keep similar topics together making for easier searches in future. Well done!

In an effort to avoid scuffing my black Nomad's top tube, I plan to apply a long strip of matte black windshield trim tape to the top surface so my foot won't catch it and cause scuffs when dis/mounting. If I have a full load on the rear rack, I'm more inclined to "step through" and that's when my shoe sole puts the paint at risk. Some similar tape with low-creep (stable) adhesive might be just the thing to address your problem at present and keep it from worsening with further use.

Really shallow scuffs as you describe are tough to touch-up cleanly on powdercoat. It is the clear-coat layer that is responsible for the "flattened" gloss on the black frames. Rubbing/cutting compound and waxing that would be appropriate for wet-painted frames isn't appropriate for powdercoat, and would remove the matte appearance and make it glossy (abrasion from trousers can do the same over time).

If the scuffs were deep enough to catch paint, then I think you'd have good luck applying some matte black wet-paint to them, and then wiping with a rag saturated in 99% isopropyl alcohol to remove what is on the surface, leaving the rest of the touchup paint in the valleys (scratches). I've had good results doing this, and my repairs to the Thorn Expedition rear rack scrapes are truly invisible from 10cm away. If the scuffs are too shallow to catch the paint, then there's not much to be done except cover them with the tape to hide them and prevent future additions. The Trim-Brite matte black windshield trim tape I use is a dead-on match for color and gloss and is virtually invisible when applied smoothly. I use it for anti-scuff patches under my cables. It doesn't shrink to expose the adhesive, yet can be removed and reapplied if necessary. Link to vendors in my earlier post here: http://www.thorncycles.co.uk/forums/index.php?topic=4465.msg21603#msg21603

For paint, I've found Krylon's semi-flat black spray is a dead-on match. More details here: http://www.thorncycles.co.uk/forums/index.php?topic=3053.msg16700#msg16700

Hope this helps.

Best,

Dan. (...who thinks Stealth Matte Black may be the easiest of Thorn's colors to touch-up cleanly)