AW: [CR]refurbishing black anodized Gios stem - need help

(Example: Framebuilders:Chris Pauley)

Date: Fri, 12 Jan 2007 10:23:43 -0800 (PST)
From: Donald Gillies <gillies@cs.ubc.ca>
To: classicrendezvous@bikelist.org
Subject: AW: [CR]refurbishing black anodized Gios stem - need help
cc: moschika@hotmail.com

There are at least two ways to restore that stem. Both ways start as follows :

(1) First, take a good PHOTOGRAPH of the writing. You want to put the stem into clear sunlight, and take a picture from as far away as possible with the highest power zoom (analog), to minimize parallax distortion. Also, include a ruler in the photo so you can accurately scale the photograph in a computerized draw program later.

(2) Input the photograph into a draw program, such as MS-Visio, Adobe Illustrator, Corel Draw, OpenOffice Draw, (but not a paint program), and trace all the letters. There are operators in these programs to take the "diff" of 2 polygons (which is how you can make an 'o' for instance, it's the difference between 2 concentric circles.) Learn how to use these features.

You can print the logo at 50% inking on clear overhead projector film and lay it atop the logo to check registration. This can help to get your logo PERFECT.

(3a) Using dry-transfer paper, make a dry-fix transfer. there are several sources on the web for dry-fix transfer paper. that's a special tissue paper coated in one side with clay. you'll need to screen print onto the clay side of the paper. You can use diablo photo-resist to transfer a black & white image onto the screen printing mesh of a silkscreen. Then, lay the silkscreen atop the transfer paper and print white paint onto the transfer. then you have a transfer that can be glued (varnished) onto the stem, and released with water. This is a hassle - process (4b) is probably easier :

(3b) Take the digital image to a decal printer, have them cut you a vinyl stencil, to be pasted down onto the stem. once pasted, you can spray-paint on the logo, using the stencil to limit where the ink lands. If you cut a few stencils it won't cost much more and there may be other CR members wanting to restore their own stems.

(4) Once you've got the transfer/stencil mastered, take your stem to a anodizing shop and have them strip and re-anodize the stem in black. Then you can redo the lettering.

You _might_ be able to cut a vinyl stencil with an exacto knife and an accurate print of the original logo, but I doubt the results would look very good. Worth a try, however, since it would save lots of time for you (but not for other CR list members.)

- Don Gillies
San Diego, CA, USA