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Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Spot anodizing for touchup
Q. I would like to know about possible spot anodizing to eliminate small handling scratches or marks after parts are received from anodizer.
Thank you,
- Groton, Massachusetts
2003
Electrochemical Metallizing by Marv Rubinstein
on AbeBooks
or eBay or
Amazon
(affil links)
A. Brush anodizing can be done with brush plating equipment. Alternatives, depending on the required finish quality and color include chromate conversion coating from a chromate dispensing "pen" or simply the use of a magic marker (indelible marker). I hate to say it but a large percentage of black parts have small rack marks and scratches disguised with a indelible marker, sometimes with the customer's knowledge, sometimes without.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Are there any ways to "touch up" hard-coat anodize without sending it back to the coater?
Q. Dear specialists,
We are a medium sized tool shop with no coating capabilities except your common machine painting, but there are several times we needed to "touch up" some hard-coat anodized parts. Are there any options out there short of sending the part back to the coaters to get stripped and recoated? Usually it's something simple like a tapped hole or a chamfer that had to be added after coating....... We understand the color may vary a little, but we are looking for something that has similar wear characteristics as hard-coat...... I am pretty sure most people want to grab a sharpie and color the spot in, but that doesn't work well on working surfaces....... Any suggestions ?
Thank you
Manufacturing - Anderson, Indiana USA
August 28, 2008
A. You should consider brush (selective) anodizing. You either would have to send it out to a shop specialized in brush anodizing or buy the equipment, chemicals, accessories and take the course to do it yourself in house.
An important additional -advantage would be that no other areas but the repaired ones will be affected. Strip and recoat always reduces dimensions overall because anodizing eats about 50% of the thickness of the anodized layer from the base material. Every time you strip you loose at least 50% of the thickness.
Monterrey, NL, Mexico
August 29, 2008
Q. I need information on brush anodizing. I have a weld repair to make to a 6061 structure that has been clear anodized. The filler rod will be 5356. The part is too big to put in a tank. I want to clean up the part and brush anodize the area where the anodize was ground off for weld prep, and the weld. Does anyone know of a kit to brush anodize small surfaces of about 12 square inches?
Dave Clayman- Alplaus, New York, USA
November 22, 2011
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A. First, you will never match the surface finish and/or color of the touch up anodize. It is not simple and requires expertise in masking as well as the anodizing operation. - Navarre, Florida November 23, 2011 A. There are several makers of spot anodizing equipment, however you're looking at quite an investment for just one part. Just to name 2 (might be cheaper for you to just send them the part):  Marc Green anodizer - Boise, Idaho November 24, 2011 |
Q. I have an aluminum bike frame that was factory painted. At
the factory they laser etched the company's logo (PIVOT) into the
frame paint finish. So the logo has the raw aluminum look to
it. On the bike I have red anodized parts and accessories
everywhere. I'd like to color the logo red (anodized red) if
possible. Is this possible to anodize this etched logo with
paint surrounding it? What options do I have. Can I color it some other way? Looking for help and advice. Attached is a picture of the bike for reference.
Thank you kindly in advance.
- San Diego, California
A. Hi Joe.
It perhaps can be done, but isn't easy, as you can read above.
This is a non-critical, no wear situation. I suggest cleaning the engraving with acetone ⇦this on eBay or Amazon [affil links] Warning! highly Flammable! (try it in an inconspicuous area elsewhere to make sure it's harmless to the paint), then use a metallic red magic marker. It may not be perfect, but I think it will turn out a lot better than brush anodizing, as well as being much easier.
If that isn't good enough, then "anodize look" spray paint should do it, but it would be extra work to mask the rest of the bike, and you'd probably need to prime first. Good luck, and let us know how it works out.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 24, 2012
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lab geek - Ennepetal NRW Germany October 27, 2013 |
Strange drink bottle mounting point, I bet it gets dirty! Q. Hi everybody
In my shop we plated hard anodize type III. We'd like to start doing touch ups. We bought powerpack 20 V / 60 A. My Question is, we need to touch up a surface area .083in^2. How can I calculate the volts and amps for this small area? We don't want to strip and re-anodize our parts.
Thank you
- Phoenix Arizona
April 4, 2017
A. Use Birchwood Casey's "Aluminum Black" if it's black.
Gary DayTitus Machining - Mineola, Texas, United States
September 6, 2018
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