Summary for magic marker on anodized aluminum Discussion
The thread on removing magic marker from anodized aluminum says the stain may point to a sealing problem rather than just a cleaning issue. Peter Toth asked how to wash off ID marks made with a marker on anodized aluminum, noting that lacquer thinner would not remove them. Bill Grayson replied that if the part is wrought aluminum and the anodize is Type III hard coat, the result suggests the coating was not sealed properly; if it is Type II, he said it may have been lacking a seal or had an insufficient seal. Robert H. Probert later suggested trying hydrogen peroxide or diluted drain cleaner containing sodium hypochlorite with silicate inhibitor, while warning not to use acid or caustic sodium hydroxide. He also advised verifying that the anodize was properly sealed and checking whether it passes the salt spray test required for Type II coatings under MIL-A-8625 / MIL-PRF-8625.
Q. I made some ID marks on the anodized aluminum surface with “magic marker” pen. I am unable to wash it off with anything. Not even with lacquer thinner
⇦ on
or
[affil link] Flammable!that works on any other surfaces as solvent. Is there any solution to wash this off.
Peter Toth
CABINETS – Berkeley, California, USA
2005
First of two simultaneous responses —
A. Well,
if you’re talking about a wrought alloy, and not a casting, I would say it sure sounds like your anodize was not sealed properly.
If you’re talking of a type III (“hard”) coating then I would expect the same result.
But, on the other hand, your part is a type II, then I would say it was lacking a seal, or at least an insufficient seal.
Bill Grayson
metal finishing – San Jose, California, USA
2005
Second of two simultaneous responses — 2005
A. Try hydrogen peroxide or diluted drain cleaner (sodium hypochlorite with silicate inhibitor). Don’t use acid or caustic (sodium hydroxide).
Verify that the anodize was properly sealed. Does it pass the salt spray test required of Type II coatings per
MIL-A-8625 / MIL-PRF-8625
[⇦ this spec on DLA]F? Additionally, testing per ASTM
ASTM B136 Standard Method for Measurement of Stain Resistance of Anodic Coatings on Aluminum seems appropriate.
Ken Vlach [deceased]
– Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
A. Try some proprietary paint stripper or mix 2 parts
acetone
⇦ on
eBay
or
and one part ammonia
⇦ on
or
Amazon [affil link] (25%), Maybe it helps!? Good luck!
Goran Budija
– Cerovski vrh Croatia
2005
Q. We had some parts hard anodized, when our Inspector inspected the parts he wrote the dimensions on the part with red ink (sharpie)after inspection, he tried to clean/removed the ink and he failed, the ink remained in the part.
Any suggestions in how to removed red ink from hard anodized parts besides using Iso Alcohol, acetone
⇦ on
eBay
or
or stripping the parts and re-anodize?
Angelica Gonzalez
– Huntington Beach, California, USA
November 9, 2012
A. Hard Coat is usually not sealed, but with time, temp cycling, humidity cycling it will partially seal itself. If the ink got into the pores and some partially sealing started, then you cannot get the ink back out.
Robert H Probert
Robert H Probert Technical Services
Garner, North Carolina
November 12, 2012