I thought it may be helpful to share my experience with anodizing/re-anodizing Muster vibe bars. This is a small sample based on unscientific experience of two sets of bars, and a total of three trips to two different anodizers. I’d sure think long and hard about taking this on myself again. Take my advice comments at your own risk! Also not all bars are anodized! Some are painted and/or have a clear coat on them.
The first set I had done for a paying customer for an M-75 on top of a custom Walnut frame (not a cheap endeavor). The bars were not in bad shape, but they did have some dings and scratches. By the way, a google search on aluminum anodization will provide some good explanations. At a high level it’s a chemical process that is basically a controlled corrosion and it yields a layer on top of aluminum that is stronger than steel. —They have to first strip the old anodization off and lay down a new layer.
Set #1: I found a place in downtown Indianapolis and I dropped by with a picture of a vibe and they gave me a bit of under $200 to strip and re-anodized the bars in gold. BTW they thought it was cool seeing the picture. After about a week I got them back. The rep at the anodizer said some of the bars came out “flakey”. To my eyes they some looked smooth like the original M55, some had a repeating pattern. He told me that they have no control how that turns out. So I took them to another Anodizer and they were stripped and basically came out the same way, some smooth, some “flaky”. The guy I was building the vibe for was fine with the appearance (thank goodness). The two strippings and two anodizations, ALL the bars were almost a semitone flat.
I had them retuned by Century Mallet in Chicago and they sounded amazing (and still do). They have a wonderfully warm and rich tone and round and thick sound to my ears. I’m going to take a little credit here. I did a complete rebuild on the century frame in Black Walnut and the new frame and replaced resonator paint etc helps the sound too. They had to take a lot of meat off of the ends of the bars to bring them back in tune. BTW
Set #2 (Also in gold) . I had them strip just ONE of the bars and interestingly there was paint on the under side. The process for removing anodization will not work on paint. So I removed all the paint (or what I thought was paint) off of the underside of the bars with scotch brite and paint thinner. They said there was some king of gunk on the under side of the bars but the tops (and sides) anodized OK. The result was almost exactly the same. Some bars had a pattern some did not I brought them back home and did some more hand cleaning before I sent them off for turning. I wished I had done this in two steps (see final thoughts).
Set #2 bars sound great too and they look fine from a distance but they don’t all look exactly the same.
Additional Commentary:
I’ve heard second hand that getting a uniform gold color on bars is not easy for some reason. As a side ote I recently picked up newer silver M-55 (circa 2006) and ALL the bars have the crosshatch pattern on them. It looks better since it’s consistent across all the bars. Part of me is curious if they’d be consistent if they were anodized in gold. Unless I win the lottery I’m not going to experiment. By they way both sets of bars were well over a quarter-tone flat after anodization
Final thoughts:
- Unless the bars are a total loss, I probably learn to live with scratches and not mess with re-anodizing. Re-tune, certainly re-anodize, I dunno.
- Before I tried this again, I’d see if one of the bar tuners would give it a go and have them do it if the price was right.
- IF I did this again I’d have the bars stripped of the anodization. I’d bring them back to my shop and go over them with some fine scotchbrite in case any paint or other residue was still on the bars. Then I’d send them back to get anodized.
- See final thought #1
Comments
A few additions
wyndorps Wed, 11/30/2022 - 10:50
A few additions:
In contrast to electroplating or lacquering, anodizing does not apply a layer to the existing surface, but chemically alters the existing surface. Thus, the result depends not only on the process parameters, but also very strongly on the existing surface, the surface quality and pretreatment (degreasing,etching).
In the actual anodizing step, the aluminum parts are immersed in an electrolyte (oxalic or sulfuric acid). The workpiece is connected as an anode, i.e. to the positive pole of a direct current source. Plates made of lead, which are not attacked by the electrolyte, often serve as the cathode. When the current flows, water is electrolytically decomposed at the cathode. The oxygen at the anode reacts with the aluminum and the oxide layer is formed.
By placing it in a dye bath, the capillary-like pores in the workpiece surface created during anodic oxidation can be partially filled with dyes. The color effect is therefore not created on the surface, but at the base of the pores.
Unfortunately, all hard aluminum materials that can be used for the bars are unsuitable for design anodizing. The process of a uniform anodized layer with a uniform optical surface can only be achieved with perfect control of all process parameters - thus actually only in a series process.
I have noticed several times that the bars of one vibraphone usually look very uniform, but that they can sometimes be considerably different on several identical vibraphones of different vintages.
It is also logical that material is removed when the anodized layer is removed and thus the mass distribution of the bar changes. Therefore, the bars need to be retuned.
During the initial anodizing process itself, I noticed only very slight changes in the tuning, but I had agreed with my anodizer to etch the surfaces only very briefly in the pretreatment.
I would not re-anodize bars, but live with the scratches.
Thank you Prof W.
IndianaGlen Tue, 12/06/2022 - 10:40
In reply to A few additions by wyndorps
Paul,
Per your posting: "I would not re-anodize bars, but live with the scratches." I wholeheartedly agree!
Thank you for your additional comments and clarifications. Were you able to achieve a uniform looking anodization on the bars? In my case I attribute the difference in appearance to be the manufacturer using aluminum from different batches and/or sources. I noticed that the bars that were originally "flaky" were also flaky when they were re-anodized. In my small sample/experience, this points to differences in material vs difference in the anodizing process itself. Also, I'm assuming that gold color may be less forgiving than black, red, or blue since manufactures seem to prefer those colors these days.
By the way, years ago Gilberto Serna at century mallet retuned a set of very old bars that were Lacquered on an M-75. He said they sounded great, and to live with the scratches, which I did (and do). So the three of us agree :) Although I didn't want to confuse my anodization post with lacquer, I have had sprayed clear lacquer on previously clear lacquered bars with very good results and no need for a retune.
--IG
uniform looking anodizing result
wyndorps Mon, 12/19/2022 - 12:40
In reply to Thank you Prof W. by IndianaGlen
Hi IG,
please excuse the late feedback.
Regarding your question:
Yes, I was able to achieve a uniform looking anodizing result.
However, the prerequisites for this were also given, because on the one hand, my bars were first roughly sawn out of a single plate and then milled. I had not further processed the plate surface (visible side). Secondly, all bars were processed together as a set in all anodizing process steps.
Paul