Jan 22, 2018

Those little sparks at higher voltage anodising.

7 comments

I am using the SMT unit and the set-up / technique as generally described by Bill Seeley. Sometimes, I see small sparks coming off the work piece at the higher voltages. What do these signal, and should I be worried?

 

Thanks in advance,

Oz

Jan 23, 2018

Hi Oz!

You've got lots of electricity going through the bath at higher voltages so it is normal to see it. Also, if you metal has some residual oxide on it, you may be seeing more sparks than usual. We find it more common when anodizing titanium than niobium but it's not unusual to see it on either metal. Enjoy the process!

Feb 12, 2018

Thank you!!! I am glad, it's mostly a friend of mine who is seeing this, and who is terrified about being left as a pile of cinders :) "Safety gear!" I told him.

Feb 12, 2018

Too right! If you have your gloves on, you can't connect the circuit. Great advice!

Feb 22, 2018

Several related Qs.

 

1. Is there a good video for using the brush, beyond the intro video on this website and Rio Grande? Brush work is where I had the most sparks.

 

2. Somewhere I saw/read that the brush shouldn't be applied at high voltage, in other words, it was the equivalent of dipping metal in at high voltage. I inferred from that it is necessary to dial down then dial up when the metal was in the electrolyte solution. I tried to do this by making contact of brush bristles to metal at low voltage then dialing up to the color I wanted (in this case 80 to 100 v). Is that the correct way to apply a high voltage color with brush? I ran into a lot of sparks trying to apply a high voltage color with small brush. I was trying to apply small areas of pink and green.

 

3. The other control issue was how to keep the brush damp enough. When I watch videos people seem to lift brush off and on into electrolyte solution without dialing up and down. I finally resorted to dribbling electrolyte solution on the metal, but that caused the colors to bleed and spread out. Is it okay to pick up brush and put it down at high voltage, keeping the rest of the plate relatively dry? Or is the dryness of the surrounding plate likely to give rise to a spark?

 

4. Are the sparks a problem? I am taking care to keep everything at hands-length, but wondered if the sparks are normal part of operation when painting a multi-color panel, some of which are at high voltage? Or are the sparks an indicator that the brush and equipment are at risk of being damaged?

 

Thnx for advice on brush work and sparks.

 

 

Feb 22, 2018

Hi Jama,

1. No video as of yet but it is on our "to do" list.

 

2. Brush anodizing can be done at high voltage but it is a different process to get there. With both bath and brush anodizing, you should start at a very low voltage and ease your way up. Because all of the current is going through the tiny little tip it is necessary to go up in 10-20 volt increments. Wet the brush, slowly move it around on the metal until the full area you're painting is an even color, then turn it up and do it again. If you just turn it straight up to the higher voltage, you are focusing high current through that tiny area and will likely see lots of sparking.

 

3. There is definitely a learning curve to using the right amount of electrolyte. If you're using the technique above (question 2) then it is absolutely ok to lift your brush and put it back down. To avoid the bleed/spreading out of color we have found it easier to paint within a guide form--like one of our Lace Tapes, Mighty Mask or anodizers tape. It gives the electrolyte an edge to stop at which will also avoid the sparking from uncolored areas.

 

4. Sparks are normal, nothing to be concerned about, especially if you're wearing your gloves!

Note my original response to Ozzy above: "You've got lots of electricity going through the bath at higher voltages so it is normal to see it. Also, if you metal has some residual oxide on it, you may be seeing more sparks than usual. We find it more common when anodizing titanium than niobium but it's not unusual to see it on either metal."

Aug 9, 2018

I am very new to doing this, I did it in class over 20 years ago

 

This is relate ted to the sparks question Is the 'steaming' I see coming off the pices at higher voltage hydrogen? and is that related to the sparking?

The scientist in me is wondering

 

Would it be better at higher voltage to dilute the electrolyte a little?

Aug 9, 2018

Hi Cairenn,

I don't think the sparks are hydrogen but don't know for sure.  The sparking happens more when you've got resistance on the surface of your metal--which could mean oxide or contamination from other metals.  Make sure if you're using titanium that you have etched it first to remove oxides and if you're processing either niobium or titanium with any kind of media (tumbling shot, sanding wheels, abrasives, polishes) make sure it contains no metals i.e.: aluminum oxide abrasives or sanding blast media, or stainless tumbling shot.  The other metals can contaminate the surface and embed tiny little bits into the surface which then cause anodizing sparks and problems.  Be sure to keep your media separate from use on other metals also so you don't cross contaminate.

 

It isn't necessary to dilute at high voltages--your electrolyte, if mixed correctly, should be the same consistency no matter what voltage you're using.  To make sure, here are the correct mixing ratios for both regular TSP and TSP-PF:

TSP = 1+1/3 cups TSP per gallon of distilled water

TSP-PF = 1/2 cup TSP-PF per gallon of distilled water

 

If you're getting burn spots when anodizing you might want to water down your electrolyte.

New Posts
  • I teach our fold forming classes and I read that niobium can be fold formed My concern is that with copper, I anneal it fairly often with some folds What folds can be done with it any hints? I love making pea pods by hammering on the folded curve, but I always have to anneal those before I can open them. I have this dream of nice green pea pod.
  • Hello, I feel really silly asking this question because I fear the answer is obvious and I’m just missing it, but I don’t want to electrocute myself. When you say rubber gloves are these like the kitchen cleaning gloves with latex, or do I need electrician gloves? Thank you.
  • Anybody have any comments regarding how to best ”pad” an anodized raised patterned disc without removing the unraised background, near its edges for example? Which Micro-mesh Soft Touch pad grit typically works the best? It seems just the slightest pressure in an effort to remove the first anodized background layer off the raised pattern surface also tends to mar the unraised area too. The coarser the pad, the worse it is. Seems there is an ”optimum” grit that hits only the raised pattern, leaving the background in tack, while having enough ”bite” to get the job done without overdoing it and marring the background. Making a lot of scrap and little finished product. Thanks again, Rick