Dye problems...

[paulr]

I have recently setup and LCD kit and am having trouble with dyes, actually just one dye. The deep red dye will not stay on any part. I have tried multiple parts which have anodized but the deep red simply washes off. The same part can then be rinsed and dyed any other color without re-anodizing it. All the dyes were mixed at the same time to the correct proportions in distilled water, I have tried both room temp and 110 (deep red will not work with either, but all others do).

Any suggestions or ideas?
Thanks!

[M_D]

I have experienced problems with red too, on parts that would take other colors fine. I don't have all the answers, but found that letting the part anodize a little longer helps. I have put parts back in the tank to anodize longer, and sometimes just a few minutes makes the difference. If you have undone the hanging wire, it may be hard to restore the electrical connection, so keep that in mind. The connection may have been marginal to begin with, causing a thin or inadequate anodize layer.

Heating the dye helps, although I have got some deep reds with cold dying. You might try heating to 130-140 and see if that helps. When the anodize layer is optimum, it seems to very easy to dye, whether it is cold or good and warm. If it isn't so good, some colors still work, guess that's probably just the nature of it. Fibergeek posted the other day that cold dying is know to be responsible for color fading.

Also, Caswell posted a while back on another red dye thread that the PH has to be between 5-6, if I remember correctly. I'm not positive if that is just the sealer, or the read dye. I'm also not sure what is best used to adjust the PH.

I have noticed that as the red dye ages a day or so, the PH drops, which is consistent with what I have read about distilled water. Apparently, it absorbs CO2 whne exposed to the atmosphere, which is slightly acidic.

Anyhow, hopefully someone who knows what they are talking about will step in and help you out.

[sawtoothrc]

I have also had alot of problems with the Red, and was told by Caswell that it is probably the PH, and red is the only dye really affected by this. It is perfect for the first batch, but as I do more, or it ages, the dye starts to wash off.

Although I haven't tried this solution, it's consistent with everything else I have heard.