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intake manifolds and valve covers ?

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  • sswee
    replied
    Yes, I have seen color change in anodize due to heat but it was in extreme heat. At 450F+ for an extended time. I don't know the temps anodize can take without effect but automotive applications usually operate at 180 to 240f with no problems.

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  • upncoming
    replied
    does anybody know if anodized parts change color when they get hot? buddy of mine said his screws changed from red to a off pink when they got hot

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  • kiwijetpilot
    replied
    Nah, don't do that, let's learn together..

    I will be concentrating on castings too. I have done quite a bit of research, and there is work being done here in NZ on de-smut systems that will allow castings to be anodised more effectively. This is cutting-edge stuff that is still a bit secret at the moment, but it is happening (although that is all I know about it).

    You might also be interested in this:

    Experience has shown that desmutting is one of the most critical steps in the aluminum pretreatment process. Historically, nitric acid solutions, with acid concentrations of 25% to 70%, have performed well to desmut etched aluminum alloys. Not all smut is easily removed with nitric acid alone, thus often additions of other components are made to improve the effectiveness of the desmut. For instance, for aluminum alloys containing high concentrations of silicon (e.g., 356A and 380 series cast alloys), additions of fluoride-containing compounds such as ammonium bifluoride or sodium fluoride, have been added such that fluoride ions are available to dissolve and remove silicon from the surface. Alternatively, a solution of nitric acid, sulfuric acid and a fluoride-containing salt has gained popularity over the years, because of its ability to chemically attack and remove a wider variety of metallic smuts.

    [0008] While nitric acid has been very effective for desmutting etched aluminum, there has been increased resistance to its use because of safety and health concerns. For instance, development of toxic NO.sub.x fumes in nitric acid-containing baths has been of particular concern. To obviate this concern, there has been significant effort to develop and use non-nitric acid containing desmuts. One such approach has employed the use of chromic acid as the oxidant, again combined with sulfuric acid and a fluoride containing salt. This approach was successful for desmutting and avoids NO.sub.x concerns. However, the use of chromic acid brings with it toxicity concerns of its own.

    [0009] An object of the present invention is to provide a composition that is free of acids such as nitric acid and chromic acid, thus eliminating the health, safety, and environmental concerns associated with these acids, but which is capable of being highly effective in its desmutting ability.
    (from http://www.freshpatents.com/Nitric-a...0040242449.php )

    There follows a highly technical (but interesting) discussion of what it does, and in the examples we find this:

    [0045] Samples of cast aluminum alloy 356 and wrought aluminum alloys 2024 and 6061 are cleaned/degreased as described above followed by etching in Alklean AC-2. The etched samples are then immersed in the aqueous composition of Example A, and the ability to remove smut is evaluated. The cleaned samples are then processed through zincate steps followed by electroless nickel plating with Nichem-2500. The desmutting action of a fresh solution of Example A is Good, and the aged solution (after continuous use for three weeks is Fair/Poor. The adhesion of the plated nickel in the 90.degree. bend test to all three alloy samples is Good.
    So what I am saying is, there is hope for anodising castings. And this is public research.

    I'm a bit of a rotor-head too...

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  • upncoming
    replied
    Originally posted by M_D
    There are 3 different possiblities with the aluminum valve covers, 1 piece stamped, fabricated(welded) sheet, and cast. The one oiece stamped will anodize well. The fabrricated will anodize well except around the welds, where there will most likely be a noticable difference. The cast valve covers and manifold can be anodized, but due to various alloys and casting methods and quality, the results may or may not be ok.

    I anodized some cast tooling plate the other day, and it turned out way nicer than I had expected. But, it is likely much higher quality than the average cast part.
    that scares me. . from the reading iv been doing it seems that castings are the hardest to get down and this is where i would be doing most of my work. . i would love to try and learn ways to get this down to simple science but theres so much involved with the learning stages to take risk with this.
    i think im going to go with the chrome plating, it seems alittle bit easier to learn with less risk involved..

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  • M_D
    replied
    There are 3 different possiblities with the aluminum valve covers, 1 piece stamped, fabricated(welded) sheet, and cast. The one oiece stamped will anodize well. The fabrricated will anodize well except around the welds, where there will most likely be a noticable difference. The cast valve covers and manifold can be anodized, but due to various alloys and casting methods and quality, the results may or may not be ok.

    I anodized some cast tooling plate the other day, and it turned out way nicer than I had expected. But, it is likely much higher quality than the average cast part.

    Leave a comment:


  • upncoming
    started a topic intake manifolds and valve covers ?

    intake manifolds and valve covers ?

    I just wanted to know what kind of results you guys are getting doing the intakes and valve covers ....?

    If you guys have pics of your work could you post a few up? For my search attempts I haven't seen to much anodized intakes or covers and im starting to think it cant be done or is to hard to do...?
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