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Phosphating and Chromating

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  • #16
    Can I wash these in my shop sink? I have septic tank. I'm not sure what these chemicals actually do so I thought I should ask.
    Thier are only two real sports!
    boxing and auto racing
    all the rest are just games.

    Drive it like you stole it!

    Comment


    • #17
      I don't see a *major* problem with it but I'll probably get called out on that one. I don't think there's enough there to upset the balance of bacteria in your tank to make a huge difference. I have a 3 stage septic here that I pour all sorts of things down (cleaning fluids from the house and soaps/detergents,etc) and have never had a problem. As a matter of fact, the septic guy came buy last week and he said everything looks really good.... so I'm happy. I'd think as long as you don't make an everyday habit of chemicals down your drain it would be allright. Just remember to flush with a lot of water as to dilute the concentration going down into the tanks and I think it just may be allright. Worse comes to worse, you can buy a box of that "good enzyme" stuff and put it down there as added insurance for bacteria.

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      • #18
        Can ytou explain to me what is happening to the metal from the wash chemical ( steel and aluminum if thier is a difference). I read what you wrote a few threads back and I'm not sure what the heck your talking about and i think it is becuase I dont know what the chemicals are actually doing to the metal and how this is effecting the pc.
        As always thank you for the knowledge I truly apreciate the help.
        Jeff
        Thier are only two real sports!
        boxing and auto racing
        all the rest are just games.

        Drive it like you stole it!

        Comment


        • #19
          You have to really be careful of anything that is a "chromate". These chemicals contain chromic acid and can cause extreme problems in the water table. If you've ever seen the movie Erin Brokovich, the contaminants that caused those people's problems were similar.

          You should always rinse in a closed system and take the evaporated rinse water to your local municipal hazmat transfer station. That way, you'll protect yourself from lawsuits and protect your grandkids from much, much worse.
          --
          Mike Caswell
          Caswell Inc
          http://www.caswellplating.com
          Need Support? Visit our online support section at http://support.caswellplating.com

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          • #20
            okely dokely.... here's the long and short of it. As stated above (fifth entry down, third paragraph) you're basically oxidizing the part chemically. Just like when salty sea water hits copper for years on end and then dries... it turns green. It's being oxidized. If you took a chunk of it and put it under a microscope, you'd see a "crystallized" structure on top. The way this helps you as a powder coater is this..... and trust me, these are very "generalized" terms, so take it with a grain of salt (no pun intended)......

            When "salts" are broken down in water, they become metals. A good explanation of this can be found here : http://www.chem4kids.com/files/elem_metal.html
            take for instance table salt. Sodium chloride ( NaCl) is divided in the water and the positive ion is attracted to the part (Na being the salt portion) The Chloride (Cl) breaks off and stays withing the water. When you pull the moisture away, or it dries... the "positive ion" (salt) is on the part. Through chemical AND electricl reaction, the part is therefore oxidized. It just so happens that sodium (Na) is an excellent conductor of electricity and is spread evenly all over the part. We have two benefits that come from this. First being.... it is a "primer" now due to the fact that it's gripped into the pores of the metal. What is left has an agressive surface profile (like when you sandblast) so therefore, the powder that sticks to the "salt" is bonded through that oxidation. Secondly.... through the sodium chloride now changed to just sodium, which is an excellent conductor of electricity because it's now a metal, the powder is very much attracted to it and sticks better. There's an even coating of it so therefore.... a smoother electrically attractive surface has been formed. It's a win/win scenario. Good grip, and more accurately conductive for your part.

            Now... with that said..... we use phosphate for steel and chromate for aluminum for two different reasons. Different metals are closer in the periodic table to other metals. Steel and aluminum generally don't like to mix... so different chemicals will want to be attracted to different metals. Someting that becomes (chemically and electrically) very close to steel, will be good for steel, and vice versa for aluminum. Will either chemical solution work for the opposite one? Sure.... I suppose it's better than not at all. But like chemicals and metals GENERALLY want to stay close to one another. Phosphate gets attracted to ferrous (magnetic... sorry, I see I entered metallic down there. that's a goof. I apologise. It should read "magnetic) metals as chromate gets attracted to non-ferrous (non-magnetic) metals. It gets broken down to what chemical fits best with what metal. A lot of people look at chemicals and metals with confusion and it's really not needed. Very simple if you stop and notice that some things on a periodic table are closer to others. Why do you think for centuries people have been trying to turn lead into gold,hummmm? So close to one another yet so far away by so little.

            If I missed anything let me know. I tend to ramble on and lose my train of thought (as if you hadn't noticed,lol). If it's still foggy to any of you, we'll break it down further. Or maybe one of our other members with insight can shed some light on the subject for us. I'm more than willing to yield the floor to better ideas and explanations, you all know that. Until then as always.... I hope that helped somebody out there ...... Russ

            p.s. ~ I in turn, always thank each and every one of you for your fresh insight as I learn from it as well. More than you know, truthfully.

            Comment


            • #21
              thank you for the explanation.
              Do all types of steel use the same wash? do all aluminum types use the same wash? also cast iron.
              do you apply the wash the same way on all metals or are their different processes for the different metals.
              Jeff
              Thier are only two real sports!
              boxing and auto racing
              all the rest are just games.

              Drive it like you stole it!

              Comment


              • #22
                generally speaking... phosphate is for steel, and chromate for aluminum. There are tons of variants out there but none that would really give you a huige advantage with the coatings you guys do as of now. Steel, Iron and the like... use the phospahte, all grades of aluminum, use the chromate, seeing as how you have the products available to you for stainless and brass/copper,etc... you can use those, but if they weren't offered here, I wouldn't write home about it. I've used cupric oxide salts before for copper when coating a thermoplastic... but if all's I had available to me was chromate... then I'd have used that instead without too much fuss. All washes are generally the same for you guys... warm/hot solution... dip in, leave for an amount of time.... rinse and then dry off. You can coat it after it's all dry. Work it all with the KISS method and you'll not have a problem, I assure you. De-Grease,Blast,Rinse/or solvent rinse if a chance of oil,Phosphate (or chromate or what have you),Rinse again,Dry,Coat. 7 steps, superior adhesion. All steps should be taken one right after the other to avoid any undue contamination or some such.... but as stated before, I think you guys know that already. Seldom does somebody blast steel, and then 3 weeks later try and coat it after it's been out for a while. If you miss a step, don't worry about it. The world won't collapse. Just start all over from square one and go through it all again. If it's something you can't blast for some odd reason.... degrease,phosphate (or again, chromate or what have you),rinse,dry,coat. It all works in the same method you just eliminated one step is all. The only one that is a necessity is the rinse off from your "chemical" prep. Other than that... I've seen every variation, but they all adhere to the same order. Degrease,blast,rinse/or chemically wash,dry,coat....... Degrease,chromate,rinse,dry,coat.... you get the idea. If it helps, write the 7 steps up on a piece of cardboard until you know it by heart. It should pretty much become second nature to you at some point in time quickly enough. If a part comes in greasy, you're not going to put it in your sandblast cabinet. If something is wet, you can't very well powder coat it until it's dry, and so on.

                1) degrease
                2) sandblast
                3) rinse/and or chemically wash (alcohol is fine)
                4) phosphate or chromate (or what have you that you choose for your substrate)
                5) rinse chemical from step 4
                6) dry thoroughly
                7) coat

                This is basically the best process you guys can use outside of buying expensive plasma and ultrasonic or parylene machines (all of which are totally un-necessary for you, might I add). Doing all of this in this manner will put you in the same league (if not better in some instances) as the pro's. A part done by you and a part done by a "big shop" will have no difference. Same 7 steps, same chemicals, same powders, same method of application.... same everything. You'll officially be coating on a "pro" level in a hobbyist form, so to speak. Good luck with it, bud. Don't forget to post your results here and of course... your pictures in the "album" for all to see ..... Russ

                Comment


                • #23
                  Okay I think I am on board so far. BUt I do have a question on the rinsing of the chemical off ( step #4). You mentioned earlier that it should be rinsed a certain way. Somebody a few threads back mentioned a halo rinse. I cant find any mention any where of a halo rinse. Can I just use a garden spray nozzle or do i need to fabricate something?
                  Jeff
                  Thier are only two real sports!
                  boxing and auto racing
                  all the rest are just games.

                  Drive it like you stole it!

                  Comment


                  • #24
                    just rinse it really really well is all that's being said. Think of your garden hose and the spray pattern you get when rinsing off soap from washing your car. ( I really had hoped our new friend Bennie would have chimed in by now and imparted his wisdom upon us about what he meant). You know that pattern you get when the spray gun is opened half way? A lot of water in a big "ring" but not a lot of pressure? That should be sufficient to rinse your part. Flush with a lot of water to get "everywhere" but not a great deal of pressure. I have no doubt that a flush of water under your kitchen tap water would also be ok. I've done exactly that before and have had no problems..... Russ

                    Comment


                    • #25
                      sounds like a plann
                      Thier are only two real sports!
                      boxing and auto racing
                      all the rest are just games.

                      Drive it like you stole it!

                      Comment


                      • #26
                        Bennie is back! Sorry I have been side tracked, have been researching blasting media and finally getting straight regarding MIls, Micron, MM, and all the rest that get connected to mesh sizes etc.

                        The suggestion of using a "halo rinse" and the response to the nozzle thing. You can check on afew general nozzles from local hardware supply outlets and fine one that renders a fine spray/fog. The "key" is not to allow the solution to flash dry. This is the important thing. Plus the finer the fog spray it will rinse better with more even distrubution than a heavy narrow stream. I will try to locate and pass along two great articles on water quality{that will add to basic understanding of rinses} And again check for water breaks on the part to confirm cleaning quality. Just cannot be too clean. I recently read a comparision statement, there is little difference between using a high quality coating on a dirty part as using a low quality coating on a super clean part. Makes sense to me. Bennie

                        Comment


                        • #27
                          Bennie is back! Sorry I have been side tracked, have been researching blasting media and finally getting straight regarding MIls, Micron, MM, and all the rest that get connected to mesh sizes etc.

                          The suggestion of using a "halo rinse" and the response to the nozzle thing. You can check on afew general nozzles from local hardware supply outlets and fine one that renders a fine spray/fog. The "key" is not to allow the solution to flash dry. This is the important thing. Plus the finer the fog spray it will rinse better with more even distrubution than a heavy narrow stream. I will try to locate and pass along two great articles on water quality{that will add to basic understanding of rinses} And again check for water breaks on the part to confirm cleaning quality. Just cannot be too clean. I recently read a comparision statement, there is little difference between using a high quality coating on a dirty part as using a low quality coating on a super clean part. Makes sense to me. Bennie

                          Comment


                          • #28
                            Thank you for adding the valuable insight,Bennie. I knew you'd be back . Keep up the good work and your research. Once again, welcome to the "boards".... Russ

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                            • #29
                              Can anyone tell me anything about a pretreatment called PickleX?

                              Comment


                              • #30
                                yeap... I most certainly can, I believe. In these very threads are comments regarding your question.

                                Picklex thread : http://www.caswellplating.com/bbs/viewtopic.php?t=1184

                                after you're done reading that.... move onto this one : http://www.caswellplating.com/bbs/viewtopic.php?t=1417 ( it's this very thread... read from first post to this one all over again to get some fresh insight)

                                and of course... you should always watch this one for updates and inspiration : http://www.caswellplating.com/bbs/viewtopic.php?t=1326

                                I must say..... that's probably the easiest reply I've never typed out,lol. Have fun with those threads and of course..... welcome to the "forum". I hope you have fun here as we all do..... Russ

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