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Finishing Q's: Re: High-Heat Automotive Paints....

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  • Finishing Q's: Re: High-Heat Automotive Paints....

    I just finished laying out some paint on a project with VHT High-Heat Burnt Copper, and went to look at the label (I know- shoulda read it FIRST!), and it said for best results to bake at 200* for 1 hour.

    I would obviously remove the xover, all wiring, drivers, and stuffing before attempting this.

    Now I'm contemplating doing it to get the full cure and hardness of the paint for durability's sake. I've just been looking up items on-line to see if they can tolerate the heat:

    Adhesives:
    Elmer's Glue-All
    Gorilla Glue

    Media:
    MDF
    1/2" thick cardboard tubing
    1/4" Hardboard
    Particle Board/Formica
    Biscuits
    Screws
    Clay kitty litter

    Paints currently on the cab:
    Krylon variety enamels testing for color, small spots
    Krylon Flat Chalkboard Black
    Krylon Matte finish
    VHT High-Heat Burnt Copper

    Now- I remember Aaron Hero used to 'bake' his boxes via a 1000W fluorescent bulb and a couple fans piping the heat through the inside of the enclosure to prevent seams and cure the glues, etc. (Not OSHA approved, but it worked under watchful eye!)

    Do I have anything I need to be concerned about in the cabs as they are currently containing the above items if I were to bake the cabs?
    Thanks for any insight any of you can offer,
    Wolf
    "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
    "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
    "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
    "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

    *InDIYana event website*

    Photobucket pages:
    http://photobucket.com/Wolf-Speakers_and_more

    My blog/writeups/thoughts here at PE:
    http://techtalk.parts-express.com/blog.php?u=4102

  • #2
    Re: Finishing Q's: Re: High-Heat Automotive Paints....

    I know that MDF can be "baked" for powdercoating, so that should be fine.

    रेतुर्न तो थे स्रोत
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    • #3
      Re: Finishing Q's: Re: High-Heat Automotive Paints....

      I always assumed the cure required for these type of paints was only needed prior to exposing them to more intense heat - I might be wrong though. Is the finish not as you expected? Maybe try a scrap test construction, with your materials, to see how it fares. Most importantly, don't let your wife catch you with a speaker in her oven.

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      • #4
        Re: Finishing Q's: Re: High-Heat Automotive Paints....

        'Bake' it in the backyard on a sunny summer day. I do so with DuraTex, it comes out as hard as a rock.
        www.billfitzmaurice.com
        www.billfitzmaurice.info/forum

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        • #5
          Re: Finishing Q's: Re: High-Heat Automotive Paints....

          Originally posted by billfitzmaurice View Post
          'Bake' it in the backyard on a sunny summer day. I do so with DuraTex, it comes out as hard as a rock.
          +1, good hot day, and some direct sunlight is all you need.
          craigk

          " Voicing is often the term used for band aids to cover for initial design/planning errors " - Pallas

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          • #6
            Re: Finishing Q's: Re: High-Heat Automotive Paints....

            We're in northern Indiana. Chances of that lately seem to be slim to none lol
            https://www.facebook.com/Mosaic-Audi...7373763888294/

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            • #7
              Re: Finishing Q's: Re: High-Heat Automotive Paints....

              my understanding of the bake process on that product is for it to reach it's full chemical resistance (think gas tank on a motorcycle)

              unless you're planning on subjecting your cab to some crazy environment, you should be fine with a normal cure and/or the backyard bake (which IMO is more about the UV rays than the heat)

              I used the VHT Copper on a tube amp chassis some time ago (it gets hot)...holds up fine. I never baked it.

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              • #8
                Re: Finishing Q's: Re: High-Heat Automotive Paints....

                So- No one sees any problem with baking it though, correct?

                I talked with Matt on the phone last night about it, since he's done some car-parts this way which were metal. He says the finish not only reportedly gets more chemical resistant, but it also gets harder and more durable as a result.

                The paint looks just as I want it to, but I want the full adhesion and durability. Being that every day this week is supposed to be muggy, stormy, and hot; I'm thinking it couldn't hurt.

                So, really- I can do this, right?

                Later,
                Wolf

                BTW- I DO have an extra oven from when we changed ours last year, sitting stored in the barn. I was going to just give it away, but maybe I'll keep it on the 220 in the garage for things such as this.
                "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
                "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
                "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
                "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

                *InDIYana event website*

                Photobucket pages:
                http://photobucket.com/Wolf-Speakers_and_more

                My blog/writeups/thoughts here at PE:
                http://techtalk.parts-express.com/blog.php?u=4102

                Comment


                • #9
                  Re: Finishing Q's: Re: High-Heat Automotive Paints....

                  the joints are very likely to show up. Did you **** join the cabs or miter folded?
                  http://www.diy-ny.com/

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                  • #10
                    Re: Finishing Q's: Re: High-Heat Automotive Paints....

                    Elmers PVA glue has pretty low heat resistance.
                    It starts to soften at 85F.
                    If the glue line is stressed it will deform or let go.

                    Make sure everything is really dry before you heat. Escaping moisture vapor and solvents can damage the finish.

                    Aaron heated the bare mdf cabs to get the glue lines really dry before finishing. His temps never got that high. You only need about 10 above ambient to drive of moisture.

                    Metal and wood behave differently. Metal won't absorb moisture or solvents so there is no worry about them popping the finish when heated. Wood products are more like sponges and it can take a very long time for excess solvents and moisture to evaporate to a point where it won't be a problem.

                    Formica is also a thermoplastic. It will soften at 200F. How is it bonded? Is it stressed?

                    Forgot to add.
                    Bring it up to heat very slowly. Don't plop the cabs in the hot oven. Pre-heat the oven a little above room temp to drive off moisture, then put the cabs in. You'll have to manually cycle the heat to bring it slowly up to temp.
                    Last edited by bobbarkto; 06-16-2014, 12:38 PM. Reason: additional comment
                    ~99%
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                    • #11
                      Re: Finishing Q's: Re: High-Heat Automotive Paints....

                      Which VHT did you use? Is it the 1500 F header paint?
                      Craig

                      The lowest possible F3 box alignment is not always the best alignment.

                      Designing and building speaker projects are like playing with adult Lego Blocks for me.

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                      • #12
                        Re: Finishing Q's: Re: High-Heat Automotive Paints....

                        No that'd be the Gold engine block paint, I see them every day at work.

                        रेतुर्न तो थे स्रोत
                        return to the source
                        leviathan system thread
                        deadhorse thread
                        shockwave build thread

                        instagram :: greywarden_13

                        in war, victory . . . in peace, vigilance . . . in death, sacrifice.

                        Comment


                        • #13
                          Re: Finishing Q's: Re: High-Heat Automotive Paints....

                          Originally posted by r-carpenter View Post
                          the joints are very likely to show up. Did you **** join the cabs or miter folded?
                          On the face of the cab, there are only 2 adjoining seams. The roundover could shift a bit, and there is one in the middle of that.
                          I covered all else with a layer of hardboard and flush-trimmed, so I eliminated a ton of the bu++-seams. These are the PE Knockdown 0.23ft^3 cabs, altered, mass-loaded, and improved.

                          Thanks,
                          Wolf
                          "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
                          "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
                          "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
                          "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

                          *InDIYana event website*

                          Photobucket pages:
                          http://photobucket.com/Wolf-Speakers_and_more

                          My blog/writeups/thoughts here at PE:
                          http://techtalk.parts-express.com/blog.php?u=4102

                          Comment


                          • #14
                            Re: Finishing Q's: Re: High-Heat Automotive Paints....

                            Originally posted by bobbarkto View Post
                            Elmers PVA glue has pretty low heat resistance.
                            It starts to soften at 85F.
                            If the glue line is stressed it will deform or let go.
                            That's mainly what I was afraid of. The Elmer's glue being the weak link. Looks like the oven is out this go around.

                            Make sure everything is really dry before you heat. Escaping moisture vapor and solvents can damage the finish.
                            Noted for future reference.

                            Aaron heated the bare mdf cabs to get the glue lines really dry before finishing. His temps never got that high. You only need about 10 above ambient to drive off moisture.
                            Noted.

                            Metal and wood behave differently. Metal won't absorb moisture or solvents so there is no worry about them popping the finish when heated. Wood products are more like sponges and it can take a very long time for excess solvents and moisture to evaporate to a point where it won't be a problem.
                            Yep.

                            Formica is also a thermoplastic. It will soften at 200F. How is it bonded? Is it stressed?
                            It's not visible from the outside of the cab. I used the formica-particle-board discs from some cutouts to give a couple screws something to bite into, and it is in turn screwed to the cab. Far as I know it came from a cabinetry shop as sink cutouts, and was likely done by a furniture grade adhesive for kitchen countertops, or maybe just regular smelly contact cement. I really can't say as I purchased them bonded.

                            Forgot to add.
                            Bring it up to heat very slowly. Don't plop the cabs in the hot oven. Pre-heat the oven a little above room temp to drive off moisture, then put the cabs in. You'll have to manually cycle the heat to bring it slowly up to temp.
                            Wow- I would not have guessed that to be operation practice. That is very helpful should I ever undertake the cure via oven. Thank you for the detailed reply.
                            Looks like I might just set it in the sun for a bit as others suggested.

                            Thanks all,
                            Wolf
                            "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
                            "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
                            "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
                            "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

                            *InDIYana event website*

                            Photobucket pages:
                            http://photobucket.com/Wolf-Speakers_and_more

                            My blog/writeups/thoughts here at PE:
                            http://techtalk.parts-express.com/blog.php?u=4102

                            Comment


                            • #15
                              Re: Finishing Q's: Re: High-Heat Automotive Paints....

                              Originally posted by greywarden View Post
                              No that'd be the Gold engine block paint, I see them every day at work.
                              I'm mainly worried about the paint flaking off, but time will tell. If applied on a sealed wood, the color is like the burnt copper on the cap. If applied on a porous surface, it yields a very rosy color, not unlike the color on the upper-end trombone's bells. Very pretty, and a NICE contrast from one color of paint.

                              Again- thanks, all! I guess I'll just use UV and time,
                              Wolf
                              "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
                              "Wolf and speakers equivalent to Picasso and 'Blue'" -dantheman
                              "He is a true ambassador for this forum and speaker DIY in general." -Ed Froste
                              "We're all in this together, so keep your stick on the ice!" - Red Green aka Steve Smith

                              *InDIYana event website*

                              Photobucket pages:
                              http://photobucket.com/Wolf-Speakers_and_more

                              My blog/writeups/thoughts here at PE:
                              http://techtalk.parts-express.com/blog.php?u=4102

                              Comment

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