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Thread: Color sanding grit progression?

  1. #16
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    be sure you're soaking the wet and dry paper for at least an hour (i let mine soak overnight) before using it. the edges can scratch pretty deep and leave marks just like those.
    hopefully you have enough clear on it so you can sand out those scratch marks.
    b marler

  2. #17
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    Iíve had similar issues with a couple panels on my truck. My question is:
    Whatís the best way to avoid orange peel in the first place? I hate taking sandpaper to my nice new shiny car. Iíve heard people talk about over reducing the clear and using relaxers and whatnot but Iím just not sure. I should be spraying a couple panels tomorrow morning before the heat and humidity kicks in. Iím painting outside in south florida. I have a spray tent that I built, definitely not optimal conditions but itís all I got.

  3. #18
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    Quote Originally Posted by bmarler View Post
    be sure you're soaking the wet and dry paper for at least an hour (i let mine soak overnight) before using it. the edges can scratch pretty deep and leave marks just like those.
    hopefully you have enough clear on it so you can sand out those scratch marks.
    Thanks for that tip. I never considered the edges could scatch it like that


    Quote Originally Posted by SFLAutoSurf View Post
    Whatís the best way to avoid orange peel in the first place?
    I'm also interested in this. From information online it's mostly due to the temperature of your spray booth and the type of reducer and hardener you use. For hot humid weather that you want heart slow reducer and slow hardner. And colder weather you want a medium reducer and medium hardener. For your situation sure you will want the slow types. However, I would like to hear what you guys recommend and I am very curious to know if using a spray booth oven makes a big difference?

  4. #19
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    As far as the "orange peel" clearcoat appearance goes...

    i am always painting cars and my goal is to recreate OEM, original vehicle clearcoat apperance as close as posible so that my repair doesnt stand out..

    i rarely try to go for glass, shiny, lack of orange peel appearance....and any paitn job will have some level of orange peel...

    i think of orange peel, clearcoat appearance, in terms of structure, depth, thickness, size of "orange peel dimples, etc...

    so for example, high end German cars have thicker structured clear coat, more depth, larger orange peel appearance but it is more smooth and leveled out, and clearcoat is of higher quality....

    higher end Lexus, they have this tight orange peel, appears finer together, sort of thinner finish but stills shiny and less orange peely, lets say...

    look at some new Hyundais or Mazdas....it has this cheaper looking clearcoat appearance...


    so, how to get away with "orange peel" and get that glass finish off the gun....?

    you want hotter temperatures, slower reducers, nothing too cold, always follow TDS clearcoat manufacturers reduction for reducing, too much reducer can lead to trouble...

    i live in colder climate, so in the winter time, i like to warm my clearcoat in the microwave so it has more energy, easier to atomize and level off and reduce flash off times, for example.....i do not suggest anyone to try this ....i know my product...

    for that flawlerss off the gun finish, you gotta know your product, how the clearcoat sprays, hard to achieve it using it for the first time...

    i would suggest doing it in medium wet coats, thinner coat for that first coat, usually 2, but for glass finish that you will cut and polish, you can apply 3 coats, but carefullly and with lots of flashh off time...you want substrate thickness that can be cut and polished..

    yes, heated spray booth and bake system can really help for that clearcoat to level off and minimize orange peel a bit more, but it depends on clearcoat .

    imortant to avoid piling clearcoat on and avoiding "urethane waves" in clear coat appearance.

    as far as the spraygun settings, usually pressure around 29-32 psi, you want gun closer to panel, moving a bit faster and enough fluid to get even flow.....

    personally, it is easier for me to achieve flat glass finish with less orange peel then some of these clearcoat finishes on these economical vehicles .....

  5. #20
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    Default Yes sir...

    Quote Originally Posted by baubau View Post
    As far as the "orange peel" clearcoat appearance goes...

    i am always painting cars and my goal is to recreate OEM, original vehicle clearcoat apperance as close as posible so that my repair doesnt stand out..

    i rarely try to go for glass, shiny, lack of orange peel appearance....and any paitn job will have some level of orange peel...

    i think of orange peel, clearcoat appearance, in terms of structure, depth, thickness, size of "orange peel dimples, etc...

    so for example, high end German cars have thicker structured clear coat, more depth, larger orange peel appearance but it is more smooth and leveled out, and clearcoat is of higher quality....

    higher end Lexus, they have this tight orange peel, appears finer together, sort of thinner finish but stills shiny and less orange peely, lets say...

    look at some new Hyundais or Mazdas....it has this cheaper looking clearcoat appearance...


    so, how to get away with "orange peel" and get that glass finish off the gun....?

    you want hotter temperatures, slower reducers, nothing too cold, always follow TDS clearcoat manufacturers reduction for reducing, too much reducer can lead to trouble...

    i live in colder climate, so in the winter time, i like to warm my clearcoat in the microwave so it has more energy, easier to atomize and level off and reduce flash off times, for example.....i do not suggest anyone to try this ....i know my product...

    for that flawlerss off the gun finish, you gotta know your product, how the clearcoat sprays, hard to achieve it using it for the first time...

    i would suggest doing it in medium wet coats, thinner coat for that first coat, usually 2, but for glass finish that you will cut and polish, you can apply 3 coats, but carefullly and with lots of flashh off time...you want substrate thickness that can be cut and polished..

    yes, heated spray booth and bake system can really help for that clearcoat to level off and minimize orange peel a bit more, but it depends on clearcoat .

    imortant to avoid piling clearcoat on and avoiding "urethane waves" in clear coat appearance.

    as far as the spraygun settings, usually pressure around 29-32 psi, you want gun closer to panel, moving a bit faster and enough fluid to get even flow.....

    personally, it is easier for me to achieve flat glass finish with less orange peel then some of these clearcoat finishes on these economical vehicles .....
    Thanks for chiming in as I find what you added, very well said.

    ALTHOUGH - I won't be MICROWAVING paint any time soon. Guess you have a technique.

    I'm not a fan of adding reducer. Yes, it may have a benefit in applying clear but tends to cause "DIE BACK the next day, so not for me. Also, air pressure depends a lot on the gun you use.

    MOST IMPORTANT are temperatures and not JUST the ambient temps but more importantly, the temp of the metal AND urethane paint cannot be applied or CURE in under 55 degree (F) temps or you'll see problems.

    BUY and infrared thermometer!

    Henry

  6. #21
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    Henry, i either leave the clearcoat cans on my heating radiator or if i forget, i put it in microwave, i got a system, sort of, 500 ml for 25 sec, 750 ml 35 sec heating....LOL...

    it works for me tru trial and error....now that warm weather is coming, i will be experiencing some issues clearcoating as tempereatures change, maybe i get some sags, runs.

    the folks shouldnt worry too much about orange peel as long as they apply enough clearcoat, some musculoskeletal effort with buffer and you get it glassy in day, day and half...

  7. #22
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    Default Yes sir...

    Quote Originally Posted by baubau View Post
    Henry, i either leave the clearcoat cans on my heating radiator or if i forget, i put it in microwave, i got a system, sort of, 500 ml for 25 sec, 750 ml 35 sec heating....LOL...

    it works for me tru trial and error....now that warm weather is coming, i will be experiencing some issues clearcoating as tempereatures change, maybe i get some sags, runs.

    the folks shouldnt worry too much about orange peel as long as they apply enough clearcoat, some musculoskeletal effort with buffer and you get it glassy in day, day and half...
    You're a good man with tons of knowledge. Just wish you posted more often. Many can learn a lot from you.

    Henry

  8. #23
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    Quote Originally Posted by Henry View Post
    MOST IMPORTANT are temperatures and not JUST the ambient temps but more importantly, the temp of the metal AND urethane paint cannot be applied or CURE in under 55 degree (F) temps or you'll see problems.
    Just to clarify henry. If I spray my car on a 71 degree (F) afternoon, and I let it cure overnight and the temperature drops down to 48 degrees (F) I could run into problems? Problems as in the occurring of orange peel on the panel?

    Quote Originally Posted by baubau View Post
    imortant to avoid piling clearcoat on and avoiding "urethane waves" in clear coat appearance.
    I think this is where I went wrong on my bonnet. Great info baubau

    bmarler those sanding scratches I posted earlier went right through to the base coat. I think the edges on the paper as you said were the problem and I may have applied too much pressure. Be wary when you color sand below 1500grit by hand everyone. Very dangerous unless you've practiced it before and are confident with the process (each color of car will be different keep in mind)

  9. #24
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    Quote Originally Posted by tom86 View Post
    Just to clarify henry. If I spray my car on a 71 degree (F) afternoon, and I let it cure overnight and the temperature drops down to 48 degrees (F) I could run into problems? Problems as in the occurring of orange peel on the panel?


    I think this is where I went wrong on my bonnet. Great info baubau

    bmarler those sanding scratches I posted earlier went right through to the base coat. I think the edges on the paper as you said were the problem and I may have applied too much pressure. Be wary when you color sand below 1500grit by hand everyone. Very dangerous unless you've practiced it before and are confident with the process (each color of car will be different keep in mind)
    As far as spraying at 71 degrees that should allow the paint to flow our properly but the drop in temperature during the curing will slow down the cure cycle and it will take longer for the paint to harden.

  10. #25
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    Quote Originally Posted by Len View Post
    As far as spraying at 71 degrees that should allow the paint to flow our properly but the drop in temperature during the curing will slow down the cure cycle and it will take longer for the paint to harden.
    Okay, thanks yes this is what I've noticed just takes longers to harden. Doesn't necessarily cause problems.

  11. #26
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    Quote Originally Posted by tom86 View Post
    Okay, thanks yes this is what I've noticed just takes longers to harden. Doesn't necessarily cause problems.
    That can depend on the type of paint. Some of the low cost products won't cure properly at low temps and can cause them to not ever cure properly even if you increase the temperature later.

  12. #27
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    Quote Originally Posted by tom86 View Post
    Okay, thanks yes this is what I've noticed just takes longers to harden. Doesn't necessarily cause problems.
    Urethane products are sensitive to curing temperature. You really need to read the p sheet and follow the manufacturers recommendations for the curing cycle. If not you could have a big mess on your hands that needs to be stripped off. And improperly cured urethane is a bugger to strip.
    I never paint if I canít maintain 60f for 24 hours.
    b marler

  13. #28
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    Quote Originally Posted by Len View Post
    That can depend on the type of paint. Some of the low cost products won't cure properly at low temps and can cause them to not ever cure properly even if you increase the temperature later.
    Quote Originally Posted by bmarler View Post
    Urethane products are sensitive to curing temperature. You really need to read the p sheet and follow the manufacturers recommendations for the curing cycle. If not you could have a big mess on your hands that needs to be stripped off. And improperly cured urethane is a bugger to strip.
    It's interesting that I've never had this issue cause every night where I live it gets below 54f. Maybe my shed is just well insulated. I've been trying to contact the manufacturer as you suggest but I think they've gone on holidays. Every time I've used it in the past, it has set like cement.

    Quote Originally Posted by bmarler View Post
    I never paint if I canít maintain 60f for 24 hours.
    For me, this would mean I only have a few opportunities every year (in summertime) I could paint without having to worry about this. I'll wait until I get in contact with the supplier to figure out my temperature window

  14. #29

    Default Question sanding clear dry

    Years ago I would dry sand the urethane clear coat with a 3/32 throw little orbital sander and 1200, 1500, 2000, then buff with a wool pad then polish with a wool pad. Everything always turned out great. My question is I see many are now wet sanding clear and using these foam pads to cut then then polish. Can I still do it the old way😳?
    Len used to sell me Sure Finish now I hear thatís not available so what do I use? Iím ready to paint so please let me know. As always thank you for your responses.

  15. #30
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    Quote Originally Posted by ghackett1 View Post
    Years ago I would dry sand the urethane clear coat with a 3/32 throw little orbital sander and 1200, 1500, 2000, then buff with a wool pad then polish with a wool pad. Everything always turned out great. My question is I see many are now wet sanding clear and using these foam pads to cut then then polish. Can I still do it the old way😳?
    Len used to sell me Sure Finish now I hear thatís not available so what do I use? Iím ready to paint so please let me know. As always thank you for your responses.
    certainly you can use your old method. i would recommend getting one of the orange foam pads from len though. i use wool for the first pass after sanding, then switch to the orange foam pad to polish. using wizards mystic cut, it's a great diminishing abrasive compound. some people use foam the entire time, but i like the speed of the wool pad for the bulk of the cutting.
    b marler

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