Cure parameters

[Guest]

I was thinking I read somewhere if you adjust your dwell times you could cure at a lower temp. I can't remember where I read that. I have been reading so damm much trying to learn all I can. And come up to speed to where you guys are I forget where.


Harley

[Guest]

Re: Doing bicycle frames

I was thinking I read somewhere if you adjust your dwell times you could cure at a lower temp. I can't remember where I read that. I have been reading so damm much trying to learn all I can. And come up to speed to where you guys are I forget where.


Harley

I think I have read this and read that but can't remember every thing for sure my self. What I do if need be is to copy the info and put in word and save it with what ever name I need to help me know what it is and that helps a bunch. Then I put all the powder info into my powder folder and paint info in my paint folder.

Most of what I have read is if the powder is to be cured at 350/450 or whatever it need to be that. You can ramp it up slow with no problems. And have also read if say you do 350 powder for lets say 15 min you can also do at 325 for 30 min? But the experts have to tell me if the powder I was to use would be a good at 325 for 30 as it would be at 350 for 15? Its their powder and they know what and how it will work best for the app.

I will send an email to one of the top companies and see what they have or what they suggest for what we need. Then Maybe we will have an answer for sure from a maker? That's the best we could do I guess?

[Guest]

Re: Doing bicycle frames

Hey King, In the powder coating manual I got (from someone awesome) in the first section on page I-11 theres a powder comparision chart. In the chart it shows two temps for all the different powders. For example, a TGIC with a typical film thickness of 2 mil cures at (part metal temp) 10 minutes @ 400 degrees to 30 minutes @ 300 degrees. Now I'm still learn the art of powder coating (kung) fu but to me this means if he was to lower the temp and increase the time the part was held at the reduced temp it should cure out fine. Right? Or did I boo-fu again?


Harley

[Guest]

Re: Doing bicycle frames

Hey King, In the powder coating manual I got (from someone awesome) in the first section on page I-11 theres a powder comparision chart. In the chart it shows two temps for all the different powders. For example, a TGIC with a typical film thickness of 2 mil cures at (part metal temp) 10 minutes @ 400 degrees to 30 minutes @ 300 degrees. Now I'm still learn the art of powder coating (kung) fu but to me this means if he was to lower the temp and increase the time the part was held at the reduced temp it should cure out fine. Right? Or did I boo-fu again?


Harley

Got a link to that page? I can't find it.

The manual I have is on a pdf file so I printed and scanned the two pages. Sorry I took so long I had to switch computers. The wifes doesn't have a scanner.

[attachment=1:3mhuqi48]Powder Comparision Chart p1.gif[/attachment:3mhuqi48]
[attachment=0:3mhuqi48]Powder Comparision Chart p2 001.gif[/attachment:3mhuqi48]



Harley

[Guest]

Re: Doing bicycle frames

So if I get it right then your chart shows the same thats in the manual I got from king. Meaning if you lower the temp increase the dwell time. To a point, you still have to stay in the parameters set by the powder maf. Right? And in that case he could powder coat the frame at a lower temp and be okay. I hope I'm not being a long winded pain. But, I do want to make sure I understand what I am reading. Remember I'm thick headed and bald. So it's hard to get in and then leaves quickly.

Harley

[Guest]

Re: Doing bicycle frames

Bummer I was hoping someone would tell me if I understod this right or not.

Harley

[Guest]

Re: Doing bicycle frames

Thanks I know you think I'm a pain or a......... but a simple yes or no to if I understood would of been fine.


Harley

[Guest]

Re: Doing bicycle frames

Thanks I know you think I'm a pain or a......... but a simple yes or no to if I understood would of been fine.


Harley

You are joking with this statement, correct? I don't think that at all, why would I? We've all been there.

By now you have to think I'm a pain in the .... ! I mean no disrespect to you. If I offended you I apollogize. You have been very helpful and patient with my thick headedness.

I am worried about agitating you by the fact I'm not sure what the two different cure schedules in the chart means. To me it seems you can but differs with powder types. But everyone says you can't. Your chart shows the same thing. Lower temp longer oven time. It makes it confusing for a person to learn.


Harley

[Guest]

Re: Doing bicycle frames

We can start a new thread to discuss this more if you think it's best. I don't want to ruin this thread for Duke. I think my original question would answer Duke's original question. In the chart I posted (cure range) and yours (cure Parameters) You could powder coat something and cure it at a lower temperature(pmt). But it has to be at the temp for a longer time. 10min.@400* or 30min.@300. This was my original question, am I reading this right? Which if I'm reading it right, Duke could powder coat the bike with a powder at the manf. recommended lower temp with a longer curing time. And no worries about harming the bike frame or welds. I did mean to help Duke not make this long winded. My apollogizes.

Harley

[Guest]

Re: Doing bicycle frames

According to the chart from HD you could cure that powder at 356f for 30 minutes. Does this answer your question?

Also your post above: I see where you were going with it and you made a good point. I have cured powder at 400f for 15 mins and shot the same powder and cured it at 356f for 35 minutes. Why the extra 5 minutes? I do that with good "over bake" stability powder just to insure a good cure. Better sometimes over than under.

[Guest]

Re: Cure parameters

Cure parameters by Powder Coating Pros:


If you are not sure of your powder curing parameters, be sure to get them from your powder supplier. Don't guess its just a phone call away. Also ask them about "over bake" stability properties. This will allow you to over cure your powder and not have burning issues etc. This helps if you like to cure your substrate just a little longer to insure a good cure or even if you forget about the substrate. More room for error (safety feature).

Lets use this sample cure parameter from Harley Dad



Notice the second dot is at 410f for 10 minutes and the 4th dot is 356f at 30 minutes.

Now you can cure this powder at EITHER of those times. Some people say there are pros and cons of each. Also you can cure within any of those parameters.

Meaning look how the top line curves into the last bottom dot. Where ever you see that line you can cure powder at that temp and time.

Examples: 392f @ 15 minutes, aprox 380f @ 20 minutes, aprox 367f @ 25 minutes

Why do they make this variable? Each substrate is different and some people like to cure aluminum and steel at different parameters for example. There are many reasons, but it is more personal in my opinion. I like to cure at around 392f-400f for 15-17 minutes depending on what powder I am using. I choose this because it works for me. Less Orange Peel, cures fully every time etc.

Now lets talk about when to start the timer!

Part Metal Temperature- PMT

This is the only way in my little book to cure powder correctly being a custom coater. Buy a good IR gun with a laser and also look on the side of the gun or directions for accuracy range.

My gun would be dead on within 1 inch of my substrate in the oven. You do not want to shoot 2 feet back and the IR gun is getting temperature from your oven elements etc.

Also a tip with Chromes or reflective powders. If you are trying to shoot chrome powders sometimes the IR gun will bounce off the reflective surface and not read accurately. What you can do is put the substrate in the oven before coating and take the temp and see how long it takes to get to desired PMT. Then use that time to add on your curring schedule.

All of the above statements work for me, but they may not work for you.

If you have any questions from above please post them and I will try to answer them to the best of my abilities.

[Guest]

Re: Cure parameters

you can cure parts at lower temperatures for longer periods of time on the recommended mil thickness..for instance a part that cures at 325 for 20 minutes can also cure at 350 for 15 minutes...

[Guest]

Re: Cure parameters

you can cure parts at lower temperatures for longer periods of time on the recommended mil thickness..for instance a part that cures at 325 for 20 minutes can also cure at 350 for 15 minutes...

THEKING is always right.... :P

[Guest]

Re: Doing bicycle frames

Thanks I know you think I'm a pain or a......... but a simple yes or no to if I understood would of been fine.


Harley

You are joking with this statement, correct? I don't think that at all, why would I? We've all been there.

By now you have to think I'm a pain in the .... ! I mean no disrespect to you. If I offended you I apollogize. You have been very helpful and patient with my thick headedness.

I am worried about agitating you by the fact I'm not sure what the two different cure schedules in the chart means. To me it seems you can but differs with powder types. But everyone says you can't. Your chart shows the same thing. Lower temp longer oven time. It makes it confusing for a person to learn.


Harley

On No you didn't!! I tell you the truth, not one question asked is a Dumb question ! In my humble opinion it is brave So much bad information is floating around (where it comes from Ijust dont know) that it is refreshing to be able to work with someone who really simply wants an explanation. Dumb is the guy who thinks he knows it all, therefore can learn nothing...we love ya Harley