Curing Powder Paint

[timbass]

So I was wondering if I am doing something wrong or if the results are to be expected.  I recently began pouring my own jigs and am powder painting them with pro-tec powder paint.  I have seen a wide range of opinions on how long and at what temp to cure the jigs.  I have been experimenting; however, I was wondering why the finish of the jigs is coming out so dull.  When I first paint them they have a nice luster, but once out of the oven, they are very flat.  I found the less I cook them the more they shine, but the finish is of course less durable.  So, do all powders dull up when cooked?  I realize that a dull finish may well be better for fish catching, but from the a crafting perspective I just want to know if I can control this or not?  Thanks.

[dlaery]

They shouldn't be dull.

[dlaery]

Here is a chart I have. I don't know where I got it. It says it came from Component Systems, that is where Pro Tec powder comes from, they are not a manufacturer.

cure temps.pdf

cure temps.pdf

cure temps.pdf

cure temps.pdf

cure temps.pdf

cure temps.pdf

cure temps.pdf

cure temps.pdf

cure temps.pdf

[cadman]

Timbass,

    Welcome to TU and your first thread.  You might want to post what heat temp are you using, duration of how long your jig is in the heat and what color. This would help all get an idea of what you are doing, and give guys that use Pro-tec some insight. I see that dlaery posted a cure temp chart for Pro-tec paints, that is a good place to start. However I do not follow that chart at all. Reason being is that I rarely use Pro-tec ( cost is very high) because I use many other different powder paint brands, along with that I do multi-color jigs (like in my avatar) so what temp do I use? Well I came up with my own temp and it works for all the powder paint I put on my jigs. 350 degrees for 15-20 minutes. There are many variables as well. I found candy paints have a tendency to run if heated too long. Some powders need more heat to cross link the polymers. Anyway your powder should not be dull if it is  a gloss powder. Maybe your toaster oven is too hot and burning the powder. You should check the output temp your toaster is putting out with an accurate thermometer. This is the only way you will know for sure. JMO

[smalljaw]

I'm going to echo Cadman for the most part, the only way they would be dull is if you are using a flat color and since you have a gloss look before curing then I would say the color isn't the problem. I've been using powder for all my baits for a long while now and I tried using the temp charts but as Cadman has talked about, it is kind of hard to do when using multiple colors. So after a lot of experimenting and trial and error I have come to the conclusion that 350 for 15-17min. is about the best all around curing temp and time, this works for every thing I made. There is another way, and it is using a lower temp like 270 degrees for 45 minutes, I tried it and it did work well but 350 is just as good and it is quicker. That being said, until you give some more detailed information what we will be telling you is just general items to look at and the first I would say is temperature as it sounds as if you are actually burning the powder, my toaster oven when I gave it its first check was at 405 degrees when I had it set for 350 so they aren't accurate and I give it a check every 6 months just to be sure. Another thing you may hear is to try heating the jig just hot enough for the powder to stick without glossing over, I don't advise this and pro-tec actually told me that the paint should already be glossed over when you go to cure it, I am telling you this as it seems there are some who practice this with success, I have tried it and unless you preheat your jigs in an oven and do one at a time it is very hard as the heat control has to be perfect, something you aren't going to accomplish with a torch or heat gun. So let us know the details but I'm willing to be the problem is your oven is too hot, I could be wrong but I believe that is where the problem lies.

[mark poulson]

I set my toaster oven at 350, and heat my powder coated jig heads for 15 minutes.  I let them hang in there with the door closed to cool.

I find that overheating causes the paint to dull, either when I'm heating the jig prior to dipping them, or afterward, if I hang them directly over the heating element in the oven.

I use 350 because it works, it's the temp. that I heat my soft plastics to, before I pour them, so it's an easy temp for me to remember.

[timbass]

Hey all.  Thank you very much for your replies and good information.  So, to be more specific, I tried curing them from 375 to 450 with the time at 375 being 30 minutes and 450 for 18 minutes.  Bottom line is that I was thinking that I was overheating or burning the paint as well.  I actually only cooked them that hot as a test to see what it would do and how the paint would behave at that temp.  I have been only doing three at a time so that I don't ruin too many and I was even thinking that doing so few would inhibit the oven's heat distribution and overheat them.  Well guys, thanks again for the info and the pro-tec heating chart.  It is interesting that everyone agrees that the ovens are inaccurate with their temp readings and it now makes sense why I see so many photos and videos of people using oven thermometers.  I will get one asap and cook up a few more and let ya know what works for me.  Thanks.

[Slammingjack]

I use Pro-tec. The first time I used it looked great. Then I took it fishing, first time I ran it over an oyster bed it chipped the paint right off the bottom of the jig. Ticked me off I'm here to tell you. So I looked that up here on TU. I found a post  I think it was by Toad frog about baking at low temp. and then stepping it up to the temp. on the jar. So I tried it. He was 100% right about it making the paint so much tougher. I preheat the oven to 170F, when It gets there I place the jigs and bake for 10 min. Then leaving the jigs in the oven I rise it to 240F. When it gets there I set the timer for 10 min. Then I go to 350F once it's there I set the timer for 20 min. When I fish with these jigs and run over an oyster bed, It may scratch it but it won't chip it at all. Some jig lasts way longer. (Thx Toad frog) Hope this helps.

[timbass]

Thanks Slammingjack.  I am in southern Oregon so all I have to deal with is reservoirs that are mostly rock.  I literally started pouring jigs and powder painting just so I would no longer spend good money on jigs only to have the paint chipped off in 10 casts.  Fortunately I don't have to contend with shell beds, but I wouldn't mind as I plan to one day experience some Florida fishing.  Anyway if your method holds up to shells then I am sure it will hold up to rocks.  I will give this a try for sure.  Thanks for your post.

[Painter1]

Interesting idea.  So if I understand correctly, 10 min @ 170, 10min @ 240 & 20min @350.

[Slammingjack]

Yeah that's it. Preheat to 170f put the jigs in and leave them in until your done @ 350f. Always wait until it's to temperature before you set the timer. Takes longer but they come out real tough and shiny.

[FishAction]

Pro-Tec is polyester powder paint and will sometimes have a dull wrinkled finish if overheated in the cure process. 450 is way too high for this type of paint.

 

The referenced chart is a good start but it appears to be old and paints are being improved and changing as a result. For instance, Pro-Tec watermelon red flake will not accept the listed temp, resulting in dull flake with no flash. Had to cure at a much lower temp to fix the problem. 

 

Charlie

[bass100]

I don't yet know of any manufacturer who provides a cure time list for powders that are applied with heat.  All powder paints were designed to be applied with static electricity.  If you follow the cure times provided with your powders you will often find that you will over cure your paint because when you applied your powder with heat you already started the curing process.  The reason I know this info is because I use to work as a powder coater painting items for the military.  I have spent countless hours finding the right cure time for all my powders and the average for me is 350 degrees for 11 min.  This time will change for everyone based on the temp that you applied your powder.  This doesn't have to be exact there is a bit of wiggle room.

 

When you first apply the powder it is hard but brittle.  When it is cured correctly it is still hard but now has elasticity and will bend when your lead bends.  When it is over cured it will start to go back to brittle.  Paint up about 4 or 5 items and preheat your oven to 350 degrees.  Then cure each item at 2 minute intervals (cure the first one for 10 min,the second for 12 min, etc.)  I then take the first item and throw it on my concrete floor.  Let me emphasis not drop but throw.  Do this to all of your items and then look at them and you will see the quality of each cure time.  On some the paint will chip off or crack but one of them will mold to the deformed lead perfectly, now you are in the ball park.  If you are fine with the results then you are good but you can take it a step further and fine tune it.  If you find that the item you cured at 12 min was the best then cure another one at 11 min and one at 13 min and then repeat the process and choose the best one.  It is time consuming but well worth the end results.  I find that the darker the color the more wiggle room you have for the cure time but the light colors are a bit more fragile and can be a pain to get the right cure time.  I have several light colors here that will not hold up to the abuse that a darker color will.  I am sure there is other ways to get the cure time right but this is how I do it and I hope it helps.

[cadman]

I don't yet know of any manufacturer who provides a cure time list for powders that are applied with heat.  All powder paints were designed to be applied with static electricity.  If you follow the cure times provided with your powders you will often find that you will over cure your paint because when you applied your powder with heat you already started the curing process.  The reason I know this info is because I use to work as a powder coater painting items for the military.  I have spent countless hours finding the right cure time for all my powders and the average for me is 350 degrees for 11 min.  This time will change for everyone based on the temp that you applied your powder.  This doesn't have to be exact there is a bit of wiggle room.

 

When you first apply the powder it is hard but brittle.  When it is cured correctly it is still hard but now has elasticity and will bend when your lead bends.  When it is over cured it will start to go back to brittle.  Paint up about 4 or 5 items and preheat your oven to 350 degrees.  Then cure each item at 2 minute intervals (cure the first one for 10 min,the second for 12 min, etc.)  I then take the first item and throw it on my concrete floor.  Let me emphasis not drop but throw.  Do this to all of your items and then look at them and you will see the quality of each cure time.  On some the paint will chip off or crack but one of them will mold to the deformed lead perfectly, now you are in the ball park.  If you are fine with the results then you are good but you can take it a step further and fine tune it.  If you find that the item you cured at 12 min was the best then cure another one at 11 min and one at 13 min and then repeat the process and choose the best one.  It is time consuming but well worth the end results.  I find that the darker the color the more wiggle room you have for the cure time but the light colors are a bit more fragile and can be a pain to get the right cure time.  I have several light colors here that will not hold up to the abuse that a darker color will.  I am sure there is other ways to get the cure time right but this is how I do it and I hope it helps.

Wow I thought I'm the only one that went to extremes with powder paint. I totally agree with everything you said. I also work with powder paints and steel. I, like you, have to make sure that the powder paint adheres to our product. You are correct in stating that "almost" all powder paint is applied electrostatically. The only exception is guys like us that put it on our jigs because lets face it, it is durable and better than any other alternative. We get spec sheets for every paint color and from every manufacturer on the ideal time and temp for the correct hardness. However there are different powder blends for different applications, and some epoxies, hybrids or TGIC's are better for some things and are not as good for others. Your testing of jigs is beyond compare, however most guys probably won't invest in the testing time. I too have gone your route of testing, however my dilemma is that I have several colors on my jigs from different manufacturers, so I came up with the numbers I posted. Not possible to come up with an exact time with all those colors. With that said even if guys are off a little, and there jigs aren't as hard as they could be per specs, most fish wouldn't care, and we would lose them before too long. Thank god we aren't making jigs for the military, because they would all fail without doing a thorough test on them. I really like your write-up.

Edited October 26, 2013 by cadman

[lbslures1]

Pro-Tec is polyester powder paint and will sometimes have a dull wrinkled finish if overheated in the cure process. 450 is way too high for this type of paint.

 

The referenced chart is a good start but it appears to be old and paints are being improved and changing as a result. For instance, Pro-Tec watermelon red flake will not accept the listed temp, resulting in dull flake with no flash. Had to cure at a much lower temp to fix the problem. 

 

Charlie

I thought Pro-Tec was an epoxy which may be the same thing as polyster

[lbslures1]

So I was wondering if I am doing something wrong or if the results are to be expected.  I recently began pouring my own jigs and am powder painting them with pro-tec powder paint.  I have seen a wide range of opinions on how long and at what temp to cure the jigs.  I have been experimenting; however, I was wondering why the finish of the jigs is coming out so dull.  When I first paint them they have a nice luster, but once out of the oven, they are very flat.  I found the less I cook them the more they shine, but the finish is of course less durable.  So, do all powders dull up when cooked?  I realize that a dull finish may well be better for fish catching, but from the a crafting perspective I just want to know if I can control this or not?  Thanks.

As others have replied to this concerning the oven temps are not all the same. I have owned a few and none of them are the same temps. Sounds like you may be overheating the heads but not a fact. I have had some containers of powder in a particular color turn out dull and the same color from another container come out glossy, go figure. Try the same color from two different batches of powder paint if available.

[cadman]

I thought Pro-Tec was an epoxy which may be the same thing as polyster

I can't tell you for sure without calling them up, as I don't remember. However attached is a sheet from Dupont on some of the types of powder paint out there and their applications. Mind you this powder like all other is really supposed to be applied electrostatically.

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

Dupont Technical_Guide.pdf

[bass100]

Thanks Cadman.  You are right, there are many manufacturers and many types of paint and many more to come in the future.  We are forced to each come up with what cure time works for our applications.  As heat application becomes more popular I am sure there will be new equipment to take more of the guess work out.  My main reason for the post was to let guys know there is no easy answer.  They are just going to have to put the time in if they want the most out of their paint.  I don't even want to know the amount of time you have put in with your multi color paint jobs.  WOW

[mark poulson]

So, riddle me this, Batman...if powder coat is applied electrostatically, is it heat cured?

[cadman]

So, riddle me this, Batman...if powder coat is applied electrostatically, is it heat cured?

So Boy Wonder, I assume you Wonder what the answer is to your question.

In sheet metal. The metal part is put on a table, rack, or hook where there is an electric charge, that transfers to the part. The electric charge then draws the powder paint usually from an air operated spray gun to the part which as you move the gun (like an air brush only lot bigger)until you cover the part with paint completely. There is a way to gauge how much paint must be put on the part and how much is on it , but I don't know how they do that. Once the part is painted it usually goes on a conveyor to a big walk in oven, which as it starts from one end, it is timed so that when it reaches the other end it has the correct baking time. The oven we had was 9 feet tall, 9 feet wide and 20 feet long. It is pretty cool to watch. Anyway as it exits the oven it cools and then they take the part off, exam it, inspect it and then pack it.

So no need to wonder anymore Boy Wonder. Holy Powder Paint Boy Wonder I think I've answered the riddle

Edited October 26, 2013 by cadman

[smalljaw]

The info Cadman and bass100 have put forth is awesome!! A couple of years back I got in touch with a rep from CS but I remember going through Do-it, anyway, I had asked about some guys heating a jig or lure just hot enough so the paint goes on but remains dull, not glossed over and wondering if that was right or not. What they told me was basically the same thing bass100 stated, the person told me that if the paint was going on with heat and not electrostatically then it doesn't matter as the curing process has begun, I was told that you can do it that way but they advise against it because if the part is only hot enough foe the paint to stick but not gloss over, there is a good chance that some of the paint can actually  drip during the final cure cycle, what happens is the paint that hasn't fully melted onto the jig melts quickly  as it reaches temp before the part that is underneath and it can run or drip and leave nipples and or bare spots so the best thing to insure a good even coat and consistent cure is to heat the jig to 350 degrees so when the part is dipped  the powder adheres to, and slowly glosses over the part. The same thing with the cure, and as a basic cure cycle they recommend 350 degrees for anywhere between 11 and 17 minutes or 270 degrees between 30-45 minutes. I didn't quite experiment as much as bass100 or Cadman but I did try out the 350 for 15 minutes, and the 270 for 45 minutes and both worked fine, I thin tried the 350 for 17 minutes and found no change so I stuck with the 15. Good post.

[RayburnGuy]

So Boy Wonder, I assume you Wonder what the answer is to your question.

In sheet metal. The metal part is put on a table, rack, or hook where there is an electric charge, that transfers to the part. The electric charge then draws the powder paint usually from an air operated spray gun to the part which as you move the gun (like an air brush only lot bigger)until you cover the part with paint completely. There is a way to gauge how much paint must be put on the part and how much is on it , but I don't know how they do that. Once the part is painted it usually goes on a conveyor to a big walk in oven, which as it starts from one end, it is timed so that when it reaches the other end it has the correct baking time. The oven we had was 9 feet tall, 9 feet wide and 20 feet long. It is pretty cool to watch. Anyway as it exits the oven it cools and then they take the part off, exam it, inspect it and then pack it.

So no need to wonder anymore Boy Wonder. Holy Powder Paint Boy Wonder I think I've answered the riddle

 

Might add that since one is positively charged and the other has a negative charge the powder paint is "drawn" to the part being painted.

 

Ben

[FishAction]

I thought Pro-Tec was an epoxy which may be the same thing as polyster

Per a phone call to Pro-Tec some time ago, the individual I spoke with confirmed it to be polyester paint. Epoxies are interior paint and will degrade in exterior use. Also, epoxy paint will crack easily after curing with hard impact or from rock contact in use. Polyester is for exterior use and doesn't crack easily after proper cure.

 

Information on powder paint types is readily available on the net.  It's good reading for those who want a better understanding about chosing and working with powder paints.

 

Charlie

[cadman]

The info Cadman and bass100 have put forth is awesome!! A couple of years back I got in touch with a rep from CS but I remember going through Do-it, anyway, I had asked about some guys heating a jig or lure just hot enough so the paint goes on but remains dull, not glossed over and wondering if that was right or not. What they told me was basically the same thing bass100 stated, the person told me that if the paint was going on with heat and not electrostatically then it doesn't matter as the curing process has begun, I was told that you can do it that way but they advise against it because if the part is only hot enough foe the paint to stick but not gloss over, there is a good chance that some of the paint can actually  drip during the final cure cycle, what happens is the paint that hasn't fully melted onto the jig melts quickly  as it reaches temp before the part that is underneath and it can run or drip and leave nipples and or bare spots so the best thing to insure a good even coat and consistent cure is to heat the jig to 350 degrees so when the part is dipped  the powder adheres to, and slowly glosses over the part. The same thing with the cure, and as a basic cure cycle they recommend 350 degrees for anywhere between 11 and 17 minutes or 270 degrees between 30-45 minutes. I didn't quite experiment as much as bass100 or Cadman but I did try out the 350 for 15 minutes, and the 270 for 45 minutes and both worked fine, I thin tried the 350 for 17 minutes and found no change so I stuck with the 15. Good post.

Smalljaw good info as well. There is so much technical stuff with powder paint, that I try not post too much. Most of the powder paint that is painted in the industry has very clear specs that have to be followed. We also made painted panels for the military and aerospace.  Talk about anal. These guys checked everything from powder paint thickness to hardness with a 2H pencil, to gloss and sheen. If it didn't pass by the source inspector, then you had to fix it. If you kept failing, then you lost the contract. But that is the government.  So we all do the best we can. After all only we're only making fishing jigs and this should be fun.

[mark poulson]

So Boy Wonder, I assume you Wonder what the answer is to your question.

In sheet metal. The metal part is put on a table, rack, or hook where there is an electric charge, that transfers to the part. The electric charge then draws the powder paint usually from an air operated spray gun to the part which as you move the gun (like an air brush only lot bigger)until you cover the part with paint completely. There is a way to gauge how much paint must be put on the part and how much is on it , but I don't know how they do that. Once the part is painted it usually goes on a conveyor to a big walk in oven, which as it starts from one end, it is timed so that when it reaches the other end it has the correct baking time. The oven we had was 9 feet tall, 9 feet wide and 20 feet long. It is pretty cool to watch. Anyway as it exits the oven it cools and then they take the part off, exam it, inspect it and then pack it.

So no need to wonder anymore Boy Wonder. Holy Powder Paint Boy Wonder I think I've answered the riddle

 

   

 

I had seen electrostatic painting at my steel guy's shop, when he primed wrought iron stuff before it left the shop, but he never heated it.  I never thought to ask him what kind of paint he was using, and it's too late to ask him now.  The inconsiderate S.O.B. up and died on me!

Edited October 27, 2013 by mark poulson