Powder coating can be used to coat many types of materials. The most common material is metal, but you can also powder coat wood, plastic, composites, glass, and MDF. The first consideration for coating objects besides metal, is can it withstand the temperature. Most plastics will melt when subjected to 400 degree heat for any length of time so it is important to research exactly what your object is made of before you try to powder coat it.
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| This glass vase was powder coated red for Valentines Day. |
How can you powder coat non-metallic items when they aren't electrically conductive?
When powder coating metal, the powder is electrostatically attracted to the metal as long as it is grounded. Well your average plastic, wood, or glass object is not electrically conductive. If you try to spray powder on them, the powder will just fall off and end up on the ground. The solution to powder coating these items is pre-heating. You can heat up the object in the oven, remove the object and powder coat it before it cools. When the powder hits the heated part, it will slightly melt on contact, causing it to stick. After coating the entire part like this, you then place the part back in the oven and cure it like normal.
Something you must watch out for when powder coating a pre-heated item is that it is very easy to put on too thick of a coating. Because the powder is melting as soon as it hits the part, it makes it difficult to judge how much powder is on the part. If a coating is too thick, it can run like paint, it can show craters, and the chip resistance will suffer. A similar method is called hot-flocking. This method involves heating the part up to the cure temperature of the powder(usually 400 degrees F), removing the item from the oven and immediately spraying with powder. The powder will melt and flow out instantly, using this technique greatly increases the chances of too thick of a coating however.
The ability to coat several types of materials is something that is not very well-known but it allows you to apply the same beautiful finishes that can with metal, to many other objects. Next time you are feeling creative, grab a glass from your cabinet, mask off some neat designs, and see what you can come up with.
Powder coated wood by The Powder Coating Institute.
Powder coating can also be used to protect dental products, such as dentures. It is safer and more durable than its conventional counterpart: paint.
ReplyDeleteLonnie Summerall
Would be interesting to try PTFE fortified powder coating.
ReplyDeleteHey great site I just ordered an air compressor and a dual voltage eastwood gun looking to start off to mainly do my bikes and go from there both have a lot of aluminum parts that I'd like to powder coat I understand that this is a relatively vague question but do you have any other tips that aren't listed on your site when it comes to doing aluminum? I work in a machine shop so I have access to a sandblasters, sandpaper, wire wheels..ect
ReplyDeleteThe only special precautions I take with aluminum is the outgassing procedure. Aluminum likes to outgas during the baking cycle which will show up as little blisters in the powder coated finish. I usually outgas aluminum in the oven at 450 degrees in the oven until I no longer see it smoking. Then I will sandblast it, mask if needed, powder coat it, and then bake it. Sometimes aluminum will still outgas no matter how long you outgas it in the oven. It is good to keep an outgas forgiving primer on hand when doing aluminum. This is a primer that you spray while the part is already hot, meaning you bake the part first and then immediately remove it from the oven and then spray the powder on. The primer partially cures as soon as it touches the part so it locks in anything that may outgas on you. After it cools, you can then continue as normal.
DeleteYou do not have to do this on all aluminum parts, but if the aluminum has been in any salt water environment, or it has been in a very greasy environment for a long period of time, chances are it will outgas on you and ruin your finish. Its best to use primer on these parts first.
Outgas the aluminum after sandblasting. If you sandblast after outgassing you will expose new material that will release gasses. Learned this from experience.
DeleteHas anyone tried priming non-conductive surfaces with heat resistant (over 400 F)carbon/graphite conductive paints?
DeleteCan you powder coat chrome parts? Are there any special procedures? Thank you.
ReplyDeleteYes, you can powder coat chrome parts but there are some exceptions. The chrome needs to be of good quality and not peeling. You also have to accept that their will be less adhesion with powder coated chrome vs. a sandblasted part as the chrome is very smooth so there is not much for the powder to grip on to. However, even with that being said, powder coating over chrome is done all of the time. The special procedure is to make sure that the chrome is completely clean. You can clean off any heavy crud with just regular degreaser. I prefer Simple Green Extreme. Then you will want to wipe it down with denatured alcohol several times to make sure it is completely free of all oils and previous cleaners. Handle it with clean gloves while doing this cleaning procedure. Then you are ready to powder coat.
DeleteI tried using a wire wheel on my bench grinder to prep chrome and found it had no affect (did nothing to the chrome). I also tried using a cheap gravity fed blast gun I bought at Harbor Freight but that had no affect on the chrome either. Eventually I used an orbital sander with a medium grit paper to sand/prep the chrome. That seemed to work well. Do I not even need to do all that but rather just make sure the chrome is clean? I would think the powder would not stick well to merely clean chrome because of it's high polish.
DeleteI am using a Craftsman compressor-less gun that seems to work ok for my use. I plan to upgrade soon to a better gun as I am getting the "powder bug" and want to coat a lot of items now.
What psi were you blasting at and what kind of media? It should leave enough profile on the surface for adhesion. As long as the chrome is in good condition and not peeling, you are just trying to scuff up the surface, not remove it, which blasting usually does very well. You are correct, in that the smooth surface of the chrome is not ideal for powder coating over. You can do it, but you are sacrificing adhesion. If your blaster is not up for the job, then sanding is also a good way to scuff up the surface.
DeleteThe Craftsman gun is surprisingly good on most jobs, I still have it and use it every once in awhile. If you are looking for an upgrade, the next step I would go is the Redline EZ50. It is in the $300 range.
I worked at a plating shop for a few years back in my youth. What a lot of people don't understand is, 1st a (typical) part is cleaned. Then its copper plated for about 15-20 minutes (to help smooth out any imperfections) then it's Nickle plated for 45min to an hour (super thick). Then the Chromium is applied for about 10-15 seconds. Just a flash is all that's needed because the element Chromium is that hard.. Also it's basically colorless. What your really seeing is the Nickel underneath. So yes, Chrome can be very hard to rough up, thats the point...
DeleteI am in powder coating business from long time but having a trouble with one of my products.The product is grill on sports helmet.I did powder coating on it no problem in finishing n outlook but while bend test the coating piles off..I am looking to avoid this as the product is in bulk quantity n really worried about rejections in testing.The grill is made of metal Wire which is passed through all chemical treatment but I want to avoid rejection as I can't bare it.please advice me as its in bulk quantity n pre heating does not fit in costing
ReplyDeleteIs it possible that you are over-curing the powder in the oven? What is your prep like? Are you media blasting before coating?
DeleteI have some antique wrought iron and glass light covers that I am thinking of powder coating after removing all their current rusty finish. How easy is it keep the spray off the glass? Can it be "blown" off or will that ruin the coated metal nearby? Please and Ty
ReplyDeleteWithout seeing what you are talking about, its hard to say. Can the glass parts be removed from the wrought iron? If so, I would do that. If they cannot be removed, you will either have to mask off the glass before you powder coat. It is next to impossible to just blow off one area without affecting the powder on the rest of the part. Masking them for powder shouldn't be too difficult, however how do you plan on removing the rust?
DeleteI've been trying to buy low temperature cure powder without success. It seems that while most other powders are available in pound or two pound packages, the really low temp powders aren't available below 50 pound containers. Do you know of any place to buy this? I've looked for some time.
ReplyDeleteAlso, any info on using low temp powder on these other materials, such as plastic, wood or MDF that you mentioned here?
Unfortunately, I have not been able to find any small quantities either. It is up to the powder re-sellers to order the low temp powder and sell it. In order to do that, they need to see a demand for it. Contact the company you buy your powder from and ask them if they would consider selling it.
DeleteCan metal parts of a BBQ Grill or the grates from a gas stove be powder coated or will the heat from use cause it to fail?
ReplyDeleteThanks
I have hi temp powder. But this only goes to 650-700 degrees Fahrenheit - max! This parts can get considerably hotter, so no. They aren't normally painted with anything. Sometimes they are porcelain coated, or finished in a non paint black.
DeleteThe powder, even if you use high-temp will most likely fail. It just gets too hot for any current readily available powder to handle. The best alternative would be ceramic coating. I like Cerakote. It must be applied with a HVLP gun and it must be blasted with aluminum oxide prior to coating. I would use their oven cure formula as it is said to withstand 1800 degrees F. The inside of your grill should between 500-700 degrees.
Deletesince I don't really work in the winter months, I decided I want to start a small project and do a restoration on my little 2003 Kawasaki kx65 and the frame is green and want to powdercoat it to a black, this would be the first time powdercoating anything and also media blasting as well. my dad had a pressure pot style media blaster for a while sitting in his garage so I figured what the hell... when media blasting the "Steel Frame" do I need to "white blast" the metal? which media do you recommend? i ordered "black beauty medium grade" (coal slag) but the dipshit i ordered it from ordered "black beauty medium grade - Iron....... do you recommend a specific type of media?
ReplyDeleteI am not familiar with iron oxide blasting, I have not used it personally. From the little info I can find about it, it seems to be relatively safe (still wear a respirator at minimum) and it says it states that it is for general purpose rust and paint removal. I would test it out on some scrap metal to make sure that it is not too aggressive. Either that or if you have a Tractor Supply in your area, they sell 50lb bags of Black Diamond Coal Slag for $10.
DeleteDo you have an oven large enough for your bikes frame?
i am in the process of finding a free used oven in my area so i can either modify it to make it larger or use the heating elements to build my own.. i know heating elements are fairly cheap online, but if i can get a free unit, why not :)
DeleteIron Oxide is too expensive to spray to waste. It will blast the frame just fine in a blast cabinet, but is "dirty". If using coal slag, the grit should be equal to 80 or 120 or it will be too aggressive. You can reuse your blast media by putting down a giant tarp and put yourself at one end with a piece of plywood under the part. When the pot runs dry sweep up the excess, filter it with a strainer or piece of screen and keep going. "White blasting" is always the proper surface prep if blasting
DeleteHey Sean thanks for taking the time to create all of the info in an organized and well laid out fashion. I have two questions I need a little more clarity on. 1. Large Part's curing - Eastwood sells a Infrared IR Head Lamp that runs on 110/115 v and is tagged as being able to cure large parts. Is that true can you use a IR Heat Lamp to do those things, or can you really only do parts in a oven. (Right now i have a small toaster oven that i can do small/med parts in the garage, as i don't have the room for a range electric oven for say a wheel, heat lamp would be better if even possible based on size etc. even if cure times take much longer.) 2. Aluminium comment from above, i have had the gas out happen to me and its annoying as hell lol. Did some quick research for "Primer" powder but need more detail if possible. Also this weekend I plan to try hydrodipping a part carbon fiber, then following up with a powder clear over the print. Not sure if the ink will hold up to the heat yet or not but just doing some R&D. Thanks in Advance!
ReplyDeleteYou're welcome and I'm happy to hear the site has a good layout. It's one of my main focuses. For your questions:
Delete1. The infrared lamps can cure parts but they work best on simple parts like sheet metal. This is because they cure by line-of-sight. Complex parts with lots of angles or recesses will most likely not cure entirely with the lamp unless you set up some type of reflector around the part so that more of the part is being cured at once. Otherwise, you will need to flip the part over several times to achieve a cure on all sides.
I personally feel that unless you have the proper setup in place, it could lead to undercured or overcured areas on the part but I don't have any personal experience with them. If you do decide to go that route, make sure you have an no-contact infrared thermometer and keep a very close eye on the temps.
2. When dealing with outgassing, some stuff is very stubborn and even if you outgas it in an oven, it's still not enough. For this, I recommend red oxide primer from Powder365. Link: http://powder365.com/store/index.php?main_page=product_info&products_id=212 (copy and paste into browser).
Clear powder over hydrographics has been done with lots of success so you shouldn't have any issues there.
Would it be feasible to coat a product with two layers of different color powder coat? I would like to coat/bake a base layer of one color and overlay a stencil(I realize only certain thinks will work as a stencil due to the extreme heat) Then coat with a second layer different color and bake. After the second coat and second bake I would remove the stencil mask to achieve a two toned product. I am hoping there is a method that would work without the need of sanding the base. Thanks for any guidance or tips offered.
ReplyDeleteYes that very feasible and it is done frequently. I highly recommend you read through this article: (copy and paste into browser) http://www.powdercoatguide.com/2015/07/spraying-multiple-coats.html
DeleteNo sanding is needed in between coats. As long as you are not using a chrome or dormant type powder, you can achieve crosslinking between the two colors. To do this, you would only bake the first color for about 75% of its cure schedule. Let it cool, apply the stencil and shoot the second color. Then you can do a final bake following the second powders cure schedule. However, I also recommend that you pull the part out of the oven after the powder flows out (around 200 degrees F) and carefully remove the stencil. Then insert the part back in the oven and complete the cure. This will ensure a nice crisp line.
It is gone over in much more detail in the article I linked. Hope that helps.
Hi Sean,
ReplyDeleteThanks very much for writing such a piece, it was greatly informative! However, I was wondering how would one go about powder coating a plastic part?
Like you said in the article it's a non-conductive part and it would certainly melt if it was anywhere nearby those temperatures!
How do you get the powder to coat on such a problematic material???
Most plastic parts cannot stand the heat. It is almost the exception that you actually find one that does. However, they do exist. Some plastic wheel centercaps have been successfully coated as well as some plastic intake manifolds. I don't know enough about the chemistry of plastic to tell you which ones do and which ones don't survive in the oven. The only way I can tell you for sure is to test it and see. Just don't try this if the part is valuable/rare.
DeleteThe way to coat non-conductive parts like plastic/glass/composites/mdf is to heat them up before applying the powder. The part will melt on contact with the part and stick. These are not ideal conditions but the only way to do it when dealing with these types of materials. It is very easy to spray the powder on too thick when spraying a hot part.
Maybe you could answer a question for me about PC on glass. Is there a specific powder to use to get a translucent ( see through) finish? Thank you for your time and input.
ReplyDeleteAny powder that is meant to be sprayed over another powder is often translucent. For example, many of the candy colors are meant to be sprayed over chrome. These are simply translucent powders that allow the chrome to shine through the color giving it the candy effect.
DeleteI'm wondering with your comment here, then is it not recommended to attempt to change colors? I have a project that my client agreed to have painted a bright yellow and now wants to know if I can change the color to more of a yellow-orange hue. Payment for the extra work isn't an issue. I'm concerned that the additional build-up will become runny. The yellow was cured at 400f so I'm also wondering if I tried to cure at for example 390f but give more time if the powder will smooth out yet retain some viscosity?
Deletethanks for the great lessons
ReplyDeleteAfter retiring from the woodworking business I decided to pick up powder coating as a hobby/new business. I specialize in powder coating MDF cabinet doors for kitchens or garages. It's a fascinating industry and I have thoroughly enjoyed reading through your website as well as the comments. Thanks!
ReplyDeleteI am interested to know, can the PE ( plastic) pipe powder coated internally. It cannot withstand high temperature ( max 60 C). Any suggestions ? \rahul
ReplyDeleteThere are some low cure powders are there but I have never seen any powders that will cure lower than 60 degrees C. Unfortunately, you would no be able to powder coat the inside of the pipe.
DeleteHey Sean....
ReplyDeleteI'm an interior designer and paintingvamd tile contractor.....I specialize in kitchen and bath design.....one of my most frequent projects is csbibets painting and/or refinishing....do you have experience powder coating wood and do you feel that I could get factory paint results for doors and drawers??....
Hey Sean...
ReplyDeleteWhen Powdercoating Glass would you recommend an adhesion primer before the glass is painted to make the paint stick better? If so, what would you recommend?
No primer is used when powder coating glass. The glass should be completely clean of all finishes, dirt, and other contaminants before powder coating. Powder primers do exist but unlike the world of wet finishes where primers are mainly used for adhesion purposes, powder primers are mostly there to provide additional corrosion protection in the event that the outermost coat of powder is breached. With glass, corrosion is not an issue so all that is needed is a thorough cleaning, a final wipe down with denatured alcohol, and enough time for the denatured alcohol to fully evaporate. You can also media blast the glass for additional adhesion.
DeleteI have been involved with glass (fashion accessories) for 27 years and now welcome experimenting with powder coating sheet glass. Please could someone tell me what I require and where I can look for the necessary DIY set-up to try out the process. Many thanks : Martyn Ellis
ReplyDeleteYou can powder coat glass with any powder coating gun so it is up to you how much want to spend to try it out. I would personally get a cheap beginner gun to start out (less than $100). with and if it something you want to continue doing, then you can upgrade to a better gun if you feel you need to. The beginner guns include the Eastwood Dual Voltage gun, the Harbor Freight system, and the Craftsman powder coating gun. You can see all of them in the article titled "powder coating guns" on this website. The craftsman gun does not need an air compressor.
DeleteWith glass, you will need to ground it to attract the powder, instead, you will rely on heating up the glass for the powder to stick. Then when you are finished spraying, you cure the glass in the oven for a complete cure.
would liquid powder coating work on wood or wold it raise the grain too much
ReplyDeletePowder coating wood is the latest breakthrough in the wood working industry and it is possible depending on the wood type and pre-treatment. The most success has been reached coating middle density fiberboard, MDF and wood types wit low porousity and consistent moisture content.
ReplyDeleteTo enhance electrostatic attraction, wood can be pretreated with a spray solution that provides a conductive surface.
Thank you enormously for such a complete and competent site; most informative. I began looking into foundries that could duplicate some wonderful twisted wood in metal. Then it occurred to me that instead of such a process, perhaps another preserving method could serve. These pieces are old, and therefore, rather infirm. Does it seem useless to pursue powder-coating for my crazy art-projects, or can I be helped? (Not mentally...) Gratefully, Ignoramus
ReplyDeletePlastics can be pre-treated with a conductive thin-film spray which then dries and allows the plastic to become static dissipative (just a step or two below conductive).
ReplyDeleteFor professional shops, use something like Akzo-Nobel's Mor-Prep. For DIY work try Static Guard anti-static spray, or make some home-made anti-static spray using alcohol water and fabric softener... there is an instructable on it.
I want to start powdercoating steel tumblers. Do I need to sandblast them, and all that or would just wiping them down with alcohol be enough. The are brand new.
ReplyDeleteIt is common practice to skip sandblasting when powder coating tumblers and just clean with denatured alcohol prior to coating. However, I think that unless you are specifically masking off the cup to show some of the stainless finish, then sandblasting will provide for a more durable finish.
DeleteHello,
ReplyDeleteI am using Nylon PA 6M sheets. when I give it for powder Coating the resulting product has deformation. Is it because of higher temperature of curing or is there any other factor that I am unaware of..