Powder Coating Advisor
 

Hi folks,
I have a powder coating company and have coated many cycle parts. If you have questions about powder coating just ask me. I can give you advise about the advantages and limitations of powder coating your parts, stripping the old finish with sand, glass beads or plastic media or chemical strippers etc. I can explain the process so you know what to expect from each step. I may also be able to help you find the resources you need to get the job done and give you an idea of the costs involved. I'll check back weekly and get you the info you need.

Hi. I was wondering what kind of price range I should expect for a simple one to two color powder coat job.

Also, what's the usual turn around time, with or without prep time?

Thanks!

Pricing and turn around time
 

Hi JonH,
Are you asking about coating a one piece frame only? Has it already been stripped? I'll make some assumtions.
If you brought me a simple frame already stripped you should expect a price @ $75 for a single basic color. Some silvers require a clear coat because the metallics lay at the surface and need to be covered to protect the metallic flakes. Candies and translucent colors require a base coat. These types of double coat colors are considered two stage colors and can increase the price by at least 50%. Using two single seperate colors would require special masking and processing the piece twice so you may be charged double plus some labor time for masking. Make sure they've done this before it can be tricky.
If you need it stripped there are many options and the price of stripping could range @ $25-$50 or more depending on the media, time and process used. It's better to let the coater handle the stripping process than taking it to two different places.
The actual time it should take to coat the part is only about an hour. Stripping the part depends on whats being removed and what process is used. Powder coating is more difficult to remove than painted coatings but it shouldn't take more than 1-2 hours for stripping either way.
I would say 1 week is a reasonable time frame for turn around.
Coaters with "batch type" processing can usually process your part quickest.
I hope this answered your question.

I have a question. I got an older lugged steel frame powdercoated a light metalic green color last summer. In a couple places around the lugs (presumably over the brazing material that was used), the color was much lighter. The powdercoater said he had never seen that and speculated that maybe the metalic paint interacted differently with the metal there.

Any insight?

jim

Hi pc4u. I had two frames coated at a local shop. This guy works out of his residential garage. The frames turned out very beautiful, and the price was right. ($65 and $80 each including stripping) My only (minor) complaint was that the finish seams to chip easier than I expected, like when bolting on wheels or dropping a wrench on it. I thought a powder coated finish would be tougher than this. These frames were chemically stripped, and when chipped the bare surface looks very smooth. Would sandblasting have provided a better surface for the pc to adhere to? Did something else go wrong? Thanks! -Mark

Great idea for a thread. Perhaps this will become a sticky.

Here is my question...I've always admired brushed steel and would love to have a brushed steel bike frame. Can a clear powdercoat give me what I want? (the brushed steel with rust prevention/resistance)

Gray

Light spots around the bolt lugs
 

Hi Jim,
Excellent question! By lighter I'll guess you mean the strength of the color not the thickness of the coat. I'll try not to get too technical. The process in powder coating involves charging the powder as it leaves the gun so it's attracted to the grounded part. Even though the brass used in welding is non magnetic it will still conduct an electrical charge. This attraction causes the powder to surround and collect on the part evenly but... in areas where there are corners where the metal starts to angle back toward itself or is close together like in the neck area or under the seat you get whats called the farraday effect. It's sort of like trying to put magnets with the same pole together, they want to push apart. As the charged powder starts to build on both sides it actually pushes the additional powder away from corners, like the magnets. The tighter the corner or closer the two pieces are the stronger the force. Metallic powders magnify the effect and are much more sensitive to the charge. Also the charge setting on the gun will effect the color of the finish. A higher charge will give you a brighter more silvery finish and a lower charge will increase color strength. Recoating the part can also be tricky because even though you can coat over powder coating the first coat acts like an insulator to the ground that the charged powder is looking for and can increase these effects. Talk with your coater and see if he's willing to try a recoat just turn the KV way down. Sorry for being wordy. Good luck

Mark

Brushed Steel Look
 

Hi Gray,
Two things will effect the look of the steel. First, steel is normally cleaned and degreased, then rinsed with an iron phosphate wash and then rinsed again with clean water and dried. This process cleans, adds corrosion resistance and adhesion. This process will also turn the steel blueish gold in a random fashion. although this step is used to increase adhesion and corrosion resistance it's not required. You can skip the iron phosphate step and sacrifice some durability. The other unpreditable discoloration will come from the high heat which will also effect the color of the steel. It may darken, show stain marks or give it and aged worn look. I'd try it on some scrap parts first. What ever you do, one thing never changes... the part must be absolutely pristine clean before coating. The high heat will amplify every defect. The clear coat will just make it shiney.
If you find a way please let me know how you did it.
Good luck!

Mark

Chipping finish
 

Hi Mark,
Its hard to say, Sand blasting creates a rough profile on the surface and a larger surface area for the powder to cling to. The more aggressive the profile the larger the surface area but also the rougher the finish. Chemical stripping works well also but the part should be washed and cleaned very well. I like to use a scotch brite pade while I wash the part. It helps lossen up evey thing so I can rinse it away.
Your right though it shouldn't chip that easy. Two things come to mind Cleaning and Time at Temperature.
I don't know what process was used to clean the metal. Is it steel or Aluminum? It must be absolutely clean. Just the touch of your hand will leave an oil residue that may cause defects in the finish or cause lifting in places. Using a solvent based cleaner will also cause adhesion failures.
One of the most common problems is a failure to get the substrate (base metal) to the correct temperature. (Not long enough in the oven) Recommendations on the powder box may say something like 398F for 10 min. That's ONLY the time required to cure the powder. The base metal of the entire part must also reach that temperature for proper adhesion. The powder may have cured properly but failed to adhere to the metal.

Mark

Chipping finish
 

Hi Mark,
Its hard to say, Sand blasting creates a rough profile on the surface and a larger surface area for the powder to cling to. The more aggressive the profile the larger the surface area but also the rougher the finish. Chemical stripping works well also but the part should be washed and cleaned very well. I like to use a scotch brite pade while I wash the part. It helps lossen up evey thing so I can rinse it away.
Your right though it shouldn't chip that easy. Two things come to mind Cleaning and Time at Temperature.
I don't know what process was used to clean the metal. Is it steel or Aluminum? It must be absolutely clean. Just the touch of your hand will leave an oil residue that may cause defects in the finish or cause lifting in places. Using a solvent based cleaner will also cause adhesion failures.
One of the most common problems is a failure to get the substrate (base metal) to the correct temperature. (Not long enough in the oven) Recommendations on the powder box may say something like 398F for 10 min. That's ONLY the time required to cure the powder. The base metal of the entire part must also reach that temperature for proper adhesion. The powder may have cured properly but failed to adhere to the metal.

Mark

Great thread Mark!

I was wondering whether home powder can be as durable as pro powder. I'm not talking some superman pro powder, but the run of the mill stuff one gets. Is there some inherent advantage to what a pro could do in his shop vs. what he could do in his garage? Size aside of course.

I also wander what difference there is between different colours. I did a rack recently for my own bike, and I wanted it to stand out, and attract attention. I got it done in red, and it has scratched a little. I just crazy glue the scratched areas and drive on. I'm happy with the job I got, but it isn't super durable. The worst damage was where I tried to protect it. I figured that the metal hooks on my panniers would mark it, so I heat shrunk tubing over those to cushion the contact areas. One day on tour after about a week, I noticed the pack had shifted to the rear. So I took my toe and kicked it back in place. Well the rubber in the shrink tube had bonded lightly to the PC, and it didn't have time to release when I kicked the bag. Big ugly mark! Anyway, I did wonder if a super hard black would be better.

I noticed my coater has several blacks, some are external or truck grade or something. Would they be better choices?

I'm happy to stick with my pro, but I wouldn't mind being able to do smaller parts. With all the flipping of houses going on, one can get an oven for as little a 20 bucks and it might be handy for little custom pieces.

all powders are not created equal
 

Hey Peterpan,
No great advantage by a pro except experience, training and better equipment which usually means better quality but not always I'm afraid. Remember a cured powder coat finish is a non porous plastic coating, you can damage it and it won't last forever.
Powder used to be only available in 50lb boxes or more but now new batch type equipment, custom colors and the need for quick color changes created new types of equipment that gives the home Joe a chance to play. You can buy powder now in 1lb bags or sample packs of almost any color or texture. The smaller equipment works ok for hobby projects. Don't use the house oven! The residues from the powder will contaminate your home oven. A small house oven will work fine for small stuff just don't get confused and coat your food or eat you parts. Theres a bit more to it than just getting a used house oven. It'll be a costly hobby to set up so after you coat every thing in your house and yard maybe you can coat all your neighbor's stuff too for some cash. Cured powder is unforgiving if you make a mistake. It's difficult to remove and can sometimes cost more to remove it than it did to coat it.
Remember the quality is in the preparation. The powder finish just makes your work look pretty. Crappy prep work makes the job pretty crappy.

Can original chrome seatstays be saved during powdercoating?

Chrome seat stays
 

Hi LV,
I'm not sure what your asking. Whats a chrome seat stay and what needs to be coated? What ever you want to coat, it must be completely disassembled, degreased and cleaned. If you can't get some parts off then you need to mask them off carefully. Chrome shouldn't be effected by the powder or the heat.
Mark

Sorry, I should have been more specific. The rear triangle of my frame is chromed, the tubets that connect the bottom bracket to the rear, and the tubes that connect the rear to the seat area. I'm wondering if this area or chrome can be masked off and preserved during powedercoating, or if the heat will damage the chrome. Thanks.

i was toying with the idea of a clear powdercoat... can you tell me anything about it? is it more expensive? will it still adequately protect my steel frame?

Is the price to powdercoat based on the size of the item, surface area? I have a very small project, and I'm not sure it's worth the effort based on the prices I've seen. What should I expect to pay for a pair of aerobar extensions? Essentially two pieces of stock unfinished aluminum tubing with a bend in each. Each would be about 300mm long. By the way, GREAT idea for a thread!

Thanks for this thread, it is very informative.

I have a frame powder-coated about 5 years ago and now I want to strip it off and paint it another colour. What is the best way to strip off powder-coating? I've searched online and the general consensus is that a gasket remover spray will work best, what do you think of that?

I am under the impression that powdercoats are porous and can allow water underneath the coating, is that correct? If so, I have another frame currently at the powder-coaters and when I get it back, I was thinking of putting a clearcoat on top of this, to prevent any rusting under the powder-coat. Is there a specific type of clearcoat I would need to use?

Thanks for any help!

Thanks for answering all these questions on this thread. I have a few of my own:

I'm having a frame powdercoated right now...it should be done next week. After the frame is powdercoated, I would like to apply a second accent color to the head tube and as a lug liner (by "lug liner" I mean a contrasting color used to pinstripe around the edges of the lugs where they meet the tubes). The powdercoater tells me I can use regular paint on top of the finished powdercoat surface to do this.

My questions:

-What type of paint can I use that will adhere to the finished powdercoated surface?

-What kind of preparation of the finished powdercoated surface is required before applying this paint so it will adhere properly?

-After applying the accent color paint (on the head tube and as a lug liner) and putting on some decals or transfers (for identifying the frame's steel tubing and the bike's brand name) can I have the entire frame/fork clearcoated (not with a powdercoat-type clearcoat, but with a regular automotive paint-style clearcoat) over the powdercoated surface, the accent color and the decals?

Thanks for your help.

I'm toying with the idea of having track drop outs fitted to my bike. I had (no very long a go) my frame and forks clear powder coated onto bare metal. I'd like to clear lacquer the new drop outs, rather than get the whole frame coated again. What would be the most durable and best blending type to use?
Thanks for any help and advice.

hey powdercoater, i have a set of velocity deep v bike rims, with machined sidewalls. they are scratched alittle, nothing to deep but i was wondering, would sand blasting and powder coating cover these up? or will i see these scratches in the final product? should i sand it smoother even tho i will get it sand blasted? what is a average price to get this done? thanks, im glad this thread is pretty recent!

you can see some examples of this at www.rivbike.com they are doing this with there new, old school mountain bike

No problems with rust as it's coated the same way a coloured paint is. I like the fact it highlights all the brazing work and picks up the markings of the steel. It's very unique. I recommend it. Here's mine.
http://i65.photobucket.com/albums/h2...n/DSC01677.jpg
http://i65.photobucket.com/albums/h2...n/DSC01681.jpg
http://i65.photobucket.com/albums/h2...n/DSC01660.jpg

First, thank you for your generosity to take questions here, Powdercoater4u!

My question is concerning the heat of the curing process. I wish thinking of powdercoating an Al mtb frame. It's made from 7005. Will the temps of the oven affect an Al frame's properties?
Will it damage the temper, strength, by annealing it?

I know 6061 T6 requires a solution heat treatment to restore strength, what about 7 series?

Chrome seat Stays
 

Sorry I didn't answer quicker I've been busy, You shouldn't have any trouble. Mask off the chrome carefully with high heat tape. If you're trying to have a clean seperation line from the powder to the chrome there's a little trick to keeping the tape line clean. Talk to your coater and see if they're familure with custom taping for a smooth line.