Welcome to
Powder Coating: The Complete Guide.
My name is Sean and here I will discuss in detail how to powder coat. If you have no idea what powder coating is, I first suggest reading "What is Powder Coating". The main focus of this guide is DIY powder coating but there will be plenty of information here for anyone that powder coats.
Being able to powder coat means being able to apply beautiful durable finishes using relatively low cost equipment, and the basics can be learned quickly. The best part about powder coating is that you don't need a large elaborate collection of equipment to do it yourself. The equipment definitely helps and improves the time spent and the final product, but how involved and how much money you want to spend on equipment is up to you. Powder coating is a great hobby and if you are willing to put in the time to learn it properly and invest in the right equipment, it can be a great career as well.
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| Only a few weeks after I received my first powder coating gun and no prior experience, I took this shifter assembly from this condition.. |
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| to this condition. This guide will teach you how to achieve the same results. |
What will set this site apart from other powder coating "how-to" resources is:
It will never be done, this will be an ongoing guide explaining the equipment and materials needed, techniques to achieve great finishes, and tips to improve efficiency.
A lot of the powder coating resources that currently exist do not offer much more than the most basic information. The more detailed resources are mainly aimed at large assembly line powder coating which use different tools and techniques than you would as a custom powder coater. I would like to guide you through every step of learning to powder coat, from not even having a powder coating gun, to getting amazing results on everything that you powder coat.
I remember when I first started powder coating and how frustrating it was to search through twenty websites every time I had a problem. I had to search all over the internet to possibly find a solution to an issue I was having, only to have to do it all over again the next time I had a problem. This site will include all the information that I have learned from my experiences since I began powder coating.
My main goal is to make it as easy as possible for someone to learn this hobby at home. I welcome any questions or advice. If you are having a specific issue that I have not answered yet, leave a comment below and I will address your question personally.
If you just found this site and like what you are reading so far, you can subscribe and get email updates every time I write something new. I would definitely like your input and questions.
HOW TO USE THIS SITE:
Using this site is pretty simple. The articles are posted on the left hand side of the page and are arranged into different categories:
- Powder Coating: Articles that are directly powder coating related (How to Spray powder coat, Powder Coating Guns, etc.)
- Ovens: These articles are specific to powder coating ovens.
- Compressor: Articles that discuss how set up and optimize a compressed air system.
- Media Blasting: These articles discuss media blasting (better known as sand blasting) and other powder coating prep procedures.
If you are looking for something specific on the site, try the search bar below the Articles list.
In case you don't bookmark this site, just remember www.powdercoatguide.com. If you would like to be notified of new articles, like our facebook page.
Thank you, sorry that I have not updated in awhile. I got busy with Christmas and I haven't had the time lately. I will have to make a new post soon now that I know people are still reading. I think I know exactly what your talking about with bending names out of wire. I tried to make one before with a coat hanger and failed miserably, lol. However, yes, they would be a great candidate for powder coating and very easy to do as well. You would not have to do any masking, very easy to hang, and I assume they are small enough that you could even use a toaster oven to fit them in. I would definitely give the Craftsman Powder Coating gun a try to see if you like it.
ReplyDeleteHey Sean,
ReplyDeleteRead about your blog. I must say you have put in a great deal of hard work. I am based in New Delhi, India and we run a business of precision turned components and cold forged components. I wanted to venture in the field of powder coating as we do get it done in huge volumes from other vendors. Thanks for the effort, let us see if I could learn something from your blog.
I am glad that I could help. Let me know if you ever have any questions regarding powder coating, I'll be happy to answer them.
DeleteIs it possible to powder coat over a good coat of paint without sandblasting?
ReplyDeleteWhile it is possible, I don't recommend it. There are several things to consider:
Delete- How well will the paint do after being baked at 400 degrees? Also if there is anything like body filler underneath the paint, it will not last in the oven.
- How well adhered is the paint to the surface? If you powder coat over paint, its durability is completely dependent on the paints durability.
- You will need to at least scuff up the paint surface to provide some adhesion, but it will not be as good as a sandblasted finish.
With that being said, why don't you strip the paint first?
To get a good finish strip it first or you could lower the temp and bake it longer
Deletewhat size sandblaster works well for motorcycle frames and what kind of sand works the best?
ReplyDeleteI'm not sure if you mean a cabinet or the sandblasting gun itself. If you do mean cabinet, it depends on how many motorcycle frames you plan on doing. A cabinet big enough for a motorcycle frame can be several thousand dollars or you can build one yourself. I would think one a cabinet that is 70" wide and 48" deep would be ok for a frame. Not only does the frame have to fit in there, you need to have a little room on all sides of it to be able to blast it from all angles.
DeleteIf you only plan on doing one motorcycle frame, I would use a pressure pot blaster outside for speedy results. A regular siphon blaster can also work, just stick the pick-up tube in a bucket of media. It will take a lot longer than a pressure pot however, it depends on what equipment you already have and what you are willing to buy. Lay a clean tarp or plastic sheet down, get yourself a blasting hood, a respirator, and cover every inch of your body with clothing. Most of the media should land on the tarp, which allows you to sweep it up and re-use it. Its a messy job, but if you only have one frame to do, its not a huge deal.
Can you powder coat multiple colors on one part and what's the heat resistance after fire on paint. Can you powder coat say a grill and have it last at high temps?
ReplyDeletePowercoating comes in high temps that withstand temps of upto 1000f but require complete blasting of material and are very sensitive in nature requiring very specific procedures while applying for a durable finish. Also to my knowledge are limited in color an a matt finish. Higher temps would require ceramic liquid coating.
DeleteYa it was a nice blog and I am very much interested in starting a powder coating company. And I see a tremendous growth in the powder coating industry. Where new decorative coatings that is now having more demand.
ReplyDeleteSean,
ReplyDeleteJust found these articles. Great info! Thanks for taking the time to post these. You have answered a dozen questions I had that I couldn't seem to find answers to anywhere else. I have a dozen more.
Thanks again.
Rick
I'm glad you found the site Rick and I appreciate the comment. Answering unanswered questions is exactly what I set out to do. If you have more questions that my site doesn't cover yet, don't hesitate to ask me. Right here in the comment section is a great place to ask so everyone else can see it too.
DeleteJust found this site, have been working on a turbo build for my car for a year now, just about to finish and am powdercoating the rims this weekend. Got a really old oven set up behind my house, and managed to find a brand new still sealed craftsman gun on ebay for 60$. Anyways just wanted to say great site, lot of awesome info, it will be what I'll use to do the rims.
ReplyDeleteThanks for the compliment on the site, I also started powder coating as a way to improve my car build. Even started with the same gun. Then the powder coat got addicting, lol. I will be writing for the site again soon so make sure to check back. Thanks again!
DeleteGood day sir. First off great sight. I know nothing about powdercoating but I have learned a lot just from a few minute sof your site.I have recently had peaked interest in powdercoating at home. I want to do wheels but a two-tone. How would one go about that process. I read somwhere to use masking tape (high heat of course) but I can not picture how that would work if I want to do the face of the wheel one color and the rim and lip another. Would you powder one portion, let it cool, mask the newly powdered area, than heat and powder the othe other portion? Also can any clear be placed above powdercoating or does it have to be a powdercoat clear. Thank you for your time and assitance.
ReplyDeleteJason G
Thank you, I am happy to hear that you learned something from the site. You are on the right track with what you suggested. First, check out these 2 links for masking suggestions: http://www.powdercoatguide.com/2013/08/masking.html#.VDTxK1e6PxU and http://www.powdercoatguide.com/2013/08/powder-coat-masking-part-ii.html#.VDTxMVe6PxU . Those explain what type of tapes can be used to mask and how to use them.
DeleteNow, as far as the actual process, you can coat either the lip first, or the face of the wheel. It depends on what colors you are using. Most colors will play nicely, but for example, if you are using red and a light color, always do red part last. If you were to coat with the red first, and then the lighter color on top of it, the red has a tendency to add a red tint to lighter colors.
With that being said, these are the steps:
- Coat the whole wheel in your 1st color and do a partial bake on it. If the powder instructions say 400 @ 10 minutes, only bake it for 6 minutes. If 350 for 15 minutes, only bake it for 9 minutes. However, if you using a chrome powder, it must be fully baked. That is the only exception to this rule.
- Let the wheel cool completely and only handle it with clean gloves at this point. You will then mask off either the face of the wheel, or the lip, depending on which color you are coating next. Read the masking articles I linked for tips on masking. Make sure the masking is a clean process, you do not want to get any oils or dirt on the wheel during this process.
- After masking is complete, put wheel in oven.
- For the cleanest masking line, only set the temp for 200, and once the wheel reaches 200 degrees, you then remove the wheel from the oven and very carefully remove your masking. You want the wheel to remain in range of 180-200 degrees while you are removing the masking from the lip. At this temp, the powder is more gel like, it won't flake and it leaves a very nice edge. If the wheel drops in temp, you can reheat in the oven or use a heatgun to keep the temp in this range. This is all explained thoroughly in "Masking Part 2".
- Once the masking is removed, you can put the wheel in the oven and either cure it completely, following instructions for the 2nd powder color OR if you plan on using a clear coat, do another partial cure. I recommend the clear coat as it will do a great job of blending the line between the 2 powders.
- If you are using a clear powder coat, remove the wheel from the oven after another partial cure and let it cool completely.
- Spray clear and put back in the oven for the final full cure. Follow the clear coats powder instructions at this point.
If done right, you should have a beautiful 2-tone wheel. Definitely practice these steps on some smaller scrap metal before doing it on wheels you care about. Get the process down and then do your wheels.
You can use a liquid clear or a powder clear. I would prefer a powder clear just to keep the wheel all done in powder, plus powder is easier and cheaper to spray than 2k clears. If you are considering a spray paint clear, definitely do the powder clear for durability reasons. Spray paint doesn't even come close the durability of powder coat.
Thanks for the help, I really appreciate what you have written on your article on how to apply powder coat. well I'm new in the business of paint and coating business. And I just recently buy high quality powder coating equipment, it may be costly but I can assure the quality and the long term used of the equipment.
ReplyDeleteThis looks like it could be really effective. I really like my parts to be looking nice when I'm finished with them. The only issue though is the cost, I'm not the most financially secure person. Where would I go to learn more about how much this would cost if I wanted to do it?
ReplyDeletehttp://www.tristatefabricators.com/PowderCoating.htm
Most of the articles on this site link to the products I recommend. Just click on the links and you can see how much everything costs. Thanks for reading!
Deletehows it going! Thank you so much for all the help. I have been doing the powder coating thing for a little while now, but i had a question about pretreatment. Do you do any sort of pretreatment like chromate? Thanks!
ReplyDeleteI have used iron phosphate pre-treaments in the past, but after I used it all up, I decided not to order any more. I was hoping it would help fend off rust in areas that I masked off prior to powder coating, but the areas still developed rust, it just took a little bit longer than normal. I know that it is not the intended purpose, but I was hoping it would help a little more than it did. It has been tested that sandblasting and then doing a pretreatment will provide superior adhesion to just sandblasting, however. But if you can only choose 1, it would be sandblasting 10 times out of 10. I used the iron phophate from Powder365.com.
DeleteHi Sean, I think this post is a must read. We also do custom powder coating services and intend to provide more information about the topic. Agree with you, there are not much information out there on custom powder coating. Hope you can also hop on our website and all the best on your blog.
ReplyDeletehy im new to powder coating and few metal parts have been great but when i tryed my alloy calipers and hangers theres lots of pin holes appeared so after researching i should de-gas so i tryed by putting item in oven at 230 degrees C for around 15 mins then letting cool then powder coat but still same finish what am i doing wrong cheer ste
ReplyDeleteSome cast aluminum and cast iron parts will outgas on you leaving pinholes in the finish no matter how much outgassing you do before hand. The cure for this is specific scenario is outgas-forgiving primer. This is a primer that is sprayed at very high temps. The idea is that the primer cures before the gasses in the aluminum have a chance to escape and then the primer locks them in allowing you to apply your color free of defects. This is a good one: http://powder365.com/store/index.php?main_page=product_info&cPath=1_18&products_id=212
DeleteHowever, it may not be outgassing, make sure you also rule out any sources of contamination on the part as well. This may be oil or water in your airlines used to blow off the part or the airline hooked to your powder coating gun. Check your airlines for any moisture and make sure your filters are functioning well.
Also make sure that you are not handling the part with bare hands after sandblasting. Use clean gloves and works surfaces. It may even be the powder that has issues, try shooting a sample panel such as a soda can or scrap metal with the powder to make sure it is not just the powder giving you issues.
Also make sure the part is grounded correctly, and that you are not spraying too heavy or too close to the part. It is a pain trying to hunt down the source of a defect, just start with the easiest and cheapest fixes, and work your way down the line until you have found the issue.
thanks for reply ill try primer , your link does not work what make primer do i need im in the uk by the way cheers ste
DeleteThanks for website, I have a particular question though. I'm trying to powder coat a fuel tank that originally had a sealer on a seam. I'm sure when the tank reaches 400 it will affect the sealer. Have you used any epoxy/sealer that can withstand the higher temps.
ReplyDeleteThanks.
Have you looked into a low cure powder for your specific job? Not a lot of colors out there but there are some basics like black, white, blue. Most are available on a cure schedule of about 250-300
DeleteAmazing blog man. Really comprehensive, so much info. I build motorcycles and paying others for powdercoat services is a pretty big expense. Been considering the idea of DIY powdercoating for a while and your guide is a great research resource. Thank you for putting this out there!
ReplyDeleteVery nice site & thanks for your work, I have a couple of question- We already have a large oven (20'x12'x10') & a Parker Ionics gun setup and I'm looking to build a smaller oven for small piece work, planning to follow the oven build that you posted with a few 'custom' additions, do you have a schematic of the way the heating elements are wired? series or parallel? Also looking for a smaller gun to facilitate quicker color changes for piece work, is the Redline EZ50 your choice or are there others in that price range?? Thank you
ReplyDeleteUnfortunately, the builder of the oven did not provide me with a wiring schematic, but they were wired in parallel as all heating elements should be. If you need help with specific wiring for your oven, I highly recommend joining the Caswell Plating Forums and posting in the Oven Building Section.
ReplyDeleteAs far as a powder coating gun, I have head that the quality has gone down on the EZ50's made in the past year or so, so I will no longer be recommending them. If you can find an old Eastwood Pro gun, it is virtually identical to the older EZ50s and works very well. If you are just looking for a gun to shoot the occasional display panel or a couple of brackets, any of the cheap cup guns should work well enough for that purpose. However, if you are still looking for a very good gun and have the budget for it, I hear good things about the Hypersmooth HS-02 and there is a cup version available. Its in the $800 range though. Hope that helps.
Hso2 is a good gun but for a couple hundred bucks less the same company makes a kk1.0 which is the exact same gun without an air gauge an led display.also they come on a upgradable chassis an you can upgrade later for the difference .
DeleteNew to powdercoating, I want coat my bike's gas tank as my first project. do you know of a sealer that can withstand 400 degrees Fahrenheit? ALSO, what do I need to do to make sure no gas fumes are inside the tank? Thanks, Rob...btw, your site doesn't show article links on my mobile.
ReplyDeleteRefinishing my oem Audi rims. 2 pounds polished aluminum base and 2 pounds black chrome top coat.sound about right??
ReplyDeleteYes, a set of 4 18" rims will take a little more or less than 1 pound of powder. It is always good to order 2 pounds to be on the safe side. 2 pounds of each color will be plenty.
DeleteI am going to be powder coating bicycle frames. The forum I am in (for custom bikes) talks about using an angle grinder with the appropriate discs for removing paint from areas to be welded. Where powder coating is discussed there is no mention of paint removal. Does sandblasting offer any advantage over using the grinder and discs to remove the old paint?
ReplyDeleteSandblasting is more thorough at removing paint than abrasive discs. Sandblasting is able to get into all of the crevices and will do less damage than an abrasive disc, especially on areas such as welds. Depending on the type of paint on the bike currently, sandblasting may not be as fast as an abrasive disc on the wide open areas, but if you plan on powder coating the frame, it needs sandblasted anyways.
DeleteThe method I would recommend if you plan on doing frames frequently, is to use a chemical stripper to remove the paint, then sandblast in order to add some profile to the frame, then powder coat. There is an article on this site "Stripping Powder Coat" which will have info pertaining to your specific situation. The stripper recommended in the article works very well on paint as well as powder coat.
Great site!!! lots of info. I'm going to start doing brake calipers and just wondering if you have any tips on doing calipers, not much about powder coating them online. I know epoxy is the way to go but I hear that its not UV stable and not much in the way of color selection, whats best to use, polyester or polyurethane, which stands up to brake fluid best. Any info. on this subject whould be appreciated.
DeleteThanks. The biggest tip I can give for calipers is to completely disassemble them and clean them out thoroughly. Order a rebuild kit for the calipers so you can replace all of the piston seals. However, you can keep the old seals, clean them up and use them to mask off the piston bores of the calipers, just put some tape over the whole of the piston seal. This perfectly seals off the caliper piston bore while powder coating and sandblasting. As far as what type of powder coating to use, epoxy wouldn't be a good choice as the calipers would be exposed to UV. Polyurethane is more chemical resistant than the standard TGIC polyester powder however the color options are much more limited and they are not as easy to find. Just about any powder coating will work well on a caliper that is not used in continuous high speed braking situations like a road course. In those situations, the powder coatings tend to discolor due to the high temperatures. Ceramic coatings are best used in that situation.
DeleteMy dad asked me to help him with a powder coating project he is doing. I don't know anything about this work so I'm trying to figure out how I can be a good help to him. This has some great points that I hope will help me figure this all out.
ReplyDeletehttp://www.supacoat.com/services/powder-coating
LOOKs better, really thank you so much sean, your effort to hel us is graet
ReplyDeleteYou're welcome Alonso. Thanks for being a dedicated reader.
DeleteI am new to powder coating and just ordered the Craftsman gun after reasing your blog. How would you recommend hanging a Yeti cup to powder coat?
ReplyDeleteAs long as you don't plan on powder coating the inside of the cup, I would put a masking layer over the opening. Then turn the cup upside down and stick it on some type of metal peg or spike that is grounded and touches the inside. This metal spike will have to able to support itself and the cup. Do a google image search for cup drying racks and you'll see a good example of how I would coat it.
DeleteI have a question about my powdered parts..I had my shovel head powdered 1.5 yrs ago..its my show bike..I now have damaged powder coating.. Its bad...I had a powder coating company tell me my parts are wet paint..can I please get more information as how to tell exactly.. And can I post pictures to show everyone so you guys can give me honest opinions on this matter before I go in asking for a refund?? Any help is appreciated, thank you!
ReplyDeleteHi great tips!! I'm having a problem coating stainless steel cups matte black. It's leaving a shiny look around the rim after they are done baking. Any reasons why or suggestions?
ReplyDeleteFrom what you are describing, it sounds like edge pull. Does the powder look thin in this area and almost transparent, allowing you to see the stainless cup through the powder? Or is the matte black itself loosing its matte appearance and behaving more like a glossy powder on the edge?
DeleteIf it is edge pull, I have never seen it happen with a matte black, it is much more common with glossy blacks.
Solutions to edge pull:
1. Switch powders. Like I said, I have never seen it happen with a matte black. Which matte black are you using?
2. Try shooting 1 coat of matte black and then cure it in the oven, but only allow the cup to reach about 200 degrees. When it reaches 200 degrees, pull it from the oven and spray another very light coat of matte black. See if this solves the issue.
2. If this is edge pull, it is most likely occurring because it is on a harsh edge (like a 90 degree machined edge). The common way to prevent this is to very minimally smooth out the harsh edge before powder coating. This can be done with a cartridge roll on a die grinder. Just a very quick pass around the edge with the grinder should smooth out the hard edge enough to prevent the edge pull.
how much powder do you apply? im new and so far the more powder the better it looks some call for 1 to 2 mill thick how do you tell the thickness? thanks great site
ReplyDeleteThanks, Generally you should spray powders between 2 and 3 mils. This can be measured with a mil coating thickness gauge. After your item is cured, you can use the gauge to determine how thick the powder is and either spray more or less in the future. There is a learning curve to it but it has its rewards.
DeleteIf powder is applied to thick, it will be much more prone to chipping.
Hope that helps!
thanks very much for your quick reply
ReplyDeletewhat is the shelf life after the box of powder coat is opened?
ReplyDeleteAs long as it is stored correctly, it is said to last up to a year, however it I have some powders that are several years old that I use on stuff around the garage and there have been no issues with it. Ideally it should be stored between 60 and 80 degrees F and the humidity should be between 40%-60%. If you are just an at home powder coater, storing it in your air conditioned home is fine.
DeleteIf you take a powder out of storage and it is clumpy, it should either be discarded or fluidized before use. Chunks in the powder will not flow out in the oven and they will be visible in the finish.
Is it possible to powder the inside of a motorcycle gas tank without ruining the paint on the outside.
ReplyDeleteI would not want to powder the coat the inside of the gas tank. Even though powder coating is very chemical resistant, I would not trust it when constantly exposed to gas containing ethanol. Chances are the powder coating would not lift, but if it did and I have heard of it doing so, it could cause a lot of issues.
DeleteIf you were to powder coat the inside of the gas tank, the paint on the exterior of the tank would most likely be degrated. It is not meant to withstand 400 degree F temps and a bake in the oven could considerably shorten its life or it can immediately yellow and start flaking.
I have a motorcycle tank that has the inside coated with Caswell Epoxy tank sealer. Would it be possible to powder coat the outside of the tank without wrecking the sealer?
ReplyDeleteI emailed Caswell plating and they said it should withstand powder coating temperatures.
DeleteGreat site. I've been doing powder and fan work for 15 years now mostly custom stuff an I find your articles spot on. Great work.
ReplyDeleteI have some metal(G30) brackets that I have powder coated but the heads of the PEM hardware are still visible. Any suggestions on a process to provide coverage of the hardware. We are using Cardinal C241-BK110.
ReplyDeleteAny help or suggestions would be appreciated
I'm sorry, I don't understand your question. I'm not familiar with G30 brackets or PEM hardware. Are you saying you are not getting coverage on the heads of your hardware?
DeleteHi Sean,
DeleteYou are exactly right. Not getting coverage on the heads of the hardware.
Hi. Im considering a change of career and have been offerd a job as a sprayer at a powder coating work shop. I have never done anything like this before so i was wondering if it is a skill anyone can learn or does somebody need to be skilled in spraying powder/paints etc to be able to get the hang of it quickly. Thanks
ReplyDeleteAs long as you have attention to detail and are willing to put in a good effort, you should do well. You will make mistakes and have parts not come out right. That's just apart of powder coating. The important thing is that when you do make a mistake, that you figure out what happened and how to prevent it in the future. As long as you consistently try to improve, you will start to turn out a quality product that keeps getting better. Previous experience spraying paints does not really transfer over to powder coating. However, the prep that goes into painting is very similar to powder coating. Everything has to be immaculately cleaned and prepped before coating. Read through some of the articles on this site. I'm sure the shop will already have their equipment set up and dialed in so you can skip over those parts but focus on the articles that talk about techniques and tips when spraying, masking, cleaning, monitoring temps in the oven, etc. Good luck!
DeleteIt's good to know that powder coating means a quality finish at an affordable price. I've been looking to update my rims but I didn't know that you could just get a powder coat put on. Before I get them done I plan on checking their portfolio to make sure that they do a good job. http://advancedindustrialfinishes.com/
ReplyDeleteI started my business of powder coating doors, specifically MDF, a few years back and the question that comes up a lot is... doesn't powder coating only work on metal? It's a process getting people to understand what we do, but the process gets easier with sites like this... so thank you!
ReplyDeleteI started powder coating about a year ago, like you with no training or experience. I can't imagine the frustration I would have saved and how much more I would have enjoyed it, if I would have found your site first! Truly wonderful. Thank you so much!
ReplyDeleteI started out just 5 years ago with nothing but a $70 Craftsman gun and a
ReplyDeletecardboard box as a booth. Now as one of the few women I know of in the powder
coating business, I have my own shop and just bought a new KCI pro gun from
http://www.powdercoatpro.com
I'm powder coating to pieces of aluminum with black wrinkle one comes ou perfect the other keeps turning flat gloss black what am I doing wrong
ReplyDeleteGenerally when you spray a wrinkle and you do not get the wrinkle effect, it means you need to spray it heavier. It's odd that one piece came out right while the other one didn't but give that a try.
DeleteHi sean castle,
ReplyDeleteI have some issue after powder coating on custom made aluminium panels
After powder coating, not happy with the finishing.join line of welding
The powder coating supplier claim that we cant putty the panel before powdercoating. Is there any ways to get the smooth finishing without visible welding join line (between 2 aluminium sheet) ..
Is there any putty special for powder coating.which can withstand the curing temperature
Hello Sean,
ReplyDeleteI need to enlarge a hole in an aluminum outboard engine powder coated mounting bracket and would like to know if anyone has ever attempted to powder coat the edges of the enlarged hole, approx. 6 3/4" diameter. Baking the powder coat would not be simple - I would guess the only way would be to use a heat gun, but the risk would be blowing the powder away, unless one could keep the electrostatic charge on while heating. Any comments? Perhaps there would be a better way to seal the aluminum against salt water corrosion? Thanks, Warren
I have some recommendations but I cannot guarantee their effectiveness due to the environment that the bracket will be in. Salt water is very good at seeping its way through any coating weak spots and starting corrosion. Obviously the best solution would be to strip and re-coat the entire bracket but if that is not feasible, you can try the following. I have seen powder coating cured with propane tank heaters and the powder has held up so far. These screw on to the top of standard propane tank and are pretty cheap (around $30-$40). I would recommend you also have an infrared thermometer to monitor the temperature of the part while curing it. Thoroughly wash the area with dish soap and hot water, then dry it. Depending on how well you want the final finish to look, you can either cleanly mask off an area close to the hole and live with a raised edge or you can treat it more like an autobody repair and mask off a wide are around the hole, spray the area and cut and buff the newly sprayed powder to try to blend it in. This would look the best but is also the most labor intensive. Enlarge the hole and scuff the powder around the hole and also the edges of the hole. Thoroughly clean the area with denatured alcohol and allow it to evaporate completely. Ground the piece and shoot the powder. Then set up the propane heater and get the area up to the cure temp and then start your timer. Remove the masking after the powder flows out. Closely monitor the temps because the heater is not going to be as consistent as an oven. That's pretty much it. I cannot guarantee this repair as I have not tested it with any marine parts so you should monitor the area to make sure that the powder does not delaminate, and check for any signs of the powder bubbling or flaking due to corrosion.
DeleteIf you don't want to go through all of that to touch it up with powder, the usual fix for touching up boat parts is marine zinc phosphate primer followed by a marine paint. You likely wont be able to get an exact color match though.
Hope that helps and good luck with the repair.