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Thread: Powdercoat or paint

  1. #1
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    Powdercoat or paint

    Am doing up a Grimac Mia which the previous owner didn't take proper care of. The machine is generally in good condition, but it's got a lot of rust. Am wondering what others prefer between painting and powdercoating after rust removal?


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  2. #2
    Zee
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    Powder coating every day of the week and 7 times on Sunday. But that's with zero experience with this sort of thing re coffee machines...

    In fact, I'm looking to stealth black our GS3, and was wondering if powder coating would create any issues - so if you don't mind me tagging, my question onto yours - otherwise I'll edit it out and start a new thread later.

    Z...

  3. #3
    Senior Member topshot's Avatar
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    Powder coating is obviously a lot more expensive, but it's hell of a lot more durable.

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    Does the powdercoating shop usually do sandblasting as well? My angle grinder rust removal method is a bit too rough for a nice flat finish.

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    The only real issue with powdercoating is that it is often a thicker film than paint, so can occasionally create issues with reassembly if parts are a tight fit.
    But a powdercoated finish is way more durable than paint.

    We do a lot of custom work on commercial espresso machines, and probably 70% to 80% of all the machines that arrive here new in the box get stripped down immediately and all the panels go out for powdercoating.
    My recommendation if considering powdercoating is don't powdercoat drip trays or any panel you are likely to to accidentally bump the group handle against while fitting or removing it, as despite its durability the powdercoat will eventually scratch and chip.
    Also don't use any really light colours (especially white) where the panel is very close to something hot, like a group head or steam tap, as it will eventually discolour and yellow due to the heat. Plus any white panel near a switch or steam knob is likely to eventually accumulate lots of minute scratches which will show up on a white panel as any dirt that accumulates in the scratches will show up clearly.

    If it is a home machine with one careful user that is not rushing to pump out commercial volumes of coffee, you can probably afford to be more adventurous with finishes as the machine is likely to be cared for better and cleaned more carefully and often than a commercial machine.
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  6. #6
    Senior Member JMcCee's Avatar
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    Our business uses a powder coater in Hastings who does all the prep work prior like sand blasting. He was the only one within a 25k radius who did everything. All the others did PC only and I would have to take it to a sand blaster first which creates problems with bare metal being exposed for any length of time if I couldn't get to the powder coater straight away. Having said that my BIL is a spray painter and he did a Cremina for me which came up a treat but generally I recommend powder coating, especially for frames.
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  7. #7
    Senior Member CafeLotta's Avatar
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    My vote would be for painting. After 2 machines with powder coated frames that have rusted in the seams and around the welds (Rancilio and Vibiemme), I would be looking at painting. Easy to repair, easier to coat in hard to reach places like seams and probably cheaper if you can do it yourself. Preparation is the key and maybe use a rust neutraliser before priming and painting. May not be as durable on exterior surfaces as powder coating but I'd prefer things not to rust in the seams and welds.

    I had a look at doing my Vibiemme and found a Paint Stripping business here in Melbourne to remove the old powder coating and rust - Services
    When I rang a while back, he said they do both wood and metal and he would do my Espresso machine frame.
    Last edited by CafeLotta; 5 Days Ago at 12:43 PM.
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  8. #8
    Coffee Nut fg1972's Avatar
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    I agree with caffelotta, itís all in the preparation. You can get a real nice finish with paint if done properly. The Durability of PC is obviously better but youíre probably not going to be banging tools at it. In regards to rust prevention, I donít believe itís any better than paint and again all comes down to preparation. For stripping paint or Powder coating, you can get sanding disc wheels for an angle grinder in various coarseness that work well.

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    Senior Member LeroyC's Avatar
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    Neither method is better or worse. The key is not what you choose to do, but the quality of that method. My Dad made paint for over 60 years, 50 of which was in his own business that I also worked in for close to 10 years. There were plenty of times we had people come in to get some paint after theyíd tried to powder coat something and the coating had failed. Not all power coating is created equal and the same goes for paint.
    Iíve sprayed a few coffee machines that Iíve refurbished just using pressure pack cans, but making sure preparation was 100% and I used lots of light coats - up to 10 coats in some cases. This gives a good quality finish that looks better and is more durable than an average powder coat. So whatever you choose make sure that the prep is done properly and the products used and application are high quality. Make sure the person doing the job knows that it will be exposed to a decent amount of heat and that there could be a bit of water around at times as well.
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    I guess the question then might be, do it myself or pay someone for a professional result. I tried spraypainting a frame for a bz35, and it didn't turn out very smoothly, probably mostly because I've a spray paint novice, and my rust removal didn't leave a smooth surface to start with. What's the best way to get a smooth surface before painting?

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  11. #11
    Mal Dimal's Avatar
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    Quote Originally Posted by LeroyC View Post
    Neither method is better or worse. The key is not what you choose to do, but the quality of that method.
    Wholeheartedly agree. There are some great epoxy/polyurethane finishes around these days that when applied properly are capable of producing outstanding results.

    Quote Originally Posted by LeroyC View Post
    making sure preparation was 100% and I used lots of light coats - up to 10 coats in some cases
    Ditto...
    The only cost is a bit of time and maybe a bit of extra elbow grease if sanding gently between coats.

    Mal.

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    Quote Originally Posted by Zee View Post
    Powder coating every day of the week and 7 times on Sunday. But that's with zero experience with this sort of thing re coffee machines...

    In fact, I'm looking to stealth black our GS3, and was wondering if powder coating would create any issues - so if you don't mind me tagging, my question onto yours - otherwise I'll edit it out and start a new thread later.

    Z...
    Zee, i powder coated my gs3 in matte black and would highly recommend it. Its been so easy to keep clean, is very durable and always seems to look clean unlike the standard s/s finish.
    So i would highly recommend it

  13. #13
    Senior Member Lyrebird's Avatar
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    Quote Originally Posted by Zee View Post
    In fact, I'm looking to stealth black our GS3,
    Here's another option:


    Carbon

    I did this as a joke: To me the bling of the gold plated E61 group is a bit much so I decided to take it competely over the top by covering the front panel in carbon fibre. Not exactly stealth, but it is black.
    Last edited by Lyrebird; 3 Days Ago at 05:15 PM.
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  14. #14
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    Lyrebird, gold E61 groupheads, off the shelf item? Or.....

  15. #15
    Senior Member Lyrebird's Avatar
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    I don't know.

    I bought this machine from a fellow CSer as a donor body for my variable speed experiments*, I was surprised to find the group was gold plated.

    It's an Izzo Alex Hx from 2001, I don't think the gold group was standard (based on pics I've seen of other Izzo Alex machines from around then). The gold plating is very well done so it may have been a factory option.

    I got it cheap partially because it had lost the fancy curved side panels that were a big part of this machine's design. I have plans.....





    * Here's a clue: check the pump motor visible at the back of the machine in the pic.
    Last edited by Lyrebird; 3 Days Ago at 06:29 PM.
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  16. #16
    Super Moderator Javaphile's Avatar
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    If you powder coat make sure you ask them how cured it is when given to you as finished. Many powder coater's only do a partial cure and the finish is then susceptible to damage potentially for months depending on how far the coater cured it.


    Java "Coat what?" phile
    Toys! I must have new toys!!!

  17. #17
    Senior Member Lyrebird's Avatar
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    For an object the size of a coffee machine chassis it's pretty easy to do a post cure. 180 oC for 20 - 30 minutes is all you need.

  18. #18
    Coffee Nut fg1972's Avatar
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    Quote Originally Posted by iampivot View Post
    I guess the question then might be, do it myself or pay someone for a professional result. I tried spraypainting a frame for a bz35, and it didn't turn out very smoothly, probably mostly because I've a spray paint novice, and my rust removal didn't leave a smooth surface to start with. What's the best way to get a smooth surface before painting?

    IMG_20181209_122412.jpgIMG_20181209_122428.jpg
    It's all do to with the preparation, the painting or coating is the easy part. I can't stress this enough. As part of removing the rust, it will obviously leave some pitting. Even if powder coating, these imperfections will still be visible unless the prep was done to deal with this so lets get back to the prep. To get a smooth surface, those pits need to be filled, an effective way to do it is with automotive spray putty (it comes in a spray can too). Spray a few light coats of spray putty to build a nice thick coat, then sand back with a sanding block until the spray putty is sanded off the already smooth metal but remains in the pitts. You may need to do this several times depending on the depth of the pitts to get an even smooth surface. The good thing is that spray putty is easy to sand and dries reasonably quick. Once you're happy with the smoothness, give the whole thing a few light coats of primer (grey primer works well if finishing in black). The key with any spraying is light coats, don't be tempted to save time by trying to get away with less coats by applying thick coats, it's not not worth it as you won't be happy and end up sanding back and doing it again wasting more time. Light sanding between coats is also very effective to remove and little paint bumps or dust, this can be wet sanded too for a fine finish towards the later coats.
    For example,
    2 - 3 light coats of spray putty
    sand back with 200 - 400 grit sandpaper
    another light coat or so of spray putty if needed and sand back as above
    2 - 3 light coats of primer
    lightly wet sand with 600 - 800 grit
    another light coat of primer
    lightly wet sand with 800 - 1000 grit (the object should look and feel perfectly smooth, if not, may need to fill any dimples and or pitts with spray putty and repeat some of the earlier steps)
    2 - 3 light coats of colour, (blacks are easy to paint, especially matt and satin finishes)
    lightly wet sand with 1000 - 1200 grit
    final light coat of colour
    let it cure properly before working with it (putting it in the sun works well)
    Good luck, let us know how you get on. Take a look at the little machine I restored a while back in this THREAD
    Last edited by fg1972; 3 Days Ago at 06:32 AM. Reason: link
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  19. #19
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    Quote Originally Posted by fg1972 View Post
    Take a look at the little machine I restored a while back in this THREAD
    Wow. Inspiring. Love it when old stuff gets a new lease of life

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    Ok, I'll try some putty and primer. I initially was a bit concerned about special paint requirements due to the higher temperatures inside the machine, but the parts of the frame that are exposed doesn't get that hot.

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