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PAINT OR POWER COAT FRAME
Posted: Mon Oct 25, 2010 8:27 pm
by so cal charlie
Paint should be fine and can tough up marks if needed ..then power coat is the better way but more money and if chipped it makes it tough for touch ups . IS FACTORY POWER COATED ?
Re: PAINT OR POWER COAT FRAME
Posted: Mon Oct 25, 2010 10:49 pm
by Chuey
The original airhead frames were painted. Current frames, I'd bet from all the manufacturers, are powdercoated.
Chuey
Re: PAINT OR POWER COAT FRAME
Posted: Tue Oct 26, 2010 4:33 am
by Nourish
I asked a similar question on another site - I hope He does't mind but here are two replies from the same author
"As someone who worked in surface coatings (of various sorts) for 25 years, I'll have a stab at answering:
Powder coating is a thermoset epoxy finish. It's sprayed onto an electrically-charged item, so the powder is attracted by "static", then it's baked on. It's pretty tough stuff. Like any suface coating, there are downsides. As with all coatings, preparation is critical. Get that wrong and you've wasted your time and money. One other problem is that it never builds up a decent thickness on any edges - fine for round tubes, not so good on a frame. Guess where the rust-fairy starts creeping under? Yup, the edges. As has been noted, the coating doesn't reveal any problem until the corrosion is quite severe.
Stove enamelling is a ceramic-like coating, baked on at high temperature. Tough as nails and lasts forever (in practical terms). It's brittle though.
2-pack paints are probably the second-best to stove enamelling but for heaven's sake you need the PROPER gear to use it safely, it's NOT a DIY option if you like the idea of being around to ride the finished bike.
Cellulose paint is also very tough stuff. Sadly, it's banned (the so-called cellulose nowadays is not actually cellulose nitrate). It's actually no more toxic (probably less actually) than any other solvent-borne paint. The "problem" with cellulose is that it's a fire-risk, it generates enough oxygen to sustain its own combustion (i.e. you can't put it out by smothering it) and it's an explosive when confined (not a problem in the end-product, realistically). With H&S paranoia, that makes it difficult to justify and its transport and use are closely controlled and licensed.
Hammerite - great for the gate hinges and not something I would EVER consider for a vehicle. From tests we did at a company I once worked for, it has very poor durability in the salt-spray/abrasion/water/weathering types of conditions that a vehicle is commonly exposed to. No thanks".
I then asked what would he use?
"For the forks, it depends on the depth of your pockets and how perfect you want. The ultimate would be to have them black anodised but I don't know if there are services available to do that. Otherwise, I'd go for a suitable etch-primer and 2-pack in a semi-gloss, that ought to last well. The curing for most refinish paint systems should not be an issue - 2-pack needs only about 50C and even OEM primers are rarely stoved at more than 165C. Just don't leave the seals in place!
For the frame, I'd investigate stove-enamelling (again, cost may be a factor), otherwise I'd definitely prefer 2-pack. Just remember 90% of the end result comes from the proper preparation. For the ultimate protection, I'd get a coat of micaceous iron oxide under the top coat but that's probably overkill and not the most available and convenient stuff - it's what they use on things like bridge steelworks! I'm not sure it makes an ideal surface to overpaint things like 2-pack either".
Hope this is of some help
so now it's "POWER" COATing, eh ?
Posted: Tue Oct 26, 2010 9:10 am
by vanzen
Nourish wrote:I asked a similar question on another site - I hope He does't mind but here are two replies from the same author
"As someone who worked in surface coatings (of various sorts) for 25 years, I'll have a stab at answering:
Powder coating is a thermoset epoxy finish ..."
Perhaps a reasonable synopsis of the options, however,
when I read the first sentence and it is incorrect – I will read the rest with a degree of skepticism ...
Powder coat is not necessarily a "thermoset" nor an "epoxy" finish –
There are two main categories of powder coatings: thermosets and thermoplastics.
The most common polymers used are polyester, polyurethane, polyester-epoxy (known as hybrid),
straight epoxy (fusion bonded epoxy) and acrylics.
Each will have it's own characteristics ...
Powder Primers have become a mainstay for some auto manufacturers.
BMW and Mercedes are using powder clear topcoats.
Re: PAINT OR POWER COAT FRAME
Posted: Tue Oct 26, 2010 3:06 pm
by Max Headroom
I would also challenge the writer's view of the smooth version of Hammerite - surprisingly enough called Smoothrite . . .
Preparation is just as important with this product as it is for any other surface coating. I used it on my R90S frame, swingarm, battery box, and headlight bucket, and five years later, there's no bubbling, peeling, flaking or corrosion anywhere. The finish is exactly what I wanted too. There are a few stone chips, yet those areas haven't flaked or peeled either. I used a primer with very high zinc content on freshly blasted surfaces, and would use the same method for my next restoration without hesitation.
I know of several folk who have used Smoothrite on their motorcycle frames with similar results. I'm surprised the writer is so dismissive.
Re: PAINT OR POWER COAT FRAME
Posted: Tue Oct 26, 2010 3:11 pm
by Garnet
"I used a primer with very high zinc content "
Is this like an oil thread?
Re: PAINT OR POWER COAT FRAME
Posted: Tue Oct 26, 2010 4:10 pm
by dougie
Garnet wrote:"I used a primer with very high zinc content "
Is this like an oil thread?
Probably worse.
Re: PAINT OR POWER COAT FRAME
Posted: Tue Oct 26, 2010 7:45 pm
by Max Headroom
Ahh, but i didn't mention the BRAND of the primer . . . .
I'll let ya know when the paint falls off the frame though.
Re: so now it's "POWER" COATing, eh ?
Posted: Tue Oct 26, 2010 9:40 pm
by Frog
vanzen@rockerboxer.com wrote:Nourish wrote:I asked a similar question on another site - I hope He does't mind but here are two replies from the same author
"As someone who worked in surface coatings (of various sorts) for 25 years, I'll have a stab at answering:
Powder coating is a thermoset epoxy finish ..."
Perhaps a reasonable synopsis of the options, however,
when I read the first sentence and it is incorrect – I will read the rest with a degree of skepticism ...
Powder coat is not necessarily a "thermoset" nor an "epoxy" finish –
There are two main categories of powder coatings: thermosets and thermoplastics.
The most common polymers used are polyester, polyurethane, polyester-epoxy (known as hybrid),
straight epoxy (fusion bonded epoxy) and acrylics.
Each will have it's own characteristics ...
Powder Primers have become a mainstay for some auto manufacturers.
BMW and Mercedes are using powder clear topcoats.
From what I understand, powdercoating is very much like the paint that we know, except that it has a different method of delivery. There is just about as much variation in the product. Often we refer to powdercoating as if it was just one product that always yields the same result. I recently contacted a powdercoat supplier to get a specification and product recommendation for an architectural application. There are many to choose from. My experience has also taught me that not every applicator is as good as the next.
Re: PAINT OR POWER COAT FRAME
Posted: Tue Oct 26, 2010 10:29 pm
by Chuey
In reply to, and in agreement with Frog's post, I can say that not only is not every applicator as good as the next, but the variance with using one powder coater only over a nine year period has resulted in variable results. I am a fairly regular account for them because I have bicycle frames coated from time to time. In addition, motorcycle parts and VW parts for personal use, and all the while, wondering how it will come out.
The local guy I used to go to had been doing bike frames for an exceptionally low price. I hadn't asked for that price but it was evidently what they charged local bicycle manufacturers of BMX frames. I was getting some pretty crappy finishes. I took a frame from a Taiwan manufacturer in and asked him if I could get the same level of finish from him. I was very careful with the way I approached him and tried very hard to not offend him. I do work for people and understand that the approach is everything. I asked him for a better job just as I would have liked to hear it from a customer. He looked at the frame and said that he didn't have that much control over what his crew did. He mentioned that the night crew was not that predictable. Clearly, he wasn't charging enough. I wouldn't have had a problem with him doubling the price he had been charging. They are still in business and are a very large operation. For the last nine or ten years, I drive an hour each way to have my powder coating done. I do my best to save up several jobs to take at one time.
Chuey