Powder coating ?

[Bob 04 H260]

The cast aluminum bracket that my Raymarine radar sits on has lost all it's paint. The surface looks a bit pitted. I think the salt got under the original paint and etched the metal. The old paint just peeled off in sheets. Can this just be powder coated ? Is there a better coating to use ?

Bob

 

[Meriachee]

I bought an Eastwood powder coat gun and have been playing with it, and I must say that the results thus far are pretty amazing. If you do this yourself, be prepared to play a bunch before you do the "real" part. If you send it out, it's a very cost effective solution. I'm baking the finish in a $20 Zellers toaster oven, so the limitation is part size. The downside thus far, is this stuff is MESSY.

The literature suggests that the coating is roughly 10 times tougher than "rattle cans". On my test pieces I took a screwdriver to the finish, and while I didn't do the chainsaw attack on it, I did only manage to gouge it, and did not get all the way through the coating without really trying. Spray on paint would not have withstood the first attack, let alone the "ok, get mad at it" approach.

The Eastwood docs (and the bottles of powder) clearly state that they have UV protection. How much and how well, only some outside testing will reveal.

Thus far, I'm quite impressed with it as a coating medium.

 

[RocketDogs]

Powder-coating is a fantastic finish for any metal. If the person doing the baking has a good feel, they can tweak the time/temp to get a harder or 'tougher' finish with the polyester. (Higher temps- more flow and a harder result, Lower- a little softer, but very resistant to chipping)
The ultimate results will be had by media blasting first. (More surface texture for better adhesion)
If you want to protect polished aluminum or brass, have the baker do the lower temp version with the clear powder to prevent yellowing of the coating. Plugging/taping any dimension critical pieces will prevent having to drill out or sand down these areas after coating. The finish material is fairly thick, compared to paint.

 

[Meriachee]

That's right about the temp tweaking. My new sprit ends are highly polished right now, but I am leaning towards the translucent colour, with low temp, high gloss over top to give some abrasion resistance to the colour coat. (and not screw up the colour finish if it ever needs re-coated) This might require a pre-coat of the "chrome" finish, I've got a bunch of cut-offs that I'm going to polish up and try the theory on, if it ever freakin warms up.

Bob, it's a great way to refinish the part, you could likely get it soda blasted and coated for cheap, and it would look like a million bucks, or if you're handy, and want a reason to clean the whole garage, the supplies (and a small toaster oven) is quite cheap.

Cheers
Gary

 

[Bob 04 H260]

Thanks for the good advice and tips. I don't think I will get into powder coating right now, but you got me interested. There are a couple of small companies doing powder coating around here I am told. I'll drop by once I get the part off the mast and see what they say about coating it.
regards, Bob

 

[dscribner]

Powder coating is a good option and you're right, you should go to a local company and have them do it for you. If you have time and aren't really picky about the color, they can add it to another order and save some money on setup and the like. At my company, we deal with finishing (outsourcing) of aluminum to the tune of about $11 million per year. The cheapest finish with the worst warranty is . . . anodizing, especially if it's near the coast. The best finish that we offer is Kynar 500, a powder coat, that carries a 5 year warranty and up to a 15 year extended warranty. Just Gee-whiz information to le you know you're making a good choice.

 

[rardiH36]

hello dscribner:

A couple of weeks ago I started another thread about powder coating (link embedded below) -- for an old and ugly chrome over bronze/brass ST cabin top winch that however still works great. Checking that thread, I see that you were not a responder.

I noted your knowledgeable response in this thread and that you are with a company that does powder coating. Do you feel that powder coating is likely to be durable enough for the winch duty described in the other thread? Also is Kynar 500 available for consumer purchase? Can a DIY'er do well with it?

http://forums.sbo.sailboatowners.com/showthread.php?t=158739

Many thanks,
rardi

 

[Bob 04 H260]

Powder coating is a good option and you're right, you should go to a local company and have them do it for you. If you have time and aren't really picky about the color, they can add it to another order and save some money on setup and the like. At my company, we deal with finishing (outsourcing) of aluminum to the tune of about $11 million per year. The cheapest finish with the worst warranty is . . . anodizing, especially if it's near the coast. The best finish that we offer is Kynar 500, a powder coat, that carries a 5 year warranty and up to a 15 year extended warranty. Just Gee-whiz information to le you know you're making a good choice.

Thanks taking the time ! Great information, feeling confident about doing this job with all the good advice.

Bob

 

[CarlN]

Looks like pent up powder coat interest

I'm planning to install some Bomar aluminum deck access hatches. Since these will be walked on I had figured that powder coat wouldn't hold up - but they would look much better if the color was closer to the nonskid.

Is a top end powder coat like the mentioned Kynar 500 up to this? Any recommendations of companies in New England to do this work?

Carl

 

[25yearslater]

Had my mast, boom and spreaders, stripped, reanodized and powder coated by Charleston Spar. Tough as nails.

 

[Meriachee]

Very cool

 

[cookwithgas]

Had my mast, boom and spreaders, stripped, reanodized and powder coated by Charleston Spar. Tough as nails.

I have a powder coat gun and a dedicated oven. I have coated several items on my sailboat. Some of it has not held up well. Anodizing aluminum is MUCH better if you are going to pay someone. Your mast looks GREAT!

Unlike anodizing, a powder finish is brittle and will chip if hit with any metal item. I saw a mention above of "messy" describing powder coating. I find the opposite. All you do is blow it away or suck it up with a vacuum. It has the consistency of talcum powder and just blows off anything when it is not cured.

Also - it is all about the oven. I have a standard kitchen oven mounted to a stand that I made. The oven was free from a neighbor. It has very accurate temperature settings and most colors are melted in 10 minutes. Remove from the heat and the finished result is a hard, shiny coating that is UV resistant. Just don't hit it with a hammer or steel winch handle. If the item to be coated is up and out of the way, or not likely to be nicked, powder coating works great.

 

[azguy]

what about just polishing your old aluminum bracket, with a wheel and some compound..??

 

[Bob 04 H260]

I have owned motorcycles for the past 40 years and have done a lot of aluminum polishing . It needs to be kept up and not easy to do when the bracket is higher than I care to climb ! We generally do not take our mast down each year so it will have to take care of itself for a while.

Being in saltwater it really needs protection, I'm sure it could fail in time and coming down in rough seas would be a danger to anyone on deck at the time.

It looks like powder coating is the way to go or just buy a new bracket. So far the powder coaters I have contacted want a $150 min. so if I can not find a better deal I may just have to buy a new bracket.


Bob

 

[25yearslater]

Just to clarify the issue. After my conversations with Charleston Spar, powder coating will take an impact provided it is bonded to the substrate metal. This is accomplished as was my case through the stripping and anodizing process. The anodizing provides the grip the coating requires. Not only does the coating hold up well it comes in just about any color one may desire with black, white and a light gray being standard.

 

[Don Crowther]

Bob
Have you thought about just painting it with something like POR-15 ? Just a thought.

 

[Bob 04 H260]

Bob
Have you thought about just painting it with something like POR-15 ? Just a thought.

Don, thanks, I did not consider that. I have used por15 on rusty metal in the past but not on aluminum. As a matter of fact I have not had much long term success painting aluminum and it was one reason I was looking at powder coating. I was told the original finish on this bracket was powder coating from the manufacturer. It only lasted 4 years in the salt water. So maybe paint is as good as the powder coating. The salt has given the aluminum a sand blasted appearance. The mast and boom etc. all look like new so the anodizing is working well.
Not sure what to look at next, Bob

 

[Sumner]

....Also - it is all about the oven. I have a standard kitchen oven mounted to a stand that I made. The oven was free from a neighbor.....

I also use a kitchen oven. Picked it up free from the local appliance store before they hauled it to the dump. Might of saved them some bucks. I couldn't find anything wrong with it. I just think they wanted a new stove. I have mine sitting outside under an overhang and it is close enough that I can run a 220 extension cord to it that I use for a welder. I bought a HF one and their powder coating and on the few projects I've done it seems to work fine,

Sum

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