Aged aluminum

[Alex]

If I don't powdercoat my chassis (I like the raw aluminum look), in 5-10yrs am I going to regret it (i.e., will it look like crap), or will the aged aluminum still look decent (decent meaning the color's changed because it's aged, but it won't be horrible to look at)? :huh:

 

[Dimi Terleckyj]

Hi Alex

The raw aluminium look is very short lived if not coated in some way.

After a period of time it will go grey and blotchy as different chemicals in the water that contacts the alloy from various sources.

Any area that uses salt on the roads will cause corrosion to begin very rapidly and the alloy will get the powdery white corrosion happening.

Personally I would opt for some kind of paint / corrosion treatment.

I have a small marine grade alloy boat that I take my boys fishing in and even though it has been etch primed and painted it is still showing signs of corrosion wherever the paint has been scratched or damaged.

Remember that as the car is driven you will also be getting stone chips which will let the moisture get to the alloy.

Alloy will begin discolouring and corroding just from the moisture in the air alone.

Dimi

 

[Randy V]

I remember the same sort of thread on the CObra forum some years ago.. The guys that wanted the raw aluminum look wanted to either leave it that way or polish it...

Seems that the consensus at the time was to:

• Either chase after it regularly by cleaning / waxing
• Clean it periodically, polish and seal it with Zoop Seal
• Clean / Polish it and
  
  [*]Powder Coat
  [*]Paint with Clear Poly Urethane​

You're going to pay one way or another... It won't stay looking good on it's own and if you drive it at all in the water or live in a humid area, you will eventually see corrosion.

 

[Tony C]

Aluminum corrosion looks like a white power has been lightly dusted on it. If I were you I would powder coat it and if you like the raw look then ask for that color type of powder coating. They have every color under the sun now..

 

[Alex]

Interesting information then.

I may try sealing it with Sharkhide - it's basically a rub-on liquid that seals the aluminum and is good for 2-3yrs at a time.

I didn't have much luck with it on polished aluminum (because it brought out all sorts of imperfections and gave it a rainbow hue) but it was invisible on raw and brushed aluminum.

Will polished aluminum oxidize and corrode as quickly as raw aluminum? Only reason I ask is because I have several polished (test) pieces from my cobra sitting in a corner, and it's been 3yrs and they look exactly as they did 3yrs ago.

 

[Alex]

I was thinking more about this, but are you guys certain corrosion will happen quickly?

I look at brushed kirkham bodies and they arn't corroded.

I look at MK1 FFRs (from the last 90s) with the original aluminum and they arn't corroded (dirty, yes, but not corroded)

I look at the uncoated parts on my cobra (e.g., RD fan shroud) that are subject to all the road slime, and while dirty, 0 corrosion.

I look at spare aluminum pieces from my cobra I have laying on the garage floor and they arn't corroded after 3yrs on the garage floor (wet and humid and whatnot).

Actually the only type of corrosion I've seen referenced to usually are ?filiform? corrosion caused by exposure to chemicals like mercuric acid.

 

[Mark]

If you keep the car clean, and dry it will look good for many years. Wiping it down with something like wd40 once or twice a year will help a lot. Have you thought about clear anodizing the suspension parts, and clear powdercoating the chassis?

 

[Tom]

a big part of this question is what grade aluminum are you using? I don't know what your chassis is fabricated from, but if it is 6000 series, it will corrode. Marine grade 5000 series alloys tend to resist corrosion better, but they aren't the best in for structural applications.

Best bet would be to paint, but if it you really prefer bare finish, make sure the material will deal with it. I'd start looking at a materials guide for more information.

 

[Eric]

...clear powdercoating the chassis?

That was going to be my suggestion. There is also a product called Zoops something or other made for use on aluminum wheels. The stuff is supposed to be the cat's meow for protecting aluminum. If it works that good on wheels, I'm sure it will work on any aluminum.

By the way, years ago I worked a lot with aluminum sheet metal. Within days of removing the protective paper, it would oxidize. I think perhaps this is what people are calling "corrosion" in this thread. Raw aluminum shouldn't corrode unless subjected to certain circumstances (like road salt or salt water). That being said, I would try to protect it somehow. The oxidation can be cleaned without a problem, but it's a bitch to stay on top of it.

Eric

 

[Jack]

Eric,
It's "Zoop Seal" pretty good stuff too.

 

[Alex]

That was going to be my suggestion. There is also a product called Zoops something or other made for use on aluminum wheels. The stuff is supposed to be the cat's meow for protecting aluminum. If it works that good on wheels, I'm sure it will work on any aluminum.

By the way, years ago I worked a lot with aluminum sheet metal. Within days of removing the protective paper, it would oxidize. I think perhaps this is what people are calling "corrosion" in this thread. Raw aluminum shouldn't corrode unless subjected to certain circumstances (like road salt or salt water). That being said, I would try to protect it somehow. The oxidation can be cleaned without a problem, but it's a bitch to stay on top of it.

Eric

Zoop seal - I tried it when polishing my cobra and didn't like it.

What I found to be really good though was Sharkhide. On raw/brushed aluminum it's totally invisible (polished is another story....), maybe it darkens the metal a little bit, but the darkness really looks good.

Where I'm leannnnnnning towards now is to to have a brushed aluminum chassis (150/220/400/maroon scotbrite) then seal with sharkhide.

The one thing I like about this is that Sharkhide resists water/salts/etc... and is only removed with laquer thinner/acetone (and quite easily, just takes some elbow grease). So if I damage an area, I can acetone it off, re-sand, re-apply.

Unlike powdercoat which, other than black (i'd go with a silver vein, not black), it's harder to touch up deep scratches, etc... ; also, I'd imagine pc would add about a bit of weight...maybe 30-40lbs or so to the chassis (when i pc'd all my cobra panels, they were definately heavier at the end)

 

[Alex]

BTW, if somebody thinks having a brushed chassis would look like ass, PLEASE tell me - I do NOT want to waste 50hrs on it if it will look like ass.

I learned my lesson on the cobra

- ~$1500 in equipment/accessories/etc.. to polish panels
- atleaset 400hrs in polishing every aluminum panel
- oh, crap, can't maintain it, powdercoat every one except the firewall!!! :drunk:

 

[Eric]

BTW, if somebody thinks having a brushed chassis would look like ass, PLEASE tell me - I do NOT want to waste 50hrs on it if it will look like ass.

Alex

I think the raw aluminum look will be great. Personally (and it is just that, a personal opinion), I don't know if I would brush it; a LOT of work, for one thing, and I don't think I would like the look.

I think I would either clear powdercoat the unbrushed aluminum or clear paint it. Again, just my personal take. I really do like the idea of a raw aluminum look (not silver paint or powerdercoat).

Eric

 

[Eric]

Alex

By the way, what you described (the steps ending with Scotchbrite) I don't know I would consider brushed. That, to me, is polished, but not to a high gloss. When I worked with aluminum sheet metal, for some jobs it was actually cheaper to brush our own instead of buying brushed sheets (we didn't do a lot of brushed products). We would sand with I think it was 100 git (it was a long time ago). Not that it matters, but we then anodized these parts.

Just some random thoughts that are completely tangential to the thread.

Eric

 

[Alex]

Alex

By the way, what you described (the steps ending with Scotchbrite) I don't know I would consider brushed. That, to me, is polished, but not to a high gloss. When I worked with aluminum sheet metal, for some jobs it was actually cheaper to brush our own instead of buying brushed sheets (we didn't do a lot of brushed products). We would sand with I think it was 100 git (it was a long time ago). Not that it matters, but we then anodized these parts.

Just some random thoughts that are completely tangential to the thread.

Eric

You don't want to know what I consider polished :laugh: (and the amount of time it takes :laugh::laugh::shout

After talking with Fran today I think i'm just going to apply some Sharkhide (wipe on clearcoat) to the chassis and call it a day.

 

[Alex]

I REALLY don't think I want to sand the entire chassis, lol!

 

[BigB98]

I polished my cobra and put several hundred hours into it. I promised I would never do that again, but time heals all wounds so to speak. I'm definately not covering the aluminum though...I love aluminum.

 

[Tony C]

I was thinking more about this, but are you guys certain corrosion will happen quickly?

I look at brushed kirkham bodies and they arn't corroded.

I look at MK1 FFRs (from the last 90s) with the original aluminum and they arn't corroded (dirty, yes, but not corroded)

I look at the uncoated parts on my cobra (e.g., RD fan shroud) that are subject to all the road slime, and while dirty, 0 corrosion.

I look at spare aluminum pieces from my cobra I have laying on the garage floor and they arn't corroded after 3yrs on the garage floor (wet and humid and whatnot).

Actually the only type of corrosion I've seen referenced to usually are ?filiform? corrosion caused by exposure to chemicals like mercuric acid.

I'm an inspector in the aviation field, but outside that I know alot of guys in the motorcycle clubs who polish thier frames.. They look good for as long as the guys have the bikes,, You just can't let stuff sit on them for to long, like road dirt. (case in point " thats why your peices in your garage look the same)
Road dirt has tons of corrosive chemicals mixed in there, oil, anti-freeze, gas and what ever other trash is out there. Aircraft corrode due to all the acid rain and oxcides they produce themselves.

All this to say. If you stay on top of it and monitor(inspect) your chassis from time to time you will be just fine.. But post some pics so we can see how it looks...

 

[EGLITOM]

this is what i did

http://www.gt40s.com/forum/gt40-build-logs/24525-toms-rcr-40-trackracer-18.html#post285630

TOM

 

[Johnny Mac!]

When I built my 289FIA, I did all the underhood ally in a dull finish.

all you need to do is:

1) Use NAPA Acid Etching and a scotch brite pad in flat straight lines.

2) Wipe down with Windex and a cloth.

3) spray WD40 into a rag and wipe it down to protect it.

Looks great for quite a while, just need to reapply WD40 once/twice a year. There is no corrosion.

pics....

http://www.cobranet.com/coppermine/albums/userpics/normal_IMG_0986.JPG

http://www.cobranet.com/coppermine/albums/userpics/normal_IMG_1018.JPG

http://www.cobranet.com/coppermine/albums/userpics/normal_IMG_1035.JPG

http://www.cobranet.com/coppermine/albums/userpics/normal_IMG_1036.JPG