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    • UnderDawg

      A Few Simple Rules   05/22/2017

      Sailing Anarchy is a very lightly moderated site. This is by design, to afford a more free atmosphere for discussion. There are plenty of sailing forums you can go to where swearing isn't allowed, confrontation is squelched and, and you can have a moderator finger-wag at you for your attitude. SA tries to avoid that and allow for more adult behavior without moderators editing your posts and whacking knuckles with rulers. We don't have a long list of published "thou shalt nots" either, and this is by design. Too many absolute rules paints us into too many corners. So check the Terms of Service - there IS language there about certain types of behavior that is not permitted. We interpret that lightly and permit a lot of latitude, but we DO reserve the right to take action when something is too extreme to tolerate (too racist, graphic, violent, misogynistic, etc.). Yes, that is subjective, but it allows us discretion. Avoiding a laundry list of rules allows for freedom; don't abuse it. However there ARE a few basic rules that will earn you a suspension, and apparently a brief refresher is in order. 1) Allegations of pedophilia - there is no tolerance for this. So if you make allegations, jokes, innuendo or suggestions about child molestation, child pornography, abuse or inappropriate behavior with minors etc. about someone on this board you will get a time out. This is pretty much automatic; this behavior can have real world effect and is not acceptable. Obviously the subject is not banned when discussion of it is apropos, e.g. talking about an item in the news for instance. But allegations or references directed at or about another poster is verboten. 2) Outing people - providing real world identifiable information about users on the forums who prefer to remain anonymous. Yes, some of us post with our real names - not a problem to use them. However many do NOT, and if you find out someone's name keep it to yourself, first or last. This also goes for other identifying information too - employer information etc. You don't need too many pieces of data to figure out who someone really is these days. Depending on severity you might get anything from a scolding to a suspension - so don't do it. I know it can be confusing sometimes for newcomers, as SA has been around almost twenty years and there are some people that throw their real names around and their current Display Name may not match the name they have out in the public. But if in doubt, you don't want to accidentally out some one so use caution, even if it's a personal friend of yours in real life. 3) Posting While Suspended - If you've earned a timeout (these are fairly rare and hard to get), please observe the suspension. If you create a new account (a "Sock Puppet") and return to the forums to post with it before your suspension is up you WILL get more time added to your original suspension and lose your Socks. This behavior may result a permanent ban, since it shows you have zero respect for the few rules we have and the moderating team that is tasked with supporting them. Check the Terms of Service you agreed to; they apply to the individual agreeing, not the account you created, so don't try to Sea Lawyer us if you get caught. Just don't do it. Those are the three that will almost certainly get you into some trouble. IF YOU SEE SOMEONE DO ONE OF THESE THINGS, please do the following: Refrain from quoting the offending text, it makes the thread cleanup a pain in the rear Press the Report button; it is by far the best way to notify Admins as we will get e-mails. Calling out for Admins in the middle of threads, sending us PM's, etc. - there is no guarantee we will get those in a timely fashion. There are multiple Moderators in multiple time zones around the world, and anyone one of us can handle the Report and all of us will be notified about it. But if you PM one Mod directly and he's off line, the problem will get dealt with much more slowly. Other behaviors that you might want to think twice before doing include: Intentionally disrupting threads and discussions repeatedly. Off topic/content free trolling in threads to disrupt dialog Stalking users around the forums with the intent to disrupt content and discussion Repeated posting of overly graphic or scatological porn content. There are plenty web sites for you to get your freak on, don't do it here. And a brief note to Newbies... No, we will not ban people or censor them for dropping F-bombs on you, using foul language, etc. so please don't report it when one of our members gives you a greeting you may find shocking. We do our best not to censor content here and playing swearword police is not in our job descriptions. Sailing Anarchy is more like a bar than a classroom, so handle it like you would meeting someone a little coarse - don't look for the teacher. Thanks.
    • B.J. Porter

      Moderation Team Change   06/16/2017

      After fifteen years of volunteer moderation at SA, I will no longer be part of the moderation team. The decision to step aside is mine, and has been some time in the works but we did not wish to announce it in advance for a number of reasons. It's been fun, but I need my time back for other purposes now. The Underdawg admin account will not be monitored until further notice, as I will be relinquishing control of it along with my administrative privileges. Zapata will continue on as a moderator, and any concerns or issues can be directed to that account or to the Editor until further notice. Anyone interested in helping moderate the forums should reach out to Scot by sending a PM to the Editor account. Please note that I am not leaving the community, I am merely stepping aside from Admin responsibilities and privileges on the site.

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xyzzy

Repairing corroded aluminum

12 posts in this topic

The aluminum strip that holds my washboards on has badly corroded around one of the screws. The corrosion was so thick around the screw it pushed the strip away from the deck over 1/4" and then cabin top lines started snagging under it.

 

The strip started 1/8" thick, but it's less than half that thickness around the one screw hole after I wire wheeled away the corrosion. The back side has some kind of black plastic coating or lamination on it.

 

What should I do to stop the corrosion from progressing where it has started? And what can I do to fill the parts that have corroded away back to original thickness?

 

I'm thinking I'll clean with a brass brush, spray with zinc chromate primer, and then fill with phenolic thickened epoxy.

 

Is the zinc chromate under epoxy a good idea, or would it only be appropriate if I was going to paint, and I should just go straight epoxy on the Al? Do I need to treat the Al with something first, like lye or alodine? I have neither. I do have some over cleaner, that's like spray on lye, isn't it?

post-39862-0-50246700-1378251617_thumb.jpgpost-39862-0-26617000-1378251626_thumb.jpg

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I'd replace it but if you want to rebuild it, put the epoxy on the aluminium - after a fresh pass with abrasives. Chromate is for use under paint - a primer if you will.

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I'd simply replace the strip.

Bronze, brass or stainless would be OK.

If using aluminum, use a corrosion resistant alloy like 6063.

McMaster is your friend.

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Im no expert by any means, but i have done a full refurbishment of an 42 ft alloy keeler.

 

for a non-structural application like youve outlined, heres my 2 cents

 

 

 

If that doesnt fix it, redo it in 3 years time

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The outside of the strips appears to be anodized and the underside has this plastic coating. If I made new ones that would be hard for me to replicate. And the port strip is perfectly fine, but probably wouldn't match a new starboard strip in appearance. I'd probably never get the screw holes to line up with the old ones either. I use clamps, transfer punches, etc. but it just never works for me to get new holes to line up with old ones. Anyway, I'd rather restore the affected area than make a whole new strip. I just don't want it to corrode away again so fast as to make the effort a waste of time.

 

Heavy Metal, is that filler somehow superior to epoxy with a fairing filling added to it?

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Heavy Metal, is that filler somehow superior to epoxy with a fairing filling added to it?

 

Umm, im not sure, its . . .different.

 

It sets, very, very, very hard, alot harder than epoxy. Its 'filler' is alloy fibers and is very impact resistant and, IMO, less likely to crack (due to the fibres) under stress than epoxy.

 

I used it for areas that required serious filling (several squ feet, upto half an inch deep), then faired the surface with epoxy and microballons - 3 years later and its still looking great.

 

The best benefit is its not a "marine" product with marine pricing, and you can easily mix small volumes - you'll buy it or something similar at the automotive supply store as its predomanently used as body filler on cars.

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The problem with alu and epoxy is that the alu corrodes VERY quickly, like instantly, in contact with air causing a bad bond.

One way around this is to coat the alu in epoxy, then sand the alu while the epoxy is still wet to get a good bond

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The problem with alu and epoxy is that the alu corrodes VERY quickly, like instantly, in contact with air causing a bad bond.

One way around this is to coat the alu in epoxy, then sand the alu while the epoxy is still wet to get a good bond

Many contradictions here.

 

From a marine/aviation view point you have to first determine how far gone the alloy is.

 

As stated before. If this is not marine (5083...) grade alloy then replace.

 

If it is and worth saving then...

 

Fully wash in fresh water with desalination agent.

 

Fully dry

 

If it looks very porous then go to you local powdercoater and get him to our it thru his 3 or 5 stage Chromate system. Or go to a aviation repair guy and get it coated in aladine.

 

These are the only two systems that will work. You can by a chromate etch and apply tour self but be sure to follow instructions to reduce the accumulation of "free acids" which will compromise longevity of alloy and coating.

 

Then once treated get a good build (300um) minimum DFT ( Dry Film Thickness) of a goid quality epoxy primer/UC)on the part. This van be either wet paint old a powder coating product ( but remember the part will have to pass thru a oven for more than ten minutes at 200 degrees C. So attached compo ants might melt). A FBE (fusion bonded epoxy) is the best and will last a very long time. But products li,e interprotect or Interlux inter prime epoxy are good to.

 

Any filling can be done now then add another epoxy coat.

 

 

 

Since epoxies offer the best resistance to water migration ( by pressure/osmosis) you need this to keep H2O and O of the alloy. But! Epoxies chalk in UV soo...

 

Sand to desired smoothness no smoother than 350 grit... but to course and sand marks will be present in top coat. ( a guide coat is good for finer sanding )

 

 

Top coat with either a polyester powder coat top coat or polyurethane topcoat to get UV protection and the color/gloss required.

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MCU aluminum paint (aluthane???) then kevlar reinforced epoxy paste. More mcu aluminum to give nice new aluminum look again.

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By chance, Paul, do you sell that miraculous stuff?

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MCU aluminum paint (aluthane???) then kevlar reinforced epoxy paste. More mcu aluminum to give nice new aluminum look again.

 

Kevlar reinforced? For what purpose, bulletproofing the piece?

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