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Redneck · 10-17-2004, 01:50 AM

Please leave the acid washing to a professional. Hydrofluoric acid is highly dangereous. Five square inches on your skin left untreated will kill you. I work in a chemical plant where we use Hydrofluoric acid in the manufactor of refrigerant gases. Maybe you meant hydrochloric acid even this should be left to a professional.

Quote:

Originally Posted by Canoe stream

Worth an extra post: I seem to recall that hydrofluoric acid dulls nerve endings as it burns skin. Therefore you would not know the difference between sweat or leaks in a glove. Eye protection goes without saying. Work very clean and with good equipment!

wahoonc · 10-17-2004, 11:33 AM

Try Vinegar

It is a mild acid, we used to use it to tone down new coppper when we did a repair. Actually it happened by accident, someone knocked over a big jar of pickles in the shop and it spilled on some scrap copper and the idea was born.

Aaron

markdoane · 10-17-2004, 11:47 AM

I bought a bunch of copper light fixtures and 'aged' them with vinegar (half white, half balsamic). Developed a nice verdegris color in a few hours. Over time it darkened and now they look about 20 years old.

CanoeStream · 10-17-2004, 04:34 PM

Don -- I'm surprised you didn't happen upon and join with the acidity of tomatoes. A bit of garlic and, as required for a vintage restoration like yours, anchovies instead of salt. Throw in salt cured olives from the 'Hidden Valley' of western Ohio and there you have it -- Airstream Puttanesca! (ahhh, my lee-tle Street-roller -- come hither....)

steelbird312 · 10-23-2004, 06:58 AM

It strikes me odd that the best suggestion of all(in my humble opinion) is totally ignored. She is very right about the truck wash, and the acid wash. It could be, not only washing the new panel, but doing the whole trailer would cause the 'match' you are looking for. After achieving the desired color, the acid is neutralized, and you should be happy.I do know that many folks in the cabover Avion community use this proceedure prior to polishing to bring about a uniform color as well as to shorten the polishing process.
If there is any scrap from the installation process, why not take it by the truck wash, and ask them to spray it during the process of the next truck they do, and take it home for comparison.
Aluminum can not be blasted by media successfully, except possibly baking soda. It will stretch the metal.
Good luck in your attempts,
jerry

markdoane · 10-23-2004, 08:09 AM

Thanks Jalina,
I'm trying various acid washes and none of them have dulled the aluminum. I suspect that the acid wash may have been followed by an alkaline rinse to neutralize the acid, and I'm currently testing some alkaline rinses. Will report if anything works.

Ken J · 10-23-2004, 08:22 AM

Truck wash on an Airstream is not a good idea. The acid will get into the rivets and very difficult to neutralize - it then causes leaks that you can never get rid of. Airstream polishing follows the airplane polishing community and you never hear of airplanes being truck washed.

Ken

steelbird312 · 10-23-2004, 05:51 PM

In May, the WBCCI Region 3 had a rally in Charleston, SC, at which there was a seminar put on by a professional polisher on polishing Airstreams. At that seminar, the man polished a 3x3 foot section on an old Airstream, showing each step and the products use to achieve certain steps. He then shocked the whole group by telling us that the brightest, most uniform polish jobs were achieved by using an acid wash after all this polishing, and then a last buffing would make it look like a mirror.
Now, I don't claim to know everything there is to know about polishing, yet, I saw one of his polish jobs that had not been touched up in a year, and it had been sitting outside. It had no problems with the rivets. I guess we might ought to contact him and let him know what he is doing it wrong.

Ken J · 10-23-2004, 06:31 PM

I don't understand why you would do a complete polish job and after all that work put acid on - its beyond me. None of the vintage folks I know with great polish jobs have used acid.

Then again, each to his/her own. There are lots of folks out there professing to be professional polishers that want to make a quick buck - acid or no acid they charge 150 or so to polish a trailer - some take 10 hours to do the job - others take 100 hours.

Ken

steelbird312 · 10-23-2004, 07:28 PM

Ken,
tHERE WERE PROBABLY 12-15 OF THE vINTAGE group of the WBCCI there. Matter of fact, they had an open house of 10 or so after the seminar. I have pics of the guy, but I swear, I do not remember his name. Yes, They spoke of the many, many hours to complete the job. Anyway, the fellow that did the first one spoke of how that after so many hours, he was so disappointed that, after following all the proper steps, using all the so called proper chemicals (polishes,etc.) that his trailer looked like all the others- it had a 'milkiness' to the finish. I have no idea where he came up with the idea to acid wash it, but he did, and then after the final buff, it looked like a doggone mirror! I saw it. It stood out among all the others.
I had an Avion cab-over camper one time, and after I was through with it, the man who bought it, kept me up on his restoration and he, too, spoke of the people dedicated to those things using an acid wash as they finished them. The guys around here, (I live south of Atlanta) use the acid wash at the truck stop to do their fuel tankers, and them polish them to where they will blind you.
Anyway, nuff of this subject for me- good luck on your project,
jerry

Silver Bullet · 10-23-2004, 07:49 PM

Don,

Just try wet sanding with 1200 grit paper and let it sit on the south side for the winter. What you are trying to do is "force" oxidation. It doesn't take much, breaking the surface should suffice.

Oscar

markdoane · 10-23-2004, 08:31 PM

Thanks for all the suggestions and tips.

I think I will forgo the acid wash, based on some articles I read about oxygen concentration cell corrosion. Acid may be a good way to brighten aluminum, but where it gets into seams and under rivet heads I think the potential for delayed and hidden damage is something I want to avoid.

Here's some FAA paper on the topic. http://www.faa.gov/avr/afs/300/pdf/2f-ch6_1.pdf

Jalina · 10-24-2004, 06:20 AM

Mark

Just read all the post on the acid wash. The pro's and con's would make me think on the way I would go. I work at a trailer mfg. company and last year I had Alum. forman get me some acid wash to use on our Kenworth tanks. He told me to reduce it down with water but not sure the percentage. Husband put it in a sprayer and I was there to rinse it off quickly. And rinsed and rinsed and rinsed again. If you are not sure that you want to do the acid wash I would for sure take it to a truck wash and have them do it for me. Hope it works out for you and I just Suggested the wash to you for the effect you are going for. Didn't mean to make a big deal out of it.
Jalina

Ken J · 10-24-2004, 07:37 AM

I've been doing the polishing thing for about seven years now - have looked and studied all the methods. It takes about 10 times as much work to get to 100% as it did to get to 80%. Airmark was the polish about six years ago - they polish the big Bowing jets, then we all switched to Rollite now the polish of choice seems to be Nuvite. I've used all three and I do find Nuvite to be the easiest. Rollite is still an excellent choice and Airmark is really designed for use with air tools - and takes a little more skill to use. I would not run my car through a truck wash, so I won't use a truck wash on my Airstream - I figure most trucks are toast after 5-6 years maybe ten max. Also the trucks I've seen use a much heavier gauge aluminum metal. My trailers are 29 and 46 years old and I plan to make them last at least as long as I'm around. Airplanes tend to stay in the air many many years and there are strict rules on how to keep them up in the air and products that are allowed to be used. For my money I'll go with the Airplane guidelines over the truck guidelines any day. I also will not us SS, Gords or mothers or any other polish that is not approved for aircraft.

If there is an easier way to polish in the hands of the average do-it-yourself polisher, I'm all ears, because it is very long tedious work - but to me it has to be a proven method over the long term.

Ken

Jalina · 10-24-2004, 07:50 AM

Ken,

I don't think you are getting what he is trying to do. He wants it to look like the rest of the trailer. (OLD) Not polished. At the truck washes they do have high pressure that you would not use on a car. But the acid is not put on with high pressure.And as of the years trucks will last all depends on the owner. We own a 89 KW and it is still making us money. They are just like anything else if you take care of it it will take care of you. On the acid wash it was just a option I thought would help him. I might just be a woman but we do know how to think.
Jalina

Ken J · 10-24-2004, 08:06 AM

Jalina

I'm aware of what Don is trying to do - you can see my earlier suggestion - leave it under a tree for 40 years and it will be all the same color.

I would not want to mess too much with trying to dull alclad - it may be permenant.

Don - what you could do is flip the panel over and use the back side - you could do all kinds of things to it, then when you get ready to polish, turn it over and viola its ready to go.

Ken

CanoeStream · 10-24-2004, 09:45 AM

Jeez Louise Ken -- We've got all sorts of thinking going on here...

I'm not trying to be an arbitrator from the non-silver side of the community, but will offer some recall from previous threads (threads that I will not dredge up due to the job of putting back front belly pan and banana wrap waiting in my driveway). Don having alclad is an extra challenge and I'm not sure any answer that makes it match now will continue to match as the respective surfaces age at their own rates. 40 years is looking better all the time.

I do not doubt that a combination of acid with other finishing materials can produce a cleaned & shiny trailer. The past advice from these forums is that common issues of sealing and leakage shared by Airstreams and aircraft have brought the aircraft refinishing industry to avoid acid use. This is echoed in Ken J's & Silver Bullet's replies in the 1st half of Page 2 of this thread.

Acids will tend to react fully after a finite time and not have a lingering effect. They are not magical catalysts that activate every time our rigs get wet. For a certain period they will age sensitive parts at a faster rate. I might suggest the question is whether an acid wash will kick the aged sealing on vintage trailers to the point that we will see leaks here and there that didn't exist before. Of course the problem is the difficulty in recognizing that a small leak even exists. The only way of testing this is to disassemble the trailer -- and I suspect the aircraft industry goes this far much more than we have. Thus has come the advice from aircraft refinishers and Andy at InlandRV -- don't use acid washes on Airstreams.

Jalina · 10-24-2004, 08:57 PM

Quote:

Originally Posted by markdoane

Thanks for all the suggestions and tips.

I think I will forgo the acid wash, based on some articles I read about oxygen concentration cell corrosion. Acid may be a good way to brighten aluminum, but where it gets into seams and under rivet heads I think the potential for delayed and hidden damage is something I want to avoid.

Here's some FAA paper on the topic. http://www.faa.gov/avr/afs/300/pdf/2f-ch6_1.pdf

Don, Jalina's mechanic here, Mac, I have used acid at truck washes for the past 21 years and I am now still driving a 1988 Kenworth W900 that we have owned for 10 years.Iunderstand the fears of getting the acid behind the rivits and thus causing leaks and things. I use it when the tanks and wheels get so dirty and road grime and they just won't come clean. On some other trucks I have owned we have used it on the paint and all, no problems. If I have time in the next couple of days I will acid wash a piece of scrap two or three times at time lenghts and post the pics for y'all to see. I will also try to get the name of the acid and the dellution rate for you. I know the look you are gooing for and this will do it , but then there's the ribbit thing!

Good luck
Mac

markdoane · 10-25-2004, 09:03 AM

Quote:

Originally Posted by Jalina

I will also try to get the name of the acid and the dellution rate for you. I know the look you are gooing for and this will do it , but then there's the ribbit thing!

Good luck
Mac

Thanks! Looking forward to your pictures.