Thread Tools Search this Thread Display Modes
Old 07-16-2011, 01:39 PM   #15
3 Rivet Member
DougZ's Avatar
1972 27' Overlander
Venice , Florida
Join Date: Dec 2010
Posts: 180
Originally Posted by Nuvite-F View Post
No, it's probably intact. Pure aluminum is more corrosion resistant than the underlying alloy, but not infinitely so. Most old trailers have ghosts of the old numbers on them. The other thing you will discover when you start polishing is that each sheet of aluminum is a little different, and at least on the one trailer I polished, the compound curved panels of the end shells seem to have "stretch marks" that are hard to polish out.

Good luck!
What do your stretch marks look like? I looked on mine (which has not been buffed) and couldn't find anything. This aluminum thing is getting complicated.

DougZ is offline   Reply With Quote
Old 07-17-2011, 06:52 AM   #16
Restorations done right
Commercial Member
Frank's Trailer Works's Avatar
1962 26' Overlander
1961 26' Overlander
Vintage Kin Owner
Currently Looking...
Baltimore , Maryland
Join Date: Aug 2007
Posts: 5,547
Images: 2
I think this may have already been said, but the numbers do not cause any damage to the skin. What does cause the issues is the area around the numbers that actually is exposed. The numbers, when stripped, do not remain, the clean perfect aluminum is exposed. You see the oxidation around the numbers. The more exposer, the deeper the ghost image will be. Sometimes this is impossible to remove and just has to be looked at as history.
Nuvi is very correct about the stretch marks. The seven panel end caps have the least due to less stretch forming required. The five panel end caps will show even more due to each segment being a wider span and having required more tonnage to form it. The modern aluminum used today does not form these stretch marks due to it being a totally different alloy of aluminum (it is the same as license plates are made from) but cannot be polished as Alclad can. Any metal can be polished. Some polish better than others.
I always wonder though, why the center panel on a new Airstream is a totally different color than the rest of the end cap. I asked someone from Colonial this and they kind of side tracked the answer. I assume they did not know either.

Frank's Trailer Works is offline   Reply With Quote
Old 07-17-2011, 08:57 PM   #17
Rivet Master

Southwestern , Ohio
Join Date: Nov 2006
Posts: 1,620
Originally Posted by DougZ View Post
What do your stretch marks look like? I looked on mine (which has not been buffed) and couldn't find anything. This aluminum thing is getting complicated.
The "stretch marks" I mentioned are kinda hard to describe. They don't show up till you start cutting through the oxide. After a couple passes with coarse polish (you will probably find it will take several passes to get through to clean aluminum--at least I did) you will notice thin dark streaks where the oxide is thicker. I suspect this is where the pure aluminum layer stretched out a little thinner when the panel was formed. It's not a problem aside from the fact that those panels will take more polishing to get the oxide off than the other panels. Or you can do like I did and let some of the oxide stay--I didn't want to polish right through the cladding.

And yeah, you're right--"this aluminum thing" is a lot more complicated than most people realize! I found a lot of variation in polishing behavior between one panel and another. It's more of an art than a science.

Dale (Pee Wee) Schwamborn worked for Airstream, and purchased their aluminum for a number of years. He has a lot of good stories to tell about it. I've forgotten the details, but I recall Airstream bought the aluminum they used for single-curved panels from one manufacturer (Reynolds, I think) but the aluminum for the compound-curved end shells from another (Kaiser) because the different brands worked better in those uses. (I may have Reynolds and Kaiser reversed.) Nobody knew why.

The other Pee Wee story is that if you look at the pictures of new 60's Airstreams, they looked like they had been polished. They weren't--that's what the aluminum looked like when it came from the rolling mill.

And therein lies a tale. The quality of the surface finish of the sheet depends on the surface finish of the rollers in the rolling mill. The rolls are reground at frequent intervals and the first batches of aluminum sheet that come off the new rolls are better than later batches.

Aluminum is purchased to a specification, and all the aluminum meets the specification. But Boeing paid extra to get the first batches off new rolls so they had the best surface finish.

But there was one relatively small customer that got their aluminum even before Boeing--Airstream.
Nuvite-F is offline   Reply With Quote
Old 07-18-2011, 05:11 AM   #18
2 Rivet Member
1969 27' Overlander
Vestavia , Alabama
Join Date: May 2011
Posts: 24
Attached should be a before pic. I did get a promising amount of the etching to smooth out through compound cut. Will post more later.

Got a little over half of the first cut done this weekend.
Attached Thumbnails
Click image for larger version

Name:	IMG-20110716-00060.jpg
Views:	65
Size:	50.9 KB
ID:	135180  
Aubiexx is offline   Reply With Quote
Old 08-15-2011, 11:19 AM   #19
Rivet Master
ALANSD's Avatar

1966 26' Overlander
Woodstock , Georgia
Join Date: Feb 2002
Posts: 8,079
I have had some success with 1000 grit wet sandpaper, and then brown tripoli. The numbers are almost totally invisible now.

1966 Overlander
AIR #005
Please visit our blogs and web pages:
ALANSD is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Aluminum expansion and contraction Rileybear Ribs, Skins & Rivets 16 07-05-2011 05:46 AM
Aluminum desk top worksology Cabinets, Counter Tops & Furnishings 33 06-30-2011 05:47 AM
Lug nut torque for aluminum wheels? blickcd Wheels, Hubs & Bearings 5 05-01-2011 08:08 PM
Coated Aluminum glh101282 Clearcoat, Exterior Paint & Trim 6 02-24-2011 10:38 PM

Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:11 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.