RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-27-2020, 08:54 AM   #1
New Member
 
Currently Looking...
Newmarket , ON
Join Date: Oct 2020
Posts: 4
Airstream Aluminum Frame

Hi. I'm new to the forum. I'm currently looking at buying a 1976 31' Airstream. This will be a project restoration. The trailer has been gutted to bare exterior shell. The shell has been lifted off the frame and a new frame and sub-floor have been installed and the shell reattached.

My concern is that the new frame is aluminum. On the face of it, this seems like a good idea with regard to corrosion and weight savings. The downside is I am not sure of what size aluminum members would be needed to achieve the same strength, torsion and flexibility to match the original steel design. I am trying to contact the welder who made the frame to find out exactly what was used as I have not been able to inspect the trailer in person yet. Apparently, the original design was copied, but in aluminum. My understanding is that up-sized members were used, but I'm not sure.

New running gear has been installed which is steel. I'm not sure if this has been isolated from the aluminum frame to avoid galvanic corrosion. Does anyone have knowledge on how this installation could be done correctly? Some kind of spacer, I assume?

The sub-floor that has been installed is painted 3/4" plywood - not marine grade or equivalent that I am aware of. Any comments about this?

I have looked at some of the other forums that discuss aluminum frames but would like to know if anyone has first hand knowledge of what an aluminum frame spec would be. I am aware that the aluminum design must be beefier than a steel design.

Thanks in advance for any helpful information.
Kawabonga is offline   Reply With Quote
Old 10-27-2020, 09:50 AM   #2
Rivet Master
 
KK4YZ's Avatar
 
2020 28' Flying Cloud
2017 23' Flying Cloud
Hiawassee , Georgia
Join Date: May 2017
Posts: 1,011
Plywood floor

Plywood floors (not marine grade) have been standard on Airstreams. I hear they might move to composite in 2022?.

The plywood flooring used is WPB which supposedly can withstand a boiling water test without coming apart. BUT it will still rot, which is the major concern.
The standard flooring does have an ďanti wickingĒ coating on the edges.

My guess is that if the new floor is painted completely itís probably as good or better than what new AS have now.

DISCLAIMER on the following: Iím an Electrical Engineer, not Mechanical, but Iíve worked closely with MEís that are responsible for structural design....and have had to understand and explain the results.

To be certain of the adequacy of the aluminum frame, youíd probably have to have an ME model both frames and do an analysis. Not cheap.
Hopefully someone with direct knowledge/experience in this area might know rules of thumb that could be applied to the situation.
KK4YZ is offline   Reply With Quote
Old 10-27-2020, 09:54 AM   #3
Rivet Master

 
1966 22' Safari
1955 22' Flying Cloud
Fredericksburg , Texas
Join Date: May 2015
Posts: 1,632
You may consider leaving your question on the VAP Podcast. Colin Hyde has either built an aluminum chassis or researched the possibility. I would also imagine there would be some forum members who have engineering knowledge for this. Good luck and be safe.
Bubba L is offline   Reply With Quote
Old 10-27-2020, 09:56 AM   #4
Is it January yet?
 
jaybauman's Avatar
 
Currently Looking...
2019 30' Flying Cloud
Katy , Texas
Join Date: Apr 2017
Posts: 432
Quote:
Originally Posted by KK4YZ View Post
I hear they might move to composite in 2022?.
Airstream began the transition for 2020 model year. All 2021 trailers (excepting Base Camp and Nest) have composite flooring.
__________________
2019 Flying Cloud 30FBB
Bunkhouse is sold...something more "classical" on order!
2020 GMC 3500HD Duramax AT4
ProPride 3P w/ 1400 lb. spring bars
jaybauman is online now   Reply With Quote
Old 10-27-2020, 10:03 AM   #5
Rivet Master
 
KK4YZ's Avatar
 
2020 28' Flying Cloud
2017 23' Flying Cloud
Hiawassee , Georgia
Join Date: May 2017
Posts: 1,011
Quote:
Originally Posted by jaybauman View Post
Airstream began the transition for 2020 model year. All 2021 trailers (excepting Base Camp and Nest) have composite flooring.
So maybe my 2020 FC might have a composite floor? It was built in summer of 2019 so Iím feeling doubtful....
KK4YZ is offline   Reply With Quote
Old 10-27-2020, 10:20 AM   #6
Is it January yet?
 
jaybauman's Avatar
 
Currently Looking...
2019 30' Flying Cloud
Katy , Texas
Join Date: Apr 2017
Posts: 432
Quote:
Originally Posted by KK4YZ View Post
So maybe my 2020 FC might have a composite floor? It was built in summer of 2019 so Iím feeling doubtful....
Airstream marketing has suggested that the flooring transition coincided with inception of production at the new manufacturing facility, which opened earlier this year. I admit my facts are a bit dodgy, but it would seem unlikely that you have the single-piece composite subfloor.
__________________
2019 Flying Cloud 30FBB
Bunkhouse is sold...something more "classical" on order!
2020 GMC 3500HD Duramax AT4
ProPride 3P w/ 1400 lb. spring bars
jaybauman is online now   Reply With Quote
Old 10-27-2020, 10:34 AM   #7
3 Rivet Member

 
1966 17' Caravel
Pine Plains , NY
Join Date: Jul 2020
Posts: 113
Blog Entries: 1
Aluminum Frame Question

Quote:
Originally Posted by Kawabonga View Post
I have looked at some of the other forums that discuss aluminum frames but would like to know if anyone has first hand knowledge of what an aluminum frame spec would be. I am aware that the aluminum design must be beefier than a steel design. Thanks in advance for any helpful information.
Hi Kawabonga. There is a thread for a 49 Trailwind - the owner, "DiscoStu" is doing a shell off resto, and just took everyone through the process he used to design the aluminum cross members (including CAD drawings). He is very responsive and I would suggest that you reach out to him - or at least check out his resto: https://www.airforums.com/forums/f48...to-214550.html - you will see just how excellent his workmanship is. Down[under]-side is that he is in Australia!

Best of luck with your restoration.
__________________
Flostream66
WBCCI #4597
VAC Region 2

------------------
Restoration of my 1966 Caravel: https://www.airforums.com/forums/f13...on-210688.html
Start at Post #7.
Flostream66 is offline   Reply With Quote
Old 10-27-2020, 12:24 PM   #8
New Member
 
Currently Looking...
Newmarket , ON
Join Date: Oct 2020
Posts: 4
Aluminum Frame

Thanks for the responses everyone. So, a little further information. I spoke with the frame fabricator. He copied the original Airstream design with 5" channels but 1/4" thick aluminum which he said is about twice as thick as the original steel frame. All the outriggers were stamped and dimpled for rigidity. Also, the frame has been powder coated for durability and to help against galvanic corrosion between hitch plate and where running gear attaches. All in all it sounds like he knows what he is doing.

He did tell me that from what he recalls, the shell leaks - so that will be another issue to resolve. His suggestion was to re-punch all rivets and seal the inside with an undercoating prior to installing interior shell.

Thoughts ... ??
Kawabonga is offline   Reply With Quote
Old 10-27-2020, 12:50 PM   #9
Rivet Master
 
57Vintage's Avatar

 
1958 26' Overlander
Battle Ground , Washington
Join Date: Jun 2013
Posts: 570
Images: 22
I would not consider 'punching' all the rivets. Water test for leaks and replace/rebuck rivets as needed. You may find some leaks are failed weather strip around doors/windows.

I do agree to reseal all the seams and rivets, but at least remove any original sealant that has failed. (Some will say remove all old sealant.)
__________________
Harold & Rebecca

Our thread:
https://www.airforums.com/forums/f97...er-172124.html
57Vintage is offline   Reply With Quote
Old 10-28-2020, 03:38 AM   #10
3 Rivet Member

 
1966 17' Caravel
Pine Plains , NY
Join Date: Jul 2020
Posts: 113
Blog Entries: 1
Quote:
Originally Posted by 57Vintage View Post
I do agree to reseal all the seams and rivets, but at least remove any original sealant that has failed. (Some will say remove all old sealant.)
Harold, I have bought Parbond from Burnstines to use as a seam sealant, based on the recommendation of Melody Ranch. It arrived yesterday. I wondered if you have used a method you thought was successful for removing old sealant. Thanks. Hollie
__________________
Flostream66
WBCCI #4597
VAC Region 2

------------------
Restoration of my 1966 Caravel: https://www.airforums.com/forums/f13...on-210688.html
Start at Post #7.
Flostream66 is offline   Reply With Quote
Old 10-28-2020, 09:42 AM   #11
Rivet Master
 
57Vintage's Avatar

 
1958 26' Overlander
Battle Ground , Washington
Join Date: Jun 2013
Posts: 570
Images: 22
I just removed any loose sealant. I used a plastic scraper from Harbor Freight that I had for another project.

https://www.harborfreight.com/4-piec...QaAuigEALw_wcB

I recall reading some people used some type of solvent to soften up the sealant and scrape off (WD40, PB Blaster, something like that).

I covered all the seams and rivets with new sealant. I used Eastwood's automotive seam sealer. It can be brushed on. I used some cheap brushes from a box store and cut the bristles shorter so they were stiff enough to force sealant into hard to reach areas.

https://www.homedepot.com/p/Better-2...0200/202197878
__________________
Harold & Rebecca

Our thread:
https://www.airforums.com/forums/f97...er-172124.html
57Vintage is offline   Reply With Quote
Old 10-29-2020, 08:41 AM   #12
Rivet Master
 
kidjedi's Avatar
 
1972 25' Tradewind
1976 31' Excella 500
1974 31' Excella 500
1975 24' Argosy 24
Denver , Colorado
Join Date: Jul 2015
Posts: 674
It sounds like you are really going to be "going for it" if you take on this project. The floors are likely adequate, but since you're this far, you might consider swapping in coosa (not cheap, but water proof and lighter). With an aluminum frame and coosa subfloors, you'd have the lightest Airstream possible. It also *sounds* like the fabricator knew what he was doing, but it's still a bit of a gamble, especially on a 31' (as opposed to something shorter). I wouldn't go drilling out rivets to try and fix an unknown leak (which is likely at a window or other opening anyway). Best to seal the seams and existing rivets, and then if you have the option, insulate with spray foam, as it will also act like a sealant and add additional rigidity to the exterior skin. Downside is if you get a dent, it makes things difficult to repair. Also, if you go this route, you need to use a cold-method application, as the heated application can warp your skins. A realistic aluminum frame is a bit of a "unicorn" on these forums, so take that into consideration when weighing this purchase. Incidently, if you get the opportunity, PLEASE post pics, as just about EVERYONE wants to see an aluminum frame in real life (not just in terms of the theoretical).
kidjedi is online now   Reply With Quote
Old 10-29-2020, 04:12 PM   #13
3 Rivet Member
 
1977 31' Excella 500
Spring , Texas
Join Date: Apr 2020
Posts: 218
Following along with this. Very shortly thought about doing an aluminum frame but decided against it. Would love to see one done.
__________________
1977 31' Excella 500 full restoration: Excella 500 Off Road Build
GPurcell is offline   Reply With Quote
Old 10-29-2020, 04:29 PM   #14
4 Rivet Member
 
mikextr's Avatar

 
1967 26' Overlander
Bugtussle , Oklahoma
Join Date: May 2014
Posts: 312
Your welder was correct using aluminum that is twice as thick as steel to get the same strength. For better or worse, it will be stiffer than the old steel frame.
__________________
1967 Overlander International 26ft
2006 Porsche Cayenne Turbo S 520hp 530ft-lbs torque 7700lb towing capacity
mikextr is offline   Reply With Quote
Old 10-29-2020, 08:37 PM   #15
New Member
 
Currently Looking...
Newmarket , ON
Join Date: Oct 2020
Posts: 4
Here are a couple of pictures
Attached Thumbnails
Click image for larger version

Name:	A1.jpg
Views:	12
Size:	265.0 KB
ID:	382182   Click image for larger version

Name:	A2.jpg
Views:	12
Size:	132.3 KB
ID:	382183  

Click image for larger version

Name:	A3.jpg
Views:	13
Size:	201.7 KB
ID:	382184  
Kawabonga is offline   Reply With Quote
Old 10-30-2020, 05:55 PM   #16
4 Rivet Member
 
mikextr's Avatar

 
1967 26' Overlander
Bugtussle , Oklahoma
Join Date: May 2014
Posts: 312
You're doing great work. Going to be real jewel.
__________________
1967 Overlander International 26ft
2006 Porsche Cayenne Turbo S 520hp 530ft-lbs torque 7700lb towing capacity
mikextr is offline   Reply With Quote
Old 11-09-2020, 12:04 PM   #17
3 Rivet Member
 
1977 31' Excella 500
Spring , Texas
Join Date: Apr 2020
Posts: 218
This is very cool. I would love to know the weight difference between the steel and aluminum.
__________________
1977 31' Excella 500 full restoration: Excella 500 Off Road Build
GPurcell is offline   Reply With Quote
Old 11-09-2020, 12:51 PM   #18
Rivet Master
 
crispyboy's Avatar
 
1994 30' Excella
alexandria , Kentucky
Join Date: Aug 2004
Posts: 2,047
Images: 3
What a perfect time to search for leaks when the interior skins are out. I would reseal the interior seams with Sikaflex or Vulkem and spend some time inspecting during the rain event. Painted plywood should work fine but at this point I would highly consider a composite type floor.
__________________
Steve, Christy, Anna and Phoebe (Border Collie)
1994 Classic 30'11" Excella - rear twin
2009 Dodge 2500, 6 Speed Auto, CTD, Quad Cab, Short Bed
Hensley Arrow hitch with adjustable stinger
WBCCI # 3072
crispyboy is offline   Reply With Quote
Old 11-09-2020, 03:43 PM   #19
3 Rivet Member
 
1977 31' Excella 500
Spring , Texas
Join Date: Apr 2020
Posts: 218
I would consider the composite floor as well. Happy I went with it on mine.
__________________
1977 31' Excella 500 full restoration: Excella 500 Off Road Build
GPurcell is offline   Reply With Quote
Old 11-09-2020, 10:19 PM   #20
New Member
 
Currently Looking...
Newmarket , ON
Join Date: Oct 2020
Posts: 4
Does anyone have any suggestions with regard to axles? I'm considering upgrading to 5200lb axles with 6 bolt rims. Does this make sense or would these be too stiff? What about tires, any suggestions there?
Kawabonga is offline   Reply With Quote
Reply


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
can a frame be repaired without frame off restoration? RhinoWW Repairing/Replacing Floor &/or Frame 12 10-29-2014 11:46 PM
Frame Rot - New Frame jcawley1 Repairing/Replacing Floor &/or Frame 3 09-01-2014 09:30 AM
Advice on gaucho/jacknife frame frame & wall remodel chiefbrody General Interior Topics 0 01-30-2013 05:38 AM
Beatrice era frame experts if you please. Odd frame issue Kevin245 Repairing/Replacing Floor &/or Frame 5 08-25-2012 10:55 AM
Frame Repair or New Frame muddy_hollow Brakes & Brake Controllers 14 09-26-2006 06:55 PM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



All times are GMT -6. The time now is 08:57 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.