Frame Rot

[monocoque]

Greetings,

And hello to you all. I have been reading back posts for a few weeks and I must say I feel comforted to be in such esteemed company.

Background: I recently purchased my first airstream. Blessing or curse!? :-)My idea was to purchase something I could remodel/renovate in my spare time. I'm quite sure I didn't know what I was getting into! :-)

I purchased a 1975, 29 ft, Ambassador, center bath, with twins. Found it parked under trees at a friends house where it had been sitting for about three years. The PO before that is unknown except for an address in Corpus Christi --when means near the coast.

So far I have removed the rear, most aft, banana skins, the rear bumper and half of the floor in the rear bedroom. Clearly the two, most aft cross-members need replacing and the two most aft outriggers, curbside and streetside, need replacing as well.

However, the main concern seems to be the frame. There is a fair amount of rot that appears to need cutting out and replacing. At this point I am still assessing the damage and looking for the next step --which seems to be to summon your collective advise and that of a good welder.

I have attached photos. Obviously I have not yet dropped the belly skin in that area below the frame. However the condition of the frame below the belly skin is much better than above..at least there are no large holes.

I would very much appreciate any comments or advise you may have. Including...abandon ship if you think it prudent. :-)

Todd

[markdoane]

Nobody here will tell you to abandon ship. Heck, you're halfway to being back on the road if you have it opened up for inspection. Get ahold of a good welder and let him have a go at it. Doesn't look too bad if you replace the rear frame and crossmembers. They're easy to fabricate.

[monocoque]

Frame: so would you suggest "replacing" the rear frame? I assume that would involve welding in a completely new frame from new material rather than cutting out sections of the old and slicing in "patches."

Crossmembers: is is possible to purchase replacement cross-members? Or would these need to be fabricated out of new material?

Outriggers: I have found outriggers for sale on the internet --will need to check my notes for the link. Although I have seen a few back post where these have been fabricated out of various kinds of material.

[maccamper]

Welcome to the Forums and the experience of Airstream renovation. We purchased our '74 Ambassador last March, and discovered many of the same problems that you can now see. I would agree that with all the work you have put in so far, you should stay the course.

My experience has been that nothing goes back in quite as quickly as it comes out, so please don't be discouraged. There are some good threads on frame repair, which can be really helpful. Part of my frustrations have been because so much had rusted away in the subframes, I could not tell how it was put together originally. Looking at the other posts and projects provided some insight, and it was nice to know someone else had been through this and had been successful.

It looks like you have the original water heater, you might want to check out the floor around it fairly carefully, that was major floor damage under ours.

Depending how much renovating you intend to do, you might want to consider getting a copy of the service manual for your model, I have found it to be a great help.

Good luck.

[markdoane]

Whether you replace the entire rear frame, or just scab in sections where needed, is something you can only tell by close up inspection.

I would recommend you check the frame thickness where it is still the original thickness, then anywhere it has lost more than 10% I would start replacing.

[PizzaChop]

Congrats on finding a center bath, it's worth holding on to! There are many more options available with that floor plan than with the rear bath.

I had a bit of frame rot on my '73 Sovereign which required a bit of fabrication.

Rear cross member Before After

Outriggers Before After

Be careful about adding too much weight back there, as the shell actually helps support the frame.

Hang in there! Everything takes longer than you think, but it'll be worth it in the end (I think).

[monocoque]

At this point it seems like the question I should really be asking is whether to replace the frame? If the frame needs replacing I think I'll reconsider how far I want to take this particular project. I'm doing the repairs in my driveway and have very little space for removing the shell. So if I can repair the frame with the shell on then I'll likely stay the course. However, if the rot is too extensive the PO, who is a friend, has agreed to take the trailer back and refund the purchase price. Of course, I'm completed hooked on AS's at this point, and would look for a new project with frame in a better condition. Tough initiation as I've invested a few weekends of work already.

[87MH]

Originally Posted by monocoque

At this point it seems like the question I should really be asking is whether to replace the frame? ....Tough initiation as I've invested a few weekends of work already.

Wow - you've gotten a lot done in just a few weekends.

On the frame and outriggers - knowing what I know now after redoing the '78 31' center bath Sovereign (http://www.airforums.com/forums/f219...ign-14737.html)- I would seriously consider a frame and outrigger system constructed mostly of standard "C" or "Z" purlins - they are readily available, easy to form, and relatively easy to weld with a MIG system. I would suspect you would need a bit more web thickness for the axle mounts.

You would have to crunch some numbers to determine the depth and thickness for proper strength, but considering the cost of 80 to 120K steel it might be worth it...Cheap, Looks Good, Lasts a Long Time...

You will never have a better opportunity to "Do It Right" than right now.

[monocoque]

Dennis,

I agree if it needs a frame, it needs a frame. Since I didn't plan on going this far I'm still gathering the facts as to what replacement would entail.

Do you know any welders in the San Antonio area who could tackle such a task? I'm pretty handy but not a welder. Most likely I would contract a professional to do the frame work.

Any idea what a ball-park figure for a new frame, parts and labor, should be these days?



Todd

[Inland RV Center, In]

Originally Posted by monocoque

Frame: so would you suggest "replacing" the rear frame? I assume that would involve welding in a completely new frame from new material rather than cutting out sections of the old and slicing in "patches."

Crossmembers: is is possible to purchase replacement cross-members? Or would these need to be fabricated out of new material?

Outriggers: I have found outriggers for sale on the internet --will need to check my notes for the link. Although I have seen a few back post where these have been fabricated out of various kinds of material.

Crossmembers and outriggers are available.

You would need to be very specific about those parts.

Lefts, rights and dimensions, etc.

With outriggers, are they slotted, solid, or tapered, and are they left or right hand.

With the crossmembers, what is their vertical dimension? There are two different sizes.

Andy

[monocoque]

Originally Posted by 87MH

I would seriously consider a frame and outrigger system constructed mostly of standard "C" or "Z" purlins - they are readily available, easy to form, and relatively easy to weld with a MIG system. I would suspect you would need a bit more web thickness for the axle mounts.

You would have to crunch some numbers to determine the depth and thickness for proper strength, but considering the cost of 80 to 120K steel it might be worth it...Cheap, Looks Good, Lasts a Long Time...

I contacted welder in my area and he's willing to make a bid and assess repair versus replacement. It will be a week or so before I can remove more of the belly skin to expose the remainder of the frame. I ask him about standar C or Z perlins and the cost of 80 to 120K steel. Anything else I should ask him to consider or I should consider?

[PizzaChop]

My idea was to purchase something I could remodel/renovate in my spare time. I'm quite sure I didn't know what I was getting into!

Todd,

If it makes you feel better, at least know that you're dealing with the worst part first. You'll have plenty of other issues to deal with later (appliances, leaks, gaskets, axles, running lights, etc.) but the frame/floor repair is a one time deal. I would prefer it that way, because at least you know what you're riding on when you're done. Many might pay $6K for something with a frame in no better condition than your's (unknowingly).

Be sure to have the belly pan (and banana wrap) removed up front as well, as you may have some major rust issues there also. Your freshwater tank sits beneath the kitchen floor atop a 1" thick piece of plywood. You want to be sure there haven't been any frozen pipe/plumbing leak issues down there, which really put a damper on your day.

Don't worry about appearances at this point, you want it to be structurally sound before you go any farther.

If you're willing and perservere, you'll learn a lot, gain confidence in your abilities, appreciate this forum even more, and have a valuable coach which will be lighter, and with less issues (once you've fixed 'em) at a fraction of the cost of a new Airstream.

Not to mention the satisfaction of saying..."I did it myself".

But prepare for a long spring.....

[monocoque]

Originally Posted by PizzaChop

If it makes you feel better, at least know that you're dealing with the worst part first...But prepare for a long spring.....

Today I got the trailer up on 6 inch blocks (three 2X8's). So I'm finally able to start removing the belly skin.

First removed the rear stabilizer jacks which are bolted to the frame and second crossmember. The street-side stabilizer had punched through the belly skin due to frame rot at the point where the crossmember joins the frame. Part of the frame even remains bolted to stabilizer! You can see the puncture in the belly skin after the skin is removed.

Removed the rear-most belly skin. Photo shows inside view of the belly skin after removal. Note the poor condition of the belly skin at points of contact with the rear crossmember and second cross-member. Looks like this belly skin needs replacing. Any suggestions about locating replacement material?

Here's the frame from above with the belly skin removed. Note the light shining through the frame on the right side (curbside) and two places on the left side (roadside) on either side of the second crossmember. As you can see there is not much left of the rear most crossmember.

The photos also show the condition of the frame where the rear crossmember meets the curbside frame. Also note the holes through the roadside frame just forward of the rear crossmember.

The good news is that the frame and cross member look good at the third cross member. However, aft of the third cross member, roadside, there are holes in the frame. The cross-member itself is sound. Aft of the third cross member the curb-side frame and cross member looks good. Luckily only the two rear-most cross-members need to be replaced.

I also removed the roadside banana-skins aft of the wheels and all the outriggers on this side need replacing. I was happy to discover that the condition of the floor and the frame just forward of the third crossmember looks good. I plan to remove the hot water heater so this should reveal the condition of the floor in that area.

[PizzaChop]

How's the front section of the frame look (especially where the A-frame disappears under the shell)?

Enquiring minds want to know....

[monocoque]

Don't say you didn't ask...

Took the front banana skins off today. All banana skins now off. It wasn't pretty. The rust continues in the front sections of the frame. The curbside is worse the roadside looks better. The rearward trend continues up front.

The first photo is the front end of the frame curbside. The second is the front end of the frame roadside. So who went scuba diving with this frame?

What's next? Gut the interior and unbolt the shell from the frame or remove the remaining belly pans and see if it can get any worse? Not sure which one I prefer.

[Wabbiteer]

Wow - I keep searching for words but few printable ones appear.

[monocoque]

It can only get better from here?

The axles are mounted to a plate of steel that is welded to the frame and skid. Not sure what this plate is called? Take a look at the rear most point of this sheet at the point where it makes contact with the skid. Notice that it is bowed or bent out. Photos are from behind looking forward and from directly below. That's rust causing the bend if I'm not mistaken.

Also there is a side picture of this axle mounting plate showing the overlap onto the frame and skids. There are a number round holes in this metal plate I assume to give more points for welding. Notice where the frame has rusted completely through some of these holes. Photos also show this plate further forward in between the curbside axles.

Finally there is a photo of this metal plate taken from below at a point in between the axles. Notice that this plate is bent out once again. Apparently the PO using this plate as a jack point. Has rust weakened the weld between this plate and the frame causing this bend which I assumed happened during jacking? I wouldn't think that using this point for as a jack point would cause that bend unless there is rust on the frame BEHIND the plate. I could be mistaken about that.

Todd

[monocoque]

Not sure why the photos didn't go through. Exceeded file quota? Didn't realize there was a limited number of photos I could upload?

[Aerowood]

You can only upload about 3 at a time, after they are uploaded simply select the manage attachments window again and upload the rest, and they will all upload to the same post. Then select the Submit reply window. It sure looks to me like you are heading for a new frame, one that wasn,t used as a boat anchor. Check out this thread, http://www.airforums.com/forums/f36/...ame-29294.html

[monocoque]

Okay here are the photos of the axle mounting plate referred to above.