Leaks and Floor Rot in '91 34' Limited

[Steve Bryant]

One issue that most everyone has to deal with is where the subfloor has rotted in the vicinity of the perimeter C Channel extrusion, the C Channel has been crushed/bent/deformed.




With most or all of the pressure removed from the bottom of the C Channel, it can be straightened to a large degree. I used various pry bars, a flat plate of 3/8” steel and a large ball peen hammer and some other techniques that I can’t remember now to spread out and flatten the C Channel to better accept the plywood floor.

[Steve Bryant]

I’ve also taken some time to write up a somewhat detailed to-do list to finish up this project. Here’s the list which was done with a word processor so that I can edit it as I go along.

• Finish sheet metal work
  • Riveting in rear
  • Design & install doublers & strengthen front as required
  • Install blind rivets near bathroom
  • Install extrusions on left rear storage compartments (cord & general)
  • Remove and seal remaining Olympic and Pop rivets
  • Check for and replace missing rivets
• Paint frame & install floor in front
• Shift support of rear frame to allow gap between shell & frame
• Paint rear frame
• Install floor in rear
  • Install PEX plumbing that penetrates floor
  • Route and connect wiring where necessary (replace grommets)
• Repair floor rot at entry door threshold
• Caulk all exterior fittings and attachments
• Make and install 4 gutter bridges for lower U channel and caulk all voids/cracks, etc. in U Channel
• Drill additional weep holes in U channel as required
• Test for leaks from exterior and repair as necessary (use hose & pressure washer and maybe it will rain someday) – reseal as required
• Install insulation
• Install belly skin, belly wrap, aft leveler jacks (op check) and rear casters
• Install rear bumper and sewer hose storage compartment lid, etc. – Caulk as required
• Install interior skins
• Complete PEX pluming installation
• Install laminate flooring
• Install interior electrical components (batteries, new converter, solar charger regulator)
• Clean walls & ceiling
• Clean and refinish furniture & upholstery
• Install furniture (replace rubber bumpers on doors, etc. as required)
• Make electrical and plumbing checks and rectify as required.
• Repack wheel bearings, replace seals, check, lubricate & adjust brakes
• Replace brake break away switch & verify exterior lighting
• Make several short test drives and correct squawks
• Replace wheels & tires (tires are too old and I've decided to move to 16" wheels and LT tires)

[perryg114]

Steve your circular plate sticks up a little. Are you going to route out the new floor to account for this or are you going to just jack up the shell to account for that?

I think you are going to have a battle ship there soon.

Perry

[Steve Bryant]

Perry,
Because plane of the bottom of the plywood will fit into the C Channel, I won't have to compensate for the plates on the plywood. However, I was concerned initially about the fact that these plates would elevate the level of the shell by 1/4". Now, I believe that the thickness of the plates won't affect anything very much except to give more support and a broader interface between the front shell and the front of the frame.

Even with Airstream's use of a fairly scanty frame, I don't believe that front or rear separation would be such a problem if they did a better job of connecting the frame and shell together over a wider area and if leaks and sub-floor rot were not so prevalent.

[perryg114]

Are you going to put the leveling jacks back in when you are done?

Perry

[Steve Bryant]

Perry,
Yes, I'll put both jacks right back where they started. The main things that I plan to leave out are carpet and the parquet flooring in the kitchen. The whole interior floor will probably be some type of laminate. Otherwise, the configuration of virtually all of the interior and exterior components will be the same as when I started.

[perryg114]

You could leave the areas covered by furniture bare so you can inspect for leaks periodically. I expect your layout is considerably different than most because of the jacks and horizontal tanks.

Perry

[Steve Bryant]

Perry, acutally, the layout of my trailer and the corresponding Excella version are identical from what you can see on the interior. The trade is that with horizontal bottles, the batteries are beneath the forward dinette seat on the Limited and take up part of the space under that seat. The part where the bottles intrude into the interior is hidden under the front cabinetry and couch/bed. The couch/bed still has the same drawer design underneath. The trim level is differentiated between the Excella and Limited to some degree, but the floor plans are identical.

[perryg114]

That is the same layout that I have. I think I may change mine to a dinet at some point.

Perry

[Landscraper]

Wow, that does look familiar! Except we had very large mushrooms under our beds. You have a project on your hands, but at least you are getting yours done. Your 34 is built exactly like our Monty. Yours looks to be the same style as all the 1970's trailers we have around our shop. I see you are thinking about testing for leaks. Have you thought about a pressure test? That's what Monty is going to get. I heard they do it all the time for school buses. My plan is to plug all the vents and hook a large carpet dryer fan to one of the stow box openings, and spray the exterior with a water/soap/corn syrup mixture. Then since the interior is out, get the leaks with prodex. It shouldn't take much pressure to show the flaws. I picture it working like a long silver "bouncy house" without the kids. A pressure wash is a good idea, but only before sealing so that you accidentally don't cause more leaks with the high pressure jet. After that test, I may use a sprinkler.

[Landscraper]

Sorry, I meant to say Tempro not prodex to seal up our inside seams.

[Steve Bryant]

Landscraper,
Here is a post about a homemade leak tester that Vernon made http://www.airforums.com/forums/f205...ml#post1155535. I'm thinking abut doing something similar. I plan to locate a used furnace squirrel cage blower and make a plug adapter for the rear trunk area with an opening through the partition that separates the trunk from the under-bed storage. I can't use the side (under forward dinette seat) door like Vernon used because that is the exterior battery access on my trailer.

Steve

[Steve Bryant]

I have a bit more progress to report. Ralph and I have drilled out the rivets in the front of the trailer and made a couple of internal doublers that we’ll rivet in when he gets back from a trip he’s been on. I’ve removed oodles of ineffective sealant goop that AS lathered on the rivets in the front so that we can get down to the bottom of some of the leaks.

[Steve Bryant]

Also, I’ve done the POR-15 prep (Marine Clean degreaser and Metal Prep acid etch) and two coats of paint (except for the place that I missed shown in the last picture). I’ll catch this area from below when we prep and clean the rear frame area.

[Mark Lee]

Bought a 89 Excella 32'. Discovered that 4' of the floor has to be replaced in the rear. I'm well into the job. Will start making templates tomorrow. Wow it was hard to believe the rot. Mine even had a colony of tiny ants eating the rotten floor material.

[Mark Lee]

I'm thinking of wrapping the new plywood floor material edge with Tyvek so that any water that gets past the seal will be ducked away from the wood and insulation. If it [water]gets past the seal it would just run down the outside of the wrap and drip into the pan. The pan has a few very small holes in it about the size of rivet holes. The wrap would hang lower than the insulation. Of course I'm using a good exterior plywood that I'm going to coat with a good sealer. Looks like the water came into the floor from a lack of a good seal on the rear bumper box.

[perryg114]

The bumper plate is a long standing FEATURE of Airstreams. They come with this outstanding leak producing plate.

Perry

[Steve Bryant]

Mark and Perry, I'll show you what I have in mind for the pesky bumper rot precipitator (AKA Bumper Plate) in a future installment.

Ralph and I have used the Marine Clean degreaser and Metal Prep acid etcher on the rear frame, cross members and outriggers. I first washed everything using liquid dishwashing detergent and a brush. This included about the lower foot of the sheet metal sides and the U channel, the frame parts, everything that I could get to down there. That will make for a cleaner repair as we progress. I have used my electric leaf blower a lot on this whole trailer repair job. It blows out trash/metal shavings/etc. that get stuck in inaccessible places. Also, the leaf blower speeds the drying process with each step of the POR-15 process. Last night, before we painted today, I ran a room fan in the back to circulate the air and try to make the metal bone dry as is recommended by POR-15 instructions.

After cleaning the metal and applying the Metal Prep and rinsing it off thoroughly with hot water, here’s what the metal looked like prior to paint.




Here’s the POR-15 painted frame (2 coats). We have some more miscellaneous riveting to do and then we’ll start installing floor. It’s getting exciting after so many months.

[Steve Bryant]

For those who later have to repeat this process, here’s a photo diary of what the frame repair process has looked like.

Here’s what things looked like once we had pulled up the OSB and insulation.


Here’s a more detailed shot.


Now, after many months the frame has been cleaned of surface rust (cup brush with rope-twist in angle grinder), welded for reinforcement and the corner brackets have been added to tie the shell to the frame in a more substantial manner.



Frame has been cleaned, and prepped.


Frame has been painted.


Bathroom area used to look like this (viewed from rear looking forward).


Now it looks like this (viewed from center hall looking outboard toward street side).

[Mark Lee]

Very nice work