Crime Scene Investigation

Floor Repair, Inner Skins, Furnishings, Interior Finishes
silverloaf
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Joined: Wed Aug 23, 2017 9:01 pm

Crime Scene Investigation

Post by silverloaf »

This is my "Where's Waldo" story.

We've had our '88 30P for about 2 months now. We have worked on it most of that time. Unfortunately, all I have done is taken stuff apart.

I have quickly learned that moisture is a trailer's worst nightmare. Further, belly pans are great for reducing wind drag but they also conceal a lot of damage.

In fact, the area above the pan can create a humidor between it and the floor above. Nothing can dry out in a closed environment. Moisture from places like roof or plumbing leaks, tire splash, and poor weatherization are problematic. Also, any fiberglass insulation that gets wet stay wet.

I learned the factory-installed linoleum can also trap moisture. You know a trailer has a long-term moisture exposure when you pull up some loose linoleum and find the adhesive has converted into a gray slime.

It is easy to take the source of a moisture problem for granted. In my case, the sub-frame around the dump valves has rusted away. One of the z-frame cross members is also rusted through. Because the floor was soft around the toilet, it became my focus.

I remove the toilet and find rotted plywood. I cut off the flange and then cut a 12" hole in the top layer of plywood. I look down and find the lower level of plywood soaked and wafer-thin. I can see water below the rotted wood.

We remove the black water tank. I am deluged with flood of water. But this isn't black water (PTL); it's clear water. The water had formed a pool on top of the tank. Who knows how long and how much water has sloshed around. But it had saturated the plywood above it, converting it into rot.

In the course of cutting out the toilet flange, I felt water dripping on my head. I look up and see rain dripping from the bath fan. The drop on my head turned into a small puddle on the floor. Who knows how long this has leaked or its contributing factor.

My task today is getting up on the roof and see what's going on. From the inside, the middle fan is missing its seal around the cover; wasps were building a fine nest in the housing.

I'll have to gut out the bathroom. A local sheet metal shop will fabricate new steel frame members. I'm blessed with a son who is a good welder. The floor re-build work follow.

I have already developed a mental list of protection measures to incorporate. Some of the items include:
1. Use all-weather flashing tape where wood meets steel. This includes any exposed plywood edges below access doors before I re-attach the skin (new tankless water heater going in).
2. Incorporate vents into the new belly pan. Ideally the vents will scavenge and re-fresh the air above while the trailer is in motion.
3. Prime and paint any rust spots both seen and not.

I'm sure there are many Avion owners who have been down this road. All ideas and thoughts will be greatly appreciated.

Make Avion Great Again!

Bob
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
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KYAvion
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Re: Crime Scene Investigation

Post by KYAvion »

Are you sure you don't have an Airstream? That sounds more similar to my 79 Sovereign. I had considered installing vents in the bellypan of that trailer, but I never did.

My 84 Avion 30R, however, seems to be in great shape. The bellypan seems to be pretty well sealed and the floor is foam so no fiberglass to soak up water running into the pan via the notorious bumper problem as with the Airstream.

That said, I haven't pulled the bellypan, but from the poking around I did things look OK.
KYAvion
1984 Avion 30R
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Re: Crime Scene Investigation

Post by KYAvion »

Correction: while the floor is foam, the tanks are insulated with fiberglass. Shoot. Thanks for reminding me that I forgot about wrapping the tanks with foam board instead!
KYAvion
1984 Avion 30R
silverloaf
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Re: Crime Scene Investigation

Post by silverloaf »

Our fresh water tank is held up by a sheet of plywood. The tank is 9" deep. It is wedged against the floor. In other words, there is no room for any foam board or even fiberglass.

Interestingly, there is a small duct that blows warm air into the tank envelope. Seems to be a tradeoff for lack of insulation.

Bob
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
John Byers
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Re: Crime Scene Investigation

Post by John Byers »

Bob,
Just read your post about ventilating the belly pans. I am working on the floor in our '71, and I had the same idea. To me, it seems like a no-brainer, but you are THE first person I have found to even mention it. I was thinking about using the aluminum soffit vents with louvers and screens. Was wondering if you had actually done it, and if so how it had worked out.
Thanks,
John Byers
silverloaf
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Re: Crime Scene Investigation

Post by silverloaf »

John Byers wrote: Sat Sep 08, 2018 11:00 pm Bob,
Just read your post about ventilating the belly pans. I am working on the floor in our '71, and I had the same idea. To me, it seems like a no-brainer, but you are THE first person I have found to even mention it. I was thinking about using the aluminum soffit vents with louvers and screens. Was wondering if you had actually done it, and if so how it had worked out.
Thanks,
John Byers
John,

Below is a pic of the belly pan on our trailer. I installed a series of 4" x 16" aluminum soffit vents w/screen last Fall. The vents are riveted to the pan.

Here are my reasons behind it:
1. Allow dry air to be exchanged with humid air when parked
2. The louvers face rearward to reduce wind drag on the road
3. Allow air to be siphoned out of the compartment above as the trailer is in motion. (aka: Bernoulli's Principle).

We've been working on our new-to-us '88 30P trailer for 14 months. We haven't done any "pulls" since we bought it. Theoretically, the vents make sense. I'll never know their success until I remove the belly pan again. But chickens will grow lips before I ever do that again!

IMG_1624.JPG
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
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KYAvion
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Re: Crime Scene Investigation

Post by KYAvion »

Those look good. How many did you install altogether?

I'm torn regarding installing vents. I agree that it makes sense as far as allowing the bellypan to air out if/when there is moisture inside. I'm hesitant though because the vents will allow cold air to enter during freezing temps, thereby making it more difficult keep the ducted heat from the furnace inside the bellypan. The heat loss through the vents may be negligible though.
KYAvion
1984 Avion 30R
silverloaf
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Re: Crime Scene Investigation

Post by silverloaf »

I installed 6 between the middle of the axles and the back of the trailer. I installed 3 closer together under black tank because that area had the greatest presence of condensation and damage.

I didn't install any under the fresh water tank. The plywood that supports that tank would block any air flow.

I suppose the vents do create a conundrum for cold-weather camping. Maybe installing some removable covers with Velcro strips could be an option.

In our case, the back half of the belly pan is now galvanized steel. We could use Velcro or even magnets.

By the way, we have ducted air into the fresh water tank cavity only. Unless I can get heat to the other tanks, covering the vents is a moot point. Winter camping is off our radar screen for now.
" Faith can move mountains, but don't be surprised if God hands you a shovel.”


Silverloaf (Bob)
Dawsonville, GA
1988 30P
John Byers
Posts: 5
Joined: Fri Jul 20, 2018 12:06 am

Re: Crime Scene Investigation

Post by John Byers »

Bob,
Thanks for your responses and picture. That looks real good, and exactly what I had in mind.
John
Rostam
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Re: Crime Scene Investigation

Post by Rostam »

This is a great idea. Where did you buy the vents from? Also, are they mesh covered? If not, you may want to add one to keep insects out.
1978 Avion 26-H
2021 Toyota Tundra SR5
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