'70 Caravanner restoration

[steinVT]

Is your source local to you? I am in the market for belly pan material.

What are your thoughts on how you would apply it, 103" is pretty wide?
Mark

[dbj216]

I've done three belly pan replacements and used the 5052 material at .025 thick. It isn't as strong as the 3003 heat treated stuff, but it is a bit cheaper. I buy it in a 48" wide roll at the length I will need to cover the area. I cut 48" wide by usually about 66" long and start at the rear of the trailer. I rivet it to the frame rails and cross members, and to the belly wraps from the exterior skins. Then I lay the next piece, and the next piece and so forth. I rivet the sections together as I go. Every piece needs hand trimmed to provide clearance for this propane line, that axle mount, and the steps over there.

Yep, I have a lot more seams than Airstream does, but I'm working on my back under the trailer, I need easy to handle. I don't worry about the seams as I hope they will allow additional draining if water gets in there.

David

[Jeremy9107]

Glad to know 3003 will work. What about at thickness of 0.040"? Thinking most use 0.025 or 0.032. Will have some 90 degree bends so want to be sure can work this stuff.

steinVT. Check out https://trailermarketing.com/product...sold-per-foot/. Have searched a long time and called dozens of places and this is only place could find that sold Alum wider than 48" without having to buy several thousand pounds. They get this from Aurora http://aurorametals.com/index.html who confirmed it is 3003.

Other option was 48" wide :
Aircraftspruce 3003 0.032" $100/4'x12' sheet http://www.aircraftspruce.com/catalo...?clickkey=3797

Aircraftspruce 5052 H32 0.032" $98.75/4'x12' sheet http://www.aircraftspruce.com/catalo...?clickkey=3797

Locally have PDM who quoted $84/4'x12' sheet of 5052H32 0.025" https://pdmsteel.com/products/stainl...-aluminum.html

For our layout, $21 per linear foot works out cheaper than if buying sheets of 48" wide (depending on shipping).

As far as how to apply...no idea yet. Am used to winging it. Probably a lot of helpers and a lot of clecos. Won't be as methodical as David. Am trying to have one beautiful piece in front of axles though except for cut out that goes below fresh water tank. Figure will never have to remove it. Over and behind axles will be different as want to create separate pieces as means to access gray and black tanks without taking too much skin off. Have also modified back there to accommodate relocation of a black tank that is deeper than the frame rails. Thus have to do some bending of Alum. Will work on diagram and post so can get feedback on how terrible the idea is.

David. Recall that during removal of ours there were spots where the belly skin wrapped far enough up the side to tuck between the outer skin and C channel. Did you originally have something similar? It looks like your belly skin stops short of wrapping up each side. Asking cause was thinking don't need all that overlap.

[HiHoAgRV]

We have a local industrial specialty metals supplier that stocks 3003 in 4x10 sheets. The last I bought was under $50 a sheet. I also piece together the belly pan. Frame rail outward I run the sheets long ways. Between the rails I run it cross ways just like the plywood decking. That way I can leave some of the cross sections held in with clecos until the final plumbing connections are made.

[dbj216]

I only overlapped about 8" under the wraps on each side.

I might add that I purchased my 5052 aluminum in a roll 48" wide.

David

[steinVT]

Jeremy, thanks for all of the sources.

I admit, there is something elegant in forming a single piece belly pan. Not sure I would be up to the stress. Maybe if you first made a full size template.

Regarding the 3003 H16, the H16 refers to the heat treat.

"3003-H16 aluminum is a type of 3003 aluminum. It is furnished in the H16 temper. To achieve this temper, the metal is strain hardened to a strength that is roughly 3/4 of the way between annealed (O) and full-hard (H18)."

I would want to get a sample to play with. It might be too stiff to do what you want.

Mark

[Jeremy9107]

Thanks for that tidbit steinVT. Maybe rugjenkins and HiHoAgRV can share if their 3003 was H16 and whether they attempted to bend?? Could use the 3003 in front which would be biggest piece as there are no bends and then 5052 48" sections where need to bend around frame and for bumper box.

[rugjenkins]

Not sure if mine was h16. 3003 bends well. I used it to make new belly wraps also. I purchased mine in Jackson, ms on advise from HiHoAgRV. We have family in Louisiana and were passing thru when I bought it. I have used it for all my patches also. 3 yrs and they still look great. No issues. I'll see if I still have the invoice and check the exact grade.

[steinVT]

I might have been a little quick to throw up an alarm, I image both will probably work.

Being a backyard mechanic, I like to literally feel how the metal bends in my hands before I am comfortable placing a big order or at least know someone else has used it successfully.

Doing some more research (google) 5052H32 0.025" thick is recommended by Airparstinc.com as belly pan material. That material is considered 1/4 hard. It has a higher tensile strength and more than twice the elongation than the 3003H16 which is considered 3/4 hard. And the 3003 material is 0.040" thick making it even stiffer.

I do so want to order the wide coil. The distance between the cross rails is 48" and I would love to cut 50" sections off of the coil to provide for an overlap. No wasted material that way. Maybe even span two bays.

I think I am going with the thinner 5052. I see lots of buck riveting in my future as I join panels together to get the width I need.
Mark

[dbj216]

I used 5/32 blind "pop" rivets to join seams, and to attach the belly aluminum to the cross members. I used big head 5/32 rivets for the attachment to the frame rails.

I see the belly pan's job it to keep the dust out, keep road spray out, and help a bit with aerodynamics, less drag. It is not a structural part of the trailer in my view. And lucky for me, no one has ever gotten on their hands and knees to look at my belly pan. Oh wait, the buyer did, but no negative comments heard.

David

[HiHoAgRV]

I've been lucky, on 3 belly pans I've had to replace cross members in order to add tanks. The new steel is 2" wide on the bottom and allowed for but joints in a couple of spots. This let me rivet the 4' wide sections without having to splice them to each other.

[Jeremy9107]

steinVT "there is something elegant in forming a single piece belly pan. Not sure I would be up to the stress. Maybe if you first made a full size template"



What better template than the old belly pan. Will mimic what David did however and leave off several inches from the sides that tucked under the outer skins. That should reduce some stress.

Agree with David about purpose of belly pan. Although would add that it works well as a barrier to keeping rodents out, helps to make trailer function better in colder weather, and looks waaayyyyy better than not having an underbelly (as realized when helped a friend peel back the wax coated cardboard from his non Airstream to fix some piping).

Tomorrow will make final measurements and order the 103" wide 3003H16 roof coil. Final quote is $16/linear foot with reasonable shipping. Hoping it will make some of the bends. Cost always factors in and if could have gotten the $50/sheet price that HiHoAgRV paid then might have had to consider.

Going to wait until it arrives before tackling drilling new holes and mounting the axles as will be easier to put the belly pan in place with axles off. Tomorrow will also include getting the gray and black tanks in place and figuring out all the plumbing connections as have some whacky ideas for venting and draining. Still working on mold for shower pan but need the long awaited evaporative cooler to arrive before can get bathroom completed (more to come on that).

[dbj216]

There's nothing better than wacky ideas when renovating these old Airstreams.

David

[Jeremy9107]

Have been putting off the task of painting the tank pans but finally had not choice but to do it. Used same process as when painted the frame...degreaser diluted 1:5 with water, rinse after 15 minutes, metal etch, rinse after 30 minutes, POR 15 diluted 5% with Xylene applied via pod spray gun at 50 psi.


Reused prior black tank pan. Had to modify slightly and ignored all the rust and corrosion.


Built tank pans for the gray water tank long ago out of 16 gauge sheet metal. The stuff is heavy. Too heavy. So eliminated the sides and went with just the bottom. Figure there is no need to try to hold water in it. Just need it for support.






Had some left over paint so painted the rims as well.


Next step will be to get the tanks in place and connect plumbing. Have decided to have switch controlled 12V solenoid valves at the fresh and gray tanks so can empty if needed (and if not against any rules). They are 1/2" valves which will be fine for the fresh tank but have been told this might be a problem for draining the gray tanks.


Gray tanks will be connected to eachother, and then will connect to the back of the black tank. Will attach a Barker electric valve http://www.barkermfg.com/auto-drains.html to control flow there.


Had thought about attaching a clean out like the Tornado...


but figure this set up will work much like a clean out. Just ned to be sure to open and close the valves in the right order! The black tank will empty out through another Barker electric valve.


Venting : Had Inca put the vent for the black tank on the back side wall at the very top and will attach 1.5" rigid ABS to it at a slight incline up in case any "fluid" wants to get in there. The gray tanks came with the vent on the tops. Had considered many options for venting them without going through floor at that spot as don't like that they will end up in the middle of some cabinets...ie using flexible hose of some sort, using canvas hose, heating and bending either PVC or ABS, etc. Only have 3/4" inch space to work with between top of tank and underside of floor though. Couldn't get any ideas to work so will probably just drill straight up inside cabinets. Any ideas??

[Jeremy9107]

Fridge is wired to trailer battery and vehicle battery so routed switches to allow cutting off either source to help prevent accidentally killing the batteries.

The Norcold's control panel was hollow on one end which was a perfect spot to install the switches.





The fridge came with a fan installed on the back of it,


but decided to install more small computer fans inside the vent space to allow for additional cooling if needed.



These fans are controlled by the 3rd switch. The fridge vents between skins and am concerned there will not be enough air flow in there so maybe these will help.

[dbj216]

It might be you can run your vent line through the subfloor and then make an immediate 90 and then up to through the roof. I have two vents that are in the bathroom closet. I just have a shelf to rather hide the vent piping.

I think flex lines would work well also for venting.

Maybe it would work for you and avoid a "pipe in the cabinet" problem.

David

[youngpeck]

I used a combination of 2" ABS and 2" hot tub water tubing, both for venting and for waste. Each of these can be heated and in different ways can then be bent for more precise placement.

[Jeremy9107]

youngpeck thanks for advice. thought of the same in 1.5" variety. just couldn't get the bend small enough to fit in the limited space above tank and below floor. think only thing that could have worked was canvas hose but didn't trust that it wouldn't collapse thus not letting air vent.

in the end, decided to drill holes in the floor. just took a lot of time measuring where the hole would be as did not want to drill through frame rails. started with pilot hole, then hole saw.

will have similar set up as dbj216. plan on immediate 90 degree bend above floor and head towards nearest hidden area. was hoping to hide all the pipe and avoid holes in floor but oh well.

[Jeremy9107]

Using 2 gray tanks sistered together and ultimately draining into black tank. Lay out will be similar to this, only there will also be a solenoid valve before the gray water drain valve to empty gray tank separately if needed. It was a bit tricky getting ABS pipe through ladder rail from 1st gray tank to 2nd gray tank but perserverence paid off :


Installed same heat pad as is on the fresh water tank to both gray tanks. Facon. They will be connected in paralell. They have thermostat pre-installed, but will place on switch inside to stop any battery draw in the warm months.


Installed tank level monitor on just one of the gray tanks. Couldn't find any others that would allow install on 4" height tanks.


Decided against sides on tank pan as was going to interfere with install and was heavy.


Insulated bay as best as possible with left over R-Max rigid insulation. Used angle iron supports resting on curb side frame rail and bolted to welded on piece on street side. Ramped tanks/tank pains in place and secured.

[Jeremy9107]

It sure was miserable working under the Airstream. Had to belt sand some of the Coosa board strips to make room for tanks and all that fiberglass dust settled in any spot it could irritate. Tenuous too as axles are off and trailer is resting on beam.

Will next install black tank. Hoping it goes alot smoother than gray tanks. This is an easier bay to access than gray tank bays which have axles underneath, so designed to have most of the "stuff" here. Barker auto drain valves. Solenoid drain valve for gray tank, electrical, etc. Black tank will exit street side near old hot water tank area. Purchased 3" threaded Aluminum pipe to attach to ABS where pipe will be visible on outside. Still haven't figured out what to use for cap though.