Replacing belly pan on '61 Avion - Advice needed

[Smoky]

I'm going to remove my belly pan to inspect the frame and add insulation and replace with 4 X 8 3003-H14 ALUM SHEET .025. I have found .032 too difficult to work with on the corners. I have read that it is possible to use an olfa cutter with a tungsten blade to cut the sheets. Should I get some of those cleco fasteners? How do I keep from breaking my drill bits when drilling out the rivets? Should I treat the frame with Por 15? Thanks for any advice.

[Smoky]

I think I'll go with some 3/16 inch cleco holders, some large flange pop rivets and some olympic sandable rivets for the sides. I read I might be able to use a flat head screwdriver and hammer to pop the heads off the old rivets instead of drilling them out. Maybe it would be easier just to cut off the belly pan since I'm replacing it. I'll try to sand the olympic rivets with a Dremel to make them look good.

[oh2bcarefree]

Our first question is why do you want to remove the belly pan???

Are there holes, gashes or otherwise big gaps in the bottom that would lead you to believe there is something wrong with the frame?

What you are proposing is not for the faint of heart. If you are just trying to do some preventative maintenance because you are worried there may be rust on the frame, we think you may be worrying too much.

Do you have some photos of why you want to do this?

What you are proposing is going to take so much time. More time than you would believe. I haven't seen anything else about your Avion, do you have another thread about it's current condition? Any leaking is coming from above and needs to be fixed from above...

We just don't feel unless there is a really really really good reason, that you would be using your time in a good way to accomplish this... Do you know how many rivets you are going to need to drill out... oh my!

Just friendly thoughts before you jump in with both feet.

Tina and Mike

PS - we just did a partial floor replacement on our '59 Avion due to rot and have some photos regarding the frame when we go it out. It's in our thread in the Vintage Kin section. Starts at post #44.
http://www.airforums.com/forums/f417...n-79207-4.html

PS II - Mike is curious if you have sheet metal experience because he says it's a bugger.

PS III - Mike thinks the aluminum you are choosing is too light and not going to do you well over time for the life of your Avion.

[Smoky]

I want to remove the belly pan to inspect the frame and add insulation...and deter mice.

No large gashes as such, there are a some patches here and there though.

I pretty much did the same thing you guys did as far as tearing up the front floor, but in my case the frame was bent and I had to straighten and weld angle iron on all four corners of the two main beams. The rest of the frame seems fine though.

I'm sure I could get away with not doing it but I want to take care of the trailer because I do a lot of traveling and I'd rather know exactly what kind of shape my trailer is in at all times.

I don't have sheet metal experience but one of my favorite things about owning an Avion trailer is learning new skills while making repairs. I'm almost disappointed when there isn't something that needs to be taken care of.

The .025 might well be too thin, if I had more skill I could have probably made the .032 work around the front corners better.

Really the biggest reason is probably insulation. I'm certain after 50 years most of it is gone, and I'd like to keep my trailer warm on cold and windy days.

Thanks for your comments, I've set aside a whole month to work on it so hopefully that is enough time. If not, perhaps it will just have to wait.

Your '59 Avion is beautiful and I like what you did with your black tank. My Avion has a clothes hamper next to the toilet but I never use it.

Eric

p.s. Can I have your German apple pancake recipe?

[oh2bcarefree]

Hey Eric,

It sounds like you have a plan, we wish you good luck and will watch your progress, well, as long as you post photos along the way.

Thanks for the nice comments about our trailer. We certainly will be happy to answer any questions if we can, our black tank has worked out great for us. We didn't have a hamper, but a lot of trailers did (do).

Here is the link to the German Apple Pancake recipe. It is really yummy!
Dutch Oven Madness!: Day 135: Emeril's German Apple Pancakes - this site has a ton of wonderful recipes if you like Dutch Oven cooking.

Tina

[ventport]

I don't know if a 61 Avion has the same floor as a 64, but my 64 Avion T21 has about an inch of foam insulation sandwiched between 2 sheets of plywood. There is no insulation under the floor. Also the frame is much thicker and taller, thus stronger then the Airstreams, so rust is not as big an issue.

[Smoky]

Originally Posted by ventport

I don't know if a 61 Avion has the same floor as a 64, but my 64 Avion T21 has about an inch of foam insulation sandwiched between 2 sheets of plywood. There is no insulation under the floor. Also the frame is much thicker and taller, thus stronger then the Airstreams, so rust is not as big an issue.

I don't have that foam insulation, just 3/4" plywood bolted to the frame. Yes the frame is quite stout and I agree it's probably fine There is large spaces between the floor and skin that I'm sure are empty right now. Maybe I'll just do the lower edges instead of the entire belly. At least it would look a lot nicer. I bought a dremel tool and titanium bits to see if that would make drilling out rivets any easier. I bought 4 4X10 .032 sheets for $55 each at a local shop.

[HiHoAgRV]

I used 3003 .025 on the belly of my '63. It worked out great!
You can knock off the head of the old rivets with a sharp chisel, then flush off the shank with a flop sander wheel in an angle grinder.

I'd suggest 1/8 clecos to fit everything, then drill out to 3/32 when you remove it and start to install the large head rivet.

Por1 is a good idea.

My '63 link in the sig has some details

[Smoky]

Originally Posted by HiHoAgRV

I used 3003 .025 on the belly of my '63. It worked out great!
You can knock off the head of the old rivets with a sharp chisel, then flush off the shank with a flop sander wheel in an angle grinder.

I'd suggest 1/8 clecos to fit everything, then drill out to 3/32 when you remove it and start to install the large head rivet.

Por1 is a good idea.

My '63 link in the sig has some details

Thanks for the tips, your thread is great and helpful. How would you recommend cutting the aluminum sheets? I have the snippers but it makes a ragged edge. I read it might be possible to score the sheet with a tungsten blade and break it. Others say they have used a jigsaw with good results.

[HiHoAgRV]

Originally Posted by Smoky

Thanks for the tips, your thread is great and helpful. How would you recommend cutting the aluminum sheets? I have the snippers but it makes a ragged edge. I read it might be possible to score the sheet with a tungsten blade and break it. Others say they have used a jigsaw with good results.

I used these...


Pistol Grip Air Shears

My manual snip skills are a bit ragged...

[Smoky]

I was going to use cheap hand nibblers but that would take me forever. I guess it's time to buy a bigger air compressor and some air tools.

[HiHoAgRV]

Cutting aluminum is, um, gummy, on some alloys. WD40 does a great job lubing the cutter and keeping it working.

Those pneu, pnu, air cutters do ok on a small compressor if you dont get in a hurry...

[Smoky]

Today I removed all the rivets on one side of the belly pan where it attaches to the main outer skin. I used the chisel hammer method with mixed results. Some holes were fine while others are a bit stretched from the force. Looking back, I wouldn't do it this way again. I should have carefully drilled them out. Regardless, the damage is done. These rivets are all visible and I planned on using 5/32 olympic rivets but now I'm thinking they aren't big enough for some of the old holes. I suppose I could try using aluminum washers, I don't really want to use those oversize pop rivets because I wanted them to look nice and use olympic rivets that I could grind. The only other thing I can think to do is to overlap the new belly skin on the sides and drill new holes. I don't like the fact that water could get in the seam but was hoping I could get away with using that Aluminum Pigmented Gutter seal that wicks into the seams. This way I can drill all new holes and use olympic rivets. The other side of the trailer I'll have to overlap anyway because of previous repairs. I'm glad I'm doing this project because when I peaked inside all I saw were acorns and very little insulation. Has anyone else run into this problem?

[Smoky]

So the side seams would look similar to this recent patch I did. Looks ok to me I guess. I like the idea of drilling new holes anyway. I'll just space them between the old holes.