Finally starting the project!! Subfloor question..

[61safari]

Hi everybody, been reading this forum for a few years now and finally have the time to start the project. I bought a '61 Safari a few years back that has good bones but a pretty shoddy interior renovation. (pictures to come soon).

I just pulled up the tile and found a rotten subfloor beneath it. Now that I've pulled it up, I'm all the way down to the underbelly.

A question for you all.. what kind of things should I do (weatherizing, moisture barrier, work on the frame) before I put new subfloor in?

Thanks!

-Seraphim

[perryg114]

Well I think the scope of your question is beyond one post. I would spend some time in the floor and frame technical forum. Most folks that have a unit as old as yours with age related issues, with take the body off the frame and rehab the frame and usually coat it with POR 15. This is a good time to replace axels as well. Rip out all the floor and replace it with marine grade plywood preferably coated with urathane or epoxie to reduce rot. Never use treated wood because it eats metals for lunch. You will need some sort of insulation to replace the fiberglass stuff that soaks up water like mad and contributes to frame and floor rot. No insulation at all is better than the fiberglass stuff. This is the time to fix skin dents and replace bad skin sections. Oh yeah, you have to polish the thing to a mirror finish or you are not worthy to own an Airstream. This mental illness is called aluminitus and there is no cure for it other that to have more Airstreams than cars. Severe cases of aluminitus can cause you to start polishing Airstreams in the night that you don't even own. Lots of OCD meds and good sleeping pills or good booze can be used to treat the illness if Airstreams are not available.

A general rule of thumb is you should spend, in dollars, the age of the trailer multiplied by 1000 or half your age multiplied by 1000 whichever is greater.

Perry

[Minno]

Hi Seraphim,
Welcome to the world of obsession. Spend what you can afford. We started with weatherizing the trailer, did a shell on floor replacement (yes it is doable if you don't have the means or interest in doing a frame off), and new tanks, etc. I would recommend getting it weather tight before putting a new floor in unless you have a garage to keep it in while you're rehabbing. We are now ending our third summer of rehab and finally starting the interior in ernest. Your trailer is a little older than ours so may need more than we did, although our frame needed repair also. We used BCX plywood for the floor, well sealed, and Rustoleum for the frame after sandblasting. According to PerryG we're not going to be worthy to own our trailer since we're not going with the mirror finish . Sounds like too much work . Speaking of rehab, I think we'll need some when we're done: is there anywhere to treat "aluminitis"?
Welcome to the forums. As always we all want PICTURES!

Kay

[perryg114]

I was joking. Mine is not polished either. I like the mill finish look. Too bad AS did not anodize these things so the finish would last forever. I don't have the time to polish a 31 ft Airstream every couple of years. I may take a stab at doing some clear coat repair. I expect the polish is easier to obtain than the original mill finish.

Perry

[Rousseau]

I am currently doing a frame on subfloor replacement. I have my subfloor cut already. I treated it with an epoxy paint. Upon reading this post though, I noticed that treated wood is a no-no. U-oh! I used treated wood, so is it gonna eat metal? What about the epoxy in between?

[perryg114]

The epoxie is going to help. What sort of bolts did you use? Assuming it does not get wet you maybe ok. Deck screw manufactures have had to find better coatings for screws to keep them from rusting away with treated wood that is outside where it gets wet and stays wet for long periods of time. Treated wood has more acids in it that the older type treated wood. Combine this with water and two different types of metals you have problems.

Perry

[Rousseau]

I have not purchased any bolts yet. I had a few questions before I decided:

Are aluminum washers the way to go?

If aluminum washers, then does it necessitate a certain bolt and nut . . .ie metal to metal

Now with the treated wood . . . what would work best?

Also, can I upgrade bolt size or stay with original, which off the top of my head appeared to be 1/4"??

[Rousseau]

In continuation upon further research, I found that galvanized is better. In fact if the bolt is 1/2 or larger in PT lumber, then they don't have to be galvanized. I am obviously going to over engineer everything due to the pain in the ass of ripping out the belly pan and removing the bath. Stainless is even better when considering its integrity versus the PT lumber. I would be using stainless, but I am concerned with interaction between the SS bolt and corresponding washer metallurgy with the aluminum C channel. This is my conundrum.

The susceptibility of different base metals to corrosion while in
contact, depends upon the difference between the contact
potentials, or the electromotive voltages of the metals involved.
The greater the potential difference is, the greater is the tendency
for corrosion. The metal with the higher potential forms
the anode and is corroded. In other words, the larger the
separation distance in the electromotive chart between the two
metals in contact, the higher the contact potential and chances
for corrosion. For example, zinc and aluminum are very short
distance apart in the chart; therefore potential for corrosion
when these two metals are in contact is very low.

Therefore; galvanized is the answer. I am going to dip all the metal used in an epoxy. While wet I will secure them. Being that a larger surface area between metals will slow the corrosion, I plan to use galvanized washers. Maybe some sort of gasket or plastic washer in between.

Thoughts? I didn't realize the change in PT lumber to get away from arsenic. I'd like to keep the lumber, but I will change if the consensus is to use regular lumber.

Thanks in advance!

[Wabbiteer]

Rousseau? Your topic is an important one to have in the library!

How about starting a new thread by lifting your text from this one to the new one?

[Bill M.]

I would go with the stainless steel. I have seen a lot of dry kilns with aluminum skins and stainless steel bolts, washers, and and fittings in a wet, acid enviroment. It seems to work okay. One thing that cuts through aluminum quickly is condensate drippings off of a copper tube. I do not know about the PT lumber. I think it still has copper in it. Easy answer is not to use it, but under the bath it would be reassuring to have it. Read up on the corrosion properties of the new treated stuff. All in all, the best approach is to seal the trailer well enough so that it all stays dry.

[perryg114]

I would go with stainless steel. It is going to have the best corrosion resistance of all of them. Between Aluminum and Zinc the Aluminum will be the Anode. Zinc only works when the coating is not broken. It is the more noble of the metals involved and it will end up as the cathode. Stainless has a self sealing oxide layer that is pretty tough. NASA uses stainless on everything. Stainless is used with Aluminum in salt spray enviroments like the launch pads at the cape. 316 stainless is best for corrosion resistance but all of them are good. I would coat the aluminum with something like POR15 to reduce corrosion. Anodized aluminum is best but aluminum will protect itself well if not under constant water, salt, and acidic enviroments. Stainless resists galvanic corrosion although it does not like salt very well.

Here are some facts on treated wood. This is for wood fasteners not wood+steel+aluminum+zinc that you might be getting into.

http://www.strongtie.com/productuse/PTWoodFAQs.html

Here is some stuff on stainless steels.

http://www.cartech.com/techarticles.aspx?id=1668


Perry

[Minno]

I was joking back, Perry! We, too, are not going with the high polish when we get to that point (someday). We used elevator bolts and lock washers for our floor. If we''re not worthy of our trailer by the time we're done (3 years and counting on renovation) then no one is!

Kay

[marzboy]

Originally Posted by 61safari

Hi everybody, been reading this forum for a few years now and finally have the time to start the project. I bought a '61 Safari a few years back that has good bones but a pretty shoddy interior renovation. (pictures to come soon).

I just pulled up the tile and found a rotten subfloor beneath it. Now that I've pulled it up, I'm all the way down to the underbelly.

A question for you all.. what kind of things should I do (weatherizing, moisture barrier, work on the frame) before I put new subfloor in?

Thanks!

-Seraphim

Welcome! I went with Aquateck it is what they make Criss Craft (wooden) boats out of. A couple vintage trailer gurus told me about it (Frank Yensen and Uwe). I love it cuts great drills great feels super solid. I also coted the edges top and bottom with West Systems Epoxy and Spar varnish on the rest. Then I used all stainless steel hardware to hold it all down. But buy what you can afford and do what you feel is right. There are a lot of opinions here (and you know what they say about opinions) remember thats all they are. Best of luck to you!!

[perryg114]

It is ashamed to cover that pretty wood up. How much did that run you a sheet? Is that mahogany plywood?

Perry

[marzboy]

Originally Posted by perryg114

It is ashamed to cover that pretty wood up. How much did that run you a sheet? Is that mahogany plywood?

Perry

Uh yeah I know... Cost about $70 a 4x8 sheet it is Maranti which is a form of Mahogany.

[perryg114]

That ain't bad I paid that much for plain old marine plywood.

Perry

[marzboy]

Originally Posted by perryg114

That ain't bad I paid that much for plain old marine plywood.

Perry

Yeah i guess its just another brand of MGP

[61safari]

Thanks for the warm welcome!!

Sadly, I've felt the first symptoms of "aluminitis". I've heard there's no real cure for it, so you're better off just letting it run its course.

Wow, lots of good information. It looks like what I thought would be a 2 day project to replace the subfloor will be a bit more involved than I had originally thought. I'm looking forward to doing this right though, and understanding how these things are rebuilt, so there's no time like the present to get started.

From what it sounds like, it's best to remove the underbelly so I can get at the old insulation, the bolts to the subfloor, and have easy access to c-channel that houses the floor. After that, a little POR15 and apoxy sealant before buttoning her back up.

I must admit that taking off the underbelly is a bit of a daunting task for a newbie... I suppose I'll read up on how to remove and replace rivets.

Here are a couple of pics of the Airstream...

[marzboy]

Originally Posted by 61safari

Thanks for the warm welcome!!

Sadly, I've felt the first symptoms of "aluminitis". I've heard there's no real cure for it, so you're better off just letting it run its course.

Wow, lots of good information. It looks like what I thought would be a 2 day project to replace the subfloor will be a bit more involved than I had originally thought. I'm looking forward to doing this right though, and understanding how these things are rebuilt, so there's no time like the present to get started.

From what it sounds like, it's best to remove the underbelly so I can get at the old insulation, the bolts to the subfloor, and have easy access to c-channel that houses the floor. After that, a little POR15 and apoxy sealant before buttoning her back up.

I must admit that taking off the underbelly is a bit of a daunting task for a newbie... I suppose I'll read up on how to remove and replace rivets.

Here are a couple of pics of the Airstream...

Nice! Looks like a fun project! The belly skin removal isnt a big deal. I cut mine out and just reskinned it. But instead of two long strips I did mine in 4x8 foot sections across the bottom and cut out 3" strips to seam each section togeather. Most of my belly skin was so corroded that it came off pretty eaisily. These two tools may be of interest. This one is for solid rivets and this one is for pop or blind rivets. I could not have lived without either one.