Treating frame rust

[Rick Alston]

After wire brushing the rust, treating the area with a rust treatment like POR 15 or Jasco, priming the metal, and then painting it with a top coat; is it OK to cover the area with an autobody undercoat (rubber-like stuff) to seal out moisture?

My thinking is this: once the ferrous iron is converted to iron phosphate via treatment and then painted to seal out oxygen, the undercoating may be overkill. But then again, what harm can that do? In my opinion, the more you do to cover the area can only result in a longer lasting fix.

Also, is it OK to seal the ends of the box frame where the end is exposed to the elements? On my Argosy's tongue, the box frame starts under the front end of the coach and ends underneath the propane tanks. From that point forward, the frame is C-channel. I think it would be wise to seal the open end to prevent water from entering.

Rick

[TomW]

Originally Posted by Rick Alston

...the undercoating may be overkill. But then again, what harm can that do? ...

My vote is that it is overkill. But it will do no harm as long as the proper undercoating is used.

There was a thread a while back that pointed out differences in undercoatings - Rubberized versus Petroleum based. As I recall the petroleum based products were better because they would not hold moisture if it got in somehow.

Tom

[74Argosy24MH]

The portion of the frame between the floor and the belly pan will only need Por 15. The only reason to topcoat is UV fading. It isn't supposed to loose effectiveness, just for appearance.

John

[Rick Alston]

Thanks for your reply, Tom.

Do you have an opinion regarding the sealing of the frame ends to prevent water from entering? I believe that any time you prevent moisture from contacting metal, you have a better shot at success in preventing rust or further decay. I can only surmise that Airstream did not seal the ends because it would take time and effort to do it and that only raises the production cost.

I'm thinking of sealing the ends with wood pieces that can be removed on dry sunny days to allow for the evacuation of moisture that may get in on humid days. How ever I do it, my goal will be to seal out water during rain storms will towing and while parked.

Rick

[Ken J]

Oh ok - when I first read your idea about sealing the box frame my thought was no because you would trap moisture and could rust from inside out, especially since you won't be able to get the POR 15 inside the box, but if you do something temporary that can be removed to let dry out, then I think your ok. On my 75 I did spary paint as best I could into the box whereever I could.

You can topcoat por15 with pretty much anything you want, but it will be for appearance only, don't think it will give any additional protection since POR really seals everything out.

Make sure the Jasco is BONE dry before you paint with POR - it seems like it takes a while to dry out good.

I think it also depends on where you live - I live in a very dry climate, the frame on my 58 is perfect, so I'm just going to give it a good paint job - nothing rusts around here.

Ken

[Rick Alston]

Ken

I shot Jasco into the box frame from both ends with a garden sprayer having a wand that reached into the box frame over half way. I think I got the inside of the box very well covered with Jasco, but not paint. Now that the rain is over, I will look for a very fluid paint to spray into the box. Yes, there goes the sprayer!! If this process doesn't work, I don't know what will.

Rick

[TomW]

Originally Posted by Rick Alston

...Do you have an opinion regarding the sealing of the frame ends to prevent water from entering? ...I'm thinking of sealing the ends with wood pieces...

Rick,

Ya know the jury's still out on that one. I thought long & hard about sealing the ends when I sandblasted & repainted the tongue area. Although there was no reasonable way to address the surface rust already inside the box channel, it really did not look bad.

In '67, Airstream did not use real box stock - They spot welded a flat plate to a C-Channel. I do not have a particular problem with it's strength, but the seam between welds is going to let water get in anyway.

I decided that if I was going to seal the ends, it would be keep critters from getting in (I found a snake skin inside the belly area ). I also decided I would use expanding foam insulation. Since I would not be doing it to guard against moisture, there would be no reason for it to be easily removable. Wood would not be my first choice as it would hold moisture against the metal if it was to get wet.

I may yet seal the ends, but today I am not making any recommendations .

Hope this helps,
Tom

[Rick Alston]

Tom, thanks for your thoughts.

Your statement that wood is not a good idea seems correct. Maybe I can coat it with paint to prevent water from soaking into the wood ends.

I chose wood because I removed, rebuilt, and then replaced the trailers umbilical cord and, by using wood, I can carve-out a neat opening for the cord to pass through and into the box frame.

Now, about the expanding foam matter. I once thought that I should do the box treatment as I did and follow it with the expanding foam to seal it for ever. However, that would prevent me from ever looking into the box ends to see what is happening in there. Maybe I am just paranoid, but not being able to see in there gives me an upset stomach, so to speak.

Rick

[Ken J]

I use steel wool (aluminum wool would be better) in mine mainly to keep the critters out. The water will run through and exit out the back, scew holes etc - so not too worried about water getting trapped. In my case the frame was not rusting from inside out, it was rusting from outside in.

Ken

[markdoane]

Originally Posted by Rick Alston

Also, is it OK to seal the ends of the box frame where the end is exposed to the elements? On my Argosy's tongue, the box frame starts under the front end of the coach and ends underneath the propane tanks. From that point forward, the frame is C-channel. I think it would be wise to seal the open end to prevent water from entering.
Rick

I decided to seal mine, after looking at all the dirt, gravel, and other stuff that gets in.

[Rick Alston]

Don

Are you busy this weekend? Bring the welder. Just kidding, of course.

I couldn't help to notice that your "box ends" (the trailer's, that is) terminate up under the hitch-ball support. Mine, however, terminate under the propane tanks which is short of the hitch-ball support by maybe a foot. I think mine may collect more water due to its exposure. Just how did you seal yours? Did you weld a cap on the end?

Rick

[Ken J]

Don - your trailer frame is upside down, don't forget to turn it over when you put the shell back on

Ken

[markdoane]

Originally Posted by Rick Alston

Don

Are you busy this weekend? Bring the welder. Just kidding, of course.

Just how did you seal yours? Did you weld a cap on the end?

Rick

Actually, that's not me, thats Ultradog. He hasn't been on the forum lately, he's really busy.

The original tounge box was split so that the outer side could be bent in to match the angle of the coupler, and the inside was left loose.

We welded a new channel over the old one, and brought the two sides of the channel together and just welded them shut. You can see a picture at:http://www.airforums.com/forum...37&postcount=3
Ken,
Thanks for the reminder. I was about to put the shell back on and it wasn't fitting right.

[Ken J]

Don

We are here to help and solve problems like shells that don't fit quite right. Don't know if you have considered laying the shell on its back (use non-scratch concrete form) and assemble that way. Seems that would be easier because the frame won't move so much due to resting on its wheels. Then because of the curvature of the shell just roll it back and viola you've got it done.

Ken

Ken

[markdoane]

Ken,
I tried that, but the rivet line is above head level, and the rivet bucker (son-in-law) was standing inside on the ceiling. I didn't mind working on a ladder, but the footprints are a big problem.

[CanoeStream]

Steel wool? I picked up some brass wool at HD a couple weeks back. Steel wool has so much surface area it seems to rust extremely easy.

My '76 has the box ends up by the hitch ball just like Don's. I had a lot of internal rust, whether from the seashore or parking long-term in overgrown grass. The hole for the breakaway wires was quite rude. I used the Por-15 Epoxy Putty. Wear gloves!! (cheap in paint finishing departments or the livestock supply areas of our fleet stores) It was easy to work and I tried to get about 3/4" contact with the beam insides. Hardened in a couple hours and was superhard overnight. I did not seal the back end up under the belly wrap -- figured I didn't want to let moisture in the odd rivet hole and never let it back out.