How much frame rust is too much?

[Toasty's Dad]

Hi All,

Our well-traveled 2004 Bambi is showing a little rust on the A-frame, so i was thinking about doing a ilttle brushing and painting. And what the heck, take a look at the frame underneath too.

So, I did, to the extent that it can be seen beneath the underbelly. I'm not sure if what I'm seeing should cause me to:

1) freak out, head up to Jackson Center, and spend $$$$ getting this thing fixed
2) remove all the underbelly and do more investigation (or have a pro do more)
3) Wirebrush/repaint what I can get to
4) Re-rivet the loose underbelly and ignore it - all iron rusts at least a little.

Pics attached (I hope). If not, will include in the next post.

Most of the rust is patchy and fine-grained, what I'd call "surface rust", and which I'd do no more than wirebrush and paint if even that, for a ferrous object I'd find around the house or under my car.

But in the rear end, by the stabilizer jacks, the rust is somewhat flakier (and flaky under the paint), the underbelly is sagging from down from corrosion around the rivets, and it's generally a lot less pretty. So is this Kryptonite (i.e. a Bad Sign)?

If the solution involves me removing and replacing the underbelly, where do I get the panels? And is there anything better to use than aluminum, which is obviously just a setup for corrosion with the iron frame. Just use the usual pop rivets (same problem), or are these special somehow?

Thanks for your patience and expertise!
Jon

[Bill M.]

That does look like a lot of rust. Was the insulation wet? Do you have a leak somewhere, or was the belly pan itself the leak?
The one thing I can answer is the rivets. Look at Outdoor mart, Vintage trailer, Inland Airstream, or other sites. You will find pop rivets with a very big head that are used for refit work on the belly pan. My belly pan is a combination of the original with some joints in it where I took part of it down, a sheet of Al from Lowes, and a couple of 1" by 1/8" Aluminum strips to provide a grip for joints and to prevent sag. And a lot of Vulkem on the joints and Aluminum tape over many of the joints.
You might check the A frame where it goes into the trailer. If the A frame is sound, the trailer is probably okay. Here we have a coperative sheetmetal shop (HVAC work mostly) that sells sheet Al and also will do bends to fit it up how you need it.

[Eric H]

Don't freak out.
While it is a bit of rust it does not look like a significant amount to threaten structural integrity.
At the minimum you will want to wire brush and paint. If you're under there already and you're up for the job you could go ahead and pull the rest of the pan. This is a big undertaking and may not be worth it, but if you're already in fixing mode then it can only help.
Since some of that rust looks a bit deeper then surface I would say to get yourself an angle grinder with a wire brush attachment and some sanding pads to make it go quicker.
This will make short work of the rust: http://www.wayfair.com/Weiler-4-Knot...FYmR7QodbmlcYQ
They are available at Lowes and Home Depot

If you don't want to do that then wire brush by hand then use rust converter and then prime and paint. Make sure to get all of that flaking off and if you can get to fresh metal all the better.
If you take a look through my frame repair you can check out some bad rust: http://www.airforums.com/forums/f421...ybe-85368.html

[perryg114]

Look for leaks at the back of the trailer. Does your trailer have a bumper storage compartment. Those are famous for funneling water under the trailer and under the floor. The way my 81 is was built and water that gets in that compartment goes under the skin in the back. It is also wise to pull the skins at some point and get rid of all the water soaked pink crap that I can see in your last photo. That suff holds the water and rots the frame. Also it looks yours has seen some road salt. I am suprised that such a new trailer has that much corrosion. I don't see anything structural yet. I would clean and treat with POR15.

Perry

[Toasty's Dad]

Originally Posted by perryg114

Look for leaks at the back of the trailer. Does your trailer have a bumper storage compartment. Those are famous for funneling water under the trailer and under the floor. The way my 81 is was built and water that gets in that compartment goes under the skin in the back. It is also wise to pull the skins at some point and get rid of all the water soaked pink crap that I can see in your last photo. That suff holds the water and rots the frame. Also it looks yours has seen some road salt. I am suprised that such a new trailer has that much corrosion. I don't see anything structural yet. I would clean and treat with POR15.

Perry

I do have a small bumper storage compartment, used for the sewer hose, etc. I can see how the way it's mounted could direct water under the outer skin. What's the cure for that? Caulk?

Also, having removed the crummy pink insulation, do ya'll recommend just leaving it out permanently?

Yes, we're winter travelors and have been through some salt. Our first stop after any winter trip is the car wash for a thorough spraydown, but obviously I'm not getting all of it off.

Thanks for your advice,
jon

[Toasty's Dad]

Originally Posted by Eric H

Don't freak out.
While it is a bit of rust it does not look like a significant amount to threaten structural integrity.
At the minimum you will want to wire brush and paint. If you're under there already and you're up for the job you could go ahead and pull the rest of the pan. This is a big undertaking and may not be worth it, but if you're already in fixing mode then it can only help.
Since some of that rust looks a bit deeper then surface I would say to get yourself an angle grinder with a wire brush attachment and some sanding pads to make it go quicker.
This will make short work of the rust: Weiler 4" Knot Steel Wire Bevel Brush With 5/8" - 11 UNC Arbor Hole For Small Angle Grinders | Wayfair
They are available at Lowes and Home Depot

If you don't want to do that then wire brush by hand then use rust converter and then prime and paint. Make sure to get all of that flaking off and if you can get to fresh metal all the better.
If you take a look through my frame repair you can check out some bad rust: http://www.airforums.com/forums/f421...ybe-85368.html

I think I know what my summer project is gonna be. I'm gonna do exactly as you advise, sounds like a lot of fun

Off to Home Depot for an angle grinder....

Thanks again,
Jon

[Toasty's Dad]

Originally Posted by Bill M.

That does look like a lot of rust. Was the insulation wet? Do you have a leak somewhere, or was the belly pan itself the leak?
The one thing I can answer is the rivets. Look at Outdoor mart, Vintage trailer, Inland Airstream, or other sites. You will find pop rivets with a very big head that are used for refit work on the belly pan. My belly pan is a combination of the original with some joints in it where I took part of it down, a sheet of Al from Lowes, and a couple of 1" by 1/8" Aluminum strips to provide a grip for joints and to prevent sag. And a lot of Vulkem on the joints and Aluminum tape over many of the joints.
You might check the A frame where it goes into the trailer. If the A frame is sound, the trailer is probably okay. Here we have a coperative sheetmetal shop (HVAC work mostly) that sells sheet Al and also will do bends to fit it up how you need it.

We've had a small leak on one side in the back; a trickle of water will appear from under one of the interior Al skin joints and dribble an ounce or two on the floor. It only shows up once a year or so, and then only during a trip. Move the trailer, and next storm it's gone. We've never been able to find a source for it. I guess there could be a lot more water getting down between the skins, but that wouldn't explain the similar corrosion on the non-leak side.

Assuming that water getting behind the belly pan one way or another is inevitable in the back of this trailer, would it make sense to reinstall neither insulation nor the belly pan in the back section? That way, it could at least dry out thoroughly between wettings. There are no pipes running through that area to freeze.

Or am I crazy?

Thanks!
Jon

[perryg114]

Caulk the heck out of it where the bottom plate goes under the frame. Caulk the area where the top plate goes under the belly trim. This is one area where an once of prevention will save you 3 yrs of renovation. Also put some drain holes in there so water can get out.

Perry

Originally Posted by Toasty's Dad

I do have a small bumper storage compartment, used for the sewer hose, etc. I can see how the way it's mounted could direct water under the outer skin. What's the cure for that? Caulk?

Also, having removed the crummy pink insulation, do ya'll recommend just leaving it out permanently?

Yes, we're winter travelors and have been through some salt. Our first stop after any winter trip is the car wash for a thorough spraydown, but obviously I'm not getting all of it off.

Thanks for your advice,
jon

[Eric H]

Originally Posted by Toasty's Dad

I think I know what my summer project is gonna be. I'm gonna do exactly as you advise, sounds like a lot of fun

Off to Home Depot for an angle grinder....

Thanks again,
Jon

A couple tips and things that will help:

- invest in a creeper, it's totally worth it.
- be careful with that grinder and wear heavy gloves (gauntlets if you have them), it will chew through your skin faster then you can imagine. If I was laying on my back I wouldn't engage the trigger lock on the grinder while using it either...
- get a full face shield.
Have fun!

[perryg114]

If you use POR15 you don't need to do a whole lot of grinding a wire brushing. The rougher the surface the better it works. I is important to get all traces of grease and oil off.

Perry

[Eric H]

Originally Posted by perryg114

If you use POR15 you don't need to do a whole lot of grinding a wire brushing. The rougher the surface the better it works. I is important to get all traces of grease and oil off.

Perry

Hi there, a quick caveat to this: I would still make sure to remove all of the flaking and permeated rust to get down to only the surface rust (or better) before the por. I have never used por and hear great things, but if you don't get all the major rust off to begin with it will eventually flake off leaving pits behind. It's hard work, but that grinder will make it a lot quicker.

[NC3]

Excuse the newbie question but should that ground clamp be on the propane tubing?

Mike

[wahoonc]

Originally Posted by NC3

Excuse the newbie question but should that ground clamp be on the propane tubing?

Mike

Interesting...I would have to assume it is factory. However the ground wire on my 1975 and my 1981 are both to the frame.

Aaron

[AIR-Quarius]

There is a rust converter they use in the oil field called OSPHO....comes in a gallon liquid green (kind of smelly) application that they brush on the rusted pipes after wire brushing....it converts the rust into an iron oxide type of mineral. I am not a rocket scientist, but the instructions will tell you the whole plan. It works over night and the rust will be black the next day, and ready to paint because this stuff acts as a primer also. You can get it at Sherwin Williams for about 40.00 a gallon if I remember correct.

[perryg114]

I have used the rust converter and it is something like phosphoric acid mixed with elmers glue. I have used it and it does not last as long as POR15. It is not totally water proof and when it gets wet it turns into a white jelly again. Painting over it may help but the POR15 loves water. It is cured by water. It is expensive and messy but it works. Solvents won't bother POR15 either. In fact, they use it to coat the inside of gas tanks.

Perry

[Eric H]

To POR or not to POR. Either way I say get as much rust off as possible, it's best to start with a clean slate . People swear by POR and I'm sure it's great but if you don't want to spend that much then use rust converter then prime then paint and then I would suggest a spray bedliner coat. It's pretty good stuff and plenty tough.

[Toasty's Dad]

Originally Posted by wahoonc

Interesting...I would have to assume it is factory. However the ground wire on my 1975 and my 1981 are both to the frame.

Aaron

It is indeed factory. And I think its purpose is to ground the propane line itself, to prevent static sparks between the line and the frame.

the ground for the battery is at the very front of the box part of the frame, just behind the where the A meets it.

[Toasty's Dad]

Originally Posted by Eric H

To POR or not to POR. Either way I say get as much rust off as possible, it's best to start with a clean slate . People swear by POR and I'm sure it's great but if you don't want to spend that much then use rust converter then prime then paint and then I would suggest a spray bedliner coat. It's pretty good stuff and plenty tough.

way i look at it, doing this is a major PITA, i'm already buying a bunch of tools to do it right, so some bucks for the best "paint" or whatever it is i can get is well worth it. especially if it means i wont' have to do it again for a long time!

but, i'm confused about the product. do I just buy the "rust preventive paint", or do I also need this "chassis coat" stuff? and will i need the "marine clean" stuff, if i'm shooting for the best rust grainding prep i can do? and what's the likely amount needed? this is just a 16-foot trailer. at 35 bucks a quart, i'd sure like to avoid getting too much.

THANKS!

[perryg114]

I would think a couple quarts of POR 15 will be enough. If you are going to coat areas that are not rusted it might be a good idea to rough up the surface. POR15 is not made to put on smooth surfaces. It loves nooks and crannies. You could put POR15 on the really rusted sections and more conventional paint in other areas although it is hard to beat the toughness of the POR15. Any area exposed to sun needs to have a top coat of paint on it. It will chaulk under UV exposure. I put some on my badly rusted frame last fall and it still looks like new.

Perry

[Becky B.]

Hi Toasty's Dad,
I've used Por-15 on two frames. It's really great stuff. You have to prep the metal by wire brushing loose metal. Since you have paint on your frame, you have to use metal ready to etch the paint. Then you have to use marine clean to remove any grease that may be on the frame. It's worth taking all the steps....no use in skipping one and having your paint job fail. This is the thread of my belly pan replacement as well as the frame painting with por-15 .... don't forget the gloves! http://www.airforums.com/forums/f476...pan-58333.html