Repairing rust hole in frame

[CA_Tallguy]

Hi everyone - I'm going to repair a rust hole in the frame and wondered what the recommended method would be. I've never done this before. Pics are below (one pic shows the back side if the rail).










The outrigger on the forward side of the street wheel well was just cut out from in front of this area.

I can access the back of the rail (side with the OPEN holes) to insert a piece of flat bar to back the welding repair but I don't really have enough access through the holes to weld it from that side. It looks like a run of conduit is going through there and prevents any hope of access.

So my thinking is to drill some holes in the frame and then I will weld through along with a lot of welding and filling in the actual rust hole.

Is this a good strategy? Should I drill a lot of holes or just a few? Big or small holes? Should I cut the rusted out section back a lot, maybe even to straight edges, or just grind back the damaged area as best I can?

Finally, is there much I can do to repair and protect the areas not directly seen from further deterioration other than ospho or por15? I'm not sure if the area between all these plates joining is rusting as well. Guess it doesn't matter to much as I can't access it any way I can think of to grind and brush stuff out.

[Wabbiteer]

Are there pictures from before the outrigger was removed?

Here's an opinion from someone who has spent a lot of time staring at a few AS frames...

Sure looks like when the stiffening plate was installed someone got sloppy with a cutting torch trimming the outrigger to eliminate interference with the supplemental stiffening plate... I'm not seeing not nearly enough surrounding damage OR adjacent material to hold corrosives to a single point to call that 'rust' as I've seen it...

If that is true corrosion then the stiffening plate seen notched around the shock mount should come off to gauge hidden damage...

As it is, if the hidden areas are not likewise cratered/perforated with deep corrosion - degrease, POR-15 metal-prep zinc treat, POR-15 it. A small sheet of PVC or other neutral sheet vulkem glued in place would handle the aesthetics. Very low loss of strength from that small of a defect when the plates are doubled/tripled as shown.

[perryg114]

Can you see the hole from the back side at all? If the back side were accessible I would weld a patch on the inside. The hole is not in a bad place. All the various plates need to be welded to each other. The top and bottom of the frame rails carry most of the load. The vertical section is there to separate them and keep them from moving relative to each other. One of my frame members had a hole in it like that. I was not real worried. The frame was not sagging and the top and bottom sections were ok. My trailer rails are two channels welded together to form a box beam. To prevent more rusting I removed all the pink stuff and put POR14 inside the frame and jacked the trailer up till it ran out the hole. The hole does not worry me but the bottom of the beam below that does. Find out if it is solid. If it is, just fill the hole with Bondo and be happy. I seem to remember another thread of yours where the axel plates were not welded properly and where coming loose.

Perry

[dbj216]

Zavalla, Texas, is close to Texas Airstream Harbor (TAHI). Our 86 Limited spent 7 good winters there years ago. We visited again last spring. Nice Airstreamers there. Lovely part of Texas.

My 86 has worse corrosion in the rear frame members. It doesn't appear this hole detracts from the strength of the frame.

David

[HiHoAgRV]

I agree with Wabbit, dat don't look like a rust hole. Sling on some paint and move forward!

[CA_Tallguy]

Thanks everyone. I feel less concerned now. I did weld it up though as we have the welder out to replace that outrigger. I just put a 3 inch piece of steel behind it and filled in the hole on top. I don't know if it was rust for sure but think it may have been possible since the outrigger had been eaten away sometime past. Perhaps there were open holes for a period that let water in there. I'm no rust expert so I don't know how these things happen. My only guess would be the holes the outrigger letting in water from the wheel well and then the paint being bad inside that hole, giving it a chance to form there rather than the top plate.

I purchased the trailer in the Great Lakes area but I thought the previous owner had gone through the frame and subfloor more than I guess he had.