Rust proofing the inside of the frame?

knotkewl

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First of all thanks to the staff and members, great forum and lots of valuable information.
I live in the rust belt and after years of watching Craigslist someone finally put the Jeep I have been looking for up for sale. I just became the proud owner of a well cared for 97 TJ Sahara. 4.0 manual 89k miles.

The previous owner has stayed on top of the frame rust and from what I can tell didn't drive it much on salted roads. The fuel tank pan has a little surface rust between the pan and the tank, but really that's about it. I spent the last weekend flushing out the inside of the the frame. I used a combination of power washer and garden hose. I was pleasantly surprised at how little rust I was able to get out. Just a few quarter sized flakes was the worst the rest was small particles mixed in with a few hand fulls of sand.

I had planed on using the Evergreen product on the inside to try and keep the frame in good shape for as long as possible. I happened to stop in to a local body shop and was talking to the owner about it. He mentioned that he has a wand with a 360 degree tip that he uses to spray por-15 inside of the frame. At first it seamed like an great idea, but after some thought I started wondering about whether the hard coat on the inside would end up giving me more problems down the road.

Has anyone tried this? I would appreciate some thoughts from the folks that have more experience than I.
Many thanks.
 
First of all thanks to the staff and members, great forum and lots of valuable information.
I live in the rust belt and after years of watching Craigslist someone finally put the Jeep I have been looking for up for sale. I just became the proud owner of a well cared for 97 TJ Sahara. 4.0 manual 89k miles.

The previous owner has stayed on top of the frame rust and from what I can tell didn't drive it much on salted roads. The fuel tank pan has a little surface rust between the pan and the tank, but really that's about it. I spent the last weekend flushing out the inside of the the frame. I used a combination of power washer and garden hose. I was pleasantly surprised at how little rust I was able to get out. Just a few quarter sized flakes was the worst the rest was small particles mixed in with a few hand fulls of sand.

I had planed on using the Evergreen product on the inside to try and keep the frame in good shape for as long as possible. I happened to stop in to a local body shop and was talking to the owner about it. He mentioned that he has a wand with a 360 degree tip that he uses to spray por-15 inside of the frame. At first it seamed like an great idea, but after some thought I started wondering about whether the hard coat on the inside would end up giving me more problems down the road.

Has anyone tried this? I would appreciate some thoughts from the folks that have more experience than I.
Many thanks.

Inside the frame, I would not spray Por 15 or similar coating. Because once the coating begins to lose some adhesion, and water gets behind the coating, it will be held against the metal and increase rate of rust. Instead I would regularly spray an oil type coating to protect the metal. I'm planning to use Fluid Film.
 
Thanks indio,
I had considered that. From all I have read this is not a one time do it and forget about it task. It sounds like a yearly bit of maintenance. My thought was that the por-15 being so thin would do a very good job of sinking in to pits nooks and cranny's then from here on out I would use the oil or wax based products on top of it.
 
OP, by Evergreen, do you mean Eastwood Internal Frame Coating?

If so, I too am gearing up to apply that to the inside but I've likewise been contemplating alternatives too. I've heard that some folks apply the Eastwood and then follow up with cavity wax (3M I think?), or the oil type coating on top of the original application.
 
OP, by Evergreen, do you mean Eastwood Internal Frame Coating?

Yes I did. Not sure where I pulled Evergreen from.
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Thanks folks! As I said it sounded like a great idea at the time. Then I started to wonder about the kind of problems you guys have mentioned and had second thoughts. I am still trying to wrap my head around the body shop owners thinking on why he believes it to be a good idea?
 
After doing a lot of work to my TJ over the winter I discovered a lot of scale inside the frame, but only on the rear portion of the frame after the aft skidplate bolt & up to the top of the rear arch. Everything forward of the aft skidplate bolt & aft of the rear arch is smooth as can be.

I was thinking about some other alternative besides dumping fluid film in there a couple of times a year & cleaning out the frame regularly with the addition of drain holes, but after some more research it seems like that is the best way to go. Any other input?
 
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Rust isn't a big concern in Oregon, but I Fluid Film the inside of my TJs' frames once a year, and when I change the oil I put some of the used motor oil in their frames. I have not used a product like Eastwood inside the frame.
 
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After doing a lot of work to my TJ over the winter I discovered a lot of scale inside the frame, but only on the rear portion of the frame after the aft skidplate bolt & up to the top of the rear arch. Everything forward of the aft skidplate bolt & aft of the rear arch is smooth as can be.

I was thinking about some other alternative besides dumping fluid film in there a couple of times a year & cleaning out the frame regularly with the addition of drain holes, but after some more research it seems like that is the best way to go. Any other input?

FWIW, the situation you're describing is pretty much exactly what happened to me. Isolated to section and only on the inside. I do exactly what you said which is pack it with FF a few times a year and periodically clean it, usually between seasons.

I've heard that the Eastwood rust converter is a good candidate for a situation like this but it's not something I've used. FF seems to be doing exactly what I need it to do. When I do my seasonal flush and reapplication, I'm not getting flakes or chunks anymore coming out, nor am I fishing anything out with a magnet. I know that the problem is not solved but as far as I can tell, FF has kept the perfect parts of the frame perfect and that not so perfect parts from getting much worse. I also apply liberally between the skid plate and frame.
 
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FWIW, the situation you're describing is pretty much exactly what happened to me. Isolated to section and only on the inside. I do exactly what you said which is pack it with FF a few times a year and periodically clean it, usually between seasons.

I've heard that the Eastwood rust converter is a good candidate for a situation like this but it's not something I've used. FF seems to be doing exactly what I need it to do. When I do my seasonal flush and reapplication, I'm not getting flakes or chunks anymore coming out, nor am I fishing anything out with a magnet. I know that the problem is not solved but as far as I can tell, FF has kept the perfect parts of the frame perfect and that not so perfect parts from getting much worse. I also apply liberally between the skid plate and frame.
Yeah I mean it's not awful, the only place you can see it from the outside is some slight scale that crept out through that tooling hole on the top of the rear arch. The inside was a little flaky, but I drilled some drain holes & blasted the shit out of the inside of the frame with a pressure washer. Once I get everything done under here I'll be putting another FF coating on everything.
 
Lived on a coastal island for a couple years. Super tides and storm surges meant driving through about 100 feet of 2-24" deep brackish water just to get home/to work. Only had the TJ for a few months there. Think I'll pick up another sprayer and take care of it. Thanks for the reminder.
ALWAYS went from home to the carwash with underspray, then to work or work to home and a freshwater hose immediately after work.
Occasionally Used a garden sprayer with used oil thinned with whatever I had, diesel, paint thinner, etc. no significant frame rust issues on any of those vehicles. The '72 F-350 had a rust free California body but developed some pretty nasty body cancer after about 3 years of salt air.
Think I'll pick up another sprayer and take care of it the TJ. Thanks for the reminder.
 
I plan on attacking this project once we get some warmer weather on a weekend. My frame has zero rust inside or out but it now will live in Southeastern PA and, although it will spend most of the time in the garage, I do want to take it down the shore. No garage there and salt water and air are a block away.

My plan is to blow out the frame with an air compressor (checking along the way with bore hole camera), add small drain holes to the frame and spray the inside with Fluid Film. I also plan on hitting some other areas with FF including the outside of the frame and other underside areas as I can reach them without a lift. I also plan to drop my transmission skid plate and clean and paint the area where it mates with the frame with frame paint. Adding anti seize to those bolts also.

Anyone have a comment on this plan?
 
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I plan on attacking this project once we get some warmer weather on a weekend. My frame has zero rust inside or out but it now will live in Southeastern PA and, although it will spend most of the time in the garage, I do want to take it down the shore. No garage there and salt water and air are a block away.

My plan is to blow out the frame with an air compressor (checking along the way with bore hole camera), add small drain holes to the frame and spray the inside with Fluid Film. I also plan on hitting some other areas with FF including the outside of the frame and other underside areas as I can reach them without a lift. I also plan to drop my transmission skid plate and clean and paint the area where it mates with the frame with frame paint. Adding anti seize to those bolts also.

Anyone have a comment on this plan?
Sounds solid. I spray fluid film everywhere. I figure its not going to hurt anything under there, so I go to town. If you get some on the exhaust you get to bathe in that sweet sweet smell even more.

Good plan with the skid plate bolts too. I just had it off for an SYE and 3/6 were toast. I had to cut them off & then replace the nutserts. I ended up doing them all with a kit from BMB, it wasn't terrible but something would be nice to avoid.
 
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Sounds solid. I spray fluid film everywhere. I figure its not going to hurt anything under there, so I go to town. If you get some on the exhaust you get to bathe in that sweet sweet smell even more.

Good plan with the skid plate bolts too. I just had it off for an SYE and 3/6 were toast. I had to cut them off & then replace the nutserts. I ended up doing them all with a kit from BMB, it wasn't terrible but something would be nice to avoid.
That was my plan with the FF, buy more than I need for the frame and then spray everything until I ran out. Haha

I am pretty confident (famous last words) that my bolts will come out as the frame and skid plate are in really good condition. Fingers crossed though. This whole project is to avoid that down the road now that the Jeep no longer lives in South Carolina.

The inside of my Jeep has more rust than the outside. I think the PO like to keep the top off and doors off so I imgine it got some rain. The underside of the seats, for example, are rusty but the frame is perfect.
 
I plan on attacking this project once we get some warmer weather on a weekend. My frame has zero rust inside or out but it now will live in Southeastern PA and, although it will spend most of the time in the garage, I do want to take it down the shore. No garage there and salt water and air are a block away.

My plan is to blow out the frame with an air compressor (checking along the way with bore hole camera), add small drain holes to the frame and spray the inside with Fluid Film. I also plan on hitting some other areas with FF including the outside of the frame and other underside areas as I can reach them without a lift. I also plan to drop my transmission skid plate and clean and paint the area where it mates with the frame with frame paint. Adding anti seize to those bolts also.

Anyone have a comment on this plan?
Sounds like a good plan. I'll be following suit when I do the SYE. I'll stick with used oil and whatever thinner is handy though. With 4 vehicles in the stable there's always a gallon or 3 waiting to go to the dump.
 
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I'm in Central NJ when i bought my TJ last year it has some scaling on the inside of the frame but only the drivers side around the skid plate attachments and near the rear control arm, I cleaned it out with an air compressor/magnet, drilled holes right behind the rear control arm, plug up the holes on top of the control arms i the front and rear and I fluid film the shit out of the inside once every 3 months or so. I periodically run a magnet in there to check and I haven't noticed any more scaling since I've done that almost a year ago.

In a couple months when its warm out im going to do my yearly cleaning of the underbody/frame ill check what's up.

I cleaned and POR-15 everything under the car (control arms/ skid plates, Axles, etc) except the frame which has almost no rust on it whatsoever.
 
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