Fluid Film inside of Frame?

[nU7OuxIx]

It's about that time of year and I would like to use fluid film to protect my JLU. I've never used fluid film, but I do have an undercoating gun already from a bedliner project.

I wanted to ask before I botch anything, do you apply fluid film to inside of the frame rails?

I ask because I normally go trail riding to sandy areas (Silver Lake, Upper Peninsula), and I flushed the frame out a month ago. I was surprised at how much sand, dirt, and gunk came out. If I apply fluid film to the inner frame rails, will the dirt, sand, and gunk get trapped in there? For what it's worth, I don't plan on wheeling in the winter in sandy areas, just back in the Spring again.

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[DenaliDan]

I've used fluid film in the past and getting ready to do it again as well. It can get pretty gunky if you spray it heavy and might very well trap sediment inside the rails as you suspect. I would try to go with a light spray if any. I typically just spray it on fasteners and joints and maybe a light spray on surfaces like the rails.

 

[nU7OuxIx]

I've used fluid film in the past and getting ready to do it again as well. It can get pretty gunky if you spray it heavy and might very well trap sediment inside the rails as you suspect. I would try to go with a light spray if any. I typically just spray it on fasteners and joints and maybe a light spray on surfaces like the rails.

I bought a YJ to restore it that had holes in the frame. Granted, a lot has changed in 25 years, but I really don't want to go through that again!

I did read something that said that fluid film drips out when the temp gets hot in the summer, like in the 90's. They also say that it can be removed with hot water. I'm wondering if, things got bad or I really wanted to clean things up, I could just hook a hose up to my hot water tank and blast it through to get rid of it all.

 

[DenaliDan]

I bought a YJ to restore it that had holes in the frame. Granted, a lot has changed in 25 years, but I really don't want to go through that again!

I did read something that said that fluid film drips out when the temp gets hot in the summer, like in the 90's. They also say that it can be removed with hot water. I'm wondering if, things got bad or I really wanted to clean things up, I could just hook a hose up to my hot water tank and blast it through to get rid of it all.

Sounds logical. You could definitely test that out on some small piece of pipe. Gunk it up, put it in the freezer, then wash it out with hot water.

 

[Sheepjeep]

it is a good idea to spray it inside the frame, you dont have to go crazy thick you are mainly doing it to keep what ever salt spry from the roads that make their way into the frame

 

[nU7OuxIx]

it is a good idea to spray it inside the frame, you dont have to go crazy thick you are mainly doing it to keep what ever salt spry from the roads that make their way into the frame

That's what I was thinking. Not put like 2" of film in there, just a quick spray and be done with it. People say FF doesn't last very long, so maybe a flush with warm water and the heat of the summer sun would make it melt out like a wax statue.

Thank You!

 

[Sheepjeep]

ff will last the winter and thats how long you need it for really, the stuff you spray down the rails will last longer because it is not getting washed away from road spray like whats on outside

 

[Nailgun]

With my winter beater sent off to the wrecker this week, I'll have to drive my JL 'only' after getting it sprayed. My main concern is also the frame. Things I noticed are a lack of useful drains mid-frame where salt water/sand is bound to collect at the lowest point. Another thing I noticed is Jeep managed to put a rather large hole in the frame right in each front wheel well, which I believe is some sort of crumple point for energy absorption. Would have been nice to see a plastic 'cap' plug stuffed in the holes to keep the majority of the wet stuff out. Might be a good place to 3D print a 'snap in' insert. I'll get some measurements and report back.

 

[nU7OuxIx]

With my winter beater sent off to the wrecker this week, I'll have to drive my JL 'only' after getting it sprayed. My main concern is also the frame. Things I noticed are a lack of useful drains mid-frame where salt water/sand is bound to collect at the lowest point. Another thing I noticed is Jeep managed to put a rather large hole in the frame right in each front wheel well, which I believe is some sort of crumple point for energy absorption. Would have been nice to see a plastic 'cap' plug stuffed in the holes to keep the majority of the wet stuff out. Might be a good place to 3D print a 'snap in' insert. I'll get some measurements and report back.

That was my YJ. I was able to stand on the frame by the back tire and it just bent in half. There were huge holes back there. Granted, it was a 25 year old Jeep, but I would really want to prevent this from happening with my JLU.

I would be really interested in some hole coverings for the frame. I have a 3d printer collecting dust and would put it to use! I've heard that those big holes behind the front wheels are to let air out of the frame if your driving through water, just so that the Jeep doesn't float down the river. Don't know if it's true, or if it's the crumble zone, or what. I've seen other people cover it with duct tape, and others purchase magnets to place over these holes.

Being in the Chicago area, I've driven up to Silver Lake Sand Dunes and had fun up there. I've also driven in the UP, which had a lot of sandy soil. When I got back from the UP trip, I was able to flush the frame out with those big holes in it, which was nice. You would never believe how much dirt and sand came out. I used the big hole behind the front wheels, and then the smaller holes in the middle of the frame. I wasn't able to get the front and back areas, but I felt like I got the majority of dirt out. I may have to take a closer look to see if there are any holes in front of/behind the wheels.

I'm glad you mentioned the mid-part of the frame where there could be a possibility of rust. I'm looking for information of what areas to make sure they get good coverage. With the YJ, historically, it's the frame, in particular the mid part, around the wheels, and the back part. On the tub you have the area around your feet and the door bottoms...I guess really everywhere... On mine it seemed like that was the areas that were most prone to it. With the JLU, I'm not sure there's any old enough to be able to make those determinations yet. I haven't really crawled under it before, but I would guess the mid-frame section, the fender area behind the rubber/plastic liner, suspension components, and maybe that's it?

Last area that I think is going to be interesting in the future is the cowl drain. It supposedly drains between the pinch weld(?). If this is true, I hope that it's at least lined. I could picture a lot of salt spray and run-off from the windshield ending up in the cowl area, which melts down the drain that's between the pinch weld...if that's true. Hopefully it's a rubber hose, but it's just something I have to look at more.

 

[Nailgun]

Looks like that hole is for access to a nut. On the drivers side it measures 2.455" long by 2.197" wide. Later I'll take a look on the passenger side. Then I'll see if I can model something up.

 

[Coops4284]

I spray it inside my frame when I apply it every year. I did Fluid Film black this year, and it looks nice. What I have noticed is that when I pressure wash and flush the frame all of the mud/sand/dirt comes right out. According to Fluid Film, even though it will make dirt stick to it, it still protects the steel from moisture.

 

[Nailgun]

Revision one fits a tiny bit loose so I'll have to adjust my model or scale. I have black PLA, but at the moment I have a roll of white in the printer. I'll also consider extending the part to cover that lower hole to the bottom left. It's a start.

 

[nU7OuxIx]

Revision one fits a tiny bit loose so I'll have to adjust my model or scale. I have black PLA, but at the moment I have a roll of white in the printer. I'll also consider extending the part to cover that lower hole to the bottom left. It's a start.

Would you be able to post the stl up here or on thingiverse?

Also, I would suggest ABS instead of PLA. It's getting cold out now, but I feel like the PLA would warp or melt in the summer or from the heat of the engine. I had PLA warp just from the sun in the summer. I printed out a bracket in ABS that goes under the hood by the battery. So far, that thing is holding up pretty good!!

 

[nU7OuxIx]

I spray it inside my frame when I apply it every year. I did Fluid Film black this year, and it looks nice. What I have noticed is that when I pressure wash and flush the frame all of the mud/sand/dirt comes right out. According to Fluid Film, even though it will make dirt stick to it, it still protects the steel from moisture.

May I ask, how do you pressure wash the inside of the frame?

I ended up taking my garden hose with one of those on/off end connectors. I set it to spray a somewhat forceful stream and just stuck it up to the big hole and smaller holes mid-frame. I did this for about 5 minutes per side and watched the gunk come out. A lot seemed to exit where the rear control arms are.

 

[Coops4284]

May I ask, how do you pressure wash the inside of the frame?

I ended up taking my garden hose with one of those on/off end connectors. I set it to spray a somewhat forceful stream and just stuck it up to the big hole and smaller holes mid-frame. I did this for about 5 minutes per side and watched the gunk come out. A lot seemed to exit where the rear control arms are.

I have an attachment for my air compressor. One end is a hose that goes into a bucket, the other is the air hose. Then it goes into a wand that has a high pressure tip. That fits in the frame. I also put my normal pressure washer gun up to each large hole and spray for a while. I want to say the one for the compressor is called an engine bay wash tool, or something along those lines.

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