Tub Replacement

I recently bought a MD Juan tub, and all the reviews are true, they are not a quality product. Hat channel doesn't line up. Rear body mount holes don't line up. Area around the cowl is wavy. I just had to vent,, it's not why I'm writing this.
I'm wondering what other fellow jeepers are using to seal the bottom of the tub? Just prime and paint or undercoat. I want to be able to seal it to prevent rust. Just looking for ideas. Thanks in advance.

 

Prime, paint, fluid film.

 

The only MD Juan tub I have experience with is one I bought for an MB clone build, it came with a thick coating of red/orange epoxy primer which I scuffed good and shot new epoxy primer and a color coat.

This MD Juan MB body is not bad and so far I have found very little to complain about with it.

The MD Juan CJ tubs I have seen were just coated with black shipping primer. I would sand that off, prime, and paint.

I haven't used the fluid film mentioned, but it sounds like a good idea for under the body.

I notice the MD Juan M38A1 bodies are primed with the same red primer as that MB body, and I am wondering if the Military bodies are perhaps from a different operation of MDJ, and may be better quality.

I was considering using one of their M38A1 bodies on my CJ5 build, but then I spoke with someone at Peter Debella's store and was told the SGI CJ5 bodies were expected to be available sometime mid Summer. The SGI bodies already in production are reported to be much better quality than any others available.

 

I heard about fluid film, but didn't know anything about it. Sounds like good product. I was hoping for. a more permanent coating.
The tub is black primer and very thin. it scratches very easily. This weekend maybe a get a picture of the hat channel that doesn't line up with a body mount. I plan on cutting a good section of the channel from my old tub and welding it in. The sides of the body aren't very straight and can see every spot weld. All the problems can be fixed, just an obstacle to overcome.

 

Just like an original Jeep tub!

 

Yes, I guess you're right about that.

 

I would get that black primer off ASAP. Watch this video in its entirety. Edit: once black primer is removed I would use an epoxy primer as others have mentioned.

 

There are a number of things you can do, but THE MOST IMPORTANT thing to do is be sure you have paint and primer everywhere. Uncoated metal is the culprit. That is the problem they had from the factory. If you have a good coat of paint and primer the tub will last for years and years. With that said all I can say is easier said than done. Spend the money and buy a good quality paint and primer. Epoxy primer is the best. (Eastwood)

When you sand use 320 grit and try not to expose the bare metal as much as possible or use a red scotchbrite pad would be better. Sand by hand if possible. A DA will go through the edges easily. It's all in the prep-work. Scuff well. The nice thing about black is you can tell when it's dull.

I would spray all the seams and inside the hat channels first. Then let dry and scuff them. Then spray the main panels. Do all your cutting, trimming, drilling BEFORE you prime and paint. If you have to after or you scratch it touch it up immediately!

Some other things you can do is bed liner inside and underside. Undercoat is ok, but not my preference. Although inside the hat channels can be done very easily that way. Another thing often overlooked that undercoat does well is inside the windshield. Something I've done in the past that worked really well was have everything powder coated. Came out the balls and the seams and hat channels were covered very well. Very durable. The best way is to have the tub dipped. I know it's new and not rusted, but POR 15 is an excellent option. Bare metal oxidizes immediately so a rust inhibitor will be very beneficial as well. Seam sealer will also be beneficial before you paint.

No matter what you choose you have to cover everything and keep the water out!!!
Spot welds are the nature of the beast and to me gives originality. I personally don't like perfect sides because it looks like a replacement body or you had body work done. It's one of the first things I look for when I buy a Jeep.

Good luck with your project.

 

Can I just say that I have friends and work colleagues -- many mechanically inclined -- who seem amazed that I can weld. I love how, on this site, we talk about it like we have to re-tie our shoelaces...

 

Thanks for all the comments and video. Anyone who wants to replace a body should watch that video. My original tub was in such bad shape that I've been looking for the last few years for another tub. I was hoping to find a used body in better shape, but are scarce around here. This tub came from a guy who was starting a jeep project and then stopped. He was selling everything and I got a good price on the tub, fenders and grill. The best part, he was only 1/2 mile from me.

The video of how the hood fits is identical to mine. I'm hoping to roll the hood inward and elongate the hinge holes to make the fit better. I'm not going to make a show jeep out of it and be afraid to take it off road. I just want it to be solid and protected from the elements.

Any more ideas or comments would be appreciated. I spotted a yellow jeep in a thread, on this site, a while back that showed the under body that had a rough finish and was painted the same color. I can't seem to find it now. Maybe it was bed liner.

 

Regarding the video, I don't have 30 minutes to watch it all the way through now. Maybe this is answered later on - I wonder how much of the bad fit is lousy assembly quality, and how much comes from badly dimensioned parts forcing the fit out of shape. One could take some of those pieces loose from the shell and weld them back at the right location, if the assembly were bad.

 

Shree Ganesh Industries, India | MFG. Reproduction Body Parts

Looks good.

 

Photo of hat channel that doesn't line up. One on the other side is off center, but useable.

 

My opinion of Rhino lining the underside of a Jeep is just not practical nor will it hold up in the long run, the moment that hidden rust on a seem or hat channel begins to rear its ugly head you have a breach and the cracking and flaking begins and it just gets worse because moisture just hangs out in those cracks and flakes. As others pointed out, a really good epoxy primer then paint followed by fluid film will keep the underside looking good and you will be able to touch up if needed. I’m sure that any of you who have separated a 4 piece Jeep front fender know exactly what I mean when it comes to hidden rust! Just my 2 cents

 

Yes, about the fenders seams, and hat channels on a Jeep. Bad places for hidden rust.

I have owned a few IH Scout II vehicles, and those things were put together at the factory with a lot of bare metal inside the fenders, body panels and doors. They were some of the worst for rusting out from the inside. I bought one once for the drive train, and you could have poked your finger through just about anywhere on the body of that hulk.

Rust never sleeps. It is not a bad idea to spray the seam areas with a good rust converter/inhibitor before priming.

 

Whatever you finish the bottom with follow it with fluid film. There is no way to get paint or liner to cover every surface any water that gets on the bottom will find the little spots with no finish and migrate under said finish. Fluid film migrates better than water and will seal the bare metal. Used oil will work too but is much messier.

 

Prime, paint and fluid film sounds the best. Today I started drilling the body mounts and found wood in the hat channels. Have to make sure to preserve the wood and keep moisture out.

 

Fluid film will soak into the wood too

 

I researched new tub(kits) extensively before I decided to buy. The tub kit I purchased is most likely an MD Juan tub also but the difference in mine is the supports and mounts etc were cut/added and additional bracing was added and fitment verified on their frame before it shipped to me. I purchased mine from WillysOverland and could not be happier. When I set the tub on my restored frame, it matched up every single mount. I honestly was expecting to have to drill etc but none had to be done.

I spent the time(prep) and sanded entire bottom that had black primer. I used the Eastwood internal frame spray/sealer in the channels and places a brush could not get to, then the next day I did the entire underside with POR15. That stuff is amazing and self leveling and looks like glass but it is extremely hard. I definitely did not want undercoating as the problems with if there is a crack or leak in it. I did my frame, differentials, trans-xfer case in the POR15. Prep is KEY!. Fluid film is a good product but it won't last long with all the road grime, washing etc, but I guess you could just keep spraying it on. Personally I don't want the slimy goop underneath that you will have if you use Fluid Film, it is lanolin based but works well for what it is intended.

 

That looks good. I can see in your photo, the small addition to the hat channel for the body mount that mine is missing. I was planning on POR15 for the frame. I didn't think of it for the underside of the body. I'll have to research it. Thanks for the advice.