Rusty undercarriage

[Mickeystamper]

Just a heads up, my 2013 378xl with 6600 miles on it looks like the photo all along the outer metal support. Both sides front to rear. This unit is stored inside when not in use. I am going to wire brush it, encapsulate the rust then undercoat it.

[ron377ts]

I have a 2014 377XL, and when under this fall , found the same. Figured I would wire wheel and paint in spring or sooner. Supposed to be warm all week.

[Bluepill]

21st century coach builders who have not learned anything since the 19th century. Amazing that with all the technology that Auto manufactures have adopted in the last 40 years to rust-proof cars, the RV builders still have their heads in the sand about these problems.

Mickey. I would suggest that you reconsider using both encapsulation AND undercoat. The reason is that anything less than 100% perfect sealing of both can cause water to be trapped between the membranes and actually promote rust. Honda had a massive recall on fuel filler pipes in the 80's because of this. The problem is 10X as bad in areas that use road salt, because the summer humidity combines with elevated temperatures.

[Still Kickin]

Wire brush it, rusty metal primer and paint. Just monitor it over time. It doesn't look to bad.

[mogman]

x2

[Mickeystamper]

The encapsulater I plan to use is a good spray from Eastwood. It is similar to POR 15 but easier to apply so it will create a good finished result that should last. POR 15 is also an excellent product I have used in auto restoration, but is a bit harder to apply.

[trbomax]

I shot the complete undercarrige of mine as soon as I got it home. Never saw rain or salt.I used 12 gal of rubberized automotive rust proofing with a dedicated rustproofing pressure pot and spray gun. I really had to turn it down as the pattern will be about 10" hight when the material screws are full open.Anyway,7000 miles later and it looks the same as the day I did it.

[Grumpy Guy]

I just bought a 2016 FR3 and decided to under coat. I used a product that we use on the underside of snow plow trucks. It is called Fluid Film. It will soak in to the rusted areas , joins and crevices .By doing that it should seal off he oxygen and eliminate further corrosion. Another nice thing about this product is that it can be sprayed on electrical connections and seal them off but be cleaned off more easily that a rubberized product.

[TURBS]

Originally Posted by Grumpy Guy

I just bought a 2016 FR3 and decided to under coat. I used a product that we use on the underside of snow plow trucks. It is called Fluid Film. It will soak in to the rusted areas , joins and crevices .By doing that it should seal off he oxygen and eliminate further corrosion. Another nice thing about this product is that it can be sprayed on electrical connections and seal them off but be cleaned off more easily that a rubberized product.

What color does fluid film dry to?

[trbomax]

Fluid Film is great stuff. I use it just about everywhere,but I dont think it would have enough resistance to stone chipping,and you would probably have to re-do it every year. I know a lot of people swear by it as an underbody rust proofer. Maybe I'm just too old school because I like asphalt base undercoat!

edit) it never really "dries". It is a amber transparent color and a waxy surface.

[Grumpy Guy]

The fluid film may need touched up or checked after a couple years. But part of the never really drying aspect is that it stays soft and plyable therefore resistant to chipping. It will self heal to a degree depending on application thickness

[trbomax]

Do you get it in gal or qts? Shurly your not doing a whole undercarrige with bug bombs.

[Grumpy Guy]

I bought a spray gun with extention wands and different pattern nozzles, three screw on application cups, a bottle with brush, two gallons and a can top funnel. It was all about $175 . I dont intend to do the non metallic surfaces. It doesnt have that nice finished look like rubberized undercoat. I will still use that or paint on the underside of my "summer" cars.

[trbomax]

OK. Ive had my pressure pot undercoat gun set up since the early 80's.The gun itself is a binks #39. The fluid stem is about 0.250". I never made any wands for it.Where I needed a wand I used a body shutz gun.My biggest problem with the trailer was getting it high enough off the ground to do it.

[Grumpy Guy]

I just use a couple ramps and a creeper. I also may not be the sharpest tool in the shed cause I pressure wash my boat the same way. The fluid film is avalible in three viscosity.

[trbomax]

What kind of ramps do you back a 12k # trailer up on? That would take some serious rams and they would have to be 6' long to catch both axels.