Hi everybody! I really hesitate to chime in at all, I choose not to be on the forum leading discussions because *YOU GUYS* really do a wonderful job promoting the Phoenix Cruiser product for us.
I'm here to clarify: The underbody spray will not cause/promote rusting by trapping in water and it cannot cause the underbelly to sag. If you do not want them, no problem
However, if you do want them, rest-easy knowing they will work as advertised without causing a problem for your coach. I'm not upset (these are common questions), but I need to set the record straight! Ron & Tom know they're welcome at my campfire anytime!!
1. The sound deadening spray is similar to a truck bed liner (it's made by Rhino-liners) - it's a thick spray-on (non-porous) undercoating with rubber elements in it. The spray does not cause rust by trapping in water, in fact the product must be applied to a clean and dry surface as it is water soluble until it sets. (Much like a latex paint that can be cleaned up with water until/unless it has cured). As a secondary measure, it does help prevent rust by keeping the elements off the chassis frame. At the bottom of this post I will include a statement from Ziebart on their frequently asked questions page. There is also a rust-preventing spray that can be installed, it's a different product that neutralizes oxidation. Ron posted that in 1983 he had a Ziebart application that did more harm that good. In more recent years I have had a lot of folks who have been very happy with the Ziebart products
2. There is no risk of a sagging underbelly with a Phoenix Cruiser motor home (whether you choose the undercoating, or whether you skip it). Every square inch of the corrugated plastic is glued directly to the subfloor structure in a process called lamination. Our floor is laminated in the following order (from bottom to top): corrugated plastic underbelly / layer of glue / steel frame with foam insulation / layer of glue / exterior grade plywood. The entire package is vacuum bonded together so that the glue is spread evenly over the entire surface. The great news is nothing can make the underbelly sag - Ever!
(Sagging underbellies are common on travel trailers and fifth wheels where the same corrugated plastic material is not laminated, but instead screwed into the bottom of the frame)
Statement from Ziebart:
- DOES UNDERCOATING TRAP MOISTURE INSIDE ?
Absolutely not. Undercoating cannot trap moisture between itself and the metal
any more than the paint on the outside of the vehicle can trap moisture under itself. It
simply can't happen. What we have seen sometimes is that a vehicle will start to rust,
someone will then spray undercoating over the rust, then sometime later the
undercoating falls off, and someone who sees that may interpret it as a failure of the
undercoating. Body shops see this very often when they're doing rust repair and they
incorrectly interpret this as the undercoating caused the rust. The fact is,
undercoating should not have been applied to existing rust as a way of covering up
the rust damage.