[DON]

Fillhobson,

thanks for the info.

JC

[Mark]

In response to Jon’s comments above:

Your point is well taken, and maybe I’m being too hard on Prevost. It’s always easy to second guess, and as a product design engineer for one of the largest (the largest? You can guess who that might be!) consumer product companies, I know first hand how challenging issues like this can be.

I will say this: I’ve had extensive experience with adhesives (granted, on much smaller parts), and I know just how tricky it is to get consistent results. In one instance we were ramping a product for production, and without warning the glue bonds started to fail, with no obvious cause. After careful analysis we discovered that the change in humidity from winter to summer in China (where it was being manufactured) caused the 2-part acrylic adhesive to fail. In another instance, we found the glue was not being stored at the correct temperature, which also caused failures. From lessons learned, I avoid glue like the plague. Given a choice, I would always opt for tape, and this application seems ideal (large, flat surfaces, and dynamic loads).

With the limited knowledge of the issue, VHB double sided tape would be one of the first things I’d look at. Granted, the assembly process, and fixturing required is a lot more involved and costly. But I’d have to ask the question; how much has this cost, and how much has it hurt Prevost reputation?

Regarding the H3 not having the same issues, there are a number of potential reasons, from interaction of the glue to the plastic (verses stainless steel), to modulus of the panel itself (I’m guessing the composite panel is less stiff… but just a guess). Like I said, gluing is a very tricky process.

[Davy]

Phil, being that I have this problem I’m very interested in any options that might be a fix that’s less expensive. I’ll talk with Prevost in April when we head to the oyster fest to see what options I might have. If you find anything please let us know.

[Davy]

Phil, I’m glad as a design engineer you can appreciate how unexpected product issues can crop up. In another life I also did product design and before the products were released to production they went through extensive testing. And as you can guess, when they hit the market stuff we never expected cropped up.

In Prevost’s XLII problem it appeared to be more likely on the stainless skins of the motor home shell. To add to the problem and their response you can bet the farm that the production people and the adhesive suppliers were pointing fingers at one another as an initial response.

Follow that up with the problem becoming more widespread as more units were put into the market, and most of those were year old chassis by the time they went into service due to the time of conversion. Making the problem worse was motor homes have limited use, unlike seated and entertainer coaches so nobody could see a pattern to the failures.

Then they repaired them by doing what they did to build them. They just stripped the panels, cleaned off the old adhesive and rebonded the panels. Now Prevost was faced with new repairs and repairs to the repair. I can only imagine at this point how people involved in finding a solution were under intense pressure, because they not only had to figure the cause and fix that, they were still building coaches and everybody involved with the bonding process was under a microscope and still the problem wasn’t going away. They had to design a field repair that would work, but more importantly they had to insure the materials used and the process for manufacturing had to be fixed.

I cannot imagine how big the challenge was to fix the problem. But apparently it has been fixed.

[phil]

On the last sentence posted.

Time will tell.