| Author | Message | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 203 Registered: 1-2009 Posted From: 24.129.232.232  Rating: N/A |
... your thoughts on foaming the outside / underside of the cargo hold ; please ? .. Might even cap it with sheet aluminum or fibreglass to keep resilient & streamlined and inject the foam. .The first b i g trade off is loss of ability to inspect for missing rivets or fatigue cracks , signs of pending chassis integrity . The main aim of this modification is insulating the cargo hold. Utilities could be run before sealing the cavity in & insulating, but not the best protected area. | ||
| Stephen Fessenden (Sffess)
Registered Member Username: Sffess Post Number: 760 Registered: 1-2002 Posted From: 66.38.120.219 Rating: N/A |
My Prevost is foam insulated underneath and in the wheel wells. This was from the factory. It is then coated with some kind of undercoating, probably to protect it from UV light. I don't think you are going to get any benefit from enclosing the insulation with aluminum. You cannot change the streamlining of a brick. Another place I would insulate would be over the engine so that the heat does not come through to the bed. Foam is not the best material there. All the foams are somewhat flamable and don't like the heat. Rockwool is ideal because it blocks fires. Note, the term mineral wool includes fiberglass which is not as fire retardent as rock wool. | ||
| Chuck Newman (Chuck_newman)
Registered Member Username: Chuck_newman Post Number: 376 Registered: 1-2005 Posted From: 75.15.95.46  Rating: N/A |
Clint, I just got back from a rally that was almost exclusively Prevosts. Most in the late '80 to mid '90 year range. The foam was chipped away/degraded substantially on many of the coaches because foam won't stand up to abrasion and/or ultraviolet rays. And this certainly is not exclusive to Prevost. I've seen it on RV's and in building construction. Foam needs some kind of protection from the elements if you want it to last. And if you foam the underside of the bay, what about heat/cold encroachment from four sides and maybe the top? It would be easier and cheaper to line the bay's interior with whatever thickness construction grade sheet foam you need, but still ideally it needs some surface protection also. I don't know if this stuff works well with cold, but with heat it is amazing. I had them send me a sample. While Elva was cooking dinner in the oven, I measured the oven door exterior surface temperature at 194 degrees F. I held a piece of this insulation on the oven door at that same spot with my bare hand for at least 10 minutes. The outside of the insulation climbed to 97 degrees and stayed there. It maintained a consistent 100 degree drop across the insulation. And it won't burn or take on water, and is durable. And I don't get a penny for saying so. I do like to pass on stuff that actually works and will last. But the thing that amazed me the most was when I took the insulation off the oven door, I put my other hand on it and it was the same temperature on both sides -- 97 degrees F. I'm definitely going to use it in the bus engine compartment and in my van. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=230344277831&viewitem=&sspag ename=STRK%3AMEWAX%3AIT | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1646 Registered: 12-2000 Posted From: 76.71.101.148  Rating: N/A |
So, it sounds like sometime between now and 15 years out, you'll have to do some touch up to the foam. Its use is not intended to last forever. At least underneath, you can see what's going on, and it can air out. A layer of insulation under a floor covering in the bay steals precious clearance and once soaked, cannot dry out, and risks being a source of mold/mildew. The entertainers also foam the road side of the wheel wells. The decrease in road noise is considerable. You've got my vote, spray away! happy coaching! buswarrior | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 874 Registered: 10-2006 Posted From: 76.216.70.120  Rating: N/A |
I would only attempt this if you can find a NON BURNING foam. Most foams are burn really well and require a fire retarding covering to be safer. Wouldn't want a cigarette but stuck somewhere to cost the coach. FF | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1558 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
If you want to see what a foam fire is like, get yourself a small piece and light it. It smokes like crazy and burns intensely. Just think how 40 feet x 8 feet would go. Fred's point should be heeded. If you live in California, go across the border to try this. They'll probably lock you up, hang you, sue you for all your worth, and fine you into poverty. This is probably slightly exaggerated;they might not hang you, can't afford rope right now; they might give you a few hundred lashes instead. | ||
| PA Doug (Padoug)
Registered Member Username: Padoug Post Number: 11 Registered: 1-2009 Posted From: 76.120.147.169 Rating: N/A |
Found this to be interesting: Look at the source information at the bottom of the page. http://www.healthgoods.com/Education/healthy_home_information/Building_Design_and_Construc tion/foam_board.htm | ||
| Jim Wallin (Powderseeker01)
Registered Member Username: Powderseeker01 Post Number: 26 Registered: 10-2008 Posted From: 208.68.48.77  Rating: N/A |
The information in Doug's link is very interesting. I had the entire interior of our bus spray foamed by a contractor during renovation, and remain very pleased with the results. Because I was skeptical of the contractors opinion of the fire resistance of the cured foam, I tried to get it to burn and found it virtually impossible to keep it burning once I removed the torch flame. Another option that also works well is insulating paint additives. Link = http://www.hytechsales.com/buy.html The site will explain the technical details but the short story is that there is no thermal conductivity in a vacuum. I used this for insulating areas that were difficult to access for foaming like the front and rear steel roof shells, which I didn't want to remove. I'm planning on using this in my bays next. Good luck with your project. | ||
| Peter River (Whitebus)
Registered Member Username: Whitebus Post Number: 117 Registered: 4-2009 Posted From: 204.62.111.51  Rating: N/A |
my bus is sprayed with foam underside, with a black undercoating on top of that. always been there so I don't know if it helps in any way, but surprisingly not much sticks to it (compared to bare surfaces that had uniform 1/2 dust+oil) I am sure it cuts down on road noise if anything. before you do spray, make a good notes on where exposed wiring and air lines were, because there will come a time when you are cutting the foam out for under carriage installation of god knows what, and you don't want to cut into something essential... | ||
| Stephen Fessenden (Sffess)
Registered Member Username: Sffess Post Number: 762 Registered: 1-2002 Posted From: 66.38.120.219 Rating: N/A |
The recommendation to do your own burn test is the only way to go. Your really cannot depend on ratings, even aircraft ratings on flamability. If you try to burn it yourself, you will quickly be able to reach a common sense decision on whether the particular product is right for your application. Some Urethane Foams are fire rated when covered with drywall. That does busnuts no good. I have been very happy with the Soythane product I am using in my basement with a bedliner type gun. Need 100 PSI at 10CFM to spray it and there is no equipment clean up. Search online under Soythane. The distributor is in Jacksonville Fl. You can also buy urethane bedliner in various colors and spray inside bays etc. A good product for those far from commercial spray companies. |