I have heard an read to use spray in insulation I have used the can stuff on home projects and it ex spans and is a total mess I 'm attempting to do all the side walls I was considering using the 1/2 " cealotex
Is there a type or brand of spray in I should be looking for
Either have a pro do the hot foam spray or "Google" spray foam and the diy kits will show up. Tiger Foam is one kit. Most kits are in the $300 to $600 range depending on how much sq ft you need and thickness.
I'm sure the 'proper' answer to this is to get a professional to do the whole bus in one go, but for me at least this is unlikely to work as for various reasons it isn't going to be practical to get the whole of the bus into a state of readiness for foaming at one time.
The DIY spray-foaming kits might be the answer but I would be nervous about the safety aspects. Celotex sheets (probably 3" rather than 1/2") might be the simplest approach, especially if any gaps are filled with 'aerosol' foam (but how do you stick the back of the sheet to the skin?)
Another method would be to use 2-part foam mix sold in liquid form in tins. This is primarily sold for boatbuilding / fibreglass-type projects so is available in various densities, but is exactly the same stuff as used for insulation. I haven't tried this, but I imagine the same effect as spray-foam could be achieved by constructing a temporary inner skin of hardboard the required distance from the bus wall, with the liquid foam then poured into the gap and allowed to expand.
The advantage of this technique would be that once the shuttering was removed you would have a perfectly smooth inner face to the foam, without any of the messy grinding usually required. The difficulty would be to correctly judge the 'pour rate' - too slow and you risk the foam begining to expand before you pour it. Too fast and you end up with more foam trying to expand than there is space available, which could result in the outer skin of the bus distorting. I've had both of these events happen to me before now, and they are really just 'beginner's mistakes' - the trick is simply to mix the foam in small batches and do the job in stages rather than all in one go - but it's as well not to learn these lessons the hard way when doing an important project.
I stress that I haven't tried this technique on the bus yet, but I probably will do in due course.
Jeremy
Here's the link about where I got mine done here in MI. The guy was great!
http://www.busconversions.com/bbs/index.php?topic=6762.0 (http://www.busconversions.com/bbs/index.php?topic=6762.0)
Good Luck!
Glenn
Thank you for your replies I have did the google search and watch the videos and the spray in is what I thought
when all said an done with the waste ground or cut off the end results is a R factor I have read the section In Dave Galleys book on insulation an it is a air density. They now sell this stuff that looks like aluminum foil with a glue type backing The way I figure is that stuff against the outer wall then the 3/4" cealtex I know this sounds
funny but all I would need it a sharp knife and a tape measure I know I have a lot of work to go but by taking the KISS way on this project might save a little time and $$ and if I was wrong the worst that could happen is I
end up spending more on heating and cooling or snugling closer with the wife in the winter and stay naked
with her in summer eather way ;D
I agree with the philosophy and suspect the thermal insulation achievable with Celotex-type board is perfectly satisfactory, plus it has the advantage of being removable to access wiring etc if needed. The only thing that is bothering me about taking this approach myself is the issue of noise - both the possible squeaking any of the Celotex sheets moving whilst traveling, but also the fact that loose boards, no matter how well fitted, will never offer the sound insulation properties of sprayed-in foam. This thought was behind my 'sticking the back of the board' comment earlier - it seems to me that sprayed-in foam will 'solidify' the bus walls and roof very considerably, and totally eliminate any drumming of the wall or roof skins, which must make for a much quieter bus, and probably make a stiffer and more solid base for building your the interior walls and cabinets etc.
How much this advantage is real, and how much it is in my head I don't really know - I'd be interested to hear other people's thoughts.
On the subject of the foiled sheets - I suspect it helps sell the product in the shop, but the actual benefit is tiny. After all, only a microscopic percentage of heat lost through walls and roofs is lost in the form of radiation, which is what the foil is there to prevent. It's a slightly different thing, but I have seen tests being done on the modern thin 'multi-layer' foiled roof insulation products that claim to match the R-values of much thicker conventional insulation. It seems that in a 'real world' situation they do not achieve anything like the performance the manufacturers claim.
Jeremy
I just did a search on the 2 part foam you were talking about I now relies what you were talking about I have used this stuff before on other projects I still have some in the Barn this stuff is good but it is
very hard to figure the end size and thickness and it is hard as steal when hardened what do you
think about Formica glue around the outer edges of the cealotex that stuff is pretty perm and I don't think i would get to much movement and spray foam in between ?
Removed
Jeremy,
this: I imagine the same effect as spray-foam could be achieved by constructing a temporary inner skin of hardboard the required distance from the bus wall, with the liquid foam then poured into the gap and allowed to expand. Is a really poor idea. You have no appreciation for the total FORCE of that foam expanding. If you reinforce the inside for that expanding period you will get BULGED exterior skin. That idea might work if the foam was contained in1/4 plate steel "if it was properly reinforced". You can go over a section a few min after the first app and closely adjust the depth of the product. Ace fit the foil backed foam in his bus and it looked just great. His was filled with foam in places but he did most of the air permeation stuff with high quality foil tape. The sound deadening performance of spray is a close second reason to use the stuff.....people RAVE about this.
HTH,
John
Quote from: JohnEd on November 25, 2009, 11:29:08 AM
Jeremy,
this: I imagine the same effect as spray-foam could be achieved by constructing a temporary inner skin of hardboard the required distance from the bus wall, with the liquid foam then poured into the gap and allowed to expand. Is a really poor idea. You have no appreciation for the total FORCE of that foam expanding. If you reinforce the inside for that expanding period you will get BULGED exterior skin.
HTH,
John
Erm, isn't that exactly what I said?
Quote from: JohnEd on November 25, 2009, 11:29:08 AM
The sound deadening performance of spray is a close second reason to use the stuff.....people RAVE about this.
HTH,
John
And that?
Jeremy
Jeramey,
In rereading my post it seems that it might be interpreted as "harsh". Nothing could be further from the truth. Any concern I have is with your well being and satisfaction with your work. As to the power of that foam, I once completely destroyed a fridge by spraying small amts into the gap between the plastic liner and the factory foam that had shrunk away. I went slack jawed when I finally got that door pried open. DESTROYED! Had I mentioned what I planned to do I am sure that someone on here would have "clued" me in. Problem is, as I see it, you don't always know that you should really ask a question about something. I keep my dismal experiences in mind when people discuss their plans and I try to read between the lines.
Erm, isn't that exactly what I said? I don't know what that means. Please!
And this is a mystery as well: And that?
In previous discussions, and there are a ton of them available that cover all this, "squeaking" was a source of major heartache for some. Spray foam was actually cheaper than foam board and the do it yourself kits were twice the expense of the Professional Job comparing square footage. Of course, these prices and comparisons are in flux and your current analysis would outweigh history. Even at greater expense, I think I would go with spray "kits" to achieve the quiet. The fumes are lethal and the dust you make in the trimming process will handicap your lungs for the rest of your natural life. I have references for that and he is not a happy camper and had to sell his Prevost cause sweeping the floor left him breathless. Sanding requires a good particulate filter and the guys that spray have a fresh air supply mask and fans exhaust the bus while they work.
Quote from: JohnEd on November 25, 2009, 01:12:42 PM
Sanding requires a good particulate filter and the guys that spray have a fresh air supply mask and fans exhaust the bus while they work.
The guys that sprayed ours, did used full face shield masks. They didn't use the exhaust fans, though, and I am VERY glad. Little tiny airborne particles of foam coated one side of the bus, from just the door being open. Most of those little specks are still there (you really can't see them, but the side feels rough). I can't imagine how it would have ruined the paint job, if they have been using exhaust fans.
So if you have a great paint job, plastic the whole exterior of your bus. We would have done that, if we would have known that the particles were going to coat the sides....
BTW, we did most of our trimming with horse curry combs (that is what the sprayer recommended). They worked pretty well for the walls. When we used those, it didn't create any dust, so we didn't have to wear masks. Now when we used a grinder on the ceiling :D :D :D different story. We looked like space creatures. We were covered in white, and had our respirators on. We had to use full face respirators, because those particles are attracted to your eyes...ouch. Also be careful when you are in there cleaning up, and you have the windows open. The wind can blow the particles, and they will get into your eyes. They are also very tough to get out. While cleaning up, I wore goggles the whole time (I know, yuck, I prefer safety glasses, but I wasn't going to risk another batch of junk into my eyes).
FWIW
God bless,
John
Knowing I was going to be full timing for a few years I opted for the hot spray foam. If I was doing a weekend or party bus different story. I have no problem cutting corners or doing anything the cheap way. But insulation is not something you can go back and redo! Cheap fridge can be replaced, close out carpet, no problem, 2 for 1 wall paper all easy fix's. But more than likely there is only one shot at the insulation!! The hot spray foam cuts down on potential leaks and reduces condensation problems. It also quiets the bus down a lot.
Just my opinion JIm
John
I wasn't meaning to be harsh, just pointing out that I had already addressed the points on which you were criticizing my idea - it did rather seem as though you had hit the 'reply' button without reading beyond the first sentence of my post. But maybe I was being a bit overly sensitive, so apologies if I was.
I used the liquid-mix expanding foam quite a lot in my boatbuilding days, where it is often used for fixed buoyancy as well as for a base for laminating. I too had some embarassing mishaps whilst learning how to use it - I think the first one was when I poured it into the tank of an old fibreglass dinghy, and it expanded so much the daggerboard slot closed up. I couldn't even dig the foam out afterwards as it had gone into an area that was impossible to reach
To be fair, I think my idea for using it in the bus is fairly risk-free if it is done with a bit of care. The trick is to allow the expanding foam somewhere to go - it's closed spaces like the tank of my ruined dinghy or your ruined fridge that creates the problem. In the case of my proposed technique for the bus the space is open on three sides, so the foam has plenty of room in which to expand without forcing itself against either the shuttering or the bus wall.
A spray foam / grind job by a professional with the proper equipment is without doubt the best option. For me though it would probably mean two or three visits by that professional ($$$) because of the way that different areas of my bus are being built in different stages around the very slow installation of four home-made slideouts. I'm proposing to experiment with my liquid-mix foam idea as an alternative to DIY spraying (safety concerns) or loose foam sheets (noise concerns).
Jeremy
PS. I just spell-checked this and it wanted to change 'liquid-mix' to 'leukemia'. Maybe this computer knows something I don't