Original Insulation . . . how impotant to replace?

[mikeypj]

So with these kits, can you stop spraying then come back and finish or...is it like the cans of the spray foam that you use it all in one shot or it's plugged? Dumb question I know.


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[AlleyCat67]

tobeamiss: That's exactly right, R7 per inch would be R21 for a three inch application.

And as for the corrosion, that only happens in cases where the foam doesn't have sufficient air to cure properly (like spraying it in an enclosed space where it fills the space completely. If you pull your ceiling panels then spray it you won't have this problem.

mikeypj: I've never used one of these so I can't really answer that. There shouldn't be any need to have to stop and restart anyway as you should be able to do the whole job in a couple of hours, barring any unforeseen problems.

[tobeamiss]

thank you AC for the reply and info....sounds like a plan I'm definitely going with once I wrap my head around it.
I've just been doing loads of reading on insulation, moisture barriers, air flow and more confused now than ever but I'll get this right. With a little studying I can do anything
So for now, I'm off to the tedious task of removing the thousands of rivets!

[Scooternj]

Originally Posted by tobeamiss

So for now, I'm off to the tedious task of removing the thousands of rivets!

Given the age of the bus (a year older than mine), its probably thousands of screws. #2 square bit on an impact driver works wonders. Just wear gloves and eyepro as you're pulling them down.

[kflowers]

Originally Posted by Scooternj

Given the age of the bus (a year older than mine), its probably thousands of screws. #2 square bit on an impact driver works wonders. Just wear gloves and eyepro as you're pulling them down.

A impact screwdriver is great if the impact gun isn't getting them moving. Two hits some pb blaster and they come out fairly easy.

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[cadillackid]

Originally Posted by Scooternj

The vents are passive vents that allow the bus to breath. Keep them or not, is up to the individual owner. I plan on keeping mine, after putting in window screen and a 12v computer fan to improve airflow

I hate those vents... they put a negative pressure on the bus which makes the bus 'BREATH' by pulling in more nasty heated engine-compartment air... ive been sealing and sealing that engine compartment and still get heat.. now the heat is coming up between the plywood and metal floors and in around spots where the plywood meets structural pillars in the chassis at the front .. grrrr..

couple that with the negative pressure the mirrors put on the driver window when its open means its tough to get a nice breeze in the bus when driving.. and windows closed the engine heat makes the A/C work really hard..

moreover i cant find a single roof hatch made that doesnt have passive vents in it also...

-Christopher

[tobeamiss]

this is what I have to use....I'm assuming I can get an adapter to be able to put a drill bit on it?

http://imageshack.com/a/img921/2022/nSiRiQ.png

edited....on second thought...I'm going to use a grinding disk and see what that does first before I go through the trouble of searching for a adapter. That thing worked wonders for cutting the bolts off to get the seats out!
I'll grind down the head and see if I can tap it off afterwards.

[tobeamiss]

Originally Posted by AlleyCat67

And as for the corrosion, that only happens in cases where the foam doesn't have sufficient air to cure properly (like spraying it in an enclosed space where it fills the space completely. If you pull your ceiling panels then spray it you won't have this problem.

I'm wondering if just spraying the foam on the bare metal is good enough. Should I coat the ceiling with something first or..... I was thinking of gluing up some radiant barrier foil first, then spraying the foam-it. I'm trying to think of ways to create that thermal bridge and reduce ALL condensation from the get go.

[tobeamiss]

Originally Posted by tobeamiss

..on second thought...I'm going to use a grinding disk and see what that does first before I go through the trouble of searching for a adapter. That thing worked wonders for cutting the bolts off to get the seats out!
I'll grind down the head and see if I can tap it off afterwards.

I found the solution to the dreaded problem of removing the Rivets...

I cut a criss cross section with the cutting wheel and then tapped it off with a chisel. It works beautifully!

[AlleyCat67]

Originally Posted by tobeamiss

I'm wondering if just spraying the foam on the bare metal is good enough. Should I coat the ceiling with something first or..... I was thinking of gluing up some radiant barrier foil first, then spraying the foam-it. I'm trying to think of ways to create that thermal bridge and reduce ALL condensation from the get go.

I'm not for sure but I think you would just prep the surface like you were going to paint it, then spray the foam directly onto the metal. I think if you put something else in there first it's not gonna be as effective.

I would say prep it, foam it, then if you want something more, put it in AFTER the foam cures. If you still have space after foaming you could put in some fiberglass batting or thin foam boards between the sprayed-in foam and whatever you will use for your ceiling.

[superdave]

Originally Posted by mikeypj

So with these kits, can you stop spraying then come back and finish or...is it like the cans of the spray foam that you use it all in one shot or it's plugged? Dumb question I know.


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they give you plenty of tips for the gun, its in the tips where the 2 parts mix. it says on the box to use 30 days after opening.

[superdave]

Originally Posted by AlleyCat67

I'm not for sure but I think you would just prep the surface like you were going to paint it, then spray the foam directly onto the metal. I think if you put something else in there first it's not gonna be as effective.

I would say prep it, foam it, then if you want something more, put it in AFTER the foam cures. If you still have space after foaming you could put in some fiberglass batting or thin foam boards between the sprayed-in foam and whatever you will use for your ceiling.

first take a hose and spray the roof in every direction to see if you have any leaks. if there is rust issues or loose paint then prep them. i kept moving around the bus spraying in layers. i used 2 of the 600 sf kits from ebay. now im putting in 1/2 " foam as a thermal break and added insulation. i have pics in my signature. were a respirator and gloves. good luck

[tobeamiss]

Originally Posted by AlleyCat67

I would say prep it, foam it, then if you want something more, put it in AFTER the foam cures. If you still have space after foaming you could put in some fiberglass batting or thin foam boards between the sprayed-in foam and whatever you will use for your ceiling.

great advice....sounds like a plan.
Oh I can't wait to get to the fun stuff like framing the walls and doing the floors!
thank you!

[tobeamiss]

Originally Posted by superdave

first take a hose and spray the roof in every direction to see if you have any leaks. if there is rust issues or loose paint then prep them. i kept moving around the bus spraying in layers. i used 2 of the 600 sf kits from ebay. now im putting in 1/2 " foam as a thermal break and added insulation. i have pics in my signature. were a respirator and gloves. good luck

hadn't thought about spraying it to look for leaks. It makes total sense. Right now we have snow which would have really served me well in finding leaks but I have her all tarped up so...
I also like the idea of layers......thanks!