Closed-cell sprayfoam insulation: learnings

VanGuy6678

Member
So I decided insulate my 2010 Sprinter 2500 HR 170 with closed-cell sprayfoam. I chose it for its unmatched R-value per inch, for its impervious-to-water property, and because it creates a true moisture barrier between sheet metal and van interior.

Some learnings:

• I applied Rattletrap all over the place beforehand. Wish I had saved the money and weight and simply let the cured sprayfoam do the job of vibration / noise dampening.

• prep is labor intensive (I taped all surfaces with red duct tape where I did NOT want sprayfoam to adhere to metal). Namely, all ribs. Also covered front seats/dash/ and wheelwells with plastic. Covered floor with cardboard roll from Home Depot.

• Wash all surfaces with citrus degreaser where sprayfoam will be applied. This will ensure it sticks.

• If you plan to add rivnuts anywhere like I did, add them before spraying foam. Just be sure to cover them with tape don't worry about foam gunking up threads. It'll act as threadlock :)

• cover all smaller holes that provide access to hollow ribs / enclosed cavities with tape. When primary sprayfoaming is done, uncover these holes and use Great Stuff Big Gap Filler with included flexible plastic hose to fill these areas.

• glad I ran wiring first (obviously) and had a completed electrical plan to work from. I wrapped all exposed wires in plastic prior to spraying. Also taped wires in places where expanding sprayfoam might push it inward toward vehicle interior. You don't want wires pushed out beyond the level of your finished walls & ceiling.



• I also took plenty of photos and a video of all wires before I sprayed. Good for future reference. Actually, this is good practice all along the way - take photos of all that will be hidden in the end. In some cases, include a tape measure in the photo, for locating things precisely in the future, if needed.

• I used two sprayfoam kits I bought online from foamitgreen.com. The "605" kits. Still ran out before I could fill the rear doors. Bette to buy 3 kits and plan to use the excess in your house, sell it to a friend.

• suit up with a tyvek suit, and HIGH-QUALITY respirator. Hat and protective eyewear too. And hydrate beforehand. The stuff creates a lot of heat as it's sprayed (parts A + B chemicals are mixed in the gun during application, this generates heat). After 1 hour of spraying, I was literally drenched in sweat. Nearly passed out. So hydrate beforehand!

• spray in light coats. THIS IS KEY. The foam gets quite warm during allocation, and this warmth causes metal to expand. The the foam cures very rigid, so whatever degree of deformation of metal panels occurs, is going to remain (rigid foam wants to remain in its cured shape).

• I wanted a full flush fill (no uninsulated space in my walls, ceiling, and headliner area. To achieve this, one needs to apply A LOT of foam. This is because it expands unevenly. You'll end up with peaks and valleys. And if you don't want valleys in your finished cavities, then your peaks will be very high. And this adds to material needed, and adds to trimming labor.

• this stuff hardens in 2 minutes, cures in 24 hrs.

• ok, so now you're done, right? True, it's all cured and insulated. And give it a test drive - you'll be DELIGHTED in the reduction of road noise. It's dramatic.



• but now the real LABOR begins. You've got to trim all that foam flush to interior ribs. In any case, use a full face mask respirator. You'll need to keep the dust out of your eyes and lungs. I used this (totally worth it):

http://www.amazon.com/gp/aw/d/B0002...SX110_SY165_QL70&keywords=3m+face+mask+filter

I experimented with many tools. A disc grinder with coarse flap wheel makes way way too much dust. Serrated saw made specifically for cutting OPEN-CELL foam: fail.

Basically, what I found best is a coarse sawtooth blade, but not one with a ground edge. Think good old wood handsaw. Except the large surface area of the blade creates tons of friction as the blade makes its way through a cut.

And flexible is important. In hindsight, I wish I'd been aware of this tool:

http://www.amazon.com/gp/aw/d/B005X...8+inch+saw&dpPl=1&dpID=31cWEwrDdEL&ref=plSrch

I used this for bulk removal of excess foam:

http://www.amazon.com/gp/aw/d/B00E6...i=AC_SX110_SY165_QL70&keywords=insulation+saw

In experimenting with various techniques, I found two most useful:

1) stab tip into a large peak of foam, twist handle. Chunk breaks off. Kind like chipping away at ice.

2) Hold handle in one hand, tip in other (with grippy gloves). Bend the blade so it bows toward the surface you want to trim. Move the blade forward and with a slicing motion; once dug in, twist the blade. Very controllable size chunks can be removed this way. Again, Experiment.

So now that you've got all surfaces roughly down to finished level (within 1" anyway), switch tools. Thanks to Iron Tent for sharing this tip, use the sharp-point side of a curry comb like this:

http://www.amazon.com/gp/aw/d/B000H...curry+comb&dpPl=1&dpID=41uuyYZvoVL&ref=plSrch

Scrape the surface from multiple directions. For quicker (but rougher) material removal, use your second hand to press down on the coils as you pull the tool by the handle with primary hand. Do this until you've reached your final flush surface.


Take care to remember where your wires are. I sliced a few by mistake. Spliced them back afterwards, no biggie.

Lastly, use the Great Stuff Big Gap Filler I mentioned earlier to fill remaining voids in wall and ceiling ribs.

One question you may be asking: so where do you spray, and where not to?

I sprayed my entire ceiling. Driver and passenger side walls. I also will spray my back doors, and the top half of sliding door. Where you find latch cables in these doors, no big problem. Just unbolt and wrap the latch mechanisms / rear handle mechanism before spraying inside the doors. Once cured, use a loose hacksaw blade to chisel out recesses so you can reinstall the latch mechanisms. I wasn't concerned about burying the sheathed cables in foam. Doubt they'll ever just break and need to be replaced. But if so, foam can be scraped out.

Oh, and disconnect tail light wires in rear doors beforehand, and cover them in plastic, then tape them outside the door. You'll reconnect them afterwards. Just take note: wherever those wires unplugged from, you need to protect that area from foam so you can reconnect afterwards.

I avoided spraying the lower half of the sliding door. So much cabling in there, I'll just use rock wool or sections of rigid polyiso / batts combination.

I also didn't spray the vertical channels at rear corners of the van. I'll stuff those areas with batts. Good to keep access to the wiring that runs through them.

That's about it. Let me know if I forgot anything. Sprayfoam is not the only way to insulate a van. It's just the method I chose for mine.

Next phase of conversion: I'll tape strips of 1/4" closed cell upholstery foam (the kind you buy in rolls) to all exposed ribs. ( I have a bunch leftover from filling in the corrugated floor). This will minimize thermal bridging between 1/4"'plywood wall panels and heat-conductive van ribs.

Thanks for reading - I hope this helps others out there :)
 

Rensho

Member
What a labor of love! Great job. I really dig your level of planning and order of tasks.

Boy, that stuff is not cheap eh?
 

CJPJ

2008 3500 170 EXTD 3.0 V6 OM642.993 4.182
By spraying multiple thin layers we're you successful in not deforming the exteriors surface?

I think you now have a quiet ride.

:thumbup: nice work.
 

VanGuy6678

Member
By spraying multiple thin layers we're you successful in not deforming the exteriors surface?

Unfortunately, as careful as I was with van sheet metal temperature, spray foam temperature, and applying multiple light coats, I still see some deformation of the sheet metal. Not very noticeable to others, and not noticeable at all unless viewing down the side of the van exterior. But it's there, for sure. Helps that my van is white, too.

I don't know how it'd be possible to avoid any deformation with 2-part spray foam that generates heat on application. But as with many things, it's a trade-off I'm glad I made :)
 

d_bertko

Active member
I had no deformation at all back in 04 when I used 50 cans of Great Stuff closed cell foam to do the walls and doors of the my 158" T1N's cargo area.

This was likely due to being conservative in my technique since write-ups and pix were rare back then. I found it easiest to get the most out of a can by using it all at once. So I would add an inch layer or less over large areas as I sprayed out the contents of a can. This solved any over-expansion problems as there was extra room left to expand if I was uneven in an application. It also might have allowed for any final expansion as the layer dried and set up.

The foam is incredibly sticky---no problems whatsoever in layer-to-layer adhesion. Foam still looked like it did on day one when I had cause to take an interior panel down after ten years.

My wiring was done inside inexpensive plastic Smurf tubes from the electrical section of HD. That came in handy when I added one more wire later on one wall.

The ceiling work was too hard for me with long stalactites before the Great Stuff set up. So I rough-cut rectangles of polyisocyanurate rigid foam and sealed the edges with the Great Stuff at the sides for a good vapor barrier.

The thermal properties are indeed excellent and sound reduction in camp also the same. But I think I'd add an initial thin layer of acoustic-tuned dampener to the middle of any sheet metal to get further suppression of low-frequency road noise.

I did not disassemble the cab doors and interior to foam there. I am braver now and would do that on a new van with road noise suppression as the as the primary goal. I expect the NV3's are quieter than my 02 T1N.

Dan
 

VanGuy6678

Member
True, canned foam is a 1-part product. So no chemical mixing during application, so no heat. But I find it harder to install, and cross-sectional comparison between it and 2-part foam shows quite a difference.

One thing I forgot to mention in my post is that I relocated the sliding door lock, so that it now protrudes horizontally. This allows full wall panel to be installed over the sliding door interior. Pretty simple mod, requiring just a new hole in horizontal divider below existing door lock location.
 

ddunaway

Active member
VanGuy,

I have to ask. Since you have gone to the extreme R factor for walls and ceiling, what are your plans for the floor? Could be the weakest R factor link..........
 

jurgen

New member
I just sprayed my Sprinter with foam last week. I used Touch 'n Foam kit from Home Depot. I did not like it the foam is a could low pressure. I tried the 200 first and it worked ok it almost did one sideIMG_0224.JPG
I than used the 600 and after using about 7/8 the foam did not get hard. I had to remove a big section.IMG_0414.JPG
I used a Multimaster with a scraper blade for bulk removal of excess foam that worked really well and no dust.81GWm-CEioS__SL1500_-002.jpg
I made a sander to sand the rest I will take a picture and send it tomorrowIMG_0416-001.JPG
 

VanGuy6678

Member
VanGuy,

I have to ask. Since you have gone to the extreme R factor for walls and ceiling, what are your plans for the floor? Could be the weakest R factor link..........
Good question. First, covered entire floor with RattleTrap. Then cut & adhered strips of 1/4" closed-cell upholstery foam (comes in a roll) to the "valleys" between the ridges in the OEM floor. Used 2-sided carpet tape for this.

Then attached 3/4" rigid foam board using adhesive caulk. Taped the seams with foil tape.

Then a 1/2" ply subfloor, biscuit jointed, without glue. But I did waterproof it with polyurethane first, for when liquids are inevitable spilled. Don't want the mildew!

Avoiding mechanical fasteners is smart from an insulation standpoint, because bolts/screws would be spots for thermal bridging. (and noise transmission).

1/16" vinyl flooring will float on top of the 1/2" ply subfloor. But only after laying down super-thin electric heating film from home depot :)
 

d_bertko

Active member
VanGuy,

I have to ask. Since you have gone to the extreme R factor for walls and ceiling, what are your plans for the floor? Could be the weakest R factor link..........
I'm several inches too tall to stand up straight under the roof beams of my 02 long-tall. So I was reluctant to raise the floor level.

My foamed walls and insulated ceiling with only 3 cargo windows proved easily heated at single digit F outside temps with my Airtronic d2.

So I quit insulating at that point.

It would be another story if I routinely camped at below zero F temps---I would have added foam window inserts for nights and closed off the glassy cab with an insulated curtain.

If more winter insulation was needed then I would have added ply-topped rigid isocyanurate panels as a temporary winter floor----and removed it for the extra headroom seasonally.

A diesel furnace provides copious heat at a low fuel cost so not especially worth going to insulation extremes.

A very different story for drycamping air conditioning. Electricity is much harder to supply quietly---probably worth twice the insulation level---floor, windows, cab isolation measures---if the intent is to run an air conditioner.

But a btu is a btu whether heating or cooling. If the d2 can raise the interior by 60F with 7500 btus then my foamed van should have half the corresponding cooling btu load compared to the typical more-windowed, less-insulated commercial rv's that require at least 11K btu ac's to drop the inside temps by 40F.

Dan
 

jurgen

New member
I made this sander with 24 grit paper works really nice. Electric carving knife suppose to work I don't have one but you can get one at Amazon for less than $12. I have a Multimaster Tool and the scraper blade works really nice for bulk removal of excess foam.
 

Attachments

PaulDavis

Member
what are your plans for the floor? Could be the weakest R factor link..........
Ignoring the many exposed metal pillars and surfaces with direct thermal connectivity to the outside, sure it might be the weakest R factor link. And those bolts in the floor and their thermal bridging could ruin everything.

It is a metal box folks.
 

VanGuy6678

Member
Some weeks later, Just a note here about loading up the ceiling ribs with Great Stuff Big Gap Filler: the stuff needs air to cure as a foam. So don't fill a rib in a single application. If you do, you'll have pockets of drippy, syrupy un-cured goo inside the ribs. I'd highly recommend filling each rib partially (say every 3 inches or so. Then let it cure. Then fill in some more, let it cure. Etc. until done). The stuff needs air exposure to foam-up correctly. Ask me how I know ;)
 

mugget

Member
Ok VanGuy, how do you know...?

Just kidding! :smilewink:

I just wanted to ask about how you approach this when considering future work, like adding electrical wiring, or if the vehicle is in an accident and needs panel beating with access from the inside? Do you just plan to remove the foam wherever required (if required), and then reapply when the work is completed?

Also would you still be able to remove the plastic side panel trim pieces on the exterior - do those require access from the inside to undo screws or anything?

I'm thinking the spray foam is definitely the best way to go, will plan for this in my next Sprinter!

Do you have any photos of the exterior of the van showing the panel deformation?

Thanks for the detailed writeup!
 

VanGuy6678

Member
I've been careful to not apply sprayfoam to interior wires. I'll do fiberglass batts there.

The plastic exterior trim panels are a separate beast. Check the forum for info on those. The body panels behind them will leak over time. I've sealed mine up with pieces of nylon sheet and SikaFlex. Then more SikaFlex to the inside of the fasteners. So they're now waterproof. But would (will) be a pain to remove down the road of ever need be.
 

VanGuy6678

Member
Ok VanGuy, how do you know...?



Just kidding! :smilewink:



I just wanted to ask about how you approach this when considering future work, like adding electrical wiring, or if the vehicle is in an accident and needs panel beating with access from the inside? Do you just plan to remove the foam wherever required (if required), and then reapply when the work is completed?



Also would you still be able to remove the plastic side panel trim pieces on the exterior - do those require access from the inside to undo screws or anything?



I'm thinking the spray foam is definitely the best way to go, will plan for this in my next Sprinter!



Do you have any photos of the exterior of the van showing the panel deformation?



Thanks for the detailed writeup!

 

natek

New member
I've been careful to not apply sprayfoam to interior wires. I'll do fiberglass batts there.

The plastic exterior trim panels are a separate beast. Check the forum for info on those. The body panels behind them will leak over time. I've sealed mine up with pieces of nylon sheet and SikaFlex. Then more SikaFlex to the inside of the fasteners. So they're now waterproof. But would (will) be a pain to remove down the road of ever need be.
I'm getting ready to spray our van. I was thinking of just wrapping the wires so the foam won't stick to the wires themselves and could be more easily dug out in the unlikely event that they should ever need to be. Is that a bad idea? It seems worse to have the air leaks and problems associated with other types of insulation.

Are leaky panels much of a concern if the fasteners are sealed with spray foam? The foam would likely keep them from wiggling and loosening over time and it is supposed to be water resistant if not water proof as long as the skin isn't cut.
 

rb3232

Member
I think wrapping the wires are a good idea. I also think the most important thing is to get at least thin layer of foam on all exposed metal to the extent possible. It may make sense not to fill all cavities. As long as the foam covers the metal you have a good vapor barrier. Good luck!
 

d_bertko

Active member
I'm getting ready to spray our van. I was thinking of just wrapping the wires so the foam won't stick to the wires themselves and could be more easily dug out in the unlikely event that they should ever need to be. Is that a bad idea? It seems worse to have the air leaks and problems associated with other types of insulation.

Are leaky panels much of a concern if the fasteners are sealed with spray foam? The foam would likely keep them from wiggling and loosening over time and it is supposed to be water resistant if not water proof as long as the skin isn't cut.
I used inexpensive electrical smurf tubes from hd as conduit for the wiring embedded in the foam. It worked great when I needed to add one more wire and it snaked through readily.

I did forget to protect the license plate light wire in the rear door. I discovered it broken at the inspection station. Only took a few minutes to dig through the foam with a screwdriver and effect a repair. Easy to add foam to touch it up.

Dan
 

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