Insulation for machine

[G.Pope]

Has anyone tried to use low-pressure foam behind the box in pop machines? I would think that if you lined the back side with 1 or 2 mil plastic and wrap the box with the same plastic sheeting, install it and using longer hoses that can reach behind the box, and fill with the foam.
Wrapping in plastic would allow you to still slide out the box at a later time if you had to.

Has anyone done this and are there any pitfalls that I have not thought of that someone may have come across already?
Thanks

[loman4ec]

I have heard of a problem with this before. The problem is that it expands quite a lot. Much more than you can predict. If you spray it in you can really dis form the outsides of the machine and destroy any paintwork and body filler that you have done.

[G.Pope]

Your talking about regular foam. They make a low pressure foam that wont distort, or apply pressure to surrounding surfaces. The window industry uses this to foam in to the joints of newly installed windows without deforming them. As for it flowing out, slow and steady. You can always add more as needed. And you would have to wrap the outside surfaces for extra flow, but when its done, I think that the moisture that is inherent with fiberglass will be eliminated

[MoonDawg]

      Un-insulated houses have had insulation blown in between the walls so I guess
that is what you are comparing to? 
      Not sure if I understand what the advantage would be though.

[Marvin]

I don't know what type of R-value the spray foam has, but any new freezer or fridge has foam instead of fiberglass insulation.  It is also a very thin layer compared to waht is in the old soda machines.

Marvin

[rogerz]

It would be interesting to know what the difference in R value would be.
If you use an old round top machine all the time, they do run alot and the
loss of cold to the outside through the meatal is amazing.

tz

[G.Pope]

The reason I brought this up is that the PINK insulation will undoubtedly become wet over time. The condensation in the air gets trapped in the machine and transfers to the insulation were it gets wet and soggy and then loses its r-value over time. I have never opened up a machine to restore it and found wonderful insulation, and the bottom 12" were always the worst along with the metal.

The R-value of fiberglass is not great anyways. My next machine has a cavity of 2.5" to fill around the inside of the machine, meaning that the max. fiberglass can offer is R-7.5.

Flat sheets of styrene foam (foam coffee cup type) in the home centers are R-10 for 2.5"
(therefore it has a 33% better insulation factor to the Pink) and rigid and water proof and easily shaped. This is also what a lot of packing material is made out of, which would also be perfect to pour into the area and let it fill up.

Flat foam polyurethane sheets are R17 for 2.5" (therefore it has more than twice the  insulation factor to the Pink) and impervious to water also. Flat sheets would guarantee no expansion.
Anyone use this any of this stuff and had success?

[SIGNGUY]

I've only ever used r19 insulation... but guess never considered that when compressed it loses R value... interesting...

I think the low pressure expansion foam would work well, as long as it doesn't "push" the inner tub and outer cabinet to distort it like Josh said.

Whats it called? where available... and how much would you need to do a cabinet of an 81 or 39?

[G.Pope]

When you squeeze insulation, or pack it, the R-value is only determined by the width of the space. So, by using R-19 (6.25") insulation and packing it into a 2.5" space, that causes the trapped air spaces in the insulation to be removed and essentially becomes R-7.5.
DAP makes a low expanding latex foam. Problem is that if it gets wet for any length of time, it can break down and loose effectiveness, because it is water based.

Great Stuff makes a Yellow top window foam that is polyurethane foam and low expanding. Problem is that the stuff is terrible to work with. Get it on your hands and its on there for a week of more. This I know personally, as I have sprayed about 15 cans of this stuff over the past 3 years. I suggested using plastic to line the machine so it does not get on the metal. If you laid the machine on its back and sprayed a layer of foam, there would be plenty of time to push the inner box into position and let the foam start to travel up the sides.
I still think this is too messy.

extruded Polyurethane and Polyisocyanurate foam in the home centers is a very rigid foam that can comes in different thichnesses. So I might use a 1" and a 1 1/2" sheet (sandwiched to make 2 1/2") and cut to fit  the exact inside of the machine. No mess and easy to cut. Water resistant, wont break down and can be cut to fit any shape. Plus the r-factor is huge compared to Pink.

You guys dont paint your machines with paint from the 50's so why insulate with 1950's insulation.

[Pat Pixley]

Very interesting  it is something to think about for the next machine

[RC kid]

I like the sound of this "Polyurethane and Polyisocyanurate foam". Working with sheets of insulation and cutting it to fit just seems much easier then guessing about the expansion rate of a foam, which by the way, I too have a lot of experiance working with. It's great for windows and around pipes during construction or at least prior to finish work, but very difficult to clean up off of nice surfaces such as paint or carpet. And it definately isn't coming out of clothes.

Line the bottom of the machine's interior with Por-15 or simular product prior to inserting the cabinet and that should handle the condensation issue. 

[SIGNGUY]

Ok
Thinking about this Polyurthene foam boards or "Pink Boards" whatever they are called...
The problem I'd see is getting it packed in their tight enough? wouldn't there be pockets of air? or spots that the cold are would escape from?? I guess if dealing with a Square top machine, maybe not an issue of lining the outer cabinet wit hthe boards,,, but when dealing with a round top? the stuff doesnt bend, and you'd have "Gaps" where near the top corners of the machine, and also on the back side, unless you where able to do a precision cut where the two meet?

This is where the regular style insulation doesn't leave any gaps? 

Just another discussion point... i'd like to hear ideas on how to combat that issue?

Or is there some sort of lose fill you could pack in there? made of the same material with the same R value ??

[G.Pope]

First, you will have to measure the depth of area you have from the back of the inner tub to the back of the cabinet (2 1/2"?). You dont have to bend foam board. Make a paper template of the inside of the back of the machine from top to bottom and side to side. Lay this on the foam and cut it out. Some machines it might fit in whole and some you might have to cut it into two pieces to fit it in.
This works best when the machine is on its back though. You might have to carve some little areas out on the foam for little things that sometimes protrude from the back of the inner tub.
You now have the entire back filled with solid foam.

Now what you are doing is building up the bottom, sides and top to form a space to just drop the tub into. Try to get the foam board to fill as close as possible the shape of the inner tub, so that when it fits in, you can hear the foam squeak.

I will do a drawing in the next few days and layout how an 81 would be fitted. I think you will be surprised how easy this is, and custom fit to the shape.

[teckman]

Has anyone tried this polyurethane technique with an Ideal 55 Slider?

[johnieG]

Has anyone tried this polyurethane technique with an Ideal 55 Slider?

It wouldn't work that well on slider, the evaporative tubing that's attached to the inside on the liner will leave a 1/2" gap all around the sides & bottom.  although it has worrked nice on some chest coolers I've done ( for the bottom to replace the original hemp-board insulation)

[teckman]

I was thinking about incorporating it into the polyurethane. Would that work?

[bmw90w]

Was this ever completed? Any pics?

[teckman]

If you are asking about the Ideal 55, the answer is no. Any help?

[bmw90w]

No I mean if the sheets of insulation were used or not.

[oscar]

I had my house foamed when i remodeled it. The R value is around 7 per inch. I've used the plastic wrapped fiberglass insulation. It's less a pain than the unwrapped and does keep the insulation dry. I think i'll try the rigid foam boards on the next one. That sounds like a very good idea.

[teckman]

Please let me know how that works out. I have a lot of metal work to do first.

[SIGNGUY]

I still use the time tested way... it has worked well for over 50 years with regular insulation, it fills in pockets, works well, easy to fit in... but if you have time to investigate another option, go for it.
Good luck!

[SGM]

G Pope,

I would have to agree with you, it's all about the science (I think)   I'm getting ready to put the tank back into my square top and I have about a 2.5 inch gap to fill with insulation.  I bought the solid pink sheets from HD and the R value is 5 for 1 inch.  I'm going to glue the sheets together and go for it.  Besides, it's not as itchy....

SGM