Builders PU Foam as a fridge insulator

[affinite]

Has anyone used builders PU expanding foam to add external insulation to their coolbox?
I have a top entry coolbox which just doesnt cope with the temp in the med. To add rigid foam panels to the outside is impractical because of the surrounding joinery and adding foam on the inside seems a little inelegant. Im guessing that there is an air gap between the outside of the coolbox and the surrounding woodwork so I was contemplating drilling some holes in the liner and then filling the void with builders foam.
Anyone tried it?
Is this stuff safe to use for that purpose?
Do you think I'll just end up with a useless sticky mess?
Thx
Steve

 

[kieronriley]

you may end up with a detachedcoolbox or even a broken one ,this foam will just carry on expanding and will omly stop when cured it is all but impossible to gauge just how much to put in,a lad in our club tried it three times before giving up and using a loose fill insulation,Kieron

 

[vyv_cox]

I have used expanding foam to patch up an area that the boat's constructors failed to insulate, the full side of the cool box adjacent to the refrigerator. Heat from the fridge condenser coils would heat up the cool box. Expanding foam filled the volume quite nicely.

Expanding foam needs to be restrained during expansion, otherwise it develops very large voids which defeat the object of using it. Unless you are filling an existing volume you may find it beneficial to arrange a temporary bulkhead that can be removed once the foam has cured. I used polystyrene foam that could be cut away easily. I then covered the whole area with aluminised sheet, to make it look better and to reflect more heat away.

Vyv

 

[saltwater_gypsy]

Ive done it on a Sigma coolbox. You have to have a good idea what the containment is like otherwise the results could be hilarious eg pans glued together with foam.
Line the coolbox with brown paper or plastic because the foam sticks like s.... to a shovel where you dont want it. Drill a few of 1/4 inch holes in vertical pairs inside thebox, one at the bottom and one near the top. Same sortof thing for the floor
Fire the foam in at the bottom and keep going until the foam starts to appear at the top. Once it sets cut off the stubs .Vyv's suggestion for a lining sounds worthwhile.
Good luck (and wear gloves)

 

[BSSOffice]

A fire report on a boat just before last Xmas found that the aerosol driver in a foam filler which contains methane, had gassed-off. The gas exploded on contact with an electrial spark from the domestic appliance beside the foam-filled area.

To reduce the risk of this happening, allow any filler to gas-off and ventilate the area well during installation and for a reasonable time afterwards as per the manufacturer's instructions.

Regards
Rob@BSS Office

 

[sunquest]

As others have commented on, the normal expanding foam will expand until it cures and will damage or distort panels. Window installers use a foam which is of 'low expansion power' which does not distort panels and mouldings as used in their industry. The noticable difference is that it is green not white. No doubt someone will be able to give it it's brand name. Geoff

 

[Endeavourquay]

I have, but I put it in very carefully, small squirt at a time so that I didnt get air pockets or bulges, Works fine, keeps the cold in no problem.

 

[Poignard]

Just a thought. Suppose, one day, you have to remove the coolbox. How difficult will it be to excavate it ?

 

[Norman_E]

Probably not too hard as the stuff seems to crumble after a time. I would not use it but either dismantle and put in rigid insulation panels or loose fill the voids with vermiculite, provided it could not escape into the bilges.

 

[asj1]

I ahve done exactly as you say. Need to drill many holes to gauge progress etc and be careful not to overfill. There is more than one sort of foam some say they are specifically for insulation.
I also stuck rigid insulation on the outside of the box - or more precisely on the outside of the wooden panels, themselves on the outside of the box.

 

[davidbains]

I used it with foam chips when constructing a box round a top loading polypropylene fridge.
However it wasn't thick enough for the Med. Since the fridge box was generous I then added
polystyrene panels internally (not stuck on so they can be easily removed when nec), which work well since now the fridge is always full.

 

[magdalena]

Can anyone recommend a supplier for rigid PU panels for coolbox insulation. I have hunted around but only found building suppliers who have a minimum order of 100 or so...

Regards,

Robin

 

[snowleopard]

I insulated my fridge/freezer using REP foam. That's the stuff that comes as two liquids you mix together. It has the advantage that it will flow to the bottom of the space and expand up from there. Builder's expanding foam is difficult to get into spaces like the bottom of the box as it is sticky and won't flow.

REP (rigid expanded polyurethane) foam is obtainable form place like Glasplies