Glueing styrofoam to inside of painted metal van wall....rust?

Denise · Senior Member

Glueing styrofoam to inside of painted metal van wall....rust?

Peter_n_Margaret · Guru

If you want better insulation, use high density urethane foam instead of styrofoam.
The insulation quality will be about twice as good for the same thickness.

Cheers,
Peter

Denise · Senior Member

Thanks for that, Is that sheet or spray on? Will I have a problem with rust if its sprayed on? Dont know anything about it. Is it expensive? DIY?

Peter_n_Margaret · Guru

I bought it in Adelaide in 25mm thick sheets. I used it for fridge and freezer insulation. Not too expensive. You can use most glues too, not like styrofoam that disolves in most.

Cheers,
Peter

Denise · Senior Member

Thanks for that...my biggest concern is whether condensation (from inside/outside temperature differentials) between the foam and metal will rust the van walls on the inside. ....thats why I thought removable panels might be wise. What do you think. Have you ever checked under yours? Thanks again....:)

Peter_n_Margaret · Guru

Denise wrote:

Thanks for that...my biggest concern is whether condensation (from inside/outside temperature differentials) between the foam and metal will rust the van walls on the inside. ....thats why I thought removable panels might be wise. What do you think. Have you ever checked under yours? Thanks again....:)

We don't have any metal in the camper walls Denise (we are fibre glass sandwich panel), so it is not an issue for us.
If the metal is cold on the outside amd is allowed to get warm and moist on the inside, then condensation is a possibility, but where it is properly insulated and sealed it should be OK.
We do get condensation around the aluminium pop-top frame sometimes because of this.

Cheers,
Peter

Denise · Senior Member

Thanks, I think I'll make them covered removeable sheets do you remember roughly how much a sheet?... :)

seonau · Senior Member

Hi....I thought ( seonau thinking? a bit of a wobbly start ) when it comes to insulating there must be an air gap between the two surfaces so heat or cold is not transferred via conduction. ?? Air is a very poor conductor of heat.
The idea of putting up panels like you plan is a really good original idea i think but it might be better, if the air gap theory is correct, to make some sort frame between the outer and inner surfaces to create that gap.
I just read a second ago you have some silicon.... while silicon is not a good adhesive generally, the one you mentioned you have is. The perfect product to use to stick a urethane foam frame work up on metal and then use magnetic tape on those.

As always my opinions are just that and since i know there are people here with a lot of knowledge, help me folks.

Peter_n_Margaret · Guru

Denise wrote:

Thanks, I think I'll make them covered removeable sheets do you remember roughly how much a sheet?... :)

4 sheets 2440 x 1220 x 25mm purchased on 15/7/2004 from Huntsman at a cost of $179.12.

There won't be condensation on the inside of the roof if the warm air is excluded and the moisture does not get there. You don't get condensation on the fridge walls for the same reason.

Urethane is a poor conductor of heat and these materials are mostly air, so an additional air gap is not required. Yes, air is a good insulator, but it must be sealed up in 'pockets' to stop circulating currents spreading the heat around. Urethane foam is the material used in fridges and freezers. It is a light brown colour.

Cheers,
Peter