Expanding foam in box sections of chassis

[macachees]

Hi

I recently bought a 71 Dormobile conversion. I've noticed that the chassis box sections have been filled with expanding foam. Has anyone else seen/done this? My gut feel it isn't a good thing to do and am wondering how best to remove it.

Cheers
Lyle

 

[Moseley]

Argh, I feel your pain, that is a horrible thing to find and I’ve no idea why anyone would think it’s a good idea. I’m pretty sure that expanding foam will absorb and hold onto water due to all the air pockets, so you’re right in thinking that it would be better off gone. God knows the least destructive way to do this, it may be better to thoroughly de-humidify wherever your van is stored and then cap off any open holes to the box sections. If it rots through in years to come, it can be cut open and removed at this point.


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[thejinx]

It would be tedious to remove u would need to find some implement to hook it out like a knife on a stick or something. :shock: not sure it could be done. I have some on a pipe outside my house and it doesn't seem to absorb water. Although this particular one is for outside use. I think and I may be wrong. It forms a crust impervious to water. Don't know if the stuff in your chassis is the same.

 

[sparkywig]

Unfortunately it's been bodged.
The foam itself is impervious to moisture, but it will trap any moisture and cause pockets of corrosion.
You need to remove all the foam before any grinding/welding work as it is flammable, and gives off noxious fumes.

 

[thejinx]

That is a very good point. It does burn and gives off some serious fumes

 

[Bullet tooth]

You may be able to spray acetone or PU foam cleaner through chassis this will melt foam but what damage it may do to painted parts it comes in contact with im not sure this will also make a hell of a mess but will disolve foam to a sticky mess

 

[StuF]

Id just get a pokey stick and a hoover and go at it a stage at a time - acetone and foam cleaner will be as difficult to remove as the foam itself and would probably make the bus smell rather unpleasant. Got any pics of the affected areas?

 

[macachees]

Thanks for the replies. No photos at the moment but if this rain stops I'll get underneath to take pics. Basically it's been fired in to all the box sections in the chassis. Very annoying

I was also thinking it is just going to have to be one of those horrible manual jobs. I thought it might be an option to attach something flexible with a plastic end (to protect the metal) to a drill and run it at a low speed to break up the foam then hoover it out. No idea what that flexible thing looks like or if it exists but I'll get googling!

 

[thejinx]

What about something like a plasterers mixing paddle on a leccy drill.

 

[macachees]

Decent idea but think that might be too rigid, and the end too big to get in there.

 

[georgeyv]

A flexible drain unblocking tool might work, they come with all sorts of different ends, maybe one with a rigid claw type attachment would do it.. Sounds like an absolute pain to sort, so good luck!

 

[ozziedog]

Thanks for the replies. No photos at the moment but if this rain stops I'll get underneath to take pics. Basically it's been fired in to all the box sections in the chassis. Very annoying

I was also thinking it is just going to have to be one of those horrible manual jobs. I thought it might be an option to attach something flexible with a plastic end (to protect the metal) to a drill and run it at a low speed to break up the foam then hoover it out. No idea what that flexible thing looks like or if it exists but I'll get googling!

This sounds like the way they are now clearing defective cavity wall insulation from houses with issues. These peeps are making up their own tools to fit into drills to break up the insulation and then Hoover it out with a Henry. I reckon something like three or four cable ties into the chuck and experiment with different sizes with the knobby bits flapping about. Perhaps a drill with a flexible extension on it with the cable ties in the flexis chuck. This might make it easier to get into the angles. But constant vacuuming is maybe the answer.

Ozziedog,,,,,,,, ,, But why oh why did they ? :mrgreen:

 

[subheatadey]

You can use Electricians flexible draw rods?

 

[rlepecha]

Old clutch cable with frayed end, ?
I know peole used to use those to clean out heater cable pipes of old grease etc.

It might act a bit like a wire brush on the inside of the box sections too, which should prep them perfectly for cavity wax or similar..

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[macachees]

Thanks for all of the ideas. I like the idea of the frayed cable, I think that might work. I will try and give it a go this weekend, assuming it's not still raining!