Spray Foam Problem

[williamsmithaud]

I have a customer with 2 2 4 Triplexed URD run underground through 1 1/2" inch PVC conduit. I have to pull another 4th (ground wire) through this conduit. The problem is that both ends of the conduit have been filled with spray foam insulation.

Can anyone tell me how to dissolve or remove this foam (without damaging the PVC or insulation on the wire) so I can pull the other wire through?

 

[Dennis Alwon]

I would pull the wires back and forth but you really should pull them out and install them together.

 

[petersonra]

I have a customer with 2 2 4 Triplexed URD run underground through 1 1/2" inch PVC conduit. I have to pull another 4th (ground wire) through this conduit. The problem is that both ends of the conduit have been filled with spray foam insulation.

Can anyone tell me how to dissolve or remove this foam (without damaging the PVC or insulation on the wire) so I can pull the other wire through?

I am curious why you want to run a ground wire in the conduit with the cable. i don't think you can count the new wire as being the EGC for the URD cable since it is not part of that cable assembly.

 

[kwired]

I am curious why you want to run a ground wire in the conduit with the cable. i don't think you can count the new wire as being the EGC for the URD cable since it is not part of that cable assembly.

Where do you find URD in chapter 3 wiring methods? It is nothing more than USE conductors twisted together. Problem one may have is the conductors that are twisted together will act like one conductor to a certain extent and the addition of another conductor may not fit in the cross sectional area of the raceway all that well - especially at bends.

 

[JDB3]

It is a common way to do a 4 wire feed around here. There have been no problems that I have heard of.:happysad:

 

[kwired]

It is a common way to do a 4 wire feed around here. There have been no problems that I have heard of.:happysad:

Just don't size the raceway too tight. OP has 1-1/2 when 1-1/4 likely would work -without triplexed conductors anyway.

You can get URD "quadplexed" - conductors are even marked for phases for using with three phase.

Main thing you have to watch out for is that they have a dual rating and not just USE if you are entering a building.

 

[drbond24]

Acetone would probably dissolve the foam.

I don't think a spritz of acetone would damage the PVC insulation any, either. After all, the stuff you use to clean PVC pipe before you glue it together is acetone (or has acetone in it, anyway). Prolonged contact with acetone would probably damage the insulation, but if you use it sparingly it evaporates so quickly that I can't imagine you'd have a problem.

This is just an opinion, though. I'm not a chemist.

I'd do it at my house, but some of the things I'd do at my house would probably make most of you shriek in terror, so I'm not necessarily recommending that anyone emulate me. hmy: Just recently I was removing a light fixture from my garage and decided to isolate it by turning off the light switch. As I squeezed down on the wire cutters, the spark by my hand and the sound of the breaker tripping across the room told me that whoever put in the fixture switched the neutral instead of the hot. That's why I'm an engineer; I'm not smart enough to be an electrician.

 

[K8MHZ]

Acetone would probably dissolve the foam.

I don't think a spritz of acetone would damage the PVC insulation any, either. After all, the stuff you use to clean PVC pipe before you glue it together is acetone (or has acetone in it, anyway). Prolonged contact with acetone would probably damage the insulation, but if you use it sparingly it evaporates so quickly that I can't imagine you'd have a problem.

This is just an opinion, though. I'm not a chemist.

I'd do it at my house, but some of the things I'd do at my house would probably make most of you shriek in terror, so I'm not necessarily recommending that anyone emulate me. hmy: Just recently I was removing a light fixture from my garage and decided to isolate it by turning off the light switch. As I squeezed down on the wire cutters, the spark by my hand and the sound of the breaker tripping across the room told me that whoever put in the fixture switched the neutral instead of the hot. That's why I'm an engineer; I'm not smart enough to be an electrician.

If the foam is the same as 'Great Stuff', acetone won't touch it. I got some on me and it dried. BAD!!!!! There is no known chemical that will dissove the foam once it dries that won't eat through skin. That info is from the company. So, that pretty much means you would have to experiment with acids or strong bases and they can be not just harmful, but deadly.

 

[texie]

If the foam is the same as 'Great Stuff', acetone won't touch it. I got some on me and it dried. BAD!!!!! There is no known chemical that will dissove the foam once it dries that won't eat through skin. That info is from the company. So, that pretty much means you would have to experiment with acids or strong bases and they can be not just harmful, but deadly.

LOL. I once got that stuff all over my hands. Learned a lesson-don't let that happen again! That stuff is really nasty to get off.

 

[Hv&Lv]

If the foam is the same as 'Great Stuff', acetone won't touch it. I got some on me and it dried. BAD!!!!! There is no known chemical that will dissove the foam once it dries that won't eat through skin. That info is from the company. So, that pretty much means you would have to experiment with acids or strong bases and they can be not just harmful, but deadly.

I wish I had read this a couple of weeks ago. I have learned to wear long sleeves and gloves with this stuff. Hated smearing it on me... Another tip: don't think you can let it dry and just pull it off your skin instead of wiping it off before it dries. (we won't get into how I found this out...) :ashamed1::dunce:

 

[K8MHZ]

Another tip: You can let it dry and just pull off your skin instead of wiping it off before it dries. (we won't get into how I found this out...) :ashamed1::dunce:

Fixed that for ya!

I actually suffered abrasions getting it off my skin about a year ago. I wear full PPE when I use it now.

 

[Ken9876]

Was wiring a new home years ago and the homeowners kid was a plumbing apprentice. Well he was setting a whirlpool tub in the master bath and decided that due to the size of the tub it would be a good idea to rig a tube to the spray foam can with a stick attached so he could reach the back side of the tub. He was lying on the floor with the can next to his face and the tub blew off, he had that stuff all over his face and arms. Then due to the burning it causes he resorted to using gas to try and remove it.

 

[kwired]

Was wiring a new home years ago and the homeowners kid was a plumbing apprentice. Well he was setting a whirlpool tub in the master bath and decided that due to the size of the tub it would be a good idea to rig a tube to the spray foam can with a stick attached so he could reach the back side of the tub. He was lying on the floor with the can next to his face and the tub blew off, he had that stuff all over his face and arms. Then due to the burning it causes he resorted to using gas to try and remove it.

If he was using spray foam to help support the tub - bad idea. It can build enough pressure to actually lift the tub. Low pressure foam will not lift the tub, will not support it very well either as it will compress easily, it is only good for use as thermal insulation. Use concrete to support the tub.

 

[Ken9876]

If he was using spray foam to help support the tub - bad idea. It can build enough pressure to actually lift the tub. Low pressure foam will not lift the tub, will not support it very well either as it will compress easily, it is only good for use as thermal insulation. Use concrete to support the tub.

I didn't feel anything he was doing was a good idea, I always have seen thin set or concrete used

 

[tom baker]

You didn't say how long the sleeve was with the foam. Could you use a 1/4" or 3/8" steel rod to poke a hole thru it?

 

[renosteinke]

If I could dissolve spray foam, I'd have save a lot of clothing. The stuff bonds almost too well.

Bonds. As in James Bond.

Some places where foam is featured:
Foam is a Forever.
FoamFinger.
You only Foam Once.
On Her Magesty's Maintenance Staff.
Foam Another Day
One Can is Not Enough
GoldenFoam