Freon/oil/concerns?

[Trip59]

Have a small repair job, bracket welded to a side tube on a condenser. The weld I can handle, but never having welded on air conditioning components, is there any concern with vapor/gas release from whatever residue is inside?

I was ASE AC certified, but that was back when the 134a change was just starting, never dealt with it at all myself. I know folks braze on systems that have had it, but what about TIG?

[todmorg]

Phosgene gas can be generated by heating some refrigerants, or exposing them to an open flame.

Do a google search, it's deadly stuff.

[Trip59]

Phosgene gas can be generated by heating some refrigerants, or exposing them to an open flame.

Do a google search, it's deadly stuff.

Indeed, I'm well aware of that, especially with the brake cleaner (though I believe that's the chlorinated ones, I don't heat either type, nor carb cleaner) Wasn't sure about refrigerants or the oils within their systems. The freon I'd assume would dissipate once it was pulled from the loop and open to atmosphere, but I am not familiar with 134a to know if there's any residue and if that residue or oil would outgas toxins.

I have a number of friends who work with AC, but brazing/silver soldering is different in two aspects... much lower temp than TIG, and no Ar to mix into the reaction.

[Gerry]

Indeed, I'm well aware of that, especially with the brake cleaner (though I believe that's the chlorinated ones, I don't heat either type, nor carb cleaner) Wasn't sure about refrigerants or the oils within their systems. The freon I'd assume would dissipate once it was pulled from the loop and open to atmosphere, but I am not familiar with 134a to know if there's any residue and if that residue or oil would outgas toxins.

I have a number of friends who work with AC, but brazing/silver soldering is different in two aspects... much lower temp than TIG, and no Ar to mix into the reaction.

They make a flush for a/c systems to remove the oil and stuff when the compressor fails, you could get a quart can of that and run thru it, BUT Read the can first. I'm not sure if it is flammable or not. Then purge it with air before welding.

[sw2x]

They make a flush for a/c systems to remove the oil and stuff when the compressor fails, you could get a quart can of that and run thru it, BUT Read the can first. I'm not sure if it is flammable or not. Then purge it with air before welding.

Do not! Under any circumstances flush/purge any refrigeration system with air. This will cause a chemical reaction and produce large amounts of phosgene gas which could explode when heated. I am by Trade a HVAC Technician.
USE NITROGEN.

If you feel a light burn in your lungs you are breathing in phosgene. I've had 15 ft flames shoot out of condensing units with accumulators that had not released all their refrigerant prior to trying to braze in a new compressor.

[everlastsupport]

Do not! Under any circumstances flush/purge any refrigeration system with air. This will cause a chemical reaction and produce large amounts of phosgene gas which could explode when heated. I am by Trade a HVAC Technician.
USE NITROGEN.

If you feel a light burn in your lungs you are breathing in phosgene. I've had 15 ft flames shoot out of condensing units with accumulators that had not released all their refrigerant prior to trying to braze in a new compressor.

Do you have any info on plasma , O/A or saw cutting on empty freon containers? Weird question, but for yard art.

[Gerry]

Do not! Under any circumstances flush/purge any refrigeration system with air. This will cause a chemical reaction and produce large amounts of phosgene gas which could explode when heated. I am by Trade a HVAC Technician.
USE NITROGEN.

If you feel a light burn in your lungs you are breathing in phosgene. I've had 15 ft flames shoot out of condensing units with accumulators that had not released all their refrigerant prior to trying to braze in a new compressor.

Yep the Pag/Ester oil is hard to get out of the system without a good chemical flush and a purge. Like welding an oil pan on a vehicle.
One thing missing is the OP didn't say what the condenser was used on or weather it was removed or still on the piece of equipment.
Nitrogen is used to purge the moisture laden air from the system after it has been open to the atmosphere and to pressure test the system for leaks.
Without more information, maybe a trip the the local ACE Hardware store for a good metal glue would be best.