We're getting into fine details here but for a 1/4" steel welding rod the resistance could be 20x to 200x that of 1/2" dia. copper wire. I shouldn't have said "dead short" in any case.
A superconducting water pipe would not thaw ice at any current level because no power [I squared x R] would be dissipated in the pipe.
Why all the talk about welding machines when Ridgid makes a pipe thawer already?
For fast thawing of frozen metal pipes 1/2" through 1 1/2" (12-36mm). The KT-190 and KT-200 Pipe Thawing Units provide continuous heating to quickly thaw 1/2" to 1 1/2" frozen metal pipes. With these lightweight, versatile units, there is no need to dig or tear apart walls. Simply attach the clamps to the metal pipe on each side of the frozen section and the pipe is thawed within minutes.
With 120 V and 15 A input it only takes something less than 1800 W, maybe 30 W per foot, to thaw enough of a gallon of ice in a pipe for water to flow again.
Probably a welding machine does it 4x quicker but the problems with that method have already been discussed.
A welder would not normally "stick" an electrode and leave it that way. Even if he did, the electrode would overheat and burn up long before the machine or cables.......
Originally Posted by hj
I am not a plumber....but I am a Lincoln and Miller certified welder repair tech........and I know more than a little about welders....been doing this work for close to 20 years now.....
Those Pipe Thawing machines sell for around $800.......They don't list the full specs so I have to guess.......they are basically a high amp battery charger..... a fairly low DC voltage output and something low enough that someone operating it is not in danger of being shocked.......
Welding machines normally have around 80 Open Circuit Volts and that can be AC or DC.......that is enough to give you a good little sting if you get across the two output studs......Once in awhile I get stung myslef and I work on them all the time......
Now the High Frequency ouptut on many tig welders and plasma cutters is a whole 'nother deal altogether........3000-3600 volts at 1 million HZ......Not enough current to kill you but it really stings when your working on a steel bench and the HF gets on you as you go to start a weld.....
Putting 30 of these
Originally Posted by Rich B
in parallel is cheaper.
Or, make your own
I'd say the thaw machine has an AC output because rectifiers cost money and the pipe won't know the difference.
I haven't run the numbers but I think that most of the power these things put out goes into heating the connecting cables and there's no way around this. The cable resistance is higher than the pipe resistance but you have to have long cables for long pipes.
Since the pitch says "fast thawing" I asked Ridgid, How fast? Still waitin' on that answer.
I will say that the women on their calendars look, well, wholesome. . .:D
Well, it is 19F here, and suprise! I turned on my kitchen faucet and heard that all too familiar sound of my pipes starting to freeze! So... I took action. Doors open, faucet dripping, all throughout the house.
The fun has begun. :( I guess I better warm up that blow dryer.
I have a 2 family house. I rented one side for about 35 years. The rental side has been vacant for over 2 years now and that is so I can do some rennovations. It is a duplex style home and each side is a mirror of the other.
I have kept the heat at a minimum on the vacant side during the winter. One cold winter morning (I think it was 12 overnight) I had NO cold water in my upstairs bathroom.....I knew immediately what it must be......I followed the pipes to an area where they were run right next to an outside wall in the basement......YUP....one elbow was getting hit with a cold air stream from outside.......I thawed it and than sealed up the air leak with foam and insulation.......I used a 500w quartz light and directed the heat to the pipe........Luckily it thawed without damage to the pipe.......
In the spring I moved all 3 copper pipes that were run in that area in further and up to the second floor........I also insulated them anywhere I could.
They were the supllies for the 2 upstairs bathrooms......1, 3/4" cold and 2, 1/2" hots.......The original "plumber" ran them right next to the oustisde uninsulated wall........With the heat always turned up on both sides it never caused a freezup in the past.....
I now have some heat from a duct sending warm air directly in the area of those pipes and sealed up any leaks I could find around the sill area. All you need to do is use you hand on a cold day and feel for a cold draft.......The foam insulation works great.....
P.S. I do believe the Pipe Thawing machines are DC as that would explain the high price.....a rectifier, just like in a battery charger or a welder....
Thawing machine, 1800 W
hair dryer, 1000 W
lamp, 500 W
but the last two waste a lot of the heat they throw off.
Oh, well. . .
I don't guess anybody makes a machine that forces superheated steam into frozen pipes? If so it's probably only for commercial use.
If Ridgid answers me I'll ask them about the DC output.
I guess for small blockages you could use a car battery for 30 second intervals but it might need a long rest between attempts and you would need to limit the current to 200 A or so with your connecting cables.
If the Rigid machine is AC output.......$800 seems like a heck of a lot of money for a box with a couple switches/ a gauge/ a couple other components and a transformer and some jumper cables and clamps.....
Those things pay for themselves after about two jobs.
I don't have one though.
Years ago I worked at a shop that had them. Too much power and you can melt the solder joints is what I was told.
To me, that would be worse then waiting for the pipe to thaw.
Can you imagine having to find a bad solder joint underground with snow on the ground?
And watch the insulating crew carefully. On one house I found they pushed all the pex up against the exterior walls wherever they could. It would have been a disaster.
It's that time of year to revive this thread.
At the moment we have freezing rain in Seattle. I went out to my car last night to grab a flashlight when the lights flickered inside, and all the doors were frozen shut. It looks like I will need to take a hair dryer to it.
quote; will say that the women on their calendars look, well, wholesome. . .:D
To me, all the heads look like they have been Photoshopped onto bodies from previous calendars.
A couple of years ago it got down to about 10 degrees and my DW supply line froze. It is under the DW after coming from the sink cabinet and was completely closed in. I removed the baseboard and got overly anxious about thawing the line with a heat gun. Made the mistake of leaving the gun blowing for a few minutes while I did something else. Toasted the line. Not a disaster, just a "learning experience". I left the baseboard cover off and have had no more problems. Also learned the hard way about taking hoses off my frost free valves. I usually learn pretty well after experiences after this, so I have few repeat performances. Best way the thaw pipe? Don't let them freeze.
Best way to keep them from freezing is not to wrap them in pipe insulation... contrary to popular belief.
You want insulation on the cold side of the pipe, and warm air reaching the pipe itself.
Insulation doesn't create heat. For example you can insulate a house till the cows come home, but you'd still need a furnace to heat it.