Who's Owns and Uses a Resistance Soldering Unit???

Bob, sent an email contact to a man, very knowledgeable on the subject. His name is Ken, sent to your email listed in your profile.

Ray

Bob, I think the only folks who can answer this are the ones who started with a lower wattage unit then had to get a higher rated one when the first one wasn't up to the job. I have a homebuilt one with a 500 watt commercial transformer. Even though it is high watts its not ideal for this task as the max voltage is 16. That means max current is just over 30. A 250 watt unit with a 6 volt transformer will output more current at 40 and its really the current that does the work.

There are forum members who have used Lionel 1033s and some surprisingly large items though I don't think you could solder a sand dome to an O scale boiler with it.

Pete

If you’ve never used a resistance soldering set before, all anyone should tell you is practice & practice....there’s no set wattage as every work piece is different from one to the next. Soldering a entire sand dome is different than soldering the lids on a sand dome,......resistance units are also different from one to the next, and the time to cycle is going to vary,......thickness of the part, thickness of the area to mount the part, all of this is factors to consider,.....and anybody that tells you “this” is the wattage you must use, is full of themselves to swollen head syndrome,...practice with scrap, and learn your equipment, that’s the best advice anybody should give you.....good luck & enjoy it, ....once you’ve figured out what works, and what doesn’t, it’s very rewarding,.....I didn’t master my outfit right out the gate, and practical hands on experience weighs a whole lot more than “ here’s what you have to do”

Pat

Bob  Read  harmonyard 's post . Very very good advice. Like he said every machine and every soldering job is different.   As you practice you'll get better at just knowing where to set the wattage.

You may even burn your finger once in awhile { I still do sometimes }

The resistance soldering unit is a great tool . Well worth the effort and the practice time

Practice , have some fun  and keep on modeling

Franky-Ogee

I have 3 of them.  2 small units and one of the larger ones.  The small ones work for small things ok, the biggest issue is that you normally start off guessing at the power too low and have to fiddle with it till you get what you want.  I am sure that the more often you use them, the better you are going to be at knowing where to set the current on each particular task.  The larger units, well, you can vaporize some or all of a brass casting pretty quickly!  And if you are not real careful, the spark you will create can do a lot of damage.  Frankly, the way I would attach a dome to a boiler would be to silver solder a brass bolt to the inside of the dome and then drill a hole in the boiler and use a nut to hold the dome to the boiler.  Then you can fairly easily soft solder the gap between the two, I'd probably use a pencil flame torch to do that...

Here's the most important fact you need to know. You can't buy skill (unless you hire someone to do it for you). Whatever type of soldering you do you're going to have to practice. The other fact I can give you is that solder flows toward the source of heat. A good illustration of this is soldering copper pipe. If you touch a piece of solder to one side of the pipe and apply the flame of your torch 180 degrees opposite, the solder will melt and flow around the pipe toward the flame. It applies the same way in smaller situations. If you do it that way, you'll never have a "cold" solder joint.

Good Luck,

Simon

Don’t hit the foot switch until you have positive contact with what you are slodering.

@LLKJR posted:

Don’t hit the foot switch until you have positive contact with what you are slodering.

Indeed!

Our club has two of the commercial units, which are needed when working with Atlas track. Definitely practice and practice some more so your solder looks smooth and not lumpy or chicken scratch dots where it arced before you got a good connection with pieces soldering.

Do you have a verable heat one. If not you can conect it to a varack and be able to adjust the the heat you need.