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View Full Version : Semi O/T but a shop tool



radkins
11-08-2012, 06:21 AM
I have three nonworking soldering guns, a Craftsman and two Wellers, and since they have the same problem I am assuming it must be a common fault. Basically when I pull the trigger switch they either work or don't (most of the time don't) but only work for a few seconds when they do work. I can shake these things or sometimes simply turn them over and they will again work but only for a few seconds, rarely do they get hot enough to use. Obviously shaking or repositioning having an effect would seem to indicate a loose part or connection and I assume this to be the problem but I have looked at everything inside these things and can not find anything loose. The tip ends are clean and tight under the nuts and I can't find anything loose or corroded inside, any suggestions on what I need to look for?

chorne27983
11-08-2012, 07:30 AM
I have three nonworking soldering guns, a Craftsman and two Wellers, and since they have the same problem I am assuming it must be a common fault. Basically when I pull the trigger switch they either work or don't (most of the time don't) but only work for a few seconds when they do work. I can shake these things or sometimes simply turn them over and they will again work but only for a few seconds, rarely do they get hot enough to use. Obviously shaking or repositioning having an effect would seem to indicate a loose part or connection and I assume this to be the problem but I have looked at everything inside these things and can not find anything loose. The tip ends are clean and tight under the nuts and I can't find anything loose or corroded inside, any suggestions on what I need to look for?
Replace the cords.

radkins
11-08-2012, 07:54 AM
They're ok, that was my first thought also.

vpt
11-08-2012, 08:01 AM
Did you pull the switch apart? Also on the cords, the outside casing can look good and a wire can be broke inside right where it meets the gun body.

Personally I only use the solder guns without the trigger.

Rustybolt
11-08-2012, 09:16 AM
Probably a thermal resistor(?) that's gone bad. We get them a lot on our heat guns. Start poking around with your multi-tester and you'll find it.

lynnl
11-08-2012, 09:43 AM
Years ago,with two teenage daughters and a wife, it seemed like I was replacing a thermal resistor in a hair blow dryer on a regular basis. I didn't do any testing; a friend told me what to look for and how to fix them.

How would you test or find an intermittent problem like that? .... keep probes on while shaking, and watch for an infinite spike in resistance? Or would it more likely have infinite resistance UNTIL shaken?

bborr01
11-08-2012, 09:46 AM
My weller soldering gun is about 30 years old and the only problem I have ever had with it was the electrical cord went bad wherei it enters the grip.

Brian

A.K. Boomer
11-08-2012, 10:51 AM
I can't believe how finicky the tip ends are, mine never seem to work till I give the tip a sideways "bump" against the vise or something - then I hear that tell tale noise of the windings catching resistance and its good to go...

mf205i
11-08-2012, 02:44 PM
Loosen and then retighten the nuts that hold the replaceable tips. They always get that way after awhile.
Mike

PTSideshow
11-08-2012, 02:59 PM
Retighten the tip screws/nuts I was told that it has to do with the oxidation layer that builds up between uses. I have no idea if true just that when I use one If I don't do that I have problems.

bborr01
11-08-2012, 03:20 PM
Loosen and then retighten the nuts that hold the replaceable tips. They always get that way after awhile.
Mike

Yup. Kind of assumed that had been tried already.

Brian

ogre
11-08-2012, 04:54 PM
+1 on cleaning or retightening the tips screws.I have had mine mysteriously not work and it had something to do with the tip holders screws. If i loosen and retighten they always work. Not an expert and im sure theres a reason for this but it works for me.

winchman
11-08-2012, 06:39 PM
Every problem I've had with a Weller soldering iron was solved by tightening the nuts that hold the tip.

mikem
11-08-2012, 07:12 PM
I have about a dozen of them and they all get that same problem. They are basically a big transformer where the 120V is lowered way down to get enough amps to get the tip hot. Evidently the lower voltage is not enough to overcome the resistance of the oxidation of the tips after they have been used a few times.

I think that people just toss them when they don't work--I see them at auctions and they sell for a few dollars. They are $30 or so new.

michigan doug
11-08-2012, 08:13 PM
Same problem, same solution as mentioned. but I have to remove the tip, sand or scrape the oxide off and then re-insert and re-tighten the nuts. Boom, just like new.

doug

darryl
11-08-2012, 10:02 PM
We used those things a lot where I once worked. The problems I found were bad switches (not often) broken or loose wires on the switches (more often) and poor contact at the tips (most often).

They typically run the tips between 1/3 volt and 2/3 volt, depending on the power rating. With an amp draw through the tip of 100 to 200, there's no room for even a slightly oxidized connection. But the tip connections aren't usually the cause of the gun cutting out completely. If there's a light on it, the light will light if the primary is being energized, and if the light seems brighter than normal, that means that the tip connections are bad. If the light doesn't come on at all, or cuts in and out fully, that means you have an intermittent circuit in the primary.

Bill736
11-08-2012, 11:33 PM
A very familiar problem ! I also have two or three Wellers and a Craftsman . And, I also frequently notice that the Wellers are erratic in operation. Sometimes tightening the tip nuts works. Other times, it seems like the position of the gun makes it come on and off. Even so, I've used the Wellers for decades , and the tips seem to solder better than the Craftsman tips . I don't know why, although I've always suspected that the tip material is slightly better on the Wellers. One of these days, I'm going to figure out what's going on with the Wellers. Maybe.

atomarc
11-08-2012, 11:59 PM
Retighten the tip screws/nuts I was told that it has to do with the oxidation layer that builds up between uses. I have no idea if true just that when I use one If I don't do that I have problems.

I think this is the ticket. Take the nuts off and scrape the oxidation off and polish the little ends where the nuts make contact with the two 'thingys'...it'll work then! If it doesn't, use the cord as a sling and fling them against the wall and break them into a thousand pieces...that's what I did before I learned it was just oxidation..and bought another soldering iron.

Stuart