Weller / ungar 921ZX soldering iron

[stiffman]

So, I scored this soldering iron from a box of junk at work some time ago, and I managed to find a single good tip with it, but eventually the tip will wear out, and new tips for it are very hard to find for this soldering iron.

I guess my question is, is there any likely possibility to retrofitting this iron with a different iron in the future?

I think there is actually another one of these sitting at work without a tip as well. but without an easy way to get a new tip, its not worth doing anything with.

[Muttley Snickers]

I have exactly the same iron sitting on the bench and it was purchased from Radio Parts Group in Melbourne Australia many years ago and the last time I looked they still had tips for them, otherwise Cooper Tools would also be another place to try as they were the importer for this region, I have no idea where you are.

Other brands of tips may also fit this model and other people will know more than me, I can have a search around in the morning even for my own benefit as I only have a few tips for these myself, not that I need them really as I think we have only used a couple in a dozen years or so with regular use. I cant post links from this device but can come back tomorrow and add a few if you like.

This is and has always been my favourite soldering iron and I do have a quite few, also I've never needed to run this iron over 350 degrees C and if I needed to work on a really big component then I would pull out one of our Weller Pyropens, just ideal for big stuff or tinning thick cables.

Muttley

[stiffman]

I couldn't find anythign on RPG's website, or any of the others. It doesn't mean they aren't there, i may just be useless at finding them.
Best I can find area a few tips on the US ebay, but with postage they look pretty pricey, and mostly very pointy looking tips, which aren't nice to work with in my experience.

I haven't seen anything from other brands that look like they might fit, the tips on these irons have a long half round length at the back, for contact to the heating element i guess.

I don't use it a terrible amount, so the tip i have will hopefully last a long time. I'd just be reassured if I had some spares for down the line, as I can only imagine the parts aren't going to get easier. Plus, I'd be tempted to rescue the other iron if I could get a tip for it easily, or replace the business end with something compatible.

[Muttley Snickers]

Yes, I also started to do a search and they are not in the catalogue or online but that really means nothing when it come to Radio Parts, half the time they don't know what they have nor what it is really worth. Seems that most sites are indicating discontinued item so with that I will ring around and see how we go, also the 9054 looks like an adapter to convert to more common screw in tips which could come in handy.

Another member was also asking about the iron or tips recently on the forum.
https://www.eevblog.com/forum/repair/weller-921z-soldering-station/msg645628/#msg645628

I photographed page six of the original manual for a bit of a reference.

 

[Muttley Snickers]

Not having much luck I'm afraid so the only solutions that come to mind are to modify some currently available similar tips by surface grinding or light milling part of the shaft to fit the Weller 921ZX or making some fresh ones out of brass on the lathe and then cutting them down with a slitting saw on the mill.

I will get out the tips we have at hand and do some measurements so as to draw up a sheet for machining, the tips pictured below are from Rhino Tools in Sydney but at this point I do not know what their shaft diameter or dimensions are or whether or not they are hollow which we do not want.

Rhino Tools
http://www.rhinotools.com.au/

Similar tips below

[nanofrog]

They've been discontinued for awhile, so eBay will be your best bet (if not only source at this point):

• 9010
• 9012
• 9015
• 9016UG
• 9017
• 9050

The adapter mentioned above is the 9054 = 1/8" tip adapter for UTC series. Do keep in mind, that Weller's current 1/8" threaded tips have a very limited selection in sizes & profiles, and the quality as of late really sucks based on others that have used them recently (1/8" threaded tips = those for the SP23 & SP25).

So you might want to start looking for a replacement station instead, as 9xxx series tip stock is very limited and starting to get expensive (i.e. one seller wants ~$16.50 for one tip shipped). Or make your own, if you've the tooling.

[stiffman]

Cheers guys,

Yea, I had found a few on the US ebay, but they are pretty pricey once you include delivery.

I guess I'll probably just use it until the tip is useless, then look at replacing the whole thing.

I was hoping that someone out there had come across the same thing and had a solution like swapping the iron for another with more common tips, but that's a bit of wishful thinking.
At the end of the day, this thing didn't cost me anything, and doesn't get used a heck of a lot.

[KL27x]

I was hoping that someone out there had come across the same thing and had a solution like swapping the iron for another with more common tips, but that's a bit of wishful thinking.

Can be done, if you have the time. I have done essentially this. A replacement iron is just a heater and a sensor. I have adapted a desoldering iron to run off a different brand soldering station. I have also built a custom station for a particular iron/wand.

You have to find a replacement iron/wand that is designed for the same voltage and power rating. 

Then you have to find the right connector (or do some soldering after hacking off the original). Pretty easy. 2 connections for the heater, 2 for the sensor, and often 1 for the grounding (which I prefer to leave off!!!)

Then there comes the trickier issue of the sensor.  If you're lucky the new iron will work fine, as is. Otherwise you will have to tune it. There are generally a couple of opamps in the station that are conditioning the sensor signal, you can fudge with the opamp resistors until you get the new iron operating, sufficiently. If the iron doesn't get hot enough, decrease the gain, and vice versa. It may not be perfectly calibrated all the way across the scale, but with the knob/slider, you will still get where you want, just fine.

But I'll tell you what. There's nothing special about your soldering station. All the mojo is in the construction of the iron, between the heater, sensor, and tip, tip shapes/quality, and handle/stand ergos.

[w9gb]

The Ungar 921ZX was a popular soldering station, introduced in the late 1980s.
Ungar had a preference for ceramic heaters (like Hakko of Japan), but Weller had a long history of resistive heaters.

In 1996, Weller (Apex, North Carolina based, owned by Cooper Tools of Houston, TX) bought out Ungar (California based). Weller continued to produce this Ungar model, offered tips, and repair parts until 2002.
==
At the end of 2002, Weller made sweeping changes to comply with RoHS regulations (lead removal).
They closed their USA production facilities in North & South Carolina (some were using Carl Weller’s original Easton, PA tooling & molds).
A New production facility, with new Non-Lead tooling & molds, was built in Mexico.
Popular models (TCP-series, heat guns, soldering guns) were migrated to No-Lead ;
while other models (EC-series, many Ungar) were discontinued.
—
Many new Weller models (RoHS compliant) were introduced stating in 2003. 
Some, like the Silver Series (WSD) used the earlier solder tips (ET-series from EC-series).
—
Many smaller electric/electronics distributors have been sources for parts and tips over the last 20 years.

greg