Weller PU-3D

[Bushbaby]

I bought a Weller PU 3D recently as a 'treat' for my workshop (I've a PU-2D in the garage which is excellent). I have been using the 3D a lot over the last few days working on a DSO138 oscilloscope kit. I've noticed that it doesn't appear to hold temp, get as hot as I would expect. The tip is very 'blued' suggesting that perhaps is been over heated some time in the past. Does this suggest a problem with the magnastat? New tip??
An advice will be most welcome.

Regards

Rob

[Refugee]

It must have been left on with little or no solder on the tip. You will need to tin it fully again, best with a tip tinning/cleaning pot or as a bodge in a pool of molten solder with plenty of flux such as freshly melted cored solder.

[Bushbaby]

Many thanks for the reply and yes I do have a tinning pot (doh - I should have thought of that).
i shall let you know how I get on tomorrow.

BR

Rob

[Murphyv310]

Never used a tinning pot.
A wet sponge or better still a damp cotton rag and then tin the bit with decent rosin cored solder. Told this as an apprentice and have rarely replaced any bits. Good soldering practice will make the bit last a long time. Never leave a soldering iron on if not needed.

[Bushbaby]

Hi Trevor
Thanks for the advice. What I forgot to add that I have been using 0.7mm Jinhu Chinese leaded solder for working on the DSO138 oscilloscope. This is not the greatest of solder by any stretch of the imagination and is very difficult to work with. The only solder that I had available is 1.5mm multicore leaded solder which is a bit too thick for the fine soldering that I have been undertaking. I received a reel of old German Stannol solder today (0.8mm) that I picked up from ebay on very speedy postage - what a defference to use. However, I did take your advice and cleaned the bit with damp cotton rag over and over, each time retinning with the Stannol solder. The Weller is back in full working use again.

Best Regards

Rob

[Refugee]

I have been using mine today replacing relays on an unleaded board from a gas boiler.
I just loaded the joint with real mulitcore branded solder and it sicked off easily.
The repaired board worked again first time with shiny new relays.

[Bushbaby]

I do think I have a problem and think its the magnstat. I'm finding that it will work for a while and then get period where it will not heat up. I've had a look within the iron and the spring unit appears very rusty?? Does this suggest a new element is needed (££££) or is there any means that I can bring it back to full working use again. Its a superb iron when it works.

Regards

Rob

[Refugee]

Those springs can be cleaned up. You need to fill the stat with water and work it gently by hand and then purge the water out with pure alcohol and then dry it with gentle to moderate heat for a few hours.
Clean the contacts and make sure the plastic cap goes on nice and square.
Stats are more expensive than elements.

[Bushbaby]

I've just been using it and I cant say that I can't hear the click as with my PU-2D of the maganetic switch cutting in and out to control the temp. It is constant engaged it will explain the tip overheating but its not to the point of getting red hot which I have read from other users. The iron seems to 'work' when the nut is not overtight to the thread.

Regards

[Refugee]

That will be due to the plastic cap on the stat being skewed.
The spring inside the stat can't be dismantled hence the washing procedure to get any dust out.
The plastic cap is the first port of call.
Holding the stat with the contacts down and the cap removed over a bit of paper and gently tapping it will allow you to see the dust from inside that causes it to stick.
If it is run overheated for too long the stat will lock solid and be a write off.