[slartibartfast01]

Depends on the type of solder you use. I use a multicore made by Silverline, 60% tin, 40% lead and the temperature I tend to use is between 250 and 300c. And of course it depends on what you are soldering, and how much heat-shunt there is, for example when I am soldering my electric guitar switches etc. I increase the temperture slightly. But for cameras, I stick to the lower temperature as a precaution, or perhaps I should say markings since I do not know EXACTLY what the markings actually give in reality - this is a cheap iron and I doubt they are that accurate. I'm guided by how the solder flows, and how much, or rather little, smoke there is from the built-in flux.

Is that temperature OK to desolder the presumably lead free solder on the original solenoid?
I ordered my replacement yesterday and my heart sank a little this morning when I realised DPD was the courier. I hope the package is too large to go through a letterbox as DPD almost always deliver to the wrong address.

[martin42mm]

I always start with the same temperature as I intend to use to resolder , and it only tends to be a higher temperture needed where battery contacts are the items to be desoldered since they are often soldered to steel, and a higher melting-point solder is used initially. With these solenoids I found the 250/300C worked fine with minimal tip contact time needed-literally a touch and the wires desoldered, which is what you want, minimal heat in the solenoid.

[slartibartfast01]

I always start with the same temperature as I intend to use to resolder , and it only tends to be a higher temperture needed where battery contacts are the items to be desoldered since they are often soldered to steel, and a higher melting-point solder is used initially. With these solenoids I found the 250/300C worked fine with minimal tip contact time needed-literally a touch and the wires desoldered, which is what you want, minimal heat in the solenoid.

The Weller irons we used for donkeys years probably had No 6 tips (316C) but the newer Chinese ones seemed to be set to 350C as default, probably for lead free solder. I'll use the same as you.
To avoid DPD problems I've diverted it to the local Post Office

[martin42mm]

The Weller irons we used for donkeys years probably had No 6 tips (316C) but the newer Chinese ones seemed to be set to 350C as default, probably for lead free solder. I'll use the same as you.
To avoid DPD problems I've diverted it to the local Post Office

Yes, the cheap Chinese iron I referenced in an earlier email, despite its low costs, actually has a variable heat control, which is why I can get down to below 300c for my camera soldering.

[photogem]

Every solder has its own best temperatur so one cannot just give a unique answer!
Variable temperature-control on a Mains AC driven soldering-iron is prone to live short.
A 24V soldering-station using a proper transformer such as Weller does lasts much longer.
Cheap China soldering stations don't use transformers but cheaper solutions, such as the T12
station. No good, partly even dangerous.

A 120/240V Ersa soldering iron with 15W or 20W does the job fine and one doesn't even

need to think about temperatures.
Often I use just quickly my Ersa Multitip and it never let me down.

As with Li-Ion batteries: Quality has its price, but ... for once a super cheap solution is perfectly o.k.,
even a USB soldering-needle!


Also I think I made it very clear in the tutorial:
Don't use lead-free solder or worse, lead-free silver solder!


Unleaded solder can be still found and is the best to use.


But please remember:
This is the K30/50/500 solenoid tutorial thread!
So please bring such discussions into your own thread for example in the DIY section.
Otherwise new-comers have to struggle through a jungle of posts.

Or do it directly via PM.

[slartibartfast01]

Every solder has its own best temperatur so one cannot just give a unique answer!
Variable temperature-control on a Mains AC driven soldering-iron is prone to live short.
A 24V soldering-station using a proper transformer such as Weller does lasts much longer.

Also I think I made it very clear in the tutorial:
Don't use lead-free solder or worse, lead-free silver solder!


Unleaded solder can be still found and is the best to use.


But please remember:
This is the K30/50/500 solenoid tutorial thread!
So please bring such discussions into your own thread for example in the DIY section.
Otherwise new-comers have to struggle through a jungle of posts.

Or do it directly via PM.

The question was directly related to the task of changing the solenoid in a K50 and I couldn't see any recommendations apart from using 60/40 leaded solder.
I am hoping a cheap Chinese variable temperature iron will last long enough to do the job.

[martin42mm]

The question was directly related to the task of changing the solenoid in a K50 and I couldn't see any recommendations apart from using 60/40 leaded solder.
I am hoping a cheap Chinese variable temperature iron will last long enough to do the job.

As I said in an earlier post, my variable temperature mains-powered Chinese soldering iron is 8 years old, and is used regularly at least once or twice a week for more than an hour at a time. Still working fine-and not expensive to replace as and when it does go.

[photogem]

The question was directly related to the task of changing the solenoid in a K50 and I couldn't see any recommendations apart from using 60/40 leaded solder.
I am hoping a cheap Chinese variable temperature iron will last long enough to do the job.

As so often one can't control everything.

Just buy it ... of course it will last long enough to do that tiny little job of soldering 2 wires.

As you wrote that you used "Weller soldering irons" for years, you have the experience.
So just do it.

Anyway, in all my (solenoid-) tutorials I wrote that a pencil-tip is the most important.
With that you don't have to worry about 316 or 350 degrees.

At least 50% who changed the solenoid on their Pentax soldered for the first time in their life and managed very well.

[slartibartfast01]

Is there a recommended method to lift the rubber covering the screws?

[photogem]

A tiny flat-head screwdriver will do it.

[The Jannie]

I use a fingernail . . . . A point which hasn't been mentioned - I don't think - is that on my K30 the double sided tape which holds the handgrip/shutter release end has stuck down again happily after being lifted. On the left side - with its socket cutaway - the diecut dst came off in random pieces. I was lucky in that I keep a roll of dst and used it to replace the original.

[photogem]

I use a fingernail . . . .

My fingernails usually would be too short for that
But even if they would be long enough:
- a) I wouldn't want to risk that the double-sided-tape could touch the skin of my fingers (no matter how well cleaned)
- b) you could move the double-sided-tape, nails usually are not that precise and fine as a tiny flathead screwdriver.

A point which hasn't been mentioned - I don't think - is that on my K30 the double sided tape which holds the handgrip/shutter release end has stuck down again happily after being lifted.


On the left side - with its socket cutaway - the diecut dst came off in random pieces. I was lucky in that I keep a roll of dst and used it to replace the original.

I never had that problem with any Pentax except when I had to replace the protective glass of an LCD. The double-sided-tape used there is very firm because it has to be WR as well.

[The Jannie]

nails usually are not that precise and fine as a tiny flathead screwdriver.

Yes, I agree, but being old and increasingly wobbly I avoid taking sharp objects near cosmetic areas!

[slartibartfast01]

Nobody mentioned the small black wire attached to a tab on the mount falling off. What a PITA that is.

[slartibartfast01]

As so often one can't control everything.

Just buy it ... of course it will last long enough to do that tiny little job of soldering 2 wires.

As you wrote that you used "Weller soldering irons" for years, you have the experience.
So just do it.

Anyway, in all my (solenoid-) tutorials I wrote that a pencil-tip is the most important.
With that you don't have to worry about 316 or 350 degrees.

At least 50% who changed the solenoid on their Pentax soldered for the first time in their life and managed very well.

Success. It took almost two hours but a lot of that was dealing with the black wire attached to the mount. The photo idea for the screws was spot on.