[AndrewFischer]

Quote:

Originally Posted by pinkfloyd4ever /img/forum/go_quote.gif what exactly is the advantage of having an adjustable temp iron?

2nd opinion:


The main advantage is not that it is adjustable (not that that's a bad thing) but that it is regulated. These irons have larger heaters (over 40W) that cycle on and off at the set temp. What does that get you:

Iron heats up more quickly.
Iron does not get crazy hot when it is sitting in the stand. Unregulated irons get to 1000F.
Iron stays hot when soldering. Doesn't cool down as much as say a 25W iron would while soldering.

For most of the kind of work we do the right setting is around 700F. If you use the right tip for the job you rarely have to change the temperature. Mono disagrees with me on this.


Once you've used either the 936 or the WTCPT you will never go back. With the price of a used WTCPT or new 936 clone around $40 I see no reason to get an unregulated iron.

 

[tomb]

Quote:

Originally Posted by pinkfloyd4ever /img/forum/go_quote.gif what exactly is the advantage of having an adjustable temp iron? I mean, I know you want to keep the temp lower when soldering heat-sensitive parts such as ICs, but then why would you ever bother turning the heat back up if as long as it melts the solder? I've thought about a temp-adjustable station, but I don't want to have the added hassle of trying to figure out the right temp for every combination of solder/part/board

Good question. As some of these guys are saying, to "save" chips and to keep them from burning up - you want a temperature-controlled iron.

However, if you get a big board with a ground plane, you may find that you can apply the tip almost forever and never get the pad hot enough to melt the solder. Also, the ease of melting existing joints for parts removal (mistakes?) seems to be proportional to the temperature. You may want that lower temp when soldering a DAC chip, but removing a soldered on tube-socket or worse - the pins on a heat sink - requires much higher temps. Some of those nice Cardas RCA jacks can be impossible at lower temps, too.

 

[AndrewFischer]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif However, if you get a big board with a ground plane, you may find that you can apply the tip almost forever and never get the pad hot enough to melt the solder.

What is happening here is the ~40~50W heater in the iron isn't able to maintain a high enough temp. The sink is too large. Cranking up the thermostat increases the heat stored in the iron and you are able to melt the solder.

If possible use a larger tip a larger iron or more power. I've found the larger Weller TC-201 to be an advantage in this case. It holds more heat then the Hakko 907.

I used my 936 to assemble the Alien DAC. I used the Weller to solder the Vampire connectors. Anything bigger and it is time to break out the soldering gun.

Hakko does make a larger 908 Iron for the 936. You can get it as a spare part or with the 936-13. They also make a micro iron. This is good. If there was no WTCPT I'd likely have two irons for my 936 or maybe a Metcal. I prefer to adjust the size of the thermal reservoir or power rather then turn up the heat.

It is worth noting that the Metcal SP-200 tips come in 500F, 600F and 700F. Metcal recommends using 600F. Because of the better heater in the Metcal, you can use a lower tip temperature.

 

[pinkfloyd4ever]

mmk, so assuming I'm a broke college student (which I am) and still can't really afford even a used soldering station which hakko dash would you guys recommend, the 15, 20, or 25 watt? The Hakko website says their max temps, respectively, are 698, 788, and 842 degrees fairenheit, or 370, 420, and 450 celcius. I already have a crap ratshack 25w iron w/the the giant cattle-prod tip, which the ratshack site says has a max temp of 600-640 degrees F. Also, I don't really like the tip that comes with the Dash, which of these do you guys like? Obviously I'll be using it mostly with audio DIY, mostly amps, tho I'm planning on doing cotdt's mod on my soundcard, as well as replacing the f'd up headphone jack on the front of my comp, so some SMT work is definitely in my future.

ps. Andrew, where do you see used soldering stations for $40? Is the weller WTCPT not variable temp?

 

[Seaside]

Well... how do you know if you do not like the tip comes with hakko dash, when you don't even have it?

Anyway, hakko dash comes with tip N45X-T-B.
The tip is of very high quality, and is adequate for almost all general soldering. I soldered Alien DAC with that basic tip without a problem. If I can do it, you can do it too.

Some people may find it is hard to solder in tiny spot with basic tip.
Then they may need narrower tip like 45X-T-I. Some experienced people prefer cheasel tips for quick soldering at wide space.

 

[tomb]

Quote:

Originally Posted by AndrewFischer /img/forum/go_quote.gif What is happening here is the ~40~50W heater in the iron isn't able to maintain a high enough temp. The sink is too large. Cranking up the thermostat increases the heat stored in the iron and you are able to melt the solder. If possible use a larger tip a larger iron or more power. I've found the larger Weller TC-201 to be an advantage in this case. It holds more heat then the Hakko 907. I used my 936 to assemble the Alien DAC. I used the Weller to solder the Vampire connectors. Anything bigger and it is time to break out the soldering gun. Hakko does make a larger 908 Iron for the 936. You can get it as a spare part or with the 936-13. They also make a micro iron. This is good. If there was no WTCPT I'd likely have two irons for my 936 or maybe a Metcal. I prefer to adjust the size of the thermal reservoir or power rather then turn up the heat. It is worth noting that the Metcal SP-200 tips come in 500F, 600F and 700F. Metcal recommends using 600F. Because of the better heater in the Metcal, you can use a lower tip temperature.

Yes, I wasn't necessarily disagreeing with you, just suggesting an answer to the question posed about the value of adjustable temperature.

The fact is, the Hakko 936 doesn't always have the power supply or tip-temperature control to do what you suggest. You could end up heating the entire ground plane to the same temperature before you melted the solder joint. A large ground plane basically acts almost like an infinite sink. Thermal leverage is the issue in that case, and a higher temperature setting can overcome that with proper care.

I agree that a different tip might help, and certainly a specific-tip-temperature control would be best, but that doesn't exist in the basic Hakko 936 (neither does the larger power supply). Consequently, the temperature adjustment provides some usefulness without letting things get too far out of control.


P.S. Pinkfloydforever - I purchased the lowest wattage Hakko Dash. It gets much hotter than the normal setting I use with the 936. So, I think it's plenty hot for any PCB.

 

[AndrewFischer]

Quote:

Originally Posted by pinkfloyd4ever /img/forum/go_quote.gif ps. Andrew, where do you see used soldering stations for $40? Is the weller WTCPT not variable temp?

eBay all the time. None right now. Careful all the used ones listed now are missing parts. There were several decent ones at BIN $50 which I think is a bit high. I've seen working complete stations sell for less then $20. You will need a new tip and a new sponge, but those are cheap.

The WTCPT temperature is set by a ferromagntic sensor in the tip. Metcal uses a similar sensor. I assume they had to license Weller's patent. You can get tips set for 600, 700, 750, 800 and 900F. Weller makes tips for other tempratures as a special order and sometimes these show up on eBay.

How the sensor works is explained in the user's manual:

http://www.cooperhandtools.com/onlin...TCPT_OI_PL.pdf


What you can't do is dial in an arbitrary temp like 730.

You do have to change tips if you want another temperature. It isn't that hard but it does take longer than it does on a Hakko. My argument is that you very rarely need anything besides 700F. If you do need something else you most likely need to change tips anyway.


Another budget option is the CircuitSpecialists Hakko Clone. The case on the new version doesn't look as much like a 936. It isn't as good as a real Hakko but it is only $35. Add in shipping and you are still under $50

http://www.circuitspecialists.com/prod.itml/icOid/7307

 

[pinkfloyd4ever]

Quote:

Originally Posted by Seaside /img/forum/go_quote.gif Well... how do you know if you do not like the tip comes with hakko dash, when you don't even have it?

hmm I suppose you're right, I'm just a little uneasy because its large tip radius reminded me of the crap ratshack one.

Quote:

Originally Posted by Seaside /img/forum/go_quote.gif Some people may find it is hard to solder in tiny spot with basic tip. Then they may need narrower tip like 45X-T-I. Some experienced people prefer cheasel tips for quick soldering at wide space.

Ya I have VEEERRYYY shaky hands, so I was thinking a smaller one might be better for me, maybe the 45x-T-SC, 45x-T-1C, or 45x-T-2C. Would those be too small? I remember seeing someone talking about taking some kind of medicine that calmed their shaking while using some crap iron, i believe a ratshack, one a tiny & complex project, does anyone know what that'd be? I actually have some that I take to reduce tremors, but it doesn't work too well anymore

 

[mono]

A temp adjustable, roughly 50W iron like the Hakko 936 w/900M, with the right tip, can solder to a solid ground plane on 1oz copper. I have some 3 oz copper material that I doubt would work with it, but the amount of heat required would be excessive for many kinds of parts you'd solder. It would be easier on a larger wand with more massive tips, but this contiually raises the price of the soldering equipment again. Certainly if only one spends enough there is tool out there for the purpose.

This is why a part is not typically soldered to the middle of a giant ground plane, the design should have thermal reliefs or short traces away from that large plane area. A "good" 30W iron should be able to solder anything to a PCB with the right tip in it.

 

[tomb]

Quote:

Originally Posted by mono /img/forum/go_quote.gif A temp adjustable, roughly 50W iron like the Hakko 936 w/900M, with the right tip, can solder to a solid ground plane on 1oz copper. I have some 3 oz copper material that I doubt would work with it, but the amount of heat required would be excessive for many kinds of parts you'd solder. It would be easier on a larger wand with more massive tips, but this contiually raises the price of the soldering equipment again. Certainly if only one spends enough there is tool out there for the purpose. This is why a part is not typically soldered to the middle of a giant ground plane, the design should have thermal reliefs or short traces away from that large plane area. A "good" 30W iron should be able to solder anything to a PCB with the right tip in it.

Yes, well - for a general statement like that, I agree. However, turn the iron down to 300deg. C., which is recommended on some IC's, and you will have trouble with some parts on a big board. Again, that is the reason for the adjustability - not just controlled temperature at a fixed value.

Ya'll don't misunderstand - I love the Hakko 936, and the Hakko Dash is a great basic iron. It's just that some of this conversation has digressed into some minute points about soldering.

 

[mono]

I think the point might be that there is no iron that can be used to sufficient heat up one point on a large continuous ground plane without overheating the part being soldered to it. No matter how massive the tip or fast the element is at reheating to maintain temp, a special technique will be necessary. That involves only pre-heating the larger part to the appropriate temp while isolating the more delicate part as much as possible from the heat, then bringing that part up to temp by method of (bridging solering iron tip across both parts, or sometimes I use a tool (depends on part, a pick or forceps or needle-noise pliers, etc) to hold the lead away then press it down on the copper, that tool also 'sinking some heat off the lead) and then flowing the solder across them.

It is a bit of a workaround though since a delicate IC should not be soldered directly to a solid ground plane for this (difficulty in soldering) reason. Any professionally made board should have the thermal reliefs around the pad or hole and those who roll their own boards should also consider doing it.

 

[cotdt]

Quote:

Originally Posted by mono /img/forum/go_quote.gif I think the point might be that there is no iron that can be used to sufficient heat up one point on a large continuous ground plane without overheating the part being soldered to it. No matter how massive the tip or fast the element is at reheating to maintain temp, a special technique will be necessary. That involves only pre-heating the larger part to the appropriate temp while isolating the more delicate part as much as possible from the heat, then bringing that part up to temp by method of (bridging solering iron tip across both parts, or sometimes I use a tool (depends on part, a pick or forceps or needle-noise pliers, etc) to hold the lead away then press it down on the copper, that tool also 'sinking some heat off the lead) and then flowing the solder across them. It is a bit of a workaround though since a delicate IC should not be soldered directly to a solid ground plane for this (difficulty in soldering) reason. Any professionally made board should have the thermal reliefs around the pad or hole and those who roll their own boards should also consider doing it.

You've never used a 100W soldering iron, have you ?

 

[nysulli]

just in case anyone who reads this is looking for one, allspec has the hakko 936-12 on sale for 80 bucks

 

[mono]

Quote:

You've never used a 100W soldering iron, have you ?

Yes, and? Last thing one wants to do is just pump even more heat into two surfaces with mismatched 'sinking characteristics when the one more delicate is the quicker of the two to heat up.

 

[kaizer]

Hah.. wow thanks for all the replies. Seems ive opened a few cans of worms

I have a Frys near by perhaps ill see what they have down there for sale. In the meantime I got a cheap 13 dollar weller iron that came with a hot knife attachment

Seems to work well to cut the techflex stuff. I managed to put together my first cable today as well.. I watched more than a few soldering videos over the last week or so, read most of the DIY guide here. Not a single hitch other than maybe the barels of the neutrik connectors being a bit small.. and burning my index finger on the soldering iron (blisters... oh fun). My first cable came out far better than I had ever expected. When I get a camera perhaps ill post a pic or two of my first attempts.