De/ re-Soldering alternator rectifier - Hakko FX888 ?

[R-mm]

I'm going to replace the rectifier on a Bosch 115a alternator. Some photos attached. I have a Hakko FX888 (rated 65w) and wide chisel tips. when one sees videos of this being done its with big 200w soldering irons, which in decades of fixing stuff Ive never needed. Don’t love buying a single use tool but do want to get this right. Can anyone comment who has done a similar repair?

 

[JradM]

I assume a soldering gun of that magnitude is required because the parts act like a big heatsink? If it was me, I would just try it with what I had. If the solder joint was too cold or I found myself adding too much heat to parts that shouldn't be heated because of the long warm-up time, I would try again after acquiring a more powerful iron.

 

[dnschmidt]

I agree it's going to take more than that but what have you got to lose with trying. I'd use a Weller pistol type soldering gun as these can get things really hot fast but since I've already got one of these that would cost me nothing. My feeling is that your bringing a pocket knife to a sword fight.

 

[Stubby1743]

It's probably using modern lead-free solder which requires a much higher temp to melt than the old (better) high lead content solder. The only answer is more heat. I hate lead-free solder for that reason.

 

[duneslider]

I have not run into something the hakko wouldn't solder. Tin the surface, tin the wire, and it should work. I use kester 6040 for pretty much everything.

 

[Firebrick43]

Do you have a temp controlled heat gun? I have a stienel and it has a small diameter adapter to go over the nozzle that takes it down to 1/4” ish in diameter and I have found it works much better that the old monster wellers with larger components

 

[Bert_]

I ended up with a big 225w iron a few years ago. It's not something I use very often but I really appreciate it on something like this. You need a big iron that holds a lot of heat to solder big parts.

There's a bunch of used ones on eBay. think this is the exact same one I have, and it's cheap enough.
https://www.ebay.com/itm/1470404626.../busw==|tkp:Bk9SR9KRsZ-gZw&LH_ItemCondition=4

 

[cgrutt]

I agree it's going to take more than that but what have you got to lose with trying. I'd use a Weller pistol type soldering gun as these can get things really hot fast but since I've already got one of these that would cost me nothing. My feeling is that your bringing a pocket knife to a sword fight.

I wss going to say old school Weller gun would make short work of that.

 

[RTM]

I wss going to say old school Weller gun would make short work of that.

I have a Weller 100/140 watt and a 240/325 watt.

 

[cgrutt]

I have a Weller 100/140 watt and a 240/325 watt.

I have a 100/140 and a 200/260 and a few standard irons.

 

[djbmw]

Try it as-is.
If that doesnt work, pre heat the thing with a heat gun or toss it in the oven, then try again.
Still not working? Buy some low-melt solder to mix itln with the lead free stuff that they uses and try again.

 

[R-mm]

The FX-888 struggled. Could be made to work, very slowly, not ideal. I ordered a Weller 200/260w from Amazon (not a 3rd party). Bad does not even begin to describe it. In decades of wrenching I've used so-so (harbor freight) to excellent (hakko, fluke etc) tools. All have done their job. Some more pleasant to use than others. Some live for a few years (HF angle grinder) some for life (Metabo angle grinder). This thing was so DOA, so lousy right out of the (broken) box I can't even start. I am done with Weller.

I'm tempted to get the Hakko 601-02 with the largest tip - much more thermal mass, lots use it for stained glass. Would be nice and ergonimic, if not a massive upgrade in heat from the 888.

But the truth is the Hakko 200w 557 is probably the baseball bat I need

Curious if you all have any experience with these.

 

[Beerhippie]

Try it as-is.
If that doesnt work, pre heat the thing with a heat gun or toss it in the oven, then try again.
Still not working? Buy some low-melt solder to mix itln with the lead free stuff that they uses and try again.

You are aware he;'s talking about a recitifer, right? A solid-state device in the oven?

 

[djbmw]

You are aware he;'s talking about a recitifer, right? A solid-state device in the oven?

Yes. Very aware. They are designed to operate in automotive environments right beside an engine. They are generally rated to handle between 150°C and 200°C (302°F - 392°F).

I suggested heating it up so that his existing soldering iron could flow the lead free solder easier. I certainly am not suggesting to cook the thing and turn it into a puddle!

Heat it to 60C and see if your soldering iron can flow the connections. Then try 80C,.. then 100C.. then 120C.

Dont leave it in the oven for long either.. just long enough to get the assembly up to temp.

 

[BurtEggley]

Normally the diode press fits the plate. Then the lead is soldered. The downside of using too low a soldering iron is it will overheat the internal diode junction. You want a heat that will quickly heat the leads so you can apply solder quickly and be done. I think 65W is doable but maybe a little low. I keep an old Weller iron around for that type work, as well as lightweight, and temperature controlled irons for other work. I can't imagine anyone who solders things not having a couple different irons. To me having one soldering iron would be like having one screwdriver or open end wrench, then trying to make them fit all applications.

 

[Davefr]

Here are a few tips:
1. Apply a good flux to the terminals and make sure the tip of your iron is clean and properely tinned.
2. Premelt the soldered terminal
3. Now go back and unsolder the connection using Chemtronics solder wick.

I think 65 watts might do it as long as the connections are shinny clean for max. heat transfer. (old oxidized connections and a dirty soldering iron tip will make if very difficult to achive the heat transfer needed). You might even want to hit the old connections with a Dremel and wire brush, they look filthy.

What you really want to do is give it max. temp and get in and get out quickly. Gradual heat soaks causes more damage then quick work at max. temp.

 

[rayik]

Add fresh solder to the joint before trying to desolder. Really does make it easier to desolder on old joints

 

[Bert_]

You already have a small iron. Don't waste your time with one that's "slightly bigger". You want something with a lot of mass that will hold heat and get the part up to temperature quickly

 

[ronkz650]

Some soldering irons are just plain garbage. They can be rated at "***" watts that seem high enough, but once the tip touches the solder it can't keep up with demand and cools down faster than it heats and you don't have a good experience to say the least.
I have two Metcal stations that use the STTC series tips. The tips determine the temperature and can be bought in small, large and anything in between. Even being only rated 50w or so depending on the model, this thing will heat and melt solder on anything. I got mine used on ebay years ago for less than $100 each.
A good rule of thumb, if it takes 5 minutes to heat the tip it's garbage. The Metcal is ready to solder in 10 seconds.

 

[American Locomotive]

The FX-888 struggled. Could be made to work, very slowly, not ideal. I ordered a Weller 200/260w from Amazon (not a 3rd party). Bad does not even begin to describe it. In decades of wrenching I've used so-so (harbor freight) to excellent (hakko, fluke etc) tools. All have done their job. Some more pleasant to use than others. Some live for a few years (HF angle grinder) some for life (Metabo angle grinder). This thing was so DOA, so lousy right out of the (broken) box I can't even start. I am done with Weller.

I'm tempted to get the Hakko 601-02 with the largest tip - much more thermal mass, lots use it for stained glass. Would be nice and ergonimic, if not a massive upgrade in heat from the 888.

But the truth is the Hakko 200w 557 is probably the baseball bat I need

Curious if you all have any experience with these.

You need the high thermal mass of the 557.

The Weller 200/260 should also do it. Maybe just return it and get another one?

 

[R-mm]

I got the Hakko 557. It came with a cute tote bag (yay).

Once the rectifier leads and terminals were clean the 888 had no trouble with it. it was probably the old solder and stiffness of the wiring that made the removal that much harder.