Using a small solder pot to dip solder a large PCB in sections? Feasible?

Thread Starter

Metatronic Mods

Joined Aug 17, 2016
18
Hey all. I'm just wondering if anyone has ever tried dip soldering larger PCBs in a small size solder pot, working in sections? I have these distribution bus PCBs that are 15 x 1.7" (38.1 x 4.32 cm), and I haven't found a pot large enough to accommodate that size in one pass for less than $10,000.

I'm wondering about the possibility of using a smaller solder pot (like the one linked below), filling it right to the brim, and then lowering my boards into the meniscus of the molten solder one section at a time.

Keeping the solder at the right level would be fidgety, but this seems like it would work. Has anyone heard of using a solder pot in this manner for small production runs? Any recommendation for a solder pot that should do the trick?
I've got some other boards that would also benefit from having the pot, plus once a year or so I recycle a lot of damaged PCBs, so I wouldn't mind spending up to say ~ $1000.

http://www.ebay.com/itm/CM558-Lead-...250620?hash=item25d64e603c:g:eLcAAOxyUgtTKWdl

Thanks!
 

Reloadron

Joined Jan 15, 2015
6,324
Your best shot would maybe be to build your own Solder Wave Flow Machine. They have been in use for decades and you may be able to fabricate your own tailored for your application.I never saw a dipping process work so can't comment on that.

Ron
 

shortbus

Joined Sep 30, 2009
9,061
Having worked where they used solder pots, to tin wires, I agree with Ron. The problem with pots is the oxidation of the surface of the solder. With the wave process the solder doesn't keep the same part of the solder exposed long enough to oxidize as much. With pots it was a constant thing for the operator to skim the oxidation off.
 

Thread Starter

Metatronic Mods

Joined Aug 17, 2016
18
There's a place near me that uses a large solder pot for assembly purposes. I think they even do the dipping process manually. I've heard that by setting the temperature just over the melting point the oxidation isn't so bad. Someone on another forum also mentioned additives that can slow down surface oxidation.

Idk, do either of you actually think I could build a wave solder machine on a $1000 budget? Admittedly I haven't really researched that route, when I saw price tags of $7-10k for a large enough solder pot I figured wave soldering would be right out of the question what with it being the superior technology.
 

SLK001

Joined Nov 29, 2011
1,548
You could probably build your own solder pot to do what you need it to do. Some stainless steel container, possibly custom made/welded and a temperature controlled calrod underneath to provide the heat. I can whip it up for you for $8000 if you're interested.
 

ErnieM

Joined Apr 24, 2011
8,217
I've seen solder pots that were approximately 6 x 12 inches used to tin transistor leads. Dross was scraped off using literally a drywall plater knife.

More to the point my last company had a mini wave soldering machine. The head was maybe 1 x 2 inches making a small wave of solder. A large PCB (typically with SMD already in place) was guiledover the wave to spot flow thru hold devices such as high current connectors.

Sorry, it is my ex company so I can't exactly drop by and read the builders plate.
 

DickCappels

Joined Aug 21, 2008
8,159
There is one way to find out -$149 + solder and flux to do the test.

You might want to to talk with the company near you that is using dip soldering. Somebody there might have a good feel for whether what you propose is feasible and he/she might enjoy being an expert being asked questions.
 

mcgyvr

Joined Oct 15, 2009
5,394
Yes you can dip solder a board in small sections.. (Done it plenty of times with our Hakko Solder pot just like the knockoff you linked in the first post..)

The dross can easily be "skimmed" right off the top of those smaller pots before each dip (or after a few dips) as needed..
Kapton tape can be used to "mask" areas you don't want soldered..

We are right in the middle of purchasing a larger DIP (18" x 24" area roughly) soldering machine here at work and yes the price is a little over $10k including pre-fluxer unit.. But we are using it for a board where we do more than 5k a year and its currently done on a selective soldering machine and have calculated ROI on the DIP machine to be under 6 months with a labor savings of about $20k a year after that..
 

Thread Starter

Metatronic Mods

Joined Aug 17, 2016
18
There is one way to find out -$149 + solder and flux to do the test.

You might want to to talk with the company near you that is using dip soldering. Somebody there might have a good feel for whether what you propose is feasible and he/she might enjoy being an expert being asked questions.
Yeah the more I thought about it the more I realized it was a pretty low risk thing to be putting so much thought into. Assembly or no, at $200 I'm sure I'll make my money back one way or another. And yeah I definitely plan to talk to the guys at this other place. They've always been really supportive and helpful in the past (I wish they had the resources to just hire me on over there =P )

Yes you can dip solder a board in small sections.. (Done it plenty of times with our Hakko Solder pot just like the knockoff you linked in the first post..)

The dross can easily be "skimmed" right off the top of those smaller pots before each dip (or after a few dips) as needed..
Kapton tape can be used to "mask" areas you don't want soldered..

We are right in the middle of purchasing a larger DIP (18" x 24" area roughly) soldering machine here at work and yes the price is a little over $10k including pre-fluxer unit.. But we are using it for a board where we do more than 5k a year and its currently done on a selective soldering machine and have calculated ROI on the DIP machine to be under 6 months with a labor savings of about $20k a year after that..
Thanks for the reassurances. I'll definitely be documenting my "experimentation" for the benefit of those who come later. Btw, you don't see any need to go with a branded unit do you? I have a lot of hakko products I use every day, but the pot would be maybe 3-4 times a year, and it seems like a pretty hard thing to really screw up (well provided it's actually be assembled properly).
 

mcgyvr

Joined Oct 15, 2009
5,394
Btw, you don't see any need to go with a branded unit do you? I have a lot of hakko products I use every day, but the pot would be maybe 3-4 times a year, and it seems like a pretty hard thing to really screw up (well provided it's actually be assembled properly).
Well.... Depending on the product there could very well be differences in materials/quality/safety,etc... between a branded product and its knockoff.. For something used only a few times a year its pretty hard to justify the higher cost of the branded product when a knockoff is there..
But if that knockoff isn't as safe well.. you could get electrocuted or seriously hurt and you need to put a value on your life/health and I'm sure its FAR more than the cost difference between the 2 products..

Buyer beware...

Having said that I do have a cheap knockoff hot air soldering gun.. I couldn't justify the price of a Hakko or similar when I only use it once a year if that... The shroud on the handle did melt on day one but its still working just fine..
 

shortbus

Joined Sep 30, 2009
9,061
Well.... Depending on the product there could very well be differences in materials/quality/safety,etc... between a branded product and its knockoff.. For something used only a few times a year its pretty hard to justify the higher cost of the branded product when a knockoff is there..
But if that knockoff isn't as safe well.. you could get electrocuted or seriously hurt and you need to put a value on your life/health and I'm sure its FAR more than the cost difference between the 2 products..

Buyer beware...

Having said that I do have a cheap knockoff hot air soldering gun.. I couldn't justify the price of a Hakko or similar when I only use it once a year if that... The shroud on the handle did melt on day one but its still working just fine..
Don't know about the soldering station/iron, but do know from experience that things 'brand' name made in China are sometimes made on the same equipment with the same materials as the 'off' brand. What I'm talking about is auto parts. The company I worked for was used two shifts a day for 'brand' name and one shift a day for 'off' brand. Didn't make us workers that lost our jobs too happy.
 

Thread Starter

Metatronic Mods

Joined Aug 17, 2016
18
Don't know about the soldering station/iron, but do know from experience that things 'brand' name made in China are sometimes made on the same equipment with the same materials as the 'off' brand. What I'm talking about is auto parts. The company I worked for was used two shifts a day for 'brand' name and one shift a day for 'off' brand. Didn't make us workers that lost our jobs too happy.
Yeah I hear ya. If anything it's probably more of a QC grading thing than anything. Like how a lot of computer components have bottom/middle/top shelf versions of the exact same parts, or the sorting of discrete components into 0.1% 1% 5% etc. tolerances. So I go with branded stuff for mission critical items, but if some downtime is acceptable, or I don't mind some "tuning" before I start using the equipment unbranded seems fine.

Actually I wouldn't be surprised if some of these clone devices are being made by the same contracting companies after their initial contract with the brand is already fulfilled. Like "well as long as we've got the molds/dies/tooling made up, we might as well churn out another few thousand of these."
 

mcgyvr

Joined Oct 15, 2009
5,394
Don't know about the soldering station/iron, but do know from experience that things 'brand' name made in China are sometimes made on the same equipment with the same materials as the 'off' brand. What I'm talking about is auto parts. The company I worked for was used two shifts a day for 'brand' name and one shift a day for 'off' brand. Didn't make us workers that lost our jobs too happy.
Oh absolutely true too..
There are numerous "production/assembly tools" that I come across that are simply the Chinese made products with an "American" (or German or whatever) brand sticker slapped on them (and marked up 500-1000% or more)..
 

shortbus

Joined Sep 30, 2009
9,061
Actually I wouldn't be surprised if some of these clone devices are being made by the same contracting companies after their initial contract with the brand is already fulfilled. Like "well as long as we've got the molds/dies/tooling made up, we might as well churn out another few thousand of these."
I worked for Delphi Packard Electric. The molds were owned by GM, and when the part was no longer "supported" (being sold by Delco or GM) The molds had to be destroyed. Usually with a cutting torch, with someone from GM watching.

Then they started sending work to China. The company had to build the building(s) and pay for the tooling. But all of it was owned by the Chinese government, even though they didn't pay anything for it. That's what it was like when they pretty much shut down the US operations. And why I laugh every time a politician says were bringing back US jobs. Sure but don't look to have a short easy restart in the US.
 
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