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Topic: Chassis ground soldering iron |
Hiro Keitora
From:
New York, New York
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Posted 11 Mar 2012 5:32 pm |
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I admit that it's about time to come out and ask;
When I do "ground" soldering to the chassis on Fender amps; for example, multi-cap can for princeton.
I have to use x2 soldering iron to let the solder flow, and it's no fun both hands holding irons and feeding a line of solder with my mouth( Lead? someone said lead??  )
What brand of soldering iron is the best for this kind of job? In the past, I used propane soldering iron too, but I still need another iron to keep it high enough to let the solder flow.
Any ideas? |
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Tim Marcus
From:
San Francisco, CA
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Posted 11 Mar 2012 6:37 pm
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In general soldering to the chassis is not a great idea. I know fender did it, and got away with it, but it's not great modern practice. You want an electronic and mechanical connection if possible - soldering only provides one of those.
If you do need to do it, use a soldering gun.
_________________
Milkmansound.com |
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Hiro Keitora
From:
New York, New York
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Posted 11 Mar 2012 6:58 pm
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Hi Tim, I can't remember well but I was told I shouldn't use "soldering gun" because of the magnetic field it creates or something? I can't remember...
And I agree and I know what you mean though, it's ALWAYS good to have a solid mechanical contact!! But for vintage pieces, you can't have that option. 
it's great that now we can have exact replacement of old mallory can cap, and not have to depend on oversized JJ can cap.
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 11 Mar 2012 8:42 pm
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| Somewhat along the lines shown HERE is how you should do it. Soldering alone is not mechanically sound. |
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 11 Mar 2012 8:53 pm
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| Hiro Keitora wrote: |
| Hi Tim, I can't remember well but I was told I shouldn't use "soldering gun" because of the magnetic field it creates or something? I can't remember... |
Generally: large soldering guns are not smart to use anywhere near Integrated Circuits (ICs) and tiny transistors for a number of reasons, one being the electromagnetic field that may burn out delicate IC circuits before proper connection is established. Most other electronic components can only be damaged by excessive heat from too large/powerful soldering irons. |
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Dave Grafe
From:
Hudson River Valley NY
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Posted 11 Mar 2012 11:59 pm
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| The preferred way to connect a ground the the chassis is to drill a hole and use a screw and nut to attach a solder lug thereby. |
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Ken Fox
From:
Nashville GA USA
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Posted 12 Mar 2012 3:14 am
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The key to chassis solder connnections is not a large wattage iron, but an iron with a large/wide tip. Like the original Tweed amps, our amps have the ground soldered firmly to the chassis using a Weller iron SP-80L iron that features a wide tip. I use the same iron for repairs to older Fender amps as well. The key is heating a larger surface area for a good bond and this iron does that very well. I just removed a soldered in filter cap can from an older Premier 71 amp using this iron. Without it I could not have removed it or replaced it with a new one. I have a 200 watt Weller soldering gun and it will not work for chassis soldering, as the tips are too small.
Here is a link.
http://www.tequipment.net/WellerSP80L.html
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Hiro Keitora
From:
New York, New York
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Posted 12 Mar 2012 4:05 am
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ah, wider tip! Thanks, Ken!
I think I'll pick up this Weller iron, it can be pretty handy to have.
Ken, should I buy x2 of them? or just one would do the job? |
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Ken Fox
From:
Nashville GA USA
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Posted 12 Mar 2012 4:29 am
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| One is all you need. I can make that solder flow very easy with just this iron. Makes a perfect joint, just let it heat up fully and clean your surface with denatured alcohol or regular alcohol first. Use a larger gauge of solder, not the fine stuff. I use a .060 diameter solder, 60/40 as well, I never use the lead free, worst solder I have ever tried to use! |
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Hiro Keitora
From:
New York, New York
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Posted 12 Mar 2012 4:49 am
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Just ordered one. Thanks Ken!
I must say you always help us out. |
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Jerry Kippola
From:
UP Michigan, USA
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Posted 12 Mar 2012 5:32 am
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| I have several old 100W soldering irons for this, they work very well, and can be used for fast heavy soldering of big connectors like Amphenol EP |
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Lee Warren
From:
Nashville, Tennessee, USA
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Posted 12 Mar 2012 6:27 am
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Speaking of soldering, what would be a good, reasonably priced, soldering station?
Any suggestions Ken?
Thanks!
Lee  |
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Tim Marcus
From:
San Francisco, CA
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Posted 12 Mar 2012 8:36 am
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I use this station for everything:
http://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU
you can probably get a wide enough tip for chassis grounds if you want to do it that way, but as I said up above - I highly recommend not running your grounds that way, even if you are doing a re-cap to an old fender.
Another thing to consider, if you must ground to the chassis via solder, is to hit the spot with a dremel tool before soldering. There is probably a lot of dirt and oxidation on there which will need to be removed - even from a brand new chassis. A quick scouring with the dremel will remove that and get you down to fresh steel.
If you are using an aluminum chassis, you can forget about soldering to it at all - its not going to happen. Also, I think Weber kits now come with stainless chassis, which will also not take solder as well.
Most modern amps do not use the old Fender style ground scheme - and for good reason. Running a lot of current through the chassis leads to noise and can cause other weird issues. I highly recommend reading Merlin's article:
http://www.freewebs.com/valvewizard2/Grounding.html
If you are just fixing an old fender - its probably best to leave it how it is. However, for new amp builds chassis grounds are ill advised.
_________________
Milkmansound.com |
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Mitch Druckman
From:
Arizona, USA
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Posted 12 Mar 2012 8:42 am
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| It looks like that Weller SP80L would be good for soldering ground connections on the back side of potentiometers. |
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Lee Warren
From:
Nashville, Tennessee, USA
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Posted 12 Mar 2012 9:09 am
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Hi Tim,
Thanks for the insight.
Much appreciated!
Lee |
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Tim Marcus
From:
San Francisco, CA
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Posted 12 Mar 2012 9:14 am
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oops - I should have mentioned that too, although its mentioned in the Merlin article. Soldering to the back of pots is also no longer considered acceptable practice as it can lead to ground loops and modern pots don't take the solder as well as the vintage ones did.
One more must read article from Randall Aiken:
http://www.aikenamps.com/StarGround.html
Again, Fender got away with all of this stuff, and there is not one grounding technique that works for everything, but there are modern conventions that should be followed.
_________________
Milkmansound.com |
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Earnest Bovine
From:
Los Angeles CA USA
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Posted 12 Mar 2012 9:14 am
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| Those links show soldering equipment with dozens of accessories, but I don't see solder. Why? Is it illegal now? |
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Tim Marcus
From:
San Francisco, CA
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Posted 12 Mar 2012 9:22 am
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nope - you can still get Kester 60/40 solder at Mouser and other fine retailers. If you are in the ROHS zone, you can no longer purchase solder with Lead - but here in the States its still widely available
_________________
Milkmansound.com |
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Ken Fox
From:
Nashville GA USA
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Posted 12 Mar 2012 2:13 pm
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| Tim, that is a great soldering station. I have two, one for each of my workbenches! |
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Lee Warren
From:
Nashville, Tennessee, USA
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Posted 12 Mar 2012 2:21 pm
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Well, that seals it - high praise from two reliable sources.
That's the soldering station for me!
Thanks guys.
Lee |
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Ken Fox
From:
Nashville GA USA
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Posted 12 Mar 2012 3:41 pm
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| I typically solder at around 750 degress for the older style amps (hand-wired types or turret board style). |
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