What is good solder tin without using heat shrink/ weather resistance?

I live in a moisture area where it rains a lot.

I want to repair the solder on the A/C fan.

I don't know what solder they used.

Is it 70/30 or 60/40 or ??

Don't know the ratio but be sure to use rosin instead of acid if soldering elex.

Mercedes used a top quality silver soldering for their electrical joints

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Which Silver soldering?

I'll tell you the truth, but you won't believe me. If it's possible, crimp the connection using a high quality ratcheting crimper. As long as you use sufficient pressure, it's better than soldering. A crimped connection is all copper, and if properly compressed, it's a gas free joint and you can ad a bit of dieelectric grease if you want it absolutely waterproof. A soldered connection will have much higher resistance, unless you silver solder.

Where it's necessary to solder, a 60/40 rosin core is good enough for almost all automotive applications, but you may want to consider lead free. Don't use solid core, and whatever you do, don't use acid core or acid paste.

As others have said above, 60/40 rosin core is your best bet for resoldering and repairs. Don't use lead-free solder, it doesn't hold up well to vibration and tends to fracture easily. It's also extremely difficult to get it to bond to old wire and can result in a lousy connection.

If you're concerned about moisture, you should be using something to help weatherproof the connection. You ideally want to keep as much moisture from wicking up the wire as possible to keep the copper from corroding.

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Current stable:
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Lead free in a wet weather environment?

I would rather go Silver solder then.

The basis for using a 60/40 rosin core solder is connection with minimal surface prep. The rosin and tin are to promote a better bond without having pristine surfaces. Sometimes 70/30 is used but a good joint can be difficult in some situations, if the temperatures of the mating surfaces aren't nearly identical.

Rarely is 100% silver used, as it requires perfect surfaces and temperatures. Acid flux is not used as just the slightest residue left behind can create corrosion on delicate electronics.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Not sure why you want to avoid heat shrink tubing - heat shrink is your friend! When I do a solder joint I use the 60/40 rosin core as noted, then heat shrink with a tail of a tie wrap shrunk into the joint to stiffen the joint. I've seen too many solder joints fatigue and crack apart as the result to vibration (this IS a moving vehicle, after all). Since I started shrinking in the tie wrap tail I've had zero failures.



I agree that, in most circumstances, a crimp joint will work just fine. Again, you can either heat shrink over the crimp or simply buy the crimp connectors that are made to shrink after you install them. They are made to keep water out - that's their very reason to be.


Lots of solutions........


Dan

This is a great idea. I never thought of that!

Shrink tubing is cheap enough. Plus it supports the transisition points where the soldered joints end and the Softer wire starts.

At that point vibration is sometimes an issue and by the support of the soldered joint and past the transistion points. Shrink tubing supports those transition areas in turn.

So shrink tubing gets my vote. Besides capable of good functions. It looks like a professional repair was done.

Sixty forty solder is best. Over the years I have heard that solder has a shelf life. I cannot remember but five to seven years comes to mind. Today I would suggest buying direct from China on ebay. Small amounts of 60/40 solder with a rosin core. Plus a dollar package of additional rosin. Both with free delivery included in their prices. I do this because they are using so much solder over there the quality is good. Plus it costs also nothing in comparison to local prices.

I am and have not been an estatic fan of lead free solders. I have found I have to use really expensive flux to get the results I want. Anyways soldering is not difficult usually if you obey a few common sense rules.

The wire has to be clean. You heat it up till the wire melts the solder. When you touch it with the solder. If it appears to flow good into the wire joint that is about it.


Solder creates a mechanical connection. As you heat the wire the copper metal expands. This increase the size of the surface pores. The solder flows on and as the joint cools the irregularities of the wire surface lock the solder on as the copper shrinks. I have not heard of a lot of issues with black metal wire corrosion being mentioned as an issue with the wiring on these cars.
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I have no real issues with crimp joints. Other than they should have even more protection from the elements. A dab of silicone grease protected from being washed off is good. Otherwise the natural oxidation of the surface of the wires with the oxygen in the atmosphere can occur. Actually it is a habit of mine on cars. Any time I open up a termination I check it for being clean. Then I coat it with a dab of grease. Silicone grease is best as it does not impact the wire insulation.

When you clean the connections many times the factory applied anti corrosive coating is reduced or eliminated if the sacrificial type metal coating is not already gone. Otherwise an issue with that connection is likely to occur much faster than it did the first time. At least in our rust belt areas.

Touching on the atmosphere. Do you pay for nitrogen gas in your tires? When the atmosphere is about eighty percent nitrogen to start with.

I used to solder everything, now I crimp and use adhesive-lined heatshrink. You can get connectors with the whole kit'n'kaboodle pretty cheap.

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I realize this is a dumb question - but by shrink wrap, do you mean those tubes of plastic that you slide over the wiring and then heat with a match and try not to burn? That is all I have ever seen and it means you must slide it over the wire before splicing it back together.

Or do they make other kinds of shrink wrap????

A crimped connection is better than a soldered connection. As long as it's closed with enough pressure, it will be gas free and corrosion resistant. The metal essentailly cold welds into a tight bundle. By contrast, a soldered connection is always high resistance, because lead doesn't conduct as well as copper. It's also corrosion prone because of the mix of metals. You won't find a single soldered connector in a modern car.

Yep, that's shrink wrap. PUT IT ON THE WIRE FIRST!!!! (I've screwed that up and it's no fun.) Don't heat it with a match - go to Harbor Freight or similar and buy a heat gun. They're not very expensive (I think I paid $12 for the current one) and they have many uses once you have one in the tool kit.


Another tip I just thought of: A couple of guys have mentioned that crimp connectors need to be FULLY crimped, which is true. Many years ago I started using Vice-Grips (believe it or not). Adjust them so that it takes a fair amount of hand pressure until the V-Gs "click" closed. Once crimped, pull heartily on the wires and make sure the connection stays connected. If you have the V-Gs adjusted properly, it will. If there's a loose connection you want to find it now rather than when you're rolling down the road. Also, shrink wrap over the connection as it looks much more "pro".


Additional tip: You can buy CLEAR shrink wrap - I get mine on line as no local place carries it. Make a tag for whatever wire you're working on (I use a Brother label maker) and heat shrink it under the clear shrink wrap. That wire will be marked forever and that info will save you heartache if you ever have to investigate that circuit again. Pic attached, from Volvo engine swap.

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