From the NASA Spec:

Solder?

1. Types and Usage. All solder used for tinning and solder connections shall conform to?ANSI/J-STD-006. Flux-cored solder?shall be either composition SN60 or SN63 containing flux?types R or RMA, or equivalent. For all soldering applications where adequate?subsequent cleaning?is not practical, only solder containing flux type R shall be used. Solid solders (no flux) for use in?solder pots shall?be of the same composition.?

6.13 Solvents and Cleaners?1.

The solvents or aqueous cleaners used to remove grease, oil, dirt, flux, or other debris,?shall be selected?for their ability to remove both ionic and nonionic contamination. The solvents or?cleaners used shall not degrade the materials or parts?being cleaned. A list of approved solvents?and cleaners is provided in Table 6-1. Mixtures of the approved solvents may be used. Solvent?containers shall be properly labeled. Refer to Material Safety Data Sheets (MSDS) for proper?handling of solvents or cleaners.

I would like to see salemans face when i ask him for 1 Mohm water.?

On Tue, Dec 24, 2024 at 06:39 PM, Ivica - YU1QRP wrote:

I would like to see salemans face when i ask him for 1 Mohm water.?

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73, Dan - W2DLC

Hint for new builders:

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If you? build with lead free solder your radio will probably not work.

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Maybe if you? have a lot of experience and? very nice equipment you could make lead free work.

But probably - when no one is looking - you will pull out the 60/40 (lead) solder you have been hiding from the goverment.

The water spec is common for what's also referred to as deionized water in industrial applications. We had a plant at pppl.gov that made thousands of gallons, since we used it to cool a number of? of high power devices like 8974 2.5 MW tube amplifier modules...

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While that NASA soldering spec dates from 2006, SN60/SN63 remains to this day in the NASA supply chain. Aerospace material suppliers still sell it. SAC305 (tin-silver-copper) is the current recommended replacement, at 4-5 times the cost.

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I would not agree to the statement that it won't work with lead free solder.

You should use a soldering station anyhow for the multilayer boards and with a good alloy there is no problem.

I'm using Stannol HS10 Sn95,5Ag3,8Cu0,7 which is so far the best lead free solder I used and I tried quite a few.

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If you use a low cost alloy without silver it makes things more complicated.

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KR

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Dirk

On Wed, Dec 25, 2024 at 12:43 PM, stan timmerman wrote:

But probably - when no one is looking - you will pull out the 60/40 (lead) solder you have been hiding from the goverment.

Or even better, 63/37 (eutectic) alloy with RMA flux core.

73, Don N2VGU

Don, if you dig into the details, 60/40 is better for tinning, since it has a plastic range, and 63/37 is better for everything else, since it does not. Yes, this thread sent me that far down the rabbit hole. :)

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Merry Christmas & 73 de AI7SY

FYI:

The US military requires leaded solder to prevent the formation of tin whiskers.?

As of 2021 the US Army, at least, requires 3% minimum lead content in solder to prevent whisker formation.

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https://www.psmagazine.army.mil/News/Article/2567624/get-the-lead-outnot/

Dirk,

?agree, the Sn95,5Ag3,8Cu0,7 ( I use a Kester product) works well. However you do have to use higher heat. I have used the lead free for a lot of projects, but for the QMX I went back to 60/40 Pb based due to the heat issues with a 6 layer board.?

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73, Dan? NM3A

Hi Daniel,

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fully agree. The higher temperature requirement can be problematic.

When I'm soldering connectors I also open my secret drawer with the remaining 60/40, to avoid melting structural parts.

Nevertheless, lead free is now my main solder.

As I mentioned above this required a reasonable soldering station (and gave me a reason to buy one) and some trials for a good solder.

Furthermore you have to close your eyes at the checkout when ordering fresh Sn95,5Ag3,8Cu0,7...

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73

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DK7CVD

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