Cleaning flux after silver soldering for large piece

[Cuong BuiParticipant @cuongbui18494]

Hi there,

Im building a rolling ball sculpture out of brass and i use silver solder for keeping joints together. I know this is model engineering forum, not about rolling ball things, however i've been looking around here for a while and i actually learn how to silver solder by reading alot of posts in this forum. Thank you guys for that.

My question is: how do i clean the flux after silver solder whole sculpture together? Put the whole set into a pickle is not a solution since the set is kinda big. Can i use some kind of strong acid, put a few drop on to the joint and clean it one by one? Or there is another better way?

Please excuse me for my english and for asking about rolling ball thing in a model forum.

Best regards.

Cuong.

[Cuong BuiParticipant @cuongbui18494]

[Sub MandrelParticipant @submandrel]

Hi Cuong,

Don't worry, this forum is for any amateur engineer. Why not use a large tray and just clean one section of the ball at a time?

If it's too big for that, perhaps you could set up some sort of spray or drip feed?

Don't use

Be aware that you will be left with a disappointing pinky/black finish that looks terrible. This WILL polish up to a decent finish without too much effort, especially if you can get some sort of rotary polishing tool.

Neil

[Ian S CParticipant @iansc]

If it's really big, quite a bit might be got cleaned with a water blaster, or a steam cleaner. Ian S C

[Sub MandrelParticipant @submandrel]

Sorry teh 'don't use' bit was meant to continue:

Don't use sulphuric or hydrochloric acid in this way, use a gentler acid like citric acid or the sulphamic acid in commercial kitchen descaler. They work just as well, but a little slower and a lot safer.

Neil

[Cuong BuiParticipant @cuongbui18494]

Thank you for the advices.

i was trying 45% silver solder on small rail joints for strenght and colour match with brass. The high melting temp of this solder not only hard to do but also makes the 4mm brass rail soft. I switched to the stay brite bearing solder made by harris with 3% silver content. its easy to do but the joint is weak. I could break it with my hand with little effort. I've ordered the the stay brite 8 with 6% silver content and will give it a try. Even if this 6% silver solder works, the joints color will be dismatch with brass.

Right now im stuck at making a good joints in term of strenght and colour match. Its kinda annoying while the project does not process at all.

Is there any better way to go?

Best regards.

[Michael GilliganParticipant @michaelgilligan61133]

Cuong Bui,

The Harris StayBrite solders are "Lead Free"

i.e. Tin, with some Silver

As such, [and despite the manufacturer's comments] they are not as strong as hard Silver Solder.

You will need mechanically sound joints if you use StayBrite … a simple butt-joint will fail, as you describe.

MichaelG.

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