PLate cooling

[Peter_1]

A picture of today how we attach copper tubes underneath the stainless plate of a counter. (Spot welding bolts)

[Peter_1]

Another One

[Peter_1]

Last one.

After this, we use cold conducting pasta to improve contact with the plate.

[rbartlett]

pasta eh?

we usually just eat it over here..

however i remember we tried silver soldering copper to the bottom of a ss tray and it warped and 'blued' badly..took hours and hours to try to get it looking okay..

however now i would use normal soft solder which would do nicely..

cheers


richard

[Peter_1]

Richard,… funny… the Dutch word for some sort of glue is pasta.
The stuff we’re using is some sort of silicone, mixed with aluminium powder to improve heat transfer.

We just come back from Italy, so I know what pasta is.

We make +/- 7 to 10 counters a year, and this since +/ 10 years now.
So I can say that I have a little experience with it.

If you solder it with the silver you use for soldering copper tubes, then you have to heat it so hot that the ss plate will deform.

A better method is using tin like the roof techs uses for soldering the zinc gutters and solder with a soldering iron.
We did it like this: solder 2 inch, then left a space from +/- 10 to 12 inch and solder 2 inch again on the other side of the tube.
But the ss plate must lay on a very flat surface (very important) when soldering, otherwise it will deform again. One tech has to push the copper rod against the ss plate while the other solders the it. As soon the solder is finished, you have too cool down with a very wet towel the soldering place.

But we found out that due to the tensions in the plate the copper tubes loosen from the ss plate.

So we’re using now this method since a year – stut welding - which can’t be better: we solder bolts from M6 mm on the ss surface and those can’t be removed without breaking them with a pinch. Over the tubes there are special bended headers to hold the tubes against the ss plate.

And on the other side of the ss plate, you don’t see (almost) nothing of the spot welding.

The final result is also nicer.

If some are interested, I can try to make some close pictures of it.

[DaBit]

Just curious: how do you soft-solder stainless steel? I've tried it once with S39 flux and SnAg solder, but that did not work. So I took out the 45% Ag rods, which do work.

[Peter_1]

Originally posted by DaBit
Just curious: how do you soft-solder stainless steel? I've tried it once with S39 flux and SnAg solder, but that did not work. So I took out the 45% Ag rods, which do work.

You we're using exactly the same products Sn/Ag with S39 flux as we always did in the past.

What did you use for heating the tubes?

What went wrong?
I can make some pictures, perhaps demonstrate it via a small movie how we did it.


A nice site with usefull info about copper.

http://www.cda.org.uk/

And for the Dutch or French speaking among us:
http://www.copperbenelux.org/

[DaBit]

Just like I used to solder copper and iron: a (plumbers-) butane torch to heat the stuff. Futher the regular way of soldering: apply flux, heat, apply solder, apply a little flux, cool down and clean.

Somehow the solder wouldn't stick to the stainless steel. The stainbless steel was sheet material, btw.

And now I think about it: it might have been 40/60 SnPb solder instead of SnAg. Would that make the difference? I can hardly imagine that the procedure for soldering stainless would be much different from soldering iron, zinc or copper.

[chemi-cool]

hi dabit,

SS is tricky metal, the secret is not to heat it too much.
if you over heat it the solder will not "hold".

a method that I use for soldering SS water trays for coolers is heating from one side of the sheet and hold the solder rod and flux on the other side. works for me.


Soft solder is used in applications below 450C where the parent material is not affected as in welding and brazing

chemi