# When is a solder joint not a solder joint?



## Cedge (Aug 26, 2007)

This tip is sure to raise the hackles among purists, but it's just one more weapon among many, when doing battle with a small engine build. 

There are times when soldering just isn't practical or even desirable.  The parts being joined are too small to work with accurately, you are working with metals that just don't solder, such as aluminum, cleaning up excess solder is going to be impossible due to the  location of the joint, or perhaps adjacent solder joints might fail if you heat the new location enough to get a good joint.  There are any number of other cases where it just isn't going to work for one reason or another.  We've all encountered them.

I've found two solutions, depending on the need.  One is Red Loctite. The other is Super Glue. 

Red Loctite is about as close to  chemical welding as one is likely to come.  It's good for use in relatively high torque and high heat applications (withstands up to 500° before it melts).  It joins the metals cleanly and can be wiped away before it dries. It gives you a few minutes of "oops time" in which to adjust things if needed. I've used it in places where solder overflow was to be avoided in order to maintain a clean appearance, but it's alao served to join metals which were later to be turned on the lathe with great success. 

Super Glue is also usable in many of the same applications but you have to be ready to work quickly when it is applied. You have only a matter of a few seconds before it sets up.  It works especially well where two pieces are machined to an interference or running fit and holds up quite nicely when it encounters a lathe tool. Acetone will dissolve it if you need to do so.

Neither trick is suitable as a replacement for soldering and silver solder is still the only thing I'd suggest where structural strength is needed, such as a boiler or where the part will encounter high physical stress. However,  they can be a real life saver when they are appropriate.

I'm off to don my asbestos flame suit before any purists spot my heresy...LOL.

Steve


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## rake60 (Aug 26, 2007)

No flames from this shop.

I've used the super glue myself many times.
One little note on that is there are two different formulas for the 
cyanoacrylate adhesives.  One is methyl based and the other has an 
ethyl base.  The methyl based product works much better on metals than
the ethyl.  Unless your eyes are much better than mine to read that
fine print on the labels it's best to just look for the product that says it's
for metal.  It will generally be a little more expensive, but not much.

Great tips Steve!


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## sidecar_jon (Sep 28, 2007)

It sets in the absence of air and the presence of water..so a tight fit as one might have for soft soldering and moisture in the air will do it. Ive used it many times but then i am a bodger!


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