Soldering "non-fitting" pieces together

[hendecp]

OK, I hope I am not starting a thread that I can find answers somewhere else, or posting this in wrong forum. Anyhow, my question is around soldering copper together that is not on a joint. I am pretty "OK" soldering standard stuff and fittings together. But, when it comes to soldering a 1/4" tube into a hole that I drilled into a cap or side of a pipe (or any size for that matter) my work looks like sh*t! It usually holds up to leaks, but not always. What is the best way for accomplishing this? Is there a write up on this somewhere on this site? I have searched (not exhaustively) but have come up with not a bunch.

I have seen some pretty copper work on this site, so someone has the answers..... But, who is willing to share the secret?

Thanks in advance!

[Prairiepiss]

I came up with a way to make a better connection a while back. It may be a little difficult for the smaller stuff like 1/4" but who knows? Here is a little tutorial I put together.
http://homedistiller.org/forum/viewtopi ... =2&t=21258

[hendecp]

I came up with a way to make a better connection a while back. It may be a little difficult for the smaller stuff like 1/4" but who knows? Here is a little tutorial I put together.
http://homedistiller.org/forum/viewtopi ... =2&t=21258

Mr. P, that is brilliant! I would just have to find some hardware to do that with 1/4". I might have better luck with 3/8", but the idea is phenomenal! Thanks for sharing....

[myles]

It is nice isn't it. There is a power tool to do the job but it is very expensive, and uses an expanding drill bit to form a cone inside the tube that forms the socket when you pull it out. If it is in the right place then you can also use a technique called "flow drilling" to form a socket.

Thin tube makes fairly weak joints that can be improved by soldering a short section of the next size up tube over the your tube to increase the wall thickness, increase the hole diameter and increase the contact area. Flaring out the tube (countersink drill bit running in the wrong direction) increases the contact area for a stronger joint.

[myles]

As for hardwear, possibly not for 1/4" but for slightly bigger stuff it might be worth having a look at expanding anchor bolts for brick work. Some of these use a steel expansion cone that could be the right size to be usefull.

[hendecp]

Ok guys.... I have some great suggestions for larger pipe sizes, but the question still remains. How do I effectively solder a pipe into the wall of another pipe with out a fitting? The soldering that I do always looks globbed up and doesn't seem to seal properly.

[myles]

Normal rules apply, you need a good tight joint for a capillary solder joint. To me this means flaring the tube that you wish to insert into the bigger tube. Then you need to hold the two sections under compression before you solder. On bigger bits I like to rivet the joint and then solder.

On smaller joints you can use some other means to hold them together and then solder.

[hendecp]

Normal rules apply, you need a good tight joint for a capillary solder joint. To me this means flaring the tube that you wish to insert into the bigger tube. Then you need to hold the two sections under compression before you solder. On bigger bits I like to rivet the joint and then solder.

On smaller joints you can use some other means to hold them together and then solder.

I finally got this to work right. I was able to solder 1/4" into a cap for my parrot I made. Tight fitting hole, flux and heat applied indirectly (not on joint) until hot, got the job done nicely! My biggest problem I had before was I heated the area directly. I did find that flaring when you can makes a difference. Sometimes that just doesn't work out because of the insertion angle...

Thanks for all the tips guys!