I do try to give the best answer I can when possible.
Sometimes the questions don't happen though.
Example the previously posted picture that I am reposting now. No questions surfaced related to it. It is a very telling picture that went unnoticed for its intent.
Brazed Aluminum Manifold
1) - showing a fully brazed runner section without any alteration or smoothing of the finished braze. That is a finished brazing using the correct temperatures for the material. It is structurally sound and not so bad looking once polished out.
2) - shows a perfectly brazed port outlet-to-runner tubing connection. The key in having excellent flow of the brazing material is in having all three metals at the same temperature. The braze relied on a capillary affect to draw the material into the joint. A very nice brazing.
3) - showing a acceptable brazing. Notice the roughness of the port outlet-to-runner tubing joint material? Not enough heat was applied to the plenum outlet causing the brazing material to cool faster than it should before setting. It is not as strong of a joint as #2, but will do the job.
4) - Gaps can be bridged by brazing. A electrical weld would have a hard time in dealing with a gap like this one.
5) - as can be seen in the brazing material, a quite excessive gap was bridged on this runner for the required bending. Look closely at #1 as it shows the same bridging.
So, if the questions do not get asked, I have nothing to answer.
Fabrication skills are much like anything else.
Practice, practice and more practice.
Brazing aluminum 》effectively《 takes some experience.
It is not out of range for us to do in our garages if some practice in the techniques in applying the right amount of heat are found.
Nobody ever bothered to ask questions about the brazing done to the manifold pictured. The pic was designed for mention ...just like what is being done of it in this post now.
Again, no questions get no answers.
I've tried to give realistic options on putting the best possible manifold together in using the least amount of required tools.
With a fair amount of "machining" done to the manifold in the pic, nothing but a Dremel was used to get it done and prepped for brazing. Any gas capable of 700ºF will do.
Now imagine this: ...that those runner tube fish-eye cuts are seamless once the bend is closed and brazed. The finished brazing would have all seams looking like #2. That would be considered a beautiful brazing-job on that sacrificial manifold I've pictured above.