Should I braze my own Evaporator?

[trainee]

As a first time phase change builder is there a benefit to brazing up my own evaporator? I decided that Im not going to try to machine one myself, but the 'kits' available seem to be in pre-brazed, or complete form. Would a complete evap give me better odds of success? Am I going to hurt myself in the long run: not learning to braze the evap on my first build? Probably seems like a dumb question, but I figured if I'm thinking about it, I might as well ask.

[tim-]

there is no stupid questions ;)

but honestly.. if you don't know how to braze you should offer time for learning before you get starting making phase units. braze copper pipes and joints, they doesn't have to be something specific.. you need learning and training before you do proper brazings.

evaps isn't the easiest part to braze either.

remember you always have to purge when brazing evaps, it's always recommended to purge but it isn't that common people purge while brazing the other stuff.

[PhilippF]

There is a lot of heat required to braze an evaporator, and it´s not the easiest thing as Tim said. For the first time I would recommend buying a pre-brazed one. Once you get more experienced, you can try braze one yourself. Also you need proper equipment for brazing an evap. Connecting pipes to each other can be done with a simple propane torch, but brazing an evap requires a powerful acetylene+oxygene torch (at least propane+oxy).

Also preheating on a camping stove or something similiar helps a lot.

Regards,

Philipp

[{.bLanK} GoD]

I strongly recommend you get an evap already brazed up.
The first evap I ever tried to braze up turned to custard. Did get it in the end, but ended up pretty messy and i was slightly disappointed with the result. And I was more than capably of brazing pipes with one hand tied behind my back.

Brazing a big mass takes practice in itself, some one good at brazing pipes is not necessarily going to be able to braze up an evap.
:2cents:

[trainee]

I'm glad I asked! I have a siginifcant amount of practice and preparation before I attempt my build, but I can safely say that I will be purchasing a completed evaporator. Thanks for the responses and thanks in advance for all the other questions I'm bound to be asking...

[killermiller]

What I did to practice, was get 10' or 20' of soft copper pipe and a swage tool. Cut 5 or 6 pieces (or more) of 1.5 inch of pipe, swage it and put it in a vice and make a little tower. Do that until you get the hang of it.

[Entsafter]

Connecting pipes to each other can be done with a simple propane torch, but brazing an evap requires a powerful acetylene+oxygene torch (at least propane+oxy).



Propane only works too! But it needs a little experience and I would recommend purging for every joint in a phase unit!

This is my third evap with propane + air oxygene torch. Works like a charm.

http://img478.imageshack.us/img478/8484/dscf2525po5.th.jpg (http://img478.imageshack.us/my.php?image=dscf2525po5.jpg)

and it's leak proof (like all other evaps), tested with 20bar nitrogen (underwater, 12 hours)