preferred brazing rods

[rogue_jedi]

i'm looking for some brazing rods to seal my waterblock(s) with. all i've found so far is "Stay-Silv" brazing rods at home depot (.com, but should be there locally as well) 20" rods, at $40 for a 28-pack. i was at lowes today, but all they had was a mapp gas/oxygen kit with copper (i think) brazing rods included. of course, i already have a bernzomatic ts4000 torch (and just got a new mapp gas canister today) so i'd like to avoid buying a new torch if possible.

couple of questions here.
1) will the ts4000 torch w/ mapp gas be enough for brazing? or do i need the mapp/oxy adaptor?
2) are the home depot brazing rods good enough to seal a waterblock (and later i'm going to build me a phase change, so will they hold up under that pressure as well)?
3) how much rod (on average) does it take to properly braze a 2x3 waterblock shut (including around the fittings)?
4) how hard is brazing to get started with (learning curve)?
5) are the home depot rods a good/average/bad price?
6) what are the best overall rods, and what are the best value rods? oh, and where can i buy them?

thanks in advance.

oh, and i'll post pics of the blocks too

you know, i should probably check my local plumbing store and ask around there too... tomorrow (1:20AM right now)

 

[weapon--]

i'm looking for some brazing rods to seal my waterblock(s) with. all i've found so far is "Stay-Silv" brazing rods at home depot (.com, but should be there locally as well) 20" rods, at $40 for a 28-pack. i was at lowes today, but all they had was a mapp gas/oxygen kit with copper (i think) brazing rods included. of course, i already have a bernzomatic ts4000 torch (and just got a new mapp gas canister today) so i'd like to avoid buying a new torch if possible.

couple of questions here.
1) will the ts4000 torch w/ mapp gas be enough for brazing? or do i need the mapp/oxy adaptor?
2) are the home depot brazing rods good enough to seal a waterblock (and later i'm going to build me a phase change, so will they hold up under that pressure as well)?
3) how much rod (on average) does it take to properly braze a 2x3 waterblock shut (including around the fittings)?
4) how hard is brazing to get started with (learning curve)?
5) are the home depot rods a good/average/bad price?
6) what are the best overall rods, and what are the best value rods? oh, and where can i buy them?

thanks in advance.

oh, and i'll post pics of the blocks too

you know, i should probably check my local plumbing store and ask around there too... tomorrow (1:20AM right now)

1). TS4000 with MAPP or propane will get copper plenty hot enough to braze it shut with most brazing rods on the market - I use a TS4000 all the time and I have brazed several waterblocks shut with it as well as several evaporators for phase change -- it has also brazed up a ton of flared fittings, etc. It can take a little while to heat the copper blocks up and you need something to insulate them from the ground - a fireblanket can usually be found at HVAC stores or plumber's supply stores - you can also use a hotplate to speed up the process.
check this link for a good how-to on brazing evaps with several really good pics:
http://www.truextreme.com/forums/showthread.php?t=23274
^same will work for waterblocks.
side note: never lap the block's base plate until all the brazing or soldering is finished - you will always get a tiny amount of warpage from the heat associated with either process and you will just have to lap it again when your done.

2). Home Depot brazing rods? you mean the StaySilv you mentioned? if so, they should be strong enough but there are several types of stay-silv. stay-silv 15 is the most common for phase change work.

info from JW Harris:
Stay-Silv 5 and Stay-Silv 6: Medium-range alloys; Stay-Silv 5 is useful primarily where fit-up can not be tightly controlled. Stay-Silv 6 is slightly more fluid and can be used where closer tolerances are available. Both alloys are somewhat more ductile than Harris O.

Stay-Silv 15: For many years, the industry standard for air conditioning/refrigeration applications. Still widely used but now often replaced by Dynaflow in many AC/R applications.

Stay-Silv 5, 6, or 15 will become liquid at these temps:
staysilv 5 =1500 deg F
staysilv 6 =1425 deg F
staysilv 15=1480 deg F
no flux required for copper to copper or copper to brass joints.

my personal favorite as of late:
Dynaflow: Premium, medium-range silver alloy, formulated to even tighter specifications than the Stay-Silv alloys to mirror the performance characteristics of the 15% silver brazing filler metals. Excellent for brazing both tight and poorly-fitted connections, Dynaflow’s proven reliability and acceptance by field service engineers has made it the leading choice of brazing operators. liquid at 1465 F
^also made by JW Harris

3). you should be able to braze a waterblock shut easily with a single rod but that will depend on how well the sections of the block mate together to some extent.

4). brazing isn't that hard - it is pretty much like soldering with a lot more heat.
you can brush up on your brazing techniques here: http://www.jwharris.com/jwref/procs/

5). home depot price on the rods isnt that bad but you arent going to use that many rods anytime soon unless you start making a helluva lot of blocks and phase change gear.

6). stay silv 15 is good - so is dynaflow - check with HVAC/ac/refrigeration supply stores - the ones around here will sell you any of the above brazing alloys by the rod.