Stove to preheat for soldering... a terrible idea?

[p_su]

I was soldering some 1.5" pipe for the bokakob mini, and had a tough time getting everything up to temp with my propane torch. It took a looong time, during which the entire 2ft section of 1.5" pipe heated up quite a bit. After ~25min of heating around the joint, it finally got hot enough (only just it seems). Well, I have a gas stove in the kitchen, and was wondering if I could use a burner to pre-heat the large copper pipe, and once the whole assembly is pretty warm, then increase heat in a specific area with my torch to solder.

I realize that a mapp gas torch is hotter (also more than 2.5x as much as a propane torch)- and oxy/acetalene would be better/faster... but this is what i have to work with for now. I bought a propane torch kit by benzomatic - and am using the flux/solder that came with it.

[Husker]

The problem with your "idea", is that you will carbonize your flux. Once that happens, you will have a hell of a time getting the solder to wick properly into the joint.

1.5" and propane is not easy to accomplish. I think this is right out on the border of what propane without O2 can do, and I imagine one would have to be pretty darn good at soldering to get it to work well.

I did some 1.5" with mapp, and it works. I had problems in that I partly carbonized flux a few times (the flame was pretty wide, and hard to pinpoint). I could clean things up and get it to work with mapp, but it was too much of a problem. Now that I have a ox/acc torch, that works so much better. Tiny little flame, that you can control REALLY well, and it is oh, so hot. Works like a champ to preheat the tube, then simply heat up the connector, and watch the solder literally jump up the joint.

H.

[p_su]

Thanks for the advice husker- I ended up trying the stove and made sure that I didn't get it hot enough from to burn the flux. I was able to hold the pipe with welding gloves on for 15 sec or so before even feeling the heat. I used the burner and heated about 4" away from where I was planning on soldering, and then used the torch to apply heat a little closer. It was much easier than just using the torch alone. I think that the copper was conducting heat away from the area I was heating with the torch before - so having the entire piece at a higher temp helped. I also recommend that you cover your stove top with aluminum foil.. helps with clean up (don't want to accidentally eat some flux later for dinner). Also do this when your wife/girlfriend/roommate is not there.

[Husker]

Also do this when your wife/girlfriend/roommate is not there.

That is great advise for every member in this forum, for MOST of the things we do

H.

[Usge]

Yes...the WAF (wife approval factor) or GAF (girlfriend approval factor)

[Husker]

Yes...the WAF (wife approval factor) or GAF (girlfriend approval factor)

Or the Wife Don't Need to Know factor

[dog1976]

I have used benzomatic torches, the standard design that they have made for more than 40 years, they were not very good for anything bigger 3/4" pipe.
I bought a torch from McMaster-Carr 8-10 years ago and I can make a 2" joint in a little over a minute. It was made by Goss, I just checked McMaster-Carr and they don't sell this torch anymore. I also checked Goss's web site and it is not shown.
May be someone on this site can tell you the brand and model of a good propane torch for for bigger pipe that they use.

[duderhead]

harbbor freight has 3/4'' ?

[pintoshine]

I don't know about 3/4" but Harbor Freight has a real nice and cheap gun style trigger lighting propane torch that can do 2" copper rather easy. It has a good rosette flame on it. I bought one a year or so ago to replace my expensive Burnz-o-matic.
http://www.harborfreight.com/cpi/ctaf/d ... mber=91061" onclick="window.open(this.href);return false;" rel="nofollow