Axiom Home Page Forums General Discussion The Water Cooler Solder for electronics used for plumbing. HELP!

I bought a bunch of unlabeled solder last year at a garage sale. It was supposed to be plumbing solder, but, as I was doing a LOT of plumbing of copper hot and cold water lines today, I noticed that it was spitting and sputtering a lot, but seemed to be working just fine. Well, after a few hours of work today, it is still eating at me that it was spitting/sputtering so I looked closely at the spool of solder and came across a number that I searched the internet for.

Long story short, it was Dutch Boy Lead Free, Rosin Code solder P/N 93295. LINK This is supposed to be for electronics, so am I totally screwed on all of my hard work today?

I've found out that it contains tin, copper, and core flux.

PLEASE HELP!

My understanding is that plumbing solder just has an evil,corrosive but very effective acid flux, while electronic solder has a gentle, non-corrosive but much less effective rosin fluc. The rosin flux protects the molten solder from oxygen but not much else, while the acid flux gives you a decent chance of soldering grungy materials together.

If the joints look good (ie the solder flowed onto the metal) they should be OK. I don't think rosin core solder will do any harm, although the opposite (acid flux for electronics) tends to be really bad news.

Then again, I don't know squat about plumbing so...

Thanks bridgman. I was able to inspect some of the joints after I did them, and if I look inside the pipe, I can see the solder on the inside of the joints like I should be able to. Not big glops of solder, but it just looks like someone made the inside edge, right where the parts come together, shiny silver (solder) colored.

Does anyone know where I can search for the answer to this? I have about another 2 hours of work before I am done, and I would abviously like to know before that if I have to start all over.

I did a bit of searching around and found a few things :

1. Not sure what the US rules are, but a lot of countries have banned the use of lead-based solder for plumbing. Lead-free is not a problem other than being more of a pain to work with.

2. Rosin core solder seems to work OK on copper pipe as long as everything is clean. If it's not clean, acid core works better. Rosin core is useless on stainless steel which is a factor for some plumbing work but not (I imagine) for your case.

Others please jump in...

I tried to find out if one can use ‘electronic’ solder on copper pipe in my code book. Nothing specific to that regards. It simply refers to ASTM B32 (Standard Specification for Solder Metal).

In potable water systems, code requires the use of lead free solder. Lead helps the solder flow around the fitting easier. All lead free solder still contains trace amounts of lead, and none are actually 100% lead free. In 07 all lead free solder is to have no more than .02% lead. I think the max allowable is 2% right now.

Solder manufactures are now incorporating nickel to replace lead. Bridgit ‘nickel-bearing’ solder already meats the newer standard.

All that being said, I really don’t know what to tell you. I haven’t ran across this problem before. You are the first, congratulations!!

Copper solder is made up of several different allows to make it flow, adhere, and resist burst pressures / expansion and contraction stresses. Silver is one of those alloys. I don’t know if electronic solder contains silver. I also don’t know if it has comparable yield strength as copper solder.

Also, copper solder doesn’t have a flux core. You use an acid based flux to clean the joint from proper bonding (in addition to manual cleaning of the joints). Nocorode is what 80% or so of the plumbers I know use. Some local code governing areas require the use of water soluble flux, and it’s a pain to use.

All that non-helpful rambling aside, if you are sweating joints that will be in walls, I’d re-do them. You will always wonder about them leaking. Sweat the electronic solder out and break them apart. Clean the piss out them with your emery cloth; get a roll of Bridgit solder and some Nocorode flux. Apply heat to the joints 180 deg away from where you lay the solder to draw it into the joint. Wipe the joints with a rag, your acid brush or your gloves.

Then you’ll be able to sleep at night not worrying about water spraying all over the place.

It might be cheaper and easier to put a bunch of those little X-10 cameras in the walls to monitor the solder joints instead

Can't help ya Nick, our house uses PEX lines, no solder needed...

Well, I decided to do it all over again. My time is more valuable to me than a few bucks, so I went out and bought all new elbows, joints, and such, plus made sure that I had plenty of the plumbing solder and plumbing flux (which I did already). Instead of undoing all of the joints, cleaning the crap out of them, and starting over, I spent about $10 on replacements and just used my pipe cutter to cut the connections out, saving any usable length of straight pipe. This was really helpful where I had a section that ran along some duct work, then had to turn up and then over the duct, then back down and then turn yet again to continue down the duct work path. Instead of 16 joints (8 for the hot run and 8 for the cold run), it was 4 quick cuts and I was done.

I've also noticed that the plumbing solder is stiffer than the other, and also melts faster, even though it is rated at a temperature as high at the electic solder. This makes for much paster re-soldering.

Thanks for the tips everyone. I wish I didn't have to do it over, but at least I caught it now and not after I had hooked it in to the main hot and cold lines running through the house and then sprung a leak!

PEX is cool!

I could have strung the "pipe" tubing in 20-30 minutes max, and then just had the plumber connect them when I was ready to finish the bathroom. Now I have to run 2 lengthly, curving runs of copper, and then cap them off so that I can finish the back half of the basement, and then this summer, get the plumber to come in and do the bathroom. PEX would have been a lot easier.

I take it there's no copper-PEX coupler yet?