High(er) Melting Point Solder

[Usge]

We'll, I'm still working on my revised deplhegmator, had a few holdups. I managed to get the tubes into the plates using the silv15 hard solder. Silv15 (noflux, copper/phos/silver) requires "extreme" heat. It requires the copper to basically be glowing red and exposed before it will flow. This was possible when working on small tubes, outside where you can get heat on all sides and the copper was exposed. But, was not possible to do once the shotgun/tube/plate assembly was pushed down into the column/head and hard solder is smeared all over the surface. I heated the outside of the 2" column until the inside of it was glowing red. And it was not enough heat to melt the solder even pushed against it.....the plate inside "also" would need to be glowing red — or at least the edge of it that touches the column. So, I tried heating by putting the flame inside. This didn't work either...and mostly the heat just came back out and turned the hard solder on the top black. So, I tried soft solder, and it didn't work (it comes unglued or leaks when I try to solder up the fittings). Then, I got contact dermatitis from either copper shavings or flux or combo of both that started chewing up my hand (and splitting). Had to stop for a while till my hand starts to heal up. In the interim, i'm looking for solutions to this issue.

I know in UK they sell solder with various melting point ranges....but here all I can find is 400-500F soft solder, and 1100-1300 hard. That's it. I need something about 700-800F range...ie., high enough that working the rest of the fittings wont' undo it, but low enough that I can get it to work inside the tube.

Does anybody have a vendor they know of that sells lead-free solder in this heat range?? Or perhaps have other tips I can try to get this plate soldered in so it stays and doesn't leak? I thought about getting the next model up Bernzomatic Map/Pro that has adjustable flame. Mine is the standard model 4000. My thinking is...if I can pinpoint the flame...it might help with working with teh plate inisde the tube...to focus the heat in a small(er) area...so I can get one small area heated up to glow/red. I'm exposing the copper at the edge...by using a dremel etching tool...to etch away the black/carbon and solder from previous attempts.

[MadsF]

http://www.cupalloys.co.uk/cadmium-free ... 00027.html" onclick="window.open(this.href);return false;" rel="nofollow

I`ve been very happy with them Maybe you will find something suitable

[Usge]

Thank you Mads. That's exactly the kind of stuff I've been looking for. But, I need to find it in the states (US). I just can't imagine it would not exist here...but I can't find it for the life of me.

edit: just realized thats all in centigrade ...ie., 700c works out to 1292F. I'm looking for something in between (ie., 700-800 F) ie., 370-425c

[MadsF]

Oh my bad, thought you were located in the UK

But when i get packages delivered from there, the shipping only takes about 1 1/2 week. Maybe you could get a approximate shipping time, unless you need it right now

[myles]

You can get an entire range of melting points from cupalloys http://www.cupalloys.co.uk/ and I believe they do ship internationally.

The only thing to help that I can think of, and if I understand right and you have already soldered the tubes into the plate and you now wish to fit this into the shell is to use a variation of a slip coupling. Whilst you can still get easy access to your end plates solder a ring onto them that will fit inside your shell with the same hard solder you already used.



Once this has been cleaned up and put into the shell, just like for example a reducing fitting, then you should be able to solder it in with soft solder. Clean it up again and solder the next section of the column onto the remaining exposed bit of the inner collar. Or do them both at once if you wish. Good luck.
EDIT: must have posted at the same time as above.

[Usge]

converting cup alloys temp ranges from C to F, I get pretty much the same temp range as I mentioned before that is available here (ie., soft solders 400-500f, hard solders 1100-1300F). I'm looking for 700-800(f)....ie., something in between. I know somebody posted a link to a site somewhere in the US that sold wire solder in this range, but I cannot for the life of me find it again. Maybe I'm imagining things anyway. Anyway, looks like I'll probably be looking at getting some kind of oxy setup to get this done. Bernz makes one for 60 bucks (oxy/mapp). I think it might be focused enough to do the trick. The mapp (bernz 4000) I have throws out enough heat...takes a min or so. But, its so spread out...that trying to work inside a 2" tube is, well, pointless. I can heat the "outside' of the tube, but again..this doesn't get the disc/plate hot enough on the inside for it to melt the solder. I held the map torch full blast shooting inside the tube until the entire thing turned black and it never got hot enough to melt the solder.

[johnhopper1957]

If you want more heat one way to do it is with multiple torches, focus two on the bottom (one one either bottom side) then use a third torch to apply your filler. A little mucking around but not that much if you can stand the torches on a bench and then position the tube in the right spot.

[myles]

Getting the entire workpiece up to temperature and using the torch on just the joint is the issue.

Early on I made a taper from 3 foot or so of 2" tube. Had the same trouble. In the end I just improvised a rectangular kiln with fire bricks just stacked up on a perforated sheet in a barbecue base, and filled it with charcoal. With forced ventilation into the base of the barbecue pan from an electric fan it got seriously hot. Lots of sparks and smoke too, looked like a volcano.

The MAP torch was enough to heat the joint sufficiently to melt the 56% silver solder (1148 to 1211) degrees. I am sure it can be done easier with propane to supply the background heat, but it wouldn't be as impressive to look at.

No doubt though a big lump of copper can soak up a lot of heat before it gets hot enough to braze with hard solder.

[kiwistiller]

Hey Usge,
I thought I'd let you know that it IS possible - just done it on a narrower shell and tube with silfos 15 (sounds similar to yours and about the same melt points).

My jacket (65mm) has a lot more mass than my core (7x 15mm), and of course it convects much more readily, so I just spent ages and ages getting the jacket up to temp. also used some firebricks to help it on its way. Got it on the second attempt after using much too much gas. My first attempt I had the same issues as you, and decided to return fresh today and make sure I get the bastard hot enough first. Was more or less simple after that, although slightly complicated by me having already brazed a stainless flange onto the end of the copper (I'm an idiot), and I didn't want to overcook the stainless.

Oh, and my hands split every time I solder with this stuff too, no idea what it is that does it.

Luck,
Kiwi

[Prairiepiss]

Here is where I got mine in the states. Mid to low page Haris stay silv 5 mite work better for you?
https://weldingsupply.securesites.com/c ... :terms::PF" onclick="window.open(this.href);return false;" rel="nofollow

Or maybe the safety silk 45 low melt?

Edited Stupid forgot the link. and again to add other look at.

[myles]

I don't use sil-fos as we have alternatives here, so I have only just looked it up. I note it is marketed as a refrigeration solder Now over here we have simmilar products for that use, and when I have contacted the manufacturers before they have stated that these solders are not to be recomended for uses where the joint will subsequently get hot. They are designed to create stable joints that are suitable for exposure to fluctuating temperatures in cold conditions.

Now it might be different over there, but here we have solders for hot applications and solders for cold applications. I tend to only use phosphorous type (self fluxing) solders for structural joints on the outside of the equipment, not in the vapour path.

I don't use refrigeration solder at all - just the stuff intended for steam boilers and model engineering, and normal lead free plumbing solder. In reality I don't know how big an issue it is, but as they make solder for boiler use - that is what I use.

As for the other issue, I always wear thin cut resistant glassworkers gloves. They are like a second skin that does not get in the way at all, slightly heat resistant and impregnated with some sort of latex type material on the palms and fingers. I used to have skin trouble too but this has sorted it out.

[Samohon]

This subject was really the crux for me when I first started to look at high melting point solders.

Initially, I looked at the way jewellers and mini-steam engine enthusiasts hard soldered parts to each other, only to find that no two hobbyists used the same materials. I then contacted Cup-Alloys by phone and spoke to there sales people. I eventually made a small square hearth from fire-bricks and like miles supplied heat at the base through a BBQ SS perforated plate. This really heated the copper I was working on upto just below the temps I needed for the solder to turn to liquid. I then used a mapp torch to bring the temps to liquidus for the alloy used but had a big problem with oxidation.

I now use a copper phosphorous rod (10 x 500mm) for a few £££'s. The phosphorous rod actually uses the oxidation on the copper to its advantage by allowing the built-in flux to move the oxidised copper out of the way and the alloy to travel through the capillary. I now just clean the copper, heat it and apply the alloy.

This can only be done using coper to copper. For copper/Brass/SS applications then a suitable flux has to be used. I just use borax mixed with a little soap and water to get a paste when I solder SS or Brass...

[mash rookie]

If you don’t have other torches heat the whole piece in your oven (if it will fit) Grab it with gloves and get going with your small torch.

I use a fluffy torch like a weed burner to overall heat pieces than I spot heat where I want to hard silver. There is less deforming when done this way.

When I hard soldered my site glass flanges on 4” copper I had a fluffy torch heating from the inside. Hard soldering was smooth and easy with a small torch on the exterior.

[Prairiepiss]

I've gotten to where I hard solder everything. But then again I'm using oxi acet. I bought a small rosebud that works good. I can't work with the mapp gas very good.

[Usge]

Thanks for the input guys. Yes, I'm using Silv 15 (the one with phosphorus that doesn't require flux). It was never listed or presented to me to be a speciality solder (ie., for refrigeration only, etc). It was only listed as lead free silver alloy. But, companies here in the US are pretty bad about that, so its entirely possible that you are right Sam...just they didn't care to point it out.

However, I dont' think it will make much difference given the use on the condenser(s). It "will" be cooler than the surrounding area and will also be cooling at different rates given the water inside it. I guess the dephelgm is probably the part that would achieve highest temps...given you shut the water off at some point. I'm not seeing any problem with this solder sustaining higher temps...given I've glown mapp gas at it for 5 mins straight and didn't get it to melt or loose it's gap. Which brings me full circle to say...I'm just not getting enough "direct" heat is the problem. My mapp pro nozzle is rather wide flame. And shooting it down 3" or so into the tube..seems to disperse the heat too much. I think this is more the problem

I can't rightly build a hearth indoors, so I plan on attempting to solve the issue by moving up to a Bernz oxy/mapp combo torch. It's 59 bucks. It's made for brazing, welding and cutting. The O2 bottles only last for about 20 mins welding and cutting, but might last long enough for brazing to get the job done. The nozzle produces much tighter flame...and it way hotter. It's like you touch the copper and it's red. So, I think this will work, and its cheaper than taking my part somewhere to have it done for me. Basically, you turn the mapp on, spark ignite it, adjust the flame, then turn the O2 on very slowly and adjust it. It's a longer, much narrower (more focused) flame that is much hotter than what I have. Can add heat by adding more 02, up to a point for brazing.

As I said before, I had "no" problem using this solder when the part was outside/exposed..and I could heat all around it. This again I think it because of the nozzle/flame I have on my mapp/pro bottle. Its rather wide and one speed. I think the more focused flame of the new unit will allow me to hit the outer edges and heat them quickly, spread the solder, as I move the flame ahead of it. But, we'll have to wait and see.

I've redesigned my dephleg and I think its going to turn out very good. But, I have to get past these few hard solder bits to make it work. I've already hard soldered other key pieces into place...(based on my past experience of what came loose). It's a very big reason my runs were not doing so well.....it was dripping water into the plates. So, I've got a few more challenges ahead after this....I'm using flanges/tri-clamp to attach the head now...so I've got that to go as well.

Hopefully, I'll have an idea if this is going to work or not by the end of the Holiday weekend here.

[Prairiepiss]

I have one of those little oxi mapp torches. I found the tip to be to small to get anything done on big stuff. The flame wasn't big enough to heat a big area up enough. If you can find one with a bigger tip it mite work better. But that little oxi bottle won't last long. Hell I went through two of the small oxi bottles and 2 b tanks of acet and didn't get much done with my build. I had to swap out for bigger bottles.

[Usge]

That's what I hear P...for small jobs only. Recon I qualify . The thing you have to remember is...I'm working in 2"...not 4. I've had no problem using the hard solder "externally" with my standard mapp/pro bernz wider tip. It's soldering "inside" a 2" tube that I'm having trouble with. The wider flame working inside 2" is a detriment....it just spreads, folds back on itself..and comes back out the top. So, the plate inside down in the 2" tube never gets enough direct heat. Outside...no problem. Inside the tube? Forget it.

So, the fact that this oxy/map bernz has a smaller more focused tip/flame is actually what I'm looking for and what I think will solve the problem and allow me to work inside the 2" tube in a small area. I can heat the outside of the tube with my other and make it glo red. But, it won't do that trying to put heat down the inside of the tube on top of the isolated plate.

[Prairiepiss]

I've actually been thinking about taking mine apart and using the oxygen valve to run a air stone to put oxygen in my washes before pitching the yeasties.

[kiwistiller]

I don't use sil-fos as we have alternatives here, so I have only just looked it up. I note it is marketed as a refrigeration solder

I'd say it's probably fairer to state that it's marketed as a general purpose solder, and because it's reasonably ductile, is often used in refridgeration. The MSDS has nothing that worries me - copper, phosphorus and silver. if it goes on at 7-800C and it's only going to get to 96-100C during use, I'm happy with that. This isn't in the boiler - just the column. If I was using it for something direct fired boilers I might have cause to look beyond general purpose, but the column is well within my comfort theshold..

Best of all, it's free.

Cool that you have specialist stuff available though.

[Usge]

I've actually been thinking about taking mine apart and using the oxygen valve to run a air stone to put oxygen in my washes before pitching the yeasties.

What a great idea P Only problem might be, (from what I hear anyway), those valves aren't too spiffy. More likely to go from barely a fizz...to blowing the stone/tube right off the end in a single turn/adjustment.
If you can get it to work...fizz...would only take a couple mins to oxygenize your wort.


Kiwi, I have no idea if it's just the flux I'm using on the soft solder, or the hard solder...but something set my hands off terrible. At first thought it was copper, but doc says that's so rare, and would have shown up before. I was certain it was the oaety flux paste cause it tends to get all over everything (including my gloves). But, I've been using that for years now....have no idea why suddenly it's an issue. Maybe cause I'm using more of it (ie., the shotgun tubes, etc.). But, it's interesting to note from you that you've experienced the same thing from using this type hard solder. I had to get cortisone cream and antibiotics (for where my hands started to split/crack). It was pretty serious issue. Hoping not to see a flare up again.

[Usge]

For those following along....if you are using sil 15 (phos, copper, silver) no flux....the heating in the oven thing didn't work. In fact, it made a mess. I thought I'd give a try one piece before heading off to put even "more" explosive things inside my small space here.

Heating it in the oven to 500F left some kind of powedery gray coating on the surface and even after blasting the inside of it with mapp/pro for 5 mins it would not take solder. The area I was working on was glowing red. The solder turned "red" at the end and melted in my hand from the heat...but the copper would not melt the solder. It ended up dropping globs of high temp solder off the rod onto the plate ..which will now have to be ground off with the dremel and the surface reprepped to expose the copper before I can proceed again. AHrrrrrggg!!!!

If you are using this type of solder...you need exposed/clean copper heated to plum red before it will flow. If you oxidize or carbonize the surface...you have to start over....grind it off clean, etc. It will not flow.

So, heading off now for the oxy/mapp and also going to pickup a different kind of solder (harris) that comes with paste flux. Prior to using it...I've got about a full days work prepping the pieces ...grinding, removing old solder, sanding, etc. So, another week down the tubes on this project. Been trying to get my dephleg up and running now for a month, but I'm determined to do it right before I seal it up this time. Arg!

[myles]

I like the high silver solder / borax flux combination, but I have found that if the flame touches the flux then the joint is going to fail. Borax flux turns into some sort of glass that bonds to the copper if you heat it directly. Well it does when I do it. Flux the inside of the tube and keep the flame outside.

Its strange but when I have used solder containing phosphorous the opposite is true. I could only get it to work by having the joint area in the outer cone of the flame untill it glowed red. Putting the hottest tip part of the inner cone on the joint seems to stop the solder from flowing. Heating from the other side of the copper to the solder just wouldnt work either. Oxidising vs reducing flames?

Can you not use soft solder to join the plate to the tube? Although with flux I suspect it will work just fine.

[Usge]

Another update: sigh. Well...the oxy mapp torch is a pretty shitty piece of kit....but it "is" a good deal hotter. oxy tank lasted about 15 mins. Recplacements are about 10 bucks. Flame was much more focused and was workable inside the 2" tube. I managed to get the solder to curl and drop off into blobs...then melt, and then scrubbing through that would flow the solder. I went through 3 sticks of solder, the entire oxy tank..and ...every seam leaks like a sieve. Some parts of it just repelled the solder. Magically, the tubes in the middle readily take the solder and do not leak. But, the disc simply will not solder to the wall of the tube. Heating from outside is pointless...even with the heat near cutting torch settings...and the inside glowing cherry red at that point...it simply would not flow the solder against it.

My conclusion: I was able to mapp the smaller parts outside the tube just fine and get it hot enough the solder would melt and flow easily. Once you put those parts inside a larger tube...the large surface area copper tube is dissipating (pulling away) the heat such that the plate simply will not heat up enough to melt 1300F solder. Putting the hotter flame/torch inside...will melt surface solder, leaving blobs, beads, etc. You need welding temps (acetylene) or some way to drive temps far beyond what you'd normally expect to use high temp solder inside a large piece of copper. Pre-heating the part in the oven does work to a certain degree....but if your oven is like mine...it only goes up to 500F or so. Using a firebox and another torch to turn the entire piece cherry red would obviously work I think. I guess a blacksmith forge would too

[Usge]

I GIVE UP:

I made a "pool" of soft solder letting it flood over into the tubes. THAT, finally stopped the leaks. The only question now is...will it hold trying to cap it with fittings? By comparison, soldering the stainless ferrule to the bottom with Harris stay-clean/soft solder method...was damn easy. Worked first time. However, if buying ferrules...I would definitely recommend the longer skirt models. Got mine from KS at Hillbilly Stills...and the short one is only 1/4" long sleeve. It also fit really loose once I froze it. But it soldered up ok...so we'll have to see if it holds up under weight.

The therm shield and 1/2 npt is in as well. So, it looks like all that's left is to put it together and solder the end caps on. I'll be updating my dephlegm thread with the pics/design of this one. I thank all those who contributed to this thread and gave advice, etc. I think unless you have a hearth or someway to fire the entire piece of copper up to cherry red....my advice is to just stay away from the high temp/silver solder.