# Need recommendations on brazing basics...



## middle.road (Nov 26, 2018)

If this is already covered in another thread please pass that info on. I've searched for an hour and have tossed in the towel.

Over the years I have gotten rid of most everything I had in regards to welding/brazing/ETC. So I'm starting over.
I've never done and proper 'welding' or 'Brazing' in my life. Been around but never enough hands-on.
And then I scored a set of tanks from and HVAC gent's estate sale and now I've got a need to braze some things and have absolutely no idea where to start.
I've installed new hoses, still have to install the safety valves and then hope there's enough gas to do what I want to do.

Glasses/Goggles? Need 'em to fit over prescription glasses. I have no idea what to go with.
Rod/Filler material? right now I want to do steel to steel and the like - nothing fancy. Currently I want to braze a 5/8" rod to 3/16 plate for and idea I have for a hand scraper so that I can repair the lathe and get going again.
(should just get a TIG but there is no way with the current budget...)
I will be trying to braze carbide later if I succeed in learning.

And any and all insights for a complete noob would be appreciated.
As always the budget has taken some serious damage the last couple of months from those d*mned unplanned expenses. Nothing major but things are rather tight.

Thanks,
_Dan


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## Cadillac (Nov 26, 2018)

Check those tanks you just got. They made be out of date and need recertifications to get filled. 
Brazing you’ll need brazing rod,some flux, and  a torch. Flux parts get red hot and let the filler rod flow. Make sure your parts are clean,get hi temp flux.


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## machPete99 (Nov 26, 2018)

See Keith Fenner on youtube, he does a lot of torch brazing repair work, typically on cast iron castings.

I have done a bit of TIG brazing with silicon bronze filler. Its generally easier than welding, no flux required. Need to keep heat below welding temperatures (until things just start to glow red).


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## 4ssss (Nov 26, 2018)

Also, you'll need silver solder for carbide.


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## benmychree (Nov 26, 2018)

For carbide, a silver solder sandwich with copper in the middle is used, the steel that is used for the shank should have a machined pocket to fit the carbide blank, clean the parts with a solvent such as acetone or a non flammable safety solvent that dries quickly, coat the braze area and blank with silver solder flux and assemble the parts, with the silver sandwich in the middle; heat the assembled parts from the bottom with the torch until red, and when the silver flows, press down on the top of the blank with something pointed until the silver solidifies, then place the tool in a place where it can cool slowly.


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## john.k (Nov 26, 2018)

If you are on a tight budget........I suggest the following money savers.....never use actylene,use liquid gas in a BBQ cylinder and refill at the hardware.Flux is expensive,but its just borax...so get some borax at the supermarket.Brazing rod is expensive,and dont use silicon bronze meant for copper pipe(unless its free).....Use plain old 70/30 brass........and for odd jobs,you can use plain brass wire....The secret of brazing is enough heat.....when the heat is sufficient the brass will flow all over ,and not just sit in blobs......For eyes,I just use green plastic safety glasses,the disposable kind.....if you need a correction,you may be able to use a combo sunglasses /indoor glasses.....The white flux is the bad part ,the steel is only at red heat,but the flux glows white in the flame...............Finally,you can braze using any heat supply,such as a forge,that gets the work hot enough.


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## middle.road (Nov 26, 2018)

We're overly blessed with acetylene. two tanks. (All chained up and capped properly.)
The first torch kit ensemble that I bought four years ago at RV dealer/repair shop auction, I went and took the O2 tank back to the vendor for re-cert and fill.
And they shafted me on it, 'leased tank' is all they said and took it. Wouldn't give a discount or anything on a new tank, nada nothing.
I was a bit dumbfounded. I asked this dude about the acetylene tank and he got this vacant look and just said bring it by, I laughed and left.

This current set from the HVAC auction is current. I replaced the hoses, and I've got safety fittings ready to install.
I figured I'd just use it for heating up iron until I used up the O2 and then sell off what I can, unless I can get the O2 refilled.

And now I've got the bug to braze...


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## john.k (Nov 27, 2018)

I havent used acetylene for 50 years due to the cost,exorbitant in 1970,who knows what now.?.....Its nice to be able to do sheet steel and exhaust pipes with acetylene,but thats all.  My gas supplier recently unilaterally increased cylinder rentals by $50 a year ($250+),in mid lease,very cunning ,as most would have part full cylinders and need to keep on.,or not notice the increase..............Iv tried TIG welding braze,but the zinc seems to vaporize,so i must be doing something wrong.


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## jbltwin1 (Aug 6, 2019)

Honestly,  you are better off BUYING the tanks from somebody like tractor supply these days. My one set of tank will DEFINITELY be out of date and the other small set might be cheaper to just buy.   There is NO substitute for heat when you need it!  Mike.


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## aliva (Aug 6, 2019)

I had the same problem with leasing, too dammed expensive for the number of times I'll use it. So I bought a small set , I own the tanks. The O2 is around $35 for 20CUft. the Acetylene is $45 for 10CUft.. This  is Canadian $ so probably cheaper in the US.


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## Cobra (Aug 6, 2019)

Cadillac said:


> Check those tanks you just got. They made be out of date and need recertifications to get filled.
> Brazing you’ll need brazing rod,some flux, and  a torch. Flux parts get red hot and let the filler rod flow. Make sure your parts are clean,get hi temp flux.


If you're going to do carbide, black flux works better than white.


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## NortonDommi (Aug 6, 2019)

Here are a couple of links that may be useful:
https://www.lucasmilhaupt.com/EN/Brazing-Academy/Brazing-Fundamentals.htm   which is about Brazing  and 
https://www.esabna.com/euweb/oxy_handbook/589oxy14_1.htm  which hsa information on te gas welding and Brazing processes.  
Are you intending to Braze or Bronze weld? The two are different.


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## RJSakowski (Aug 6, 2019)

I own my tanks but when I take them in for refill, they just exchange them.  I have asked what happens of I should move and was told that they would just give me a new set of tanks with paperwork.  If you buy a set of tanks from someone, ask for the original sales documents or some other proof of ownership.  Otherwise they may well be considered leased.


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## Bi11Hudson (Aug 7, 2019)

I occasionally use brazing (rarely), with supply house rod and silver solder. The supply house rod is called brass, but is actually an alloy of bronze. The flux is borax; it goes on as a powder, heats to a liquid and then turns solid again. That's when it's ready. Mixing in a small amount of water to make a paste cuts out the first stage.

Soldering (soft), silver soldering, and brazing (hard soldering) are basically the same. Get the metal hot enough to melt the "solder" when it's touched. Then flow it on. It is a skill, not a recipe so be prepared to redo things that come out "not quite right". The base metal should be hot, the solder just melts into blobs.

I use Propane and compressed air for the small stuff I do. I have O2 and Acet tanks but they are out of date (bad) so I am waiting to turn them around, "in the shadows".

.


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## Janderso (Oct 2, 2019)

This is an interesting subject.
I had a set of O2/acetylene for 20 years, went to fill them and they swapped them out no problem. I know the shop owners. If I had moved? I'd have to start over.
I own all my new equipment. All 5 tanks. I bought the big ones! Same welding outfit I buy all my equipment from.
I have the receipt somewhere but if I ever move I may have a problem.
Interesting subject.


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## Cobra (Oct 2, 2019)

Janderso said:


> This is an interesting subject.
> I had a set of O2/acetylene for 20 years, went to fill them and they swapped them out no problem. I know the shop owners. If I had moved? I'd have to start over.
> I own all my new equipment. All 5 tanks. I bought the big ones! Same welding outfit I buy all my equipment from.
> I have the receipt somewhere but if I ever move I may have a problem.
> Interesting subject.




I have moved several times across Canada and have never had a problem with getting my tanks refilled.
Asked several about how they track rental vs owned and to a shop they have said that they track who has their rentals and assume that if you are not renting, you own the tanks.


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## pontiac428 (Oct 2, 2019)

I have a dozen or more "customer owned containers".  They often go out of hydro in the time it takes to empty them.  When you bring a COC back to the supplier, they will charge you for hydro (it's cheap enough) and swap you a full, clean tank for the cost of the gas.  Tanks cost a hundred bucks or so if you don't own one or want another.  It's not a prohibitive cost, especially compared to leasing.  Another good trick for welding gas is to mix your own using a Smith's proportional mixer.  You can get them for 75/25 Ar/CO2, variable mixes, and various tri-mixes.  That way you can use straight argon for TIG and mix for MIG running only a pure argon and a small CO2 tank.  As you can imagine, I don't worry about welding consumables when I'm on a project.

Back on brazing, I'd like to mention that the material matters.  Good fluxed brazing rod from a supplier will kick the pants off of borax.  Borax works, and has forever, but you really need to pack that stuff into your joints.  Fluxed rod flows like solder in comparison to borax and bare rod.  Dull red and it sucks the filler in.

Goggles- you can get a number of different types that fit over glasses.  Shade #4 for torch work.  I like to use a tinted full-face shield myself, since I wear glasses all the time.  I like things that say "Jackson" on them much better than I like things that say "China" on them with a false ANSI stamp.  Unlike welding hoods, goggles and screens are cheap cheap.


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## middle.road (Jan 16, 2020)

Thank you all for the responses. I apologize for not remembering I had posted this.
Life and the Holidays must have gotten in the way.
That or else 'sometimers' has set in. Place your bets on the latter.


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## cathead (Jan 17, 2020)

Setting the torch properly is important too.  I  use a neutral flame for brazing usually.  Also, Another basic is to open the
acetylene valve about a half turn or so and the oxygen valve all the way open to the stop.


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## ericc (Jan 17, 2020)

I saw a cheap acetylene tank, maybe 100 cf, at a garage sale.  It was $5.  The seller told me that it may or may not be possible to "recertify" it, since they go through another process than hydrotest.  It was cheap enough to give it a try, but I passed and commended him for his honesty.  Should I have picked it up?  For the heat value, acetylene is way more expensive than propane.


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## Smudgemo (Feb 13, 2020)

Note that if you want to use propane (which is way, way cheaper and seems to last forever), the standard acet hoses may not be compatible (you need properly rated "T" hoses) and the proper regulator.  You can get a pound of 1/16" bronze rod and a pound of flux (both Gasflux products) for about $17/$14. I also popped for the fancy kevlar (?) hoses since my brazing is mostly bicycle frames and I like feeling free to move around, but they are much less tough than standard hoses. Acet for my skills is way easier to control for brazing thin-wall tubing, but for general heating or if I was going to build something bigger like another lathe stand, I'd grab the BBQ tank, a bigger tip and probably some thicker fluxed-bronze rod. The Gasflux rinses off in warm water if the project isn't too big, though.


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## middle.road (Feb 14, 2020)

A friend's father suggested the same about propane.
The current tank is full plus I've got one other Acetylene tank chained up to the fence.
After those are out and _if_ I can get the Oxy refilled then I'll be looking at going with propane.
I still need to learn all about 'rod'.
I wanted to make some brazed tip cutters for a scraper last spring/early summer and life got in the way of hobby.

PS: that 550Four in your Flicker album is Sharp!


Smudgemo said:


> Note that if you want to use propane (which is way, way cheaper and seems to last forever), the standard acet hoses may not be compatible (you need properly rated "T" hoses) and the proper regulator.  You can get a pound of 1/16" bronze rod and a pound of flux (both Gasflux products) for about $17/$14. I also popped for the fancy kevlar (?) hoses since my brazing is mostly bicycle frames and I like feeling free to move around, but they are much less tough than standard hoses. Acet for my skills is way easier to control for brazing thin-wall tubing, but for general heating or if I was going to build something bigger like another lathe stand, I'd grab the BBQ tank, a bigger tip and probably some thicker fluxed-bronze rod. The Gasflux rinses off in warm water if the project isn't too big, though.


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## john.k (Feb 14, 2020)

There is a technical reason why brazing needs a oxidising flame ....and I used acet hoses for years,only recently found some orange hoses at a hrdware store closing down ,so I now use the corect hoses.


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## rwm (Feb 14, 2020)

If you want to braze relatively small items using an oxygen concentrator is a great alternative to leasing an O2 tank. It works great with propane. Here is my setup. No more trips to Airgas. Well, maybe for Argon....



You should be able to find one of these on Craigslist for less than $200. Using 56% silver solder this works very well on parts 1" in diameter or less.
Robert


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## ddickey (Feb 15, 2020)

This video might help.


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## middle.road (Feb 15, 2020)

rwm said:


> If you want to braze relatively small items using an oxygen concentrator is a great alternative to leasing an O2 tank. It works great with propane. Here is my setup. No more trips to Airgas. Well, maybe for Argon....
> 
> View attachment 313629
> 
> ...


That setup looks sweet. Going to have to put that on the 'wish list'. I've never seen that before. 
The big bottle set I scored for only $50, figured the head and regulators made it worth it. 
Set of hose from Northern and Flashbacks off of eBay, all in for under a $100.
Next time before I blindly go returning the o2 tank I'll make some calls first. 
Then if it doesn't work out I'll call the 'Wind Chime' guy I met awhile back.



ddickey said:


> This video might help.


Thanks, of all the ones I've watch I hadn't come across that one.


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## john.k (Feb 15, 2020)

Here s a funny thing....gas supplier was charging me $250 a year rental,(like for 40 years ) I m ,now getting popup ads saying same supplier,no cylinder rental ,and gas prices reduced.....Funny what a bit of competition does.


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