Building Prototypes Dan Gelbart part 14 of 18 Brazing

Building Prototypes Dan Gelbart
brazing

[@aedengasser-brennan2120]

I’ve been watching this series in order. This was my favorite of the videos so far. I want to thank you Dan for freely giving this knowledge to the world.

[@idiyerbill1968]

20k view and 0 dislikes this is what I call perfect teacher

[@NSResponder]

I never realized just how strong a brazed joint could be. I always thought of it as a light-duty substitute for welding. -jcr

[@neatmachine]

Fantastic video! Please continue to make these machining and fabrication videos. Your explanations and demonstrations are treasures. I envy you your dream machine shop!

[@qzorn4440]

there is also a hydrogen torch for brazing and soldering. 😎 thanks. great video.

[@zacharyhuser828]

For joining copper alloys to ferrous metal you can also hit it with some silicon bronze TIG rod or MIG wire, and avoid having to wait for the oven and heat up your whole part.

[@davidhawley1132]

I presume the point is that by heating the whole thing up, you don't get heat distortion.

[@robindebreuil]

Tape on the vice jaws, great idea.

[@Xynudu]

Interesting video. Well explained. I do torch brazing, but an oven like that would be nice. I saw a display of miniature old time engines created using steel composite brazing, as demonstrated, and the result was indistinguishable from cast. I didn't think to ask if he used a torch or oven, but they were all very impressive and actually ran on fuel. I think a lot of people never try brazing, and miss out badly. Cheers Rob

[@dgelbart]

xynudu If you look at this video: kzbin.info/www/bejne/mZTNhYCHrLCKhNU, all the parts that look like castings are actually brazed assemblies.

[@loganofnorth880]

Thanks again ❤️

[@jimgourgoutis]

I'd like to see a video on the Plasma Needle Arc Welder!

[@habiks]

so... which school did they name after you?

[@ljubomirculibrk4097]

Fluoborate flux is best but its corosive and toxic fumes are generated during work. Great on stainless, works well whit silver braze

[@littlestworkshop]

Some hidden location pins between the parts and some weight on top would be an alternative for those without laser welders. I've added a saved search on ebay but I'm not holding out much hope ;)

[@dgelbart]

There is a "poor man's version" of a laser welder available from many sources like: www.amazon.com/Sparkle-Welding-Machine-Necklace-Platinum/dp/B00BWO9LTE

[@littlestworkshop]

Hi Dan, I've looked into these previously, there are some slightly better versions with a pneumatically (edit probably a solenoid actually) operated electrode (withdrawn from material to strike arc) and an option for shielding gas, they are somewhere between spot welding and TIG (Lampert is one brand, Orion another). I'd be interested to see how well the cheap ones do joining large pieces. I'd also thought about building something either stand alone or as an attachment for my TIG welder. (I realise I am teaching you to suck eggs so this is more for the benefit of discussion or other readers)

[@hamiltonpianos]

Dang. £20k on a laser welder; that’s m’ whole workshop budget gone! TWICE!!! 😆 Absolutely loving these tutorials.

[@emillianocabrera8760]

Would you have time for a quick call to discuss potentially?

[@glassjb]

Dan have you tried eutectic welding rods?

[@charleshendry5978]

Oy Vey, my shopping list just keeps getting bigger! Water Jet, Hydraulic Press (have a manual, 3 ton arbor press) and now a metal kiln\oven......Please don't add an EDM to my list! :) Thanks again for sharing your outside-of-the-book er box approach to problem solving, and keep throwing in the science side. Charles

[@viperup]

Great video, thank you for putting all of these together. I have a question, is it possible to use this method of brazing for joining aluminum parts ? If so, why do people prefer dip or vacuum brazing ? Thank you for your help.

[@dgelbart]

+Alper Unal There are many commercial brazing wires for Aluminum, the ones I tried all worked well but aluminum melts before it change color so you can easily overheat and melt. Oven brazing works less well for aluminum. With some practice it will work well.

[@HondoTrailside]

Dan, this is a bit off topic, but I want to get a flux to gas weld aluminum. Do you have any idea what would work. I know one place in the US that sell this product, but importing is getting expensive, so if there is a substitutable material, all the better.

[@dgelbart]

Hondo Trailside I tried several (also sold as "aluminum brazing") and they all work well. The trick is not to melt the parts, as aluminum does not change color before it melts.

[@seabiscuit1909]

תודה לך פרופסור שאתה משתף אותנו. אוצר בלום של ידע

[@keithammleter3824]

I've been sticking things together for decades, and worked with others sticking things together. I've never seen anyone braze with an oven before. No reason why not to, except that a) an oxy torch is far faster, and b) ovens are expensive. One oven will buy a lifetime's supply of gas. However, using an oven like Dan did will eliminate distortion, as the whole assembly is slowly brought up to an even temperature. I feel Dan dismisses welding too quickly. In many cases, problems with distortion can be avoided by suitable design and welding in the right order. Often when distortion may still be a problem, assemblies can be preheated to an even temperature before doing the actual welding. The advantages of brazing become less as parts thicknesses increase.

[@dgelbart]

I should have phrased it differently: for small and delicate assemblies brazing is the best, for large objects you need to weld, as it is difficult to supply the heat you need to braze or it would require a large oven. BTW, ovens are cheap to build. All the ovens in the video are home made. You can also use a small ceramics kiln.

[@keithammleter3824]

@@dgelbart : The relative costs of ovens vs heating with acetylene may be region specific. It certainly won't pay for most work where I am - Australia. Due to the introduction of low cost invertor arc welders and plasma cutters from China about 10-15 years ago, people have been giving up the use of oxy-acet welding and cutting in droves. The gas suppliers thus now have huge over-capacity. My gas supplier reacted by slashing cylinder rental by nearly half, and gives me 2 refills a year of each gas free. As I am also in the small run prototyping game, the 2 refills a year meets my needs most years. Incidentally, after using oxy-acet welding and brazing for decades, I recently bought a low cost Chinese MIG/TIG/Stick welder myself - I should have done that before. Stick welding electrodes are now readily available as small as 1.5 mm, letting you have the low distortion advantages of stick on sheet metal as thin as ~1.00 mm, however it takes some skill. Dan, looking at you advocating water jet cutting - an extremely expensive method, can I actually have confidence in your claim that ovens are cheap to build? I do have some oven experience - I built a precision environmental chamber for a client (the precision comes from the cheapest part of it - the PID electronic control).

[@zoravar.k7904]

@@keithammleter3824 well in places where you do not get free oxy acetylene, an oven or a kiln (which tend to be more plentiful and affordable) is a pretty reasonable purchase, most uni labs will also have some ovens, so it's not outside of the realm of possibility. It's not like he implies that gas cannot be used for brazing, brazing can also be done with hot stones, it's just a matter of what you happen to have in your shop. Also he didn't always have the water jet, some of Dan's machines are very old, when he had to build them on a tight budget. Even that oven in the video is using an some salvage avionics for temp control.

[@keithammleter3824]

@@zoravar.k7904 : Fair enough perhaps, however it's clear from Dan's various videos that he has far more money than most of us - money to burn. Good on him, he is of the age where his priority should entirely be having fun. Consequently his views on what tools to have are skewed. Dan is much to be admired for his commercial/business success in his life, but his advice for us more ordinary mortals is a bit off. In response to watching Dan's videos, I investigated water-jet cutting. It's very much an expensive method suited for niche markets. Expensive in terms of purchase cost, and expensive in terms of ongoing time needed to keep the machine operational. The cheapest water jet cutter for metal is the Wazer, about AU$18,000 installed and usable - but it is a toy with pressure too low for useful work. In the time needed to set it up for the job, wait for the cutting to be done, and after cut clean-down, I would have a typical prototype job done twice over, with much the same precision using ordinary hand tools. For metal sheet far beyond what the Wazer can handle, a plasma cutter is cost effective, and not a lot less precise. Heck, most of us who do prototyping couldn't afford the floor space Dan has available.

[@zoravar.k7904]

@@keithammleter3824 sure, but students and researchers tend to have well kitted shops at their disposal. This group also tends to discount sheet metal processes and other 2d processes in favour of multi-axis CNC mills or resin 3d printing for everything since fabrication isn't necessarily their primary vocation. I think this series is more tailored to them, rather than machinists, or small enterprises. Once you look into building your own shop, then no single person's advice is particularly useful, as your machines will be based off of your workflow, output volume, work requirements, geography (parts supply), and budget. Anyways, all the best to you in Australia, I must imagine fabrication is even harder when you have to do it all upside down.

[@HistoricSteamTV]

Stacking waterjet cutting works great. I made turbines based on .500" cuts. I will be making 2"x2" or so horizontals with tig welded parts. I use a tig welded stainless boiler welded by a red seal welder. No rust no silver solder. I run a flowjet table,

[@mb-ql1gb]

6:18 Dan should have used a Fluxcompensator .. Doc Brown might have one left.

[@rioresearchanddev]

I have seen brazing done with a torch, can you comment on this method?

[@dgelbart]

Torch brazing is the standard way of brazing, but when you want to build up something that looks like a casting , a torch does not have sufficient heat output and the non-uniform heating will distort the assembly. If no oven is available, use several torches at ones (needs two people).

[@antigen4]

what about doing the first 350C in a toaster oven (cheap) and the rest with a single torch? - is it enough of a 'platform' (temperature wise) to use a single torch from?

[@zoravar.k7904]

@@antigen4 preheating will help a lot. Depends on what kind of tolerance you need at the end of the day.

[@glenndavis2762]

Hey Dan, is this your personal shop? Just curious what machine's you have built? I know the lathe and spot welder, but what about the 100 ton press?

[@dgelbart]

Yes, personal shop. The press I rebuilt from an old one, you can also see the ovens I built.

[@glenndavis2762]

Very nice Dan, if you don't mind me asking, how much was the waterjet?

[@dgelbart]

Was about 120 grand but you can buy a Maxiem 1515, made by Omax as well, for much less.

[@dgelbart]

A full size waterjet will be close to 100 grand, but Omax has now a small one, max size 12"x12" for under 20 grand. @@glenndavis2762

[@paulbirkner7082]

I don't have a laser welder. Would any problems arise from simply using super glue to hold two pieces in place while I apply the flux?

[@dgelbart]

You don't want to use anything that leaves a residue in the brazed area. On top of it, any adhesive will disappear at brazing temperatures so it will not hold the parts. You can tack parts with a TIG welder, tie them with wire, drill and place location pins or any other trick.

[@colusafrwv]

Could brazing of carbide to make lathe tool be done in a toaster oven? Since it a small pieces ...

[@dgelbart]

You can easily do it with a propane torch.

[@247chiranjeevi]

I have a question, Since u have built Your Own ovens. I see some ovens have fans and some don't ,what decides that? , is fan not required above a certain temperature? Or is fan not required for certain metals? Convection vs radiation heat treatment? I'm a bit confused. From what I've seen Upto 550c ovens(alu t6 HT) have fan but steel heat treating (1000c+ ?)furnaces don't.

[@dgelbart]

Above a certain temperature you don't need a fan as radiation coupling is so strong that the temperatures even out. Below 300 deg C you definitely want a fan, Between 300 deg C and 600 deg fan adds a uniformity.

[@247chiranjeevi]

@@dgelbart wow! Thanks for such a quick response.

[@rioresearchanddev]

Is this brazing or soldering? I am confused by the terms people use.

[@dgelbart]

Brazing, also known as "hard soldering" , is similar to soldering but done at a much higher temperature using stronger filler metals.

[@rioresearchanddev]

Dan Gelbart One last question and I think I will understand. Is there a "welding" which is done with a torch. Or does all "welding" involve a process involving electricity? i.e. is a torch only good for hard or soft soldering? I know "welding" can be done in a forge by a blacksmith.

[@dgelbart]

rioresearchanddev Welding can be done with a torch, by forging and other methods. It is called "welding" when the base metal melts or flows. It is called "brazing" or "soldering" when only the filler metal melts.

[@rioresearchanddev]

rioresearchanddev Thanks Dan, great help to me.

[@emillianocabrera8760]

Hello Dan. At my work I have been tasked with Oven brazing aluminum to stainless steel is this even possible? Our oven isn't vacuum sealed yet we did try to have a controlled atmosphere of Nitrogen running through it. Is there a solder material that you recommend to do this task?

[@dgelbart]

It will be very difficult if not impossible.

[@emillianocabrera8760]

@@dgelbart What about if we implied induction brazing instead of furnace?

[@emillianocabrera8760]

@@dgelbart Also what specifically are the factors that make this impossible? Is it due to the differeing thermal expansion of the metals?

[@dgelbart]

@@emillianocabrera8760 The oxide on the aluminum.

[@dgelbart]

@@emillianocabrera8760Same.

[@loktinl]

Hello Dan, I've previously run into issues with laser welding hardened material (440C, 58-62HRC) to unhardened material (303 SS), mainly in cracking of the welds (as described to me by a machinist when he tried it, as I don't have access to a laser welder at my work facility). Could you comment on how big an issue this is?

[@dgelbart]

Any material that become hard and brittle when cooled rapidly after melting will have this problem: series 400 stainless, all high carbon and tool steels etc. Aluminum has a similar problem because of high shrinkage when cooling. Series 300 stainless does not have this problem. Some standard solutions exist, like pre-heating part.

[@loktinl]

Dan Gelbart Thanks for the guidance!

[@brianburke7440]

flux should not be touched, use an acid brush, and avoid fumes. flouride is very dangerous, loves calcium (in your bones). Are my fears misplaced please?

[@dgelbart]

Brian, you're absolutely right. I'm not the best example on safety. Thanks!

[@buka9993]

Would roughing up/filing recesses into the edges increase the strength of brazed connection? If yes - by how much? Thanks.

[@giorgiocanal1659]

Peerless!